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of the
University of California
Los Angeles
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£,30
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This book is DUE on the last date stamped below
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Form L-9-2w.-12,'23
FOUNDRY PRACTICE
A Text Book for Molders
Students and Apprentices
BY
R. H. PALMER
Molder, Foreman and Superintendent of Foundries ; Sometime Instructor
in Foundry Practice at the Worcester Polytechnic
Institute, Worcester, Mass.
FIRST EDITION
FIRST THOUSAND
NEW YORK
JOHN WILEY & SONS
LONDON : CHAPMAN & HALL, LIMITED
1912
MAY 3 19if
COPYRIGHT 1911
By R. H. PALMER
I OF THE PUBLISHERS PRINTING COMPANY, NEW YORK, U. 8. A.
3
0
PREFACE
DURING his experience as instructor in foundry practice
at the Worcester Polytechnic Institute, the author was
handicapped by the lack of a suitable text-book. The vol-
ume presented here follows the scheme of instruction used by
him, and, beginning with the simplest type of mold, endeav-
ors to lead the student and apprentice gradually through the
more difficult lines of work in green and dry sand and loam.
From the many possible examples which might have been
used to illustrate the different practices, only those have been
selected which are typical of the class of work to which they
belong. It is recommended that the reader, whenever pos-
sible, supplement his study of this book by actually making
molds of the character described in the various chapters. It
is impossible to learn the art of molding by reading only.
Such other matters as the student of foundry work should
be acquainted with are included in the book, these including
the subjects of cupola practice, mixing and melting, cleaning
and repair of castings, etc.
The author has endeavored to make a text-book for the
student, apprentice, and molder, rather than a reference work
for the finished foundryman. His thanks are due to Mr.
Robert Thurston Kent, M.E., for editing the manuscript and
reading the proofs.
R. H. PALMER.
BELMONT, ALLEGANY Co., N. Y.,
October i, 1911.
iii
CONTENTS
CHAPTER PAGE
I. THE MOLD — ITS FORM AND THE METHODS OF MAKING IT, . . i
Molding a Split Pattern, 8
Molding a Split Pattern with a Web Center 12
II. IRREGULARLY SHAPED PATTERNS, 15
Molding a Hand Wheel 17
Coping Down Irregular Patterns, 18
Molding in a Three-Part Flask, 20
Molding with a False Cheek, 21
Molding Double Groove Sheave in a Three-Part Flask, . 22
Gear Molding, 25
III. FLOOR MOLDING, 30
Molding Lathe-Bed Legs, 30
Pouring Floor Molds 36
Molding Pulleys, 37
Molding Bevel Gears 39
IV. LIGHT CRANE FLOOR WORK, 43
Molding Wire-cloth Loom Frame, 43
V. BEDDING PATTERNS IN THE FOUNDRY FLOOR 48
Molding a Draw-Bench Frame in the Floor, 49
Molding a Gap-Press Frame, 58
VI. MOLDING COLUMNS 65
Ornamental Columns, 65
Round Columns, 69
VII. MOLDING WITH SWEEPS, 75
VIII. MOLDING CAR-WHEELS, 84
IX. SKIN-DRIED MOLDS, 90
Molding an Engine Bed in a Skin-Dried Mold 91
X. DRY-SAND MOLDS, 100
Molding a Corliss-Engine Cylinder in Dry Sand, . . . 101
Molding Printing-Press Cylinders in Dry Sand 108
v
vi CONTENTS
CHAPTER PAGE
XI. LOAM MOLDING, 116
Molding a Cylinder in Loam 120
Molding Balance Wheels in Loam, 128
Loam Mixtures, . . 132
Sweeping Loam Cores, 132
XII. MOLDS FOR STEEL CASTINGS, 134
XIII. DRY-SAND CORES, 138
XIV. SETTING CORES AND USING CHAPLETS, 156
XV. GATES AND GATING, 163
Types of Gates 168
XVI. RISERS, SHRINKHEADS AND FEEDING HEADS, 174
XVII. TREATMENT OF CASTINGS WHILE COOLING, 176
XVIII. CLEANING CASTINGS, 181
XIX. MOLDING MACHINES, 184
Power Squeezers, 185
Split-Pattern Machines 190
Jarring Machines 194
Roll-Over Machines 197
When to Use a Molding Machine 202
XX. MENDING BROKEN CASTINGS 204
Burning 204
Thermit Welding 207
Oxy-Acetylene Welding 208
XXI. MOLDING TOOLS, 210
XXII. MOLDING SANDS, 217
Preparation of Sand for Molding, 226
Facing Materials, 228
XXIII. IRON AND ITS COMPOSITION, 234
Grading of Pig Iron 237
Specifications for Foundry Pig Iron 239
Analyses of Castings, 241
Shrinkage of Cast-Iron, 244
XXIV. THE CUPOLA AND ITS OPERATION, 245
Calculation of Cupola Mixtures, 265
CONTENTS Vll
CHAPTER PAGE
XXV. THE AIR-FURNACE AND ITS OPERATION, 271
XXVI. THE BRASS FOUNDRY, 275
XXVII. FOUNDRY EQUIPMENT, 280
GLOSSARY, 288
APPENDIX, 298
Circumference and Areas of Circles, 298
Surface and Volume of Spheres, 304
Weight and Specific Gravity of Metals 307
Melting Points of Various Substances, 308
Strength of Rope, 309
Strength of Chains, 310
Analyses of Fire-Clay, 311
Sizes of Fire-Brick 312
Number of Fire- Brick Required for Various Circles, 313
Weight of Castings Determined from Weight of Pattern, . . .314
Dimensions of Foundry Ladles, 314
Composition of Brass Foundry Alloys 315
Useful Alloys of Copper, Tin, and Zinc, 316
Composition of Various Grades of Rolled Brass, etc., . . . .317
Shrinkage of Castings 317
Sizes of Pipes for Tumbling Barrels, 318
Diameter of Exhaust Fan Inlets for Tumbling Barrels, .... 318
Steel Pressure Blowers for Cupolas, . . . ., 319
Capacity of Sturtevant High Pressure Blowers 321
Speed, Capacity, and Horse-Power of Sirocco Fans, . . . . . 322
Capacity of Rotary Blowers for Cupolas, 323
Diameter of Blast Pipes 324
FOUNDRY PRACTICE
CHAPTER I
THE MOLD— ITS FORM AND THE METHODS OF
MAKING IT
IN all foundry practice, the mold is the essential feature.
A mold is the form or cavity in a refractory material such as
sand or loam, or in metal, into which molten metal is run or
poured, and which determines the final shape of the poured
metal after cooling. See Fig. I.
While molds are made in many different materials, and of
many different shapes and by different methods, yet in their
essential characteristics they are all alike. They are all made
from a pattern, which may be of wood, metal, or other material ;
except for the very largest molds, which are bedded in the
floor of the foundry, and for certain other special kinds of
molds, they are supported by and enclosed in a flask, which
may be either of wood or metal, and which may be either
rigid or hinged, the latter being known as a snap flask; they
are formed in a material which will withstand the heat of the
molten metal when it is poured into the mold, the more
common materials being sand, either-dry or green, loam, plaster
of paris, and iron, the latter being used for chitted work such as
car wheels, etc.; cavities in the casting, by which name the
final product of the foundry is known, are formed by means of
cores which may be either baked cores, or green-sand cores.
Molding operations are variously subdivided. Thus,
according to size, there is what is known as bench work, usually
for the lighter class of castings, and floor work, for the heavier
castings. According to materials of which the mold is com-
2 FOUNDRY PRACTICE
posed, the work is classified as green-sand, dry-sand, loam, or
chilled work. Another subdivision is hand work and machine
work, depending on whether the mold is made by hand or in a
molding machine. Each of these classifications may be still
further subdivided, as will be shown in subsequent chapters.
In order to introduce the student to the art of molding we
will consider the simplest class of mold, and discuss the various
operations in its production — a green-sand mold made at the
bench, with a one-piece pattern, the entire pattern being
FIG. i. — OPENED SMALL GREEN-SAND MOLD IN SNAP FLASK.
placed in one section of the flask, and made without cores or
other complications.
In order that the description of the actual molding opera-
tions may not be burdened with descriptions of tools and
equipment, more or less irrelevant, and yet which are used in
the work, it will be assumed for the time being that the reader
is familiar with these, and with their use. Each piece of equip-
ment and every tool mentioned, however, is described in
detail in Chapter XXI devoted to tools and equipment, and
THE MOLD
the reader is referred to that chapter or to the glossary, page
288, for such information as may be necessary as to render
the description more explicit.
Referring now to Fig. I , the pattern to be molded is shown
at A. This is a rectangular block eight by five inches and
five-eighths of an inch thick. It is to be molded in green sand
in a snap flask, the two parts of which are shown at C and D.
As the pattern is quite shallow the short sides are parallel. A
deeper pattern will have a slight taper, to enable it to be with-
drawn from the sand more readily. This taper is known as
the draft. The lower portion of the mold, that contained in
flask C, is known as the nowel or drag. The upper portion is
called the cope. Fig. I also
shows the usual arrangement
of the molder's bench, com-
prising the grating on which
the actual work is done, the
sand bin below it, and the
tool rack above, on which is
shown the usual equipment
of molder's tools, consisting
of rammers, brush, riddle, bel-
lows, and a tool box contain-
ing his small tools.
BOARD PATTERN ON BOARD
FIG. 2. — ARRANGEMENT OF PATTERN AND FLASK ON MOLD-BOARD.
In making the mold, the molder first places his mold-board
on the bench, with the cleats on the board extending away
from him, this being the most convenient position for rolling
over the drag. The pattern A is placed on the mold-board as
shown in Fig. 2, and the drag of the flask placed over it with
the pins projecting downward on either side of the board. An
4 FOUNDRY PRACTICE
iron band H is slipped inside the flask and rests on lugs or
ears F, having slots cut in it to permit it to slip over these lugs.
It is important that there be plenty of sand over the pattern
when the mold is complete, not only to prevent the bottom
board from burning but to hold the metal in the mold. In the
present case, the pattern being shallow, there is no doubt on
this score, but with a deeper pattern the molder will place his
strike across the top of the drag and thus ascertain the distance
between the top of the pattern and the edge of the flask, and
govern his selection of the flask accordingly. Being assured
that there will be a sufficient depth of sand over the pattern,
sand is sifted on the pattern as it lies on the mold-board by
means of the riddle until the pattern is completely covered.
The molder then tucks the sand around the edges of the pat-
tern with his fingers, but does not press it down on top of the
pattern unless there is some special reason for so doing. The
drag is next shoveled full of sand and heaped high. The sand
is then rammed around the inside of the flask with the peen or
sharp end of the rammers. The rammer is held at this time
with the butt inclining toward the center of the flask, so that
the blow is somewhat outward in direction, compressing the
sand at the edges of the mold. More sand is then shoveled
on to the flask, the rammers are reversed, and the entire sur-
face of the mold rammed. After ramming, the surplus sand is
scraped off the mold by means of the strike.
In order that the mold will bear firmly at all points on the
bottom-board, which is next placed on what is now the top of the
drag, loose sand is thrown on the mold and the bottom-board
placed over it and rubbed to a firm bearing. Were this not
done, and should there exist any space between the bottom-
board and the mold, the pressure of the iron when poured
might cause the mold to break or cause a distortion of the
casting. After placing the bottom-board, the drag is rolled
over, so as to bring the pattern, and also the joint or pin side
of the flask, to the top, as shown in Fig. I . If the sand has been
properly rammed, a perfect joint can be made by rubbing the
palm of the hand over the surface of the nowel. If the ram-
THE MOLD
ming has been imperfectly done, the sand should be tucked
around the pattern with the fingers. The surface of the drag,
or joint, is next brushed off with a soft brush or blown off with
the bellows, the former method being preferred as it leaves the
joint in better condition to receive the parting sand. Parting
sand is now thrown over the joint to insure a good separation
of the cope and drag, any excess sand being blown from the
FIG. 3. — PEEXIXG THE SAXD AGAINST
THE SIDES OF THE FLASK.
FIG. 4. — BUTT-RAMMING THE
SURFACE OF THE MOLD.
pattern as it would cause the casting to have a rough surface.
A small amount, however, will do no harm and will prevent
the sand in the cope from adhering to the pattern.
The cope D is next placed on the drag, the two parts of the
flask being kept in their proper relation by means of the pins
on the drag fitting into the ears on the cope. The iron band H
is placed in the cope, although with this type of pattern, often
called a flat-back — that is, a pattern molded entirely in the
drag, and with a flat surface at the joint — it is not altogether
necessary as there is no side pressure to be resisted. It may be
stated here that these bands are necessary only in snap-flask
work. The gate-stick which forms the hole through which
6 FOUNDRY PRACTICE
the metal is poured into the mold is next placed in position,
being driven down a slight distance in the sand of the drag.
In ramming, it is important that the sand should be firmly
rammed around the edges of the flask with the peen end of the
rammer in order that it will withstand the side pressure of the
molten metal. Care should also be used to keep the peen
end of the rammer not less than one and one-quarter
inches away from the pattern when ramming, as the sand
must be porous enough to allow the gases to escape when the
metal is poured into the mold. A mold can be rammed too
hard and it also can be rammed too soft. The proper degree
of firmness can be learned only by experience.
The gate-stick is withdrawn from the sand and the cope
is next lifted from the drag and placed at one side as shown
in Fig. i. Any imperfections left on the cope which are not
desired, are smoothed off with the slicker. These imperfections
consist of excrescences on the mold due to holes or other imper-
fections in the pattern. In finishing the mold the cope should
be perfected before the pattern is drawn from the drag, as in
case of damage to the cope the sand can be knocked out and
the cope rammed up a second time, whereas this would be im-
possible had the pattern been removed from the drag.
The hole left by the gate-stick is beveled over at the joint
so that the molten iron entering the mold will not wash sand
in with it. The hole left by the gate-stick at the top of the
cope is reamed out to a bell-shape to facilitate pouring of the
metal. The sand around the pattern is next dampened by
water squeezed from the swab, which is passed gently around
the edges of the pattern, care being taken to prevent the water
from running on the pattern, which if constantly repeated,
would cause the pattern to swell and become distorted. The
object of wetting, or boshing, the sand around the pattern is
to cause the various grains of sand to cohere and to prevent
the sand from breaking when the pattern is withdrawn. The
pattern is withdrawn by means of the draw-nail, which is
driven into the pattern. The molder grasps the draw-nail with
his left hand and, by means of a rapping-iron, jars the pattern
THE MOLD 7
loose in sand by striking the draw-nail a few sharp blows,
first on one side and then on the other, close to the pattern.
He then lifts the pattern vertically upward, using the draw-
nail as a handle, at the same time rapping it gently with his
rapping-iron. When the pattern has been lifted to a point
where the molder can feel that it is free from the sand, he
balances it and moves it up and down slightly to make sure
that it is entirely free and then with a quick motion lifts it
directly upward entirely out of the mold. It is important
that the pattern be drawn straight upward, as the slightest
sidewise motion will break the edges of the mold at the joint,
making necessary expensive and more or less unsatisfactory
repairs. The pattern being drawn, any imperfections in the
mold or breaks at the joint are repaired with the slicker.
All imperfections having been repaired, a channel is cut
in the sand from the impression in the nowel left by the gate-
stick, to the mold. This channel is known as the gate or sprue
and is made with the sprue-cutter. It is shown at B. At E a
cavity is hollowed out in the cope, being known as a cleaner.
Any dirt which may be washed through the gate wi.th the iron
will tend to rise to the surface and be caught in the cleaner
and thus be prevented from passing into the mold.
These various operations having been completed, the mold
is closed, that is, the cope is placed on the drag, the pins on the
drag fitting into the ears on the cope bringing the two halves
of the mold into the same relation they bore to each other
when they were rammed up. The mold is then placed on the
floor at a point convenient for pouring metal into it and the
fastenings on the flask are loosened, the flask opened up, and
removed from the mold. Weights as shown in Fig. 5 are
placed on top of the cope to hold it down firmly on the drag
while the metal is being poured into it and to prevent the
metal from working its way out of the mold through the
joint. At this point, the importance of striking the sand
evenly from the top of the cope becomes evident, for, should
the weight not bear evenly at all points on the surface of the
cope, the pressure of the iron in the mold will lift the cope
8 FOUNDRY PRACTICE
away from the drag on the side on which the weight does not
bear, and allow the iron to flow out at the joint, this being
known as a run-out. Furthermore, if the weight does not
bear all over the cope, a "strained casting" or one thicker than
desired will result, often causing the rejection of the casting.
The molds are placed on the floor for pouring as close together
FIG. 5. — MOLDS WEIGHTED FOR POURING.
as possible as shown in Fig. 5, only enough room being left
between the different rows of molds to permit the molder to
pass with his ladle. Here again the importance of proper
weighting is evident, since the molder is in serious danger of
being burned in the event of a break-out while pouring.
MOLDING A SPLIT PATTERN
Where the pattern is of such shape that it would be incon-
venient or impossible to mold it with the pattern entirely in
the drag, a split pattern is employed. Such a pattern is shown
THE MOLD 9
in Fig. 6 and the mold made from this pattern in Fig. 7. This
mold also illustrates the use of green-sand cores. One half the
mold is in the drag and the other half in the cope. The line
B, Fig. 6, on which the pattern is separated is known as the
parting. Referring now to Fig. 6, the method of molding is
shown. The mold board J is placed as was the case for the
rectangular, one-piece pattern described above and the drag
half of the pattern D is placed as shown on the mold board with
PATTERN ON MOLDBOARD
SIDE VIEW OF PATTERN
FIG. 6. — METHOD OF MOLDING A SPLIT PATTERN*.
the parting down. The drag of the flask with its iron band L
is placed in position exactly as was the case with the pattern
described above. Sand is next riddled on to the pattern and
tucked down with the fingers into the pockets between the
ribs R and the ends 5 and laid up against the side of the pat-
tern. The drag is then rammed up as in the first case, the
bottom-board placed, rubbed to a bearing, and the drag turned
over.
On removing the mold-board, the joint is made by rubbing
the sand from around the pattern with the palm of the hand.
If the sand has been properly tucked down in the pockets and
around the sides of the pattern, there is no need of using a
IO FOUNDRY PRACTICE
trowel. If this has not been done and the sand is too soft
around the pattern, fresh sand must be tucked in and slicked
with the trowel. The joint being made, the cope half of the
pattern is placed on the drag half, as shown at M, Fig. 6, and
parting sand is dusted on the sand joint. In order that the
cope and drag halves of the pattern will align properly, dowel
pins are provided in the cope portion as shown at C, Fig. 7,
which fit in holes in the drag at D. The cope of the flask is
FIG. 7.— MOLD MADE FROM FIG.
then set, as shown at M, Fig. 6, with the iron band TV inside
of it. In order to strengthen the green-sand cores, E, the
nails P, Fig. 6, are placed in position. These are necessary, as
the sand has not sufficient strength to sustain itself in deep
pockets, such as we have here, and would break of its own
weight when the pattern is withdrawn. The nails are placed
after about one-half inch of sand has been riddled into these
pockets in the pattern. The nails are wet and are set heads
down in the corners of the pockets.
The gate-stick is next placed, sand is riddled into the cope,
tucked down around the nails and pattern, and the cope is
THE MOLD II
rammed up. It should be remembered when ramming, that
after having peened between the sides of the flask and the
pattern, and the mold is being rammed with the butt of the
rammer, that the same blow struck over the top of the pattern
will pack the sand harder there than it will the sand alongside
of the pattern, due to the fact that there is a smaller body of
sand to absorb the shock of the blow. As the molten iron fills
the mold, it drives ahead of it to the highest parts of the mold,
the gases and steam generated in the mold. If the sand has
been rammed too hard over the pattern, these gases may have
difficulty in escaping through the sand and, being pocketed
in the mold, will expand and force the iron back through the
gate, leaving an imperfect surface in the casting. It is essen-
tial, therefore, in ramming, that the blows struck over the
pattern shall be somewhat lighter than those struck on the
sand alongside the pattern.
The cope being rammed up and struck off, loose sand is
thrown on top of the cope, the gate-stick is removed, and
the mold-board rubbed down on the cope in a similar manner
to the bottom-board on the drag. At this point; vihe.mold is
vented with a vent-wire, provided a close-grained molding sand
has been used, which is not permeable enough to permit the
ready escape of gases through it. The venting is done by
pricking the sand full of holes over the top of the pattern.
To vent a mold properly, it is essential that the molder be
able to carry in his mind the shape of the pattern, and he
should trace in the sand the outline of the pattern, as it lies in
the flask. Care should be taken not to drive the vent-wire
into the pattern, as this will damage the pattern and cause
imperfect castings. After venting, the mold-board is placed
and the cope is lifted from the drag and laid on its back on
the board.
The pattern is next boshed and is then removed from the
mold by means of a draw-nail. It is essential that the mold-
board be rubbed to a firm bearing on the top of the cope, other-
wise, in driving the draw-nail into the pattern, the pattern
will be driven down into the back of the cope, and in this case,
12 FOUNDRY PRACTICE
when the cope is turned on its side after the pattern is with-
drawn, there would be danger of the sand in the back of the
cope sliding out and ruining the mold.
The parts of the pattern in the cope and drag being drawn,
the mold is finished with the trowel or slicker, the gate in the
cope is reamed out at the top, and the gate is cut in the drag
from the impression of the gate-stick to the ribs in the mold,
as they form the deepest parts. (See F, Fig. 7.) After cutting
the cleaner G in the cope, the mold is closed, set on the floor,
and weighted ready for pouring.
MOLDING A SPLIT PATTERN WITH A WEB CENTER
In Fig. 8 is shown a pattern somewhat similar to that in
Fig. 6, with the exception that there is a web A at the center.
The green-sand pockets in the mold formed by Fig. 6, are in
this case cut off by this web. The molding of this pattern is
similar to the operation of molding the pattern shown in Fig. 6.
The portion of the pattern with the web is molded in the drag,
with two bands H inside the flask. The principal difference
in the operation of molding is in the placing of the nails which
strengthen the green-sand cores. After the pattern has been
placed on the mold-board, sand is riddled over it until it has
a depth of about three-eighths of an inch in the pockets of the
pattern, after which nails of the correct length are wet or
clay-washed and set with the heads down in corners of the
pockets. Sand is then riddled on the pattern, tucked down, and
the flask rammed up as usual. The nails are set in the green-
sand cores of the drag to hold the pockets down and to support
the corners, since, when the drag part of the pattern is rapped
and drawn, the pocket of sand may be cracked away from the
drag and when the melted iron is poured into the mold it will
enter the crack and float the sand against the green-sand
cores of the cope, thus spoiling the casting. The nails pre-
vent this.
Molding the cope of the pattern shown in Fig. 8, is carried
out in the same manner as was the pattern in Fig. 6. In pat-
THE MOLD 13
terns having pockets too deep to allow the use of nails, wooden
rods or soldiers are used. These must be well soaked with
water before using, inasmuch as dry soldiers will absorb
moisture from the sand and swell, thereby cracking the mold.
After soaking, the soldiers should be dipped in clay wash to
enable them to hold to the sand.
Too much emphasis cannot be laid on the fact that it is
possible to ram a mold too firmly over the pattern. The proper
degree of firmness can be learned only by experience, but a
test can be made by applying pressure with the fingers to the
finished mold. The face of the average small mold, prop-
SIDE VIEW OF PATTERN
PATTERN ON MOLDBOARO
FIG. 8. — MOLDING A SPLIT PATTERN WITH A WEB IN THE CENTER.
erly rammed, will yield slightly to pressure. If it is ram-
med so hard that it is unyielding to finger pressure, it is
certain that the gases will be unable to escape and a casting
full of blow-holes will result.
We have described above three simple molding operations
in green sand. They are typical of all green-sand work, ex-
cept that when large castings are made, modifications in the
practice are necessary. Special arrangements must be made
for strengthening certain parts of the molds, and also for
venting, as will be described in later chapters. The bulk of
foundry molding is done in green sand, and therefore many of
14 FOUNDRY PRACTICE
the later chapters will take up in detail che making of molds
in this material, describing the methods to be employed and
the precautions to be taken.
While green-sand molding is the most common, there are
other varieties of molds employed for special purposes, which
are also described in detail later in the book. Thus there is a
skin-dried mold which is a green-sand mold with the surface
baked by means of an oil or gas torch or a fire basket; the dry-
sand mold which is a green-sand mold baked in an oven, and
which is employed for making steel castings and in other situ-
ations where a particularly accurate casting is desired; the
loam mold built up from a mixture of sand and clay, backed
with brick work, employed for large castings where the expense
of pattern work is to be avoided; the chill mold made of iron,
used for car wheels and other castings in which a particularly
hard, close-grained surface is desired. These various molds
all have their uses which will be enumerated together with
the method of making them at the proper point in this book.
For the present, however, we will confine ourselves to the
further consideration of green-sand molds.
CHAPTER II
MOLDING IRREGULARLY SHAPED PATTERNS— COPING DOWN
—MOLDING IN A THREE-PART FLASK— THE USE OF
A FALSE CHEEK— MOLDING GEARS
THE patterns described in the previous chapter have been
molded on a plain mold-board, cope side down, and have been
rammed up in the drag. The joint has been made by simply
brushing off the sand or slicking it with the trowel, which is
all that is required with a pattern having a plain cope side,
which allows it to lie on the mold-board while being molded.
In Fig. 9, at C, D, E, and F, are shown patterns which it would
be impossible to place on a plain mold-board and ram up in
the drag, since they would not remain in position on the mold-
board to cause the desired portion to come in the cope. To
mold a pattern of this character, it is necessary to cope down,
in order to bring the proper portions of the pattern in the cope
and drag respectively, and also to permit the pattern to be
drawn from the mold.
Referring to Fig. 9, the method of molding these four
patterns is shown. None of these patterns will lie in the cor-
rect position on the mold-board and, therefore, a rough
bottom-board is placed on the bench and on that an upset, a
wooden frame of the required size and depth, is placed. The
opening in the lower side, adjoining the bottom-board, is a
trifle larger than that in the top side. The upset is usually
attached to the bottom-board with screws. Sand is riddled
into the upset and is rammed in the same manner as a flask,
and struck off level with the top. The patterns to be molded
are placed on the sand in any desirable position. The sand is
then dug out under them, so as to allow them to sink in the
sand to the same depth that it is desired they shall project
into the cope when this is rammed later. The sand is then
15
1 6 FOUNDRY PRACTICE
roughly formed around them and a little parting sand dusted
on. In Fig. 9, at A, is shown the bottom-board with the
upset B attached to it, and the sand formed in place as de-
scribed. The drag of the flask is next placed over the upset
and is rammed up in the same manner as would be patterns
laid on a plain mold-board as described in Chapter I. After
rolling the drag over, this frame of wood with the sand in it,
is lifted off and the parting is made to follow the shape of the
FIG. 9. — MOLDING IRREGULARLY SHAPED PATTERNS WITH A GREEN-SAND
MATCH.
pattern in the drag, thus causing the sand in the cope to ex-
tend down on each side, so that the lower side of the pattern
will be formed in the drag and the upper side in the cope.
The line of parting having been determined in this manner,
the sand is shaken out of the upset and the frame removed
from the board. The frame is then placed on the drag in the
same manner as would be the cope, the side with the small
opening being down. The frame is rammed up in a similar man-
ner to a cope and the sand struck off level with the top. The
bottom-board is then rubbed to a bearing and screwed to the
MOLDING IRREGULARLY SHAPED PATTERNS 1 7
frame. The upset is then lifted off, being now what is termed
a green-sand match, as shown at A , B. It is evident that the
patterns C, D, E, and Fcan easily be replaced in their respec-
tive positions in the match.
The joint of the drag is then blown off with the bellows,
fresh parting sand is dusted on, and the cope is rammed up and
lifted off in the ordinary manner. The cope is shown at G.
The joint is now blown off to free it of loose sand, the patterns
are boshed and drawn from the drag, after which the mold is
finished and the gate J cut to carry the iron to each one of the
impressions left by the four patterns.
The casting made from pattern F is to have a hole in it at
L. This hole will be formed in the casting by means of a core
which is shown set in position in the drag at K. The position
of the core is determined by means of the core-print L on the
pattern. This core-print will form holes in the cope and drag
as shown at M. A vent-wire is run up through the cope from
this core-print to permit the escape of gas from the core. The
venting of the core itself is fully described in Chapter XIII,
devoted to cores. The mold is now ready for closure, weighting,
and pouring.
The green-sand match may be used many times for ram-
ming up the drag if care is exercised in handling it and in
placing the patterns. In many cases, where but one casting
is wanted from a pattern, the cope is rammed up in the same
manner as an upset, and the pattern is bedded down in it and
the drag then rammed up. After the joint has been made, the
cope is knocked out and is again rammed up to form the cope
of the mold.
MOLDING A HAND WHEEL
Let us consider the operation of molding a hand wheel,
the rim of which is set some distance forward of the hub.
The wheel is laid on a level mold-board and strips of wood,
one-half the thickness of the rim, are placed under the drag of
the flask, in order to raise it so that one-half of the rim will
come in the cope. Sand is rammed around the pattern, and
2
1 8 FOUNDRY PRACTICE
when the drag is rolled over and the mold-board removed, the
rim of the wheel is found to be above the joint of the drag, by
just the thickness of the wooden strips, this operation being
termed upsetting the drag. The joint is then made and, as
the hub of the pattern is lower than the rim, there will be
quite a body of sand to lift out. The arms of the wheel being
rounded on the edges, will add more. The parting is made by
removing sand until the point is visible where the pattern
begins to round under. After the joint has been made and
parting sand has been rubbed on, some riddled sand is laid by
hand on the slanting parting in order to make the parting
sand remain in place. If the molding sand is riddled directly
on the steep parting, it will slide down and carry the parting
sand with it and the cope will stick to the drag and break the
mold.
There will be a considerable body of sand hanging from
the face of the cope due to the recession of the hub from the
rim of the wheel, and it is necessary to support this by means
of a soldier, a piece of wood in this case, about eight inches
long, one inch wide, and half an inch thick. These soldiers
are placed, after being first dipped in the wash pot,
by scraping the sand from the pattern adjoining the core-
print in the hub, so that there is about five-sixteenths inch
thickness of sand outside the core-print. One soldier is placed
between the core-print and the slanting parting and another
soldier is placed on the opposite side of the print with a nail
quartering from the soldier each way. This gives four supports
for the sand which is firmly tucked around them and rammed
in the center, using a gate-stick for a rammer. The cope is
then rammed up as usual, the gate-stick being set to gate into
the rim.
COPING DOWN IRREGULAR PATTERNS
Referring to the patterns in Fig. 10, P is a pattern which
can be molded in the same flask with Q. Both these patterns
require coping down in order to permit the pattern being drawn
from the mold. The upset is rammed full of sand and each
MOLDING IRREGULARLY SHAPED PATTERNS 19
pattern is bedded so as to throw it into the cope. The pattern
P is placed in the upset in the position shown in Fig. 9, being
set somewhat deeper than the thickness of the plate connecting
the two lugs. It is parted as described above down to the
middle of the bosses on the lugs, while the plate part of Q is
placed in the upset to the depth of the plate containing the
two square holes. The drag is rammed up, rolled over with
the upset, and the upset removed. The joint is made and, when
FIG. 10. — ODD-SHAPED PATTERNS WHICH ARE MOLDED BY COPING DOWN
IN DRAG OR IN COPE.
ramming the cope, soldiers are used as described above, for
lifting the sand around the lugs while the hanging sand over
Q should take care of itself with a properly arranged parting.
Pattern R requires a flask by itself. In molding, the end
which is foremost in the illustration is thrown into the cope
above the joint, the other end of the pattern being kept below
the joint. This pattern is upset in the cope and coped down
from the drag, requiring a very irregular joint. The two
square holes in the end are formed by green-sand cores. It
is unnecessary to place nails in these cores to hold them as, if
20
FOUNDRY PRACTICE
they are well boshed and the pattern carefully drawn, they
will remain in better shape in the mold than if nailed. Often
nails in small green-sand cores do more harm than good, as in
rapping the pattern, when drawing it, the nails in the core
hold while the sand moves, thus breaking the core. Patterns
5 and T may be molded in the same flask and will require
some coping down. The remaining patterns can be molded
together as they can be best arranged, three or four in a flask,
according to the ideas of the molder.
MOLDING IN A THREE-PART FLASK
Fig. 1 1 shows a sheave together with the method of mold-
ing it in a three-part flask. When molded in the three-part
flask, the pattern is laid on the mold-board in the center of the
i 1G r^
\ r-vii
BT \ML-
FIG. ii. — MOLDING A SHEAVE IN A THREE-PART FLASK.
cheek D, as shown at C, the parting of the pattern being at E.
The cheek is rammed up around the pattern, which operation
tends to force the two halves of the pattern apart and thus
make the sheave thicker than desired. To prevent this, the
weight F is placed on top of the pattern, while the cheek is
MOLDING WITH A FALSE CHEEK
21
being rammed. After the joint in the cheek is made, the drag
M is placed and rammed up, nails being placed as shown. The
cheek and drag are rolled over together and the second parting
is made, after which the cope is rammed up, nails being set
as shown at G. The cope is lifted off and the portion H of
the pattern drawn, after which the cheek is lifted off, set
aside, and the portion of pattern / drawn. After the core is
set, the gate is arranged as shown at / in the cope.
MOLDING WITH A FALSE CHEEK
The method of molding with a false cheek is shown in Fig.
12. The pattern is placed on the mold-board as is shown in
Fig. II, an upset often being used instead of a cheek. After
E "N
FIG. 12. — MOLDING A SHEAVE IN A TWO-PART FLASK WITH A FALSE CHEEK.
ramming up the cheek, removing the sand, and forming the
parting on the line K, Fig. 12, the cope is placed on the cheek
or upset, being raised by strips one-half the thickness of the
pattern, so that, in the finished mold, half the pattern will be
in the cope and the other half in the drag. The arrangement
22 FOUNDRY PRACTICE
is the same at this point as shown in Fig. 1 1 , at L. The board
is rubbed to a bearing on top of the cope which then is rolled
over, the strips removed, and a parting made at the line N,
Fig. 12. The drag is placed and rammed up, the bottom-
board is rubbed to a bearing, and the drag lifted off. Consider-
ing now the flask X, Fig. 12, as a whole, the false cheek is
shown between the lines K and N, the cope being rammed up
on one side of it and the drag on the other. The drag being
lifted, one-half the pattern is drawn, the parting being on the
line E. The mold is finished in the drag and the drag replaced,
the whole flask rolled, and the cope lifted. Bearing in mind
that there is only the sand forming the outside of the sheave
groove to hold the cope part of the pattern up, the cope portion
of the pattern is carefully drawn from the sand. The core is
set, the cope finished, and the gate is punched and the basin
made as shown at J.
MOLDING A DOUBLE GROOVE SHEAVE IN A THREE-
PART FLASK
Frequently it is necessary to mold a double-groove sheave
when only a three-part flask is available. The method of
doing this is shown in Fig. 13, being a combination of the two
methods above described. The pattern is laid on the mold-
board and the cheek F rammed up, after which the cope G is
made. The cheek and the cope are rolled over and the false
cheek H made with a parting at X, after which the drag is
made. The drag is lifted, together with a portion of the pat-
tern L, to which are fastened the ribs M. This portion of
the pattern is drawn from the drag, which is finished and re-
placed. The entire flask is then rolled over and the cope lifted
together with the cope portion of the pattern. After draw-
ing the pattern the solid cheek is lifted from the drag and
the middle part of the pattern drawn. The pattern is parted
on the lines C and D. The mold is now finished and
closed. It may be poured either through the hub, as was
the first sheave, or it may be gated. If the grooves in the
MOLDING IN A THREE-PART FLASK 23
sheave are very deep, they should be supported with nails
as shown in Figs. II and 12.
At times, the sheaves are molded by using a pattern with
a core-print around it and making a set of cores in a core-box.
After the pattern is drawn from the mold, the cores which
form the grooves in the edge of the sheave are set. Such a core
would occupy the position of the false cheek KN, Fig. 12.
If it is necessary to mold a sheave from a solid pattern,
that is, one without a parting, the false cheek may be formed on
FIG. 13. — MOLDING A DOUBLE GROOVE SHEAVE IN A THREE-PART FLASK,
USING A FALSE CHEEK.
two pieces of paper, cut to the shape of the circumference of
the sheave, a parting being made by each sheet of paper.
After the cope is lifted, the pieces of paper, having the cheek
built on them, are pulled apart, thus drawing the sand side-
ways out of the groove. The pattern is then lifted from the
mold and the two parts of the cheek are pushed together in
their original form.
MOLDING SOLID SHOT
Fig. 14 shows the arrangement of the patterns and gates
in molding solid shot. The four patterns are rammed up in
the drag, with the bottom of the patterns flush with the sur-
face. Shrinkheads or risers C and a pouring gate D are formed
24
FOUNDRY PRACTICE
in the cope. After lifting off the cope, whirl-gates F are cut
from the pouring gate to cause the iron to enter the mold
tangentially. This imparts to the iron entering the mold a
swirling motion, which drives the dirt collected in the mold
Riier
_>"o
Shrink
Joint of Shot mold
PATTERNS DRAWN AND GATED
•v f
O) CO
© ©
COPE SHOWING RISERS
FIG. 14. — MOLD FOR SOLID SHOT.
toward the center and enables it, therefore, to rise in the
shrinkhead, thus leaving a clean casting. As the shrinkhead
is made large enough to supply molten iron to the body of the
casting when it cools and shrinks, a clean, sound casting, free
from blowholes and impurities, is secured.
GEAR MOLDING 25
GEAR MOLDING
Gear blanks, that is, the casting in which gear teeth are to
be cut, must be free from dirt, blow-holes, and other imperfec-
tions to a greater degree than the usual run of castings. In
molding gear blanks, the mold is usually arranged so that the
iron will enter at the hub in order that the face in which the
teeth are to be cut shall be as far away as possible from the
iron which first enters the mold, and which may carry with it
dust or dirt which will render imperfect the face of the casting.
In molding cast gears, that is, gears with the teeth cast on
them, the sand must be selected with regard to the size of the
teeth; the finer the teeth, of course, the finer the grade of sand
that must be used. The sand having the smallest grains will
naturally be selected for those gears having the smallest teeth,
and as gears with larger teeth have to be molded, coarser-
grained sand can be used.
The operation of molding a set of gears will now be de-
scribed. The patterns being in position on the mold-board,
and the drag of the flask placed, sand is riddled over the pat-
terns with a No. 12 riddle. The sand is carefully tucked in
the teeth in the gear pattern and the drag rolled over and the
joint made, coping down between the arms of the gear as pre-
viously described, and the parting sand dusted on. It will be
assumed that there are a number of gears to be made from the
patterns, so therefore, after making the joint, the cope is
placed with an iron band fitted to the inside, and is rammed
up. The bottom-board is rubbed down on top of the cope,
which is lifted off, placed at one side, and the snap flask re-
moved. The cope part of the flask is then replaced on the
drag and the regular cope is rammed up, lifted off, and set
on its side. With a small brass tube, a hole is punched
through the cope from the joint side, in the center of the mold
of the hubs of the gears in the cope. After having lifted off the
cope, the patterns are boshed, rapped, and drawn.
The process of rapping and drawing a gear pattern is some-
what different from the process of rapping and drawing an
26 FOUNDRY PRACTICE
ordinary pattern. To rap a gear pattern sideways would
distort the teeth and thus cause the finished gears to bind on
each other when put in service. Furthermore, rapping the
pattern sideways would tend to break the teeth in the sand
from the body of sand back of them. When the pattern is
withdrawn from the mold, these broken teeth would fall and
make an imperfect casting. In rapping gear patterns, a raw-
hide mallet is used and the pattern itself is tapped slightly,
just enough to jar it free from the sand but not enough to
distort or crack the teeth.
To draw the pattern, a pair of tweezers are used, being
placed in the drawhole of the pattern and spread apart so as
to fill the hole. Lifting on the tweezers and drawing the pat-
tern with his left hand, the molder gently taps the pattern with
his mallet and as soon as it feels free of the sand, lifts it clear
of the mold with a quick vertical motion. Should any sidewise
motion be given the pattern while drawing it and a tooth
thereby knocked down, it will be economy to knock the mold
out of the flask and make it over a second time, rather than
attempt to patch up the teeth.
Care must be taken in tucking the teeth of the pattern to
have the sand uniformly firm. Should soft spots be left in the
sand forming the teeth, bunches will be formed between the
teeth of the gear, and it will be rough. Should the sand be
rammed too hard, the teeth will stick to the pattern and be
broken. Hot iron must be used in pouring in order that the
gear shall come out of the mold with sharp, clean teeth. A
facing comprising one part of bolted seacoal and fourteen parts
of fine tempered sand should be used between the teeth, other-
wise difficulty will be experienced in cleaning the casting.
To return now to the cope which was first rammed up and
set aside. This is known as the false cope and is to be used as
a match-plate on which the patterns are laid when the second
mold is made. This match or false cope is placed on top of
the bench and the cope part of the flask closed around it, with
the joint up. The patterns are placed in the impressions in the
cope, the drag put in position, and sand riddled in on top of
GEAR MOLDING 2J
the cope in the same manner that the drag was made for the
first mold. The false cope and drag are then rolled over to-
gether, the cope removed and set aside as in the first case, and
the true cope made and finished as before. The use of the
false cope in this case is to avoid making the joint every time
a mold is made. Instead of using a false cope, an upset may
be employed, having guides which fit the pins on the drag of
the flask.
At E in Fig. 15, is shown a horn gate. The use of this is
described in Chapter XV. After the drag has been made, the
horn gate patterns are placed in position as shown and the
Fie. .15. — -METHOD OF MOLDING GEAR WHEELS, ILLUSTRATING USE
OF HORN GATE.
A, Cope of mold- B, drag of mold with pattern drawn; C, drag of mold with horn gate
pattern set; D, opening of horn gate in cope.
cope is set on the drag and rammed up, the sand being tucked
in under the horn gates. These gates are larger at one end than
at the other, and after being boshed, can be removed from the
sand by letting them describe a sort of semicircle as they are
drawn. A gate is cut in the center of the cope and is connected
with each of the horn gates leading to the various gear molds.
The horn gates are placed so that the iron will flow to near
the center of the gear. The green-sand cores in the molds
28
FOUNDRY PRACTICE
are vented by means of a fine vent-wire before the patterns
are drawn.
MOLDING GEARS AND SPLITTING THEM
Fig. 16 illustrates the method of molding and splitting a
bevel gear. The pattern is shown resting on the cope, and in
molding is placed on the mold-board in the same position.
The drag is placed around it with the pins down. Sand is rid-
dled into the drag, which is next heaped full and rammed up.
The flask used in this case is a tight flask and remains on the
FIG. 16. — MOLDING AND SPLITTING A BEVEL GEAR.
mold when the latter is poured, and therefore no iron band is
required inside of it. Before heaping the sand into the drag,
the riddled sand is tucked into the teeth of the gears. After
the drag has been rammed, it is rolled over and the sand is
scraped away from the pattern down to the ends of the teeth.
In this case the teeth are formed on an angle on the face of the
drag, and we are obliged to cope down to the ends of the
teeth in forming the joint.
MOLDING AND SPLITTING GEARS 29
The cope is then made up, and after the mold has been
finished and parted, splitting plates, shown at A, are set in the
prints B in the mold of the hub in the drag. Pouring gates D
are punched through the cope with a rod or tube of tke proper
diameter, and a pouring basin formed in the top of the cope.
The following points may well be borne in mind in molding
gears: In boshing a gear pattern avoid putting any excess of
water on the mold, else it will be necessary to dry the pattern
before using it again. Hard ramming on the point of a tooth
makes a rounding instead of a sharp edge. A gear mold must
be rammed firmly to stand the strain of the molten metal and
to keep the teeth from becoming fat. In winter the patterns
should be warmed. At all times iron patterns should be
smeared with barberry tallow mixed with naphtha. The tallow
should be allowed to set until the naphtha has evaporated,
when it may be applied to the pattern with a stiff brush.
This will enable the pattern to be drawn from the sand so as to
leave a perfect mold. Mending the teeth of small gear molds
seldom pays. It is usually better to make the mold over.
CHAPTER III
FLOOR MOLDING
THE term floor molding is applied to work which is too
large for the bench and which is molded either on the side
floor or on the main floor of the foundry. The term is usually
applied to green-sand work. The patterns molded on the side
floor are those which, while too large for the bench, can yet
be handled by one or several men. Patterns molded on the
main floor are usually those which require the services of a
crane for handling the completed mold. Floor molding re-
quires somewhat different equipment from bench molding and
the procedure is also different. The castings being larger, the
question of pouring so as to secure uniformity in the finished
casting, without setting up undue strains in the metal, is also
important. The matter of pouring will be discussed at the
end of this chapter.
In order to illustrate the practice of floor molding, we will
consider the molding the legs of a lathe bed, shown in Fig. 17.
In the first place, a rigid flask is used instead of a snap flask.
This is a frame of wood C solidly nailed together, with tie-
rods extending across it as shown. Furthermore, while the
sand in a small flask, say up to fifteen inches square, properly
tempered, will support itself when lifted with the cope, it will
break away from the flask and fall when the flask is lifted if
the latter is of greater area. Therefore some provision must
be made to support the sand in the cope in the larger flasks
which are used in floor work. This provision takes the form
of ribs, such as are shown at E in the cope of the flask in the
background of Fig. 17. These ribs or bars extend from one
side to the other of the cope, being firmly nailed in place. At
intervals, to keep them from being sprung sidewise, are cross
bars M known as chucks. This construction forms, in effect,
30
FLOOR MOLDING 3 1
a series of copes extending from side to side of the flask. In
order to tie all of these copes together, and form one cope as a
whole over the casting, the sand must extend under the bars
and chucks; therefore, the bars are made about three-quarters
of an inch less in depth than the depth of the cope. The pat-
tern which is under consideration, is of the flat-back type,
that is, no part of it will extend up into the cope. The bars
then extend down to a uniform distance from the joint of the
TIG. 17. — PATTERN OF LATHE-BED LEGS LAID ON MOLD-BOARD READY FOR
FLOOR MOLDING.
mold. Should the pattern be of such shape that it is necessary
for it to extend into the cope, a portion of the bars would be
cut away to permit the pattern to fit under them, and to allow
a thickness of about three-quarters of an inch to an inch of
sand to come between the pattern and the bottom of the bars.
The sand is necessary not only to protect the bars from com-
ing in contact with molten iron and burning, but should
the wood be allowed to form a portion of the side of the mold,
molten iron coming in contact with it would tend to boil and
32 FOUNDRY PRACTICE
thus make an imperfect casting. The edges of the bars are
chamfered to a narrow edge at the bottom, so as to divide the
sand near the joint as little as possible.
In molding the pattern shown in the illustration, the mold-
board is first rubbed to a firm bearing in the sand of the floor,
loose sand to a depth of about two inches first having been
shoveled over the space where the molding is to be carried on.
The pattern is placed on the board as shown and the drag of the
flask set around it with the pin holes G down. Sand is riddled
on the pattern and around it to a depth of about two inches
and is scraped up and laid against the deep upright sides of
the pattern until its entire surface is covered with riddled
sand. Ten-penny nails, dipped in clay wash, are set point
down, one in each corner of the pattern and the sand tucked
around them. It is often advisable in a deep pattern of this
character to vent the sand in the corners with a vent-wire.
The sand is next shoveled in from the heap, the point of the
shovel being placed close to the pattern, and the sand slid off
gently into the flask, to avoid knocking the riddled sand away
from the pattern. After the pattern is well covered in this
manner, sand is shoveled in without further precaution to a
depth of about five inches and rammed around the pattern.
In ramming, the sand should be struck a sharp blow with the
rammer rather than merely pushed down. In floor molding,
the long-handled iron rammer is used and in this first operation
is held peen down, the sand being rammed alongside the flask
and around the edges of the pattern, care being used to strike
not closer to the pattern than one inch. Especial care must
be used when ramming the sand in the pockets not to strike
the pattern or to ram the pockets too hard, which will prevent
the easy escape of gases from the mold. After the sand has
been rammed to a depth equal to the height of the pattern, it
is vented with the vent-wire, and is often trodden down with
the feet. A second lot of sand is then shoveled in and the sand
outside the pattern is rammed with the butt end of the rammer
and also rammed over that portion of the pattern where it lies
the deepest. At this stage, the molder must use his own judg-
FLOOR MOLDING 33
ment as to how firmly the mold must be rammed and in time
will be able to judge by the feeling of the sand under his ram-
mer, whether or not the mold is rammed sufficiently hard.
After second ramming, the flask is heaped full, trodden down,
rammed with the butt end of the rammer, and struck off level
with the top of the flask. Loose sand is then thrown on and the
bottom-board rubbed to a bearing the same as in bench mold-
ing. The board is then raised and the mold well vented, after
which the board is replaced and fastened by means of clamps,
which extend from under the-mold-board to the top of the bot-
tom-board, being made firm by wedges driven under the toes of
the clamps. The mold is then rolled over preferably to a point
back of where the molding was begun. However, should the
foundry be cramped for room, the flask can be twisted around
and lowered on its original bed, and the drag rubbed to a firm
bearing on the floor, sand having previously been thrown
there for the bottom-board to bed in.
The clamps are now removed, together with the mold-
board, and the molder assures himself that the pattern rests
solidly on the sand in the flask. Occasionally, with a thin pat-
tern, the pattern itself may be warped and on the removal of
the mold-board, a portion of it spring up from the sand. In
such a case, the spirit level should be placed on the pattern and
weights used to hold the pattern level until the joint is made.
After making the joint, parting sand is dusted on, the weights
removed, and one-half inch of sand riddled over the joint. To
locate the position of the gate and the risers which are set in the
cope, balls of molding sand are placed in the position desired
for the gate and risers to ascertain whether these positions will
be clear of the bars and chucks of the cope, and after the joint
of the flask and the pin holes have been cleaned, the cope is put
in position, having been first wet or clay-washed. Some of the
molding-sand balls will probably be found to come directly
underneath a bar in the cope and the gate-stick and gaggers
must be shifted accordingly. The gate-stick must be set far
enough away from a thin pattern of this character, to avoid
danger of the gate breaking into the mold when the casting is
3
34 FOUNDRY PRACTICE
poured. Gaggers (see Fig. 138, page 214) are next set. The
gaggers should be of such size as to come close to the top
of the bars, but they should not project above if it can be
avoided. Gate-sticks and gaggers being in place, sand is
riddled through a coarse riddle to a sufficient depth in the
cope to permit it to be tucked firmly around the gaggers and
between the pattern and the lower edge of the bars. In doing
this, the molder places a hand on either side of the bar so
that his fingers can push the sand underneath the bar from
either side. The sand must be tucked firmly, otherwise
soft places will be left in the mold which will cause trouble
when it is poured. Sand is shoveled in next to a depth of
about five inches, and rammed along each bar with the peen
of the rammer. The peen is then held transversely to the
bar and the sand cross-rammed. More sand is shoveled into
the flask and is again peened, after which the flask is heaped
with sand which is rammed between the bars with the butt
end of the rammer. The loose sand is now struck off from the
top of the flask with a wedge, special attention being given to
the detection of any gaggers which may project above the
bars. Should such a gagger be struck and loosened, the sand
is immediately punched down alongside the gagger until it
holds firm.
The cope is then vented all over and the gate-sticks drawn,
after which the cope is lifted off and placed on set-off boxes,
that is, a box having ends and sides but no bottom or top.
One edge of the flask is lowered on to these boxes, the other
being raised in the position occupied by the drag in Fig. 17,
being held up by a prop at the back. In this position the
molder finishes it, by first feeling it all over to see that no soft
spots have been left in tucking the bars, in which case they are
repaired by first cutting up the sand slightly with the trowel
and then pressing fresh sand into place and finishing it with
the trowel. Should soft spots not be repaired, iron will force
its way into them when the mold is poured and form excrescen-
ces on the casting. The cope is finished in the usual manner,
breaks in the sand being repaired, and shining spots in the
FLOOR MOLDING 35
sand which indicate the presence of gaggers too close to the
face of the mold are filled in with fresh sand. The joint in the
drag is next brushed off and the pattern boshed and rapped for
drawing from the sand.
Instead of using a draw-nail or a bar set in a hole in the
pattern for rapping, which would assuredly damage a light
pattern such as is shown, the joint is cut down in a number of
places around the pattern and the butt end of a wedge placed in
these cuts against the pattern. Light blows are struck with a
hammer on the wedge until the pattern is freed from the sand.
The sand is then built up at the spots where it was cut out
and the pattern is drawn by means of eye-bolts screwed into
the pattern. In drawing a pattern of the kind shown, in fact
in drawing practically all patterns used in floor molding, two
men are required, one at either end. These must lift the pat-
tern at exactly the same time and each must be prepared to
stop lifting at a signal from the other which is given when
either notices any indication of the sand breaking on the edges
of the mold as the pattern is lifted. When this happens, the
sand is pressed back in place and slicked over with the trowel
before the pattern is drawn any further.
The pattern being drawn, the mold is carefully looked
over for imperfections and breaks in the sand. As far as pos-
sible, broken sand is carefully replaced with-the fingers, pressed
back into position and dampened slightly. The face of the
mold is then finished with proper tools at this point, and the
entire mold is gone over in a similar manner until all broken
parts are repaired. Sprues are now cut from the upright gates
into the mold and the mold is cleaned of all loose sand by
means of the bellows and lifters. As any sand which will not
blow off, will not wash off under the influence of molten iron
flowing over it, the bellows afford an indication as to whether
there are any loose parts of the mold which have been over-
looked.
On a thin mold of this character, it is advisable to sprinkle
a light coating of talc over which the iron will run freely and a
cooler iron can therefore be used in pouring. The sprues and
36 FOUNDRY PRACTICE
gates are arranged so that the iron will enter the deeper parts
of the mold and also at the feet. In a mold of this character,
peg-gates (see Fig. 129, page 171) are advisable. Cores are next
set and the mold is closed. Five men are required for this
operation with a flask of this size, one at each corner of the
flask while the fifth looks in under the cope as it is closed on
the drag to see that no part of the mold falls down. It is es-
sential that all four men lift and lower the flask simultaneously,
otherwise they may warp the flask and thus cause a portion
of the mold to fall. The man who watches to see that this
does not happen is called the "peeker."
The mold is now clamped, that is, the cope is fastened to
the drag by means of clamps as shown at K, Fig. 17. These
U-shaped pieces of iron are set with the legs of the U projecting
over the edges of the cope and drag respectively, being fast-
ened firmly in position by means of wooden wedges L driven
under the toes of the clamps. The usual method of wedging
the clamps is to pry the clamps on to the wedge rather than
drive the wedge home with a hammer which might, from the
force of the blow, jar the sand down into the mold.
POURING FLOOR MOLDS
In pouring this mold, two ladles are used. The one from
which the iron is to flow to the deeper part of the mold is
poured a little in advance of the other. As there is no part
of the casting above the joint of the flask in the cope, the rising
of the iron in the gate indicates when the mold is filled. In
general, in pouring side floors, the same ladles are used as
for pouring bench molds. A sufficient number of ladles, how-
ever, are used to pour the entire mold at one time. This some-
times requires six to eight ladles, pouring simultaneously at
different gates in order that the iron may reach all parts of the
mold in a fluid condition. A large wash sink is a typical
casting requiring pouring of this character. In pouring from
many ladles, the men all start and stop pouring at a given sig-
nal, thus avoiding straining the casting which might occur were
FLOOR MOLDING 37
iron poured in the gate after the mold is filled, thus putting
pressure, due to head, on the mold. Other classes of castings
poured in this manner, include castings for cotton, woolen, and
other light machinery.
In pouring the light and heavy molds on the side floor, large
ladles are often used holding from one hundred and fifty to
three hundred pounds of iron, in which case several men are
required to handle the ladle. Many castings made on the
side floor may require several of these ladles. It is advisable
to have available, in pouring a heavy casting, approximately
the exact amount of iron required. Therefore, foundries are
usually supplied with a number of ladles of varying sizes so
that by a combination of sizes the required amount of iron
may be brought to the mold. It often is necessary to pour
One portion of the mold with very hot iron and another portion
With slack or cooler iron. Different gates are therefore ar-
ranged in which the two kinds of iron are poured from dif-
ferent ladles. Such a case occurs when a casting has both
light and heavy parts; the hotter iron is fed to the light part.
It is evident from the foregoing, that floor molding requires
that consideration be given to other points than the actual
making of the mold. It is impossible in a book of this charac-
ter to lay stress on all these points and the student is urged to
observe the methods of more experienced molders when gating
and pouring the various kinds of castings.
MOLDING PULLEYS AND WHEELS ON THE FLOOR
A common job of floor molding with green sand is shown
in Fig. 1 8, where a wheel is to be molded and poured with a
cast iron rim and hub, and with wrought-iron spokes set in
the mold around which the iron flows. In the larger sizes of
wheels of this character, provision should be made for pouring
the rim and the hub separately. The mold is made up with
the rim and hub pattern in the usual manner and after the
mold has been opened and the pattern withdrawn, the
wrought-iron spokes are set in place as shown. The ends of
38 FOUNDRY PRACTICE
the spokes which are to come in contact with the molten iron
are coated with a mixture of red lead and benzine or naphtha.
The rim is first poured, and, in shrinking, forces the spokes
inward. After the rim has cooled the hub is poured. Wheels
of this character are made weighing up to six tons and up to
ten feet diameter. It is a quite common practice to cast iron
around iron or steel shafts. If the shaft should be given a
coating of liquid glass (silicate of soda) prior to being placed
in the mold, the iron will lie quietly against this and when cold,
FIG. 1 8. — MOLDING A WHEEL IN WHICH WROUGHT-IRON SPOKES ARE TO
BE SET.
a pressure of many tons will be necessary to separate the two.
Aluminum paint often serves the same purpose well.
In molding pulleys, the work is now ordinarily done on
machines, which will take patterns up to, say, six feet diame-
ter. Many pulleys, however, are still molded by hand. In
some foundries it is customary to have as a pulley pattern,
a rim, arms loose in the rim, and a loose hub. In molding,
the rim is rammed up in a cheek, which may be part of a
flask or a drag staked on the floor, having enough chucks
around it to hold the sand, if the mold is of sufficient size to
FLOOR MOLDING 39
require it. After the sand is rammed around the outside of
the rim, it is rammed inside to the required depth and a hole
dug at the center for the hub. The arms are placed inside
the rims, at the proper distance below the top, and sand is
tucked under them and around the hub, and the joint made.
A lifting plate having projections of the shape of the spaces
between the arms on its surface, is placed inside the pulley,
the two projections between the arms being fastened together
by clamps which pass over the arms and tie all the plates to-
gether. A lifting screw is usually placed in three of the plates.
The inside of the pulley, over the arms, is rammed up with the
gate-stick in the center as if the upper half were molded in a
cope. After ramming, the pattern is drawn and the cheek
lifted. The rim is finished and the cope and drag halves of
the center are marked so that they can be replaced. The
upper half of the center is lifted off, the hub drawn, and
the arms drawn from the drag with the hub. The center core
is set and the cope half closed. The rim is then blackened and
rings, half to three-quarters of an inch in thickness, are laid
on the center, the runner built, and the center weighted for
pouring.
MOLDING LARGE BEVEL GEARS ON THE FLOOR
Fig. 19 illustrates the making of a large bevel-gear mold.
The pattern A is placed on the mold-board as shown, with
the drag hub B in the center. The cope side hub is loose and
is shown at E. The drag is placed with the joint side down and
No. i Albany sand mixed with seacoal in the proportion of
five parts new sand to five parts old sand to one of seacoal is
tempered and riddled over the pattern. The facing is tucked
in between the teeth to insure that the sand teeth thus formed
shall be of sufficient hardness, and surplus sand is then scraped
from the face of the teeth by hand. Facing sand is next riddled
over the teeth and the drag rammed. The same precautions
must be observed in ramming as were observed in the making
of small gears at the bench, as described in Chapter II. After
4O FOUNDRY PRACTICE
rubbing the bottom-board to a bearing, the drag is vented over
the pattern, care being taken to avoid puncturing the sand
teeth. The drag being rolled over, the joint is made by coping
down around the pattern to the bottom of the outside of the
teeth as shown at D, the sand being pressed firmly in between
the teeth with the fingers while making the parting. Parting
sand is rubbed on the face of the sand teeth and the cope hub E
placed on the center of the pattern. Facing sand is laid around
the tooth part of the joint to the proper thickness for setting
the gaggers, and the cope placed on the drag. Gaggers are
next set around the gear to lift the hanging sand formed by
the outside of the teeth and over the pattern.
Sand is then shoveled in from the heap, the flask bars are
tucked, the gate-sticks set on top of the hub to form the pour-
ing gate, and the cope rammed up. After the cope is lifted
the hub E is drawn and the teeth around the pattern are
boshed. The pattern is rapped very lightly as described in
the operation of molding small gears in Chapter II, and drawn
from the sand, and after the mold is finished, a light coating of
talc or of lead mixed with talc, is dusted over the face of the
mold. A vent-wire is passed through the core-print in the drag
and core G of the proper diameter and length, is set after the
vent hole in the tapered end has been filled with sand to pre-
vent iron entering the vent holes. The cope is then closed on
the drag. The gate-stick should be placed in the gate hole
before closing the cope. The pouring basin H is built on top of
the cope in order that a shallower cope may be used than
would be necessary were the pouring basin to be built in the
flask. It is thus seen that the molding of a gear on the floor
is the same operation as molding a small gear at the bench,
with the exception that, there being a larger body of sand
contained in a larger flask, different means must be used to
secure the sand. Furthermore, the flask is clamped instead
of being weighted.
In the flask N is seen the same gear with cores set to form
a split gear for fastening in place on a shaft over the end of
which the gear cannot be slipped. In molding this gear, the
FLOOR MOLDING 4!
mold is made exactly as before, but is gated so that the iron
will enter on either side of the splitting cores L and flow up as
evenly as possible on either side of them. The gates are shown
at S. The splitting cores L are extremely thin and require
special rodding to strengthen the sand. Instead of sand cores,
iron plates, of the same shape as the splitting cores, are some-
times used, having a thick coat of blacking dried on them in
the oven to protect the plate from the molten iron, and to
FIG. 19. — MOLDING BEVEL GEARS ON THE FLOOR.
prevent the latter from burning on the plate when the mold
is formed. It is evident that the hubs for split gears must be
of special design and have prints on them, not only for the
center core but for the splitting core. Such hubs are shown in
the flasks at N and 0.
In molding straight tooth spur gears, of twenty-four inches
diameter and over, it is customary to place the gear pattern
on the mold-board and to throw handfuls of sand, taken
from a heap alongside the mold-board, in between the teeth.
42 FOUNDRY PRACTICE
Sand rammed in this fashion forms very firm teeth. After
the teeth are formed, sand is scraped away from the outside
of the pattern and fresh sand is riddled into the flask and
tucked up around the outside of the teeth after which the mold
is rammed up as any other mold would be.
Gear patterns are often molded by using the floor as the
drag and bedding the pattern in it. Usually where the face of
a gear is quite deep, and the pattern has coarse teeth, nails or
pieces of rods are set in the teeth of the gear. Suppose the
depth of the face to be fourteen inches. After the gear is ram-
med up a distance of three inches, nails or spikes are laid
radially in the teeth and it is rammed up three inches more,
after which additional nails are inserted. The operation is
repeated at a depth of nine and twelve inches. Thus the teeth
formed in the sand will be fastened by the nails to the main
body of sand back of the teeth. They are thus stronger and
resist the strains of pouring better, and also are better able to
sustain the weight of the cope. This practice is adopted only
with gears of rather coarse teeth and weighing from four
hundred pounds to several tons.
CHAPTER IV
LIGHT CRANE FLOOR WORK
MOLDS which are to be made under the crane, require con-
siderable skill on the part of the molder and only the more
experienced men should be entrusted with this work, inasmuch
as the castings made are large and the spoiling of one, due to
poor molding, involves considerable loss. A typical mold made
on the floor is illustrated in Figs. 20 and 21, being one side of
a wire cloth loom frame. The finished casting weighs about
four hundred and fifty pounds, but in pouring it, two ladles are
used in order to obtain the proper distribution of the iron in the
mold.
An iron pattern B, Fig. 20, is used. This is placed on a
mold-board which is bedded level on the floor. The drag of
the flask is placed around it, joint side down. The pattern
must bear firmly on the mold-board, or else wedges must be
driven between it and the board, or the corners of the board
wedged up until it comes in contact with the pattern. The
pattern is then covered with a mixture of seacoal facing in the
proportions of one part seacoal, five parts new No. I Albany
sand and five parts heap sand. This mixture is wet with water,
shoveled over, tramped down and riddled through a No. 4 sieve,
after which it is riddled through a No. 8 sieve on to the pattern,
being then carefully laid against the sides. Sand from the
heap is then riddled through a No. 3 sieve over the facing sand,
after which sand is shoveled in over the entire surface to a
depth of five inches. Sand is now rammed adjoining the sides
of the flask and around the pattern, the rammer being kept
about one inch from the pattern, as in ramming flasks on the
side floor. The sand is then rammed with the butt end of the
rammer between the openings in the pattern and in the remain-
der of the flask, excepting immediately over the pattern, which
43
44 FOUNDRY PRACTICE
would cause the sand to be too hard at this point. An ad-
ditional five inches of sand is then shoveled in and peened down
along the edges of the flask and trodden down all over the drag
and afterward butted with the butt of the rammer, over the
pattern, in addition to the other portions. This operation of
adding sand and ramming it with the butt is continued until
the flask is completely filled. It is then struck off and leveled,
the bottom-board placed and rubbed to a bearing, after which
the drag is vented over the pattern, the bottom-board replaced
and clamped to the mold-board with the flask between them.
FIG. 20. — PATTERN OF WIRE CLOTH LOOM FRAME ON MOLD-BOARD READY
FOR MAKING DRAG.
The total weight of the flask, pattern, and sand is about forty-
four hundred pounds and the services of the crane will be
required to roll it over.
A chain is placed around the drag and hooked over the
crane hook, after which the crane raises the flask clear of the
floor. While suspended in the air, it is turned over and lowered
on the original bed of molding sand with the mold board up.
The ends of the mold-board are leveled, a spirit level being
used for this purpose, and sand is rammed under the cleats of
the bottom-board to maintain the level. After removing the
mold-board, the joint is made as in ordinary small castings.
Parting sand having been dusted on the joint, the pattern
is covered with a seacoal facing to a depth of three-eighths of an
LIGHT CRANE FLOOR WORK 45
inch, and the cope, previously wet down, is placed on the drag,
after which gaggers are set. 'Gate-sticks are set and sand
tucked in between the bars of the flask in exactly the same
manner as is done in side floor molding.
In side floor work, considerable reliance is placed on the
clay washing of the bars of the cope to retain the sand in place,
but in crane floor work, the flasks being larger, careful gag-
gering is required, as the bars cannot be depended on to hold
FIG. 21. — DRAG OF WIRE CLOTH LOOM FRAME ON FLOOR. COPE is STAND-
ING AGAINST WALL.
the larger body of sand. When placing the cope, should it be
found that it does not bear evenly on the drag, it should be
clamped down to it, or if it is too stiff to permit of this,
the cope should be wedged up and care must be taken to
see that this wedge is replaced when the mold is closed for
pouring.
Referring now to Fig. 21, it will be noted that the top of
the pattern is coped out and gaggers, with long shanks, are
required to lift the hanging belly of sand in the cope. In set-
46
FOUNDRY PRACTICE
ting these gaggers, they are placed so that they will assist in
supporting each other, and in«proportion to the size of the flask
a greater number are used than in side floor work. After the
sand has been tucked in between the bars and the pattern,
sufficient sand is shoveled in between the bars of the cope to
form a ramming and the cope is rammed up as in side floor
work. After the top has been scraped off, the cope is well
vented. The crane is then brought over the center of the
FIG. 22.— WIRE CLOTH LOOM FRAME MOLD CLAMPED READY FOR POUR-
ING AND BOUND DOWN WITH BINDER.
cope and chains are hooked into staples or eyes set in the sides
of the cope flask and the cope lifted and set to one side, one
edge resting on set-off boxes as shown in Fig. 21. Care must
be exercised in doing this as any jar is liable to shake sand
from the cope. Therefore, strain should be brought on the
chains gradually, and lifting and lowering commenced slowly.
It is almost invariably the case, that when the cope is lifted,
some parts will be broken down. When these are repaired, the
sand should be nailed to insure its remaining in place. The
LIGHT CRANE FLOOR WORK 47
cope being finished, a coating of silver lead is applied, over
which a light facing of talc is dusted.
The joint being brushed off, the pattern is boshed and
rapped. Eye-bolts are screwed into the pattern and it is
lifted from the sand by the crane, the pattern being rapped as
the crane lifts it. The mold is finished and the gate D is cut
and also a second gate at E. The principal body of iron enters
through this and therefore it is made considerably larger than
the other. Sharper iron is poured through this gate than
through E. At X a gate is cut to the riser.
The mold being finished, cores are set in the prints formed
by the core-prints F and G on the pattern. Sand is slicked
around them and the mold coated with silver lead over which
talc is dusted. The cope is now lowered on to the drag, being
guided to the point where the pins enter the pin holes by the
wooden guides H. Before lowering the cope, flour is placed
on all the small cores to indicate whether or not the cope
bears on them. When the cope comes to a bearing one clamp
is set on each side to give the same conditions which will ensue
when the mold is finally closed. The clamps are then removed,
the cope lifted and examined and the cores resting in the prints
A A placed, after which the mold is closed and clamped as
shown in Fig. 22. In order to prevent the cope springing at
the center, when poured, blocks of wood are set at either end
of the flask and a rail clamped across them as shown in Fig.
22. Wedges are driven between this rail and the bars of the
flask. Paper is laid over the top of the cope, which is lighted
when the mold is poured and gases escape from the vents.
The gases escaping from the vents in the drag will be lighted
with a red-hot skimmer.
CHAPTER V
BEDDING PATTERNS IN THE FOUNDRY FLOOR.— MOLDING
A DRAW-BENCH FRAME IN THE PIT.— MOLDING
THE FRAME OF A GAP PRESS
OFTEN large patterns are molded in pits in the foundry
floor, cope and cheek plates being the only part of the flask
used. In this way, the floor is used as a drag and a large part
of the expense of flask manufacture is avoided. In case the
foundry floor is damp, tanks of large size are sunk in the floor
and molds made in them. If this is not done, the floor being
slightly damp, the inside of the pit may be lined with tar paper.
Work of this character is usually known as pit molding.
Most of the molds made in pits are of green sand, although
skin-dried molds are also made.
Instead of using but one pattern in the flask, the molder
is, in many cases, given patterns of various sizes and shapes
which he is required to mold in a certain space in the floor.
For instance, at the foundry of R. Hoe & Co., New York,
printing press manufacturers, it is the custom for two molders
to work together, assisted by two helpers and to use a cast
iron cope fourteen feet long by five and one-half feet wide,
molding in the floor enough patterns to fill the space covered
by the cope.
The space allotted to a molder, on work of this character,
is termed his "floor." When the number of castings desired
from a medium-sized pattern is small, they often are molded
in a hole dug in the floor. Assume that there are several
pipes to be made, each three feet long and six inches diameter.
A hole is dug in the floor about four feet long, in order to allow
for the core-prints in the pattern, and four and one-half inches
deep. Where the flanges come on the end of the pipes, the
hole is made deep enough and wide enough to accommodate
48
BEDDING PATTERNS IN THE FOUNDRY FLOOR 49
them. Molding sand is riddled in the hole and the pattern
placed in it with the joint side up. A long block of wood being
placed on top of the pattern, the pattern is driven down into
the sand the proper distance by pounding on the block, thus
ramming the sand underneath the pattern. The pattern is
now weighted in position and riddled molding sand laid along-
side of it by hand. Sand is then shoveled in from the heap
and is peened down around the pattern with the rammer. If
necessary, the pattern will be rapped down and lifted out and
the flange pattern fixed up, after which the pattern is replaced
and the sides rammed up. The sand being rammed even with
the top of the floor, the joint of the pattern is made and the
cope part of the flask placed over the pattern. Parting sand is
dusted on and the cope made up in the ordinary manner.
Before lifting off the cope, the molder drives down in each
corner of the cope on the outside, an iron rod or a wooden stake
about twelve inches long to act as guide when lifting and re-
placing the cope. The cope is then lifted and finished, the
pattern is drawn and the drag finished, after which the cope is
replaced and weighted for pouring and the stakes removed
when the mold is ready to pour. Instead of weighting the cope,
it may be held down by bolting it by means of binders across
the cope, which engage bolts rising from binders underneath
the mold. This method will be described in detail in the
description of the next mold.
MOLDING A DRAW-BENCH FRAME IN THE FLOOR
Having described the construction of a comparatively
small mold, we will now take up the process of bedding a
rather large pattern in the floor. Assume that we have the
pattern shown in Figs. 23-27. This is a comparatively
shallow pattern, long and narrow. We will also assume that
it is to be molded in a pit prepared for a much larger pattern.
The pit is first dug in the foundry floor, say sixteen feet long,
nine feet wide, and six feet six inches deep. Referring to Fig.
28, binders of cast iron, spaced four feet on centers, are placed
4
50 FOUNDRY PRACTICE
across the bottom of the pit. The ends of the binders should
be in line and the tops leveled to a straight edge, after which
sand is firmly rammed between and around them. Each
binder has a vertical slot in each end in which an eye-bolt with
a nut and washer on the lower end, is slipped, as shown in the
illustration. Sand is then rammed around the end of the
binders and that between them is struck off level with the top.
Iron plates, one inch thick, are placed on top of the binders,
covering them and extending to within six inches of the eye-
bolts. Six-inch square timbers are stood on end inside of each
eye-bolt and on top of the binder. These pieces of timber are
allowed to extend above the floor line about four inches. Sand
is rammed around the bottom of them and scantling is nailed
from one to the other at the top as shown. The end timbers
are also tied across the ends with scantling.
On top of the iron plates is laid about five inches of molding
sand, on top of which is placed a cinder bed, both firmly ram-
med. Over the cinder bed, straw or newspapers are placed,
to keep the sand, which is later rammed on top of the cinders,
from working down among them and filling the voids in the
cinder bed which are depended upon to bring the gas from
under the casting to pipes which extend from the cinder bed
to a little below the top of the floor line, as shown in Fig. 28.
In the top of the pipes, a plug of rolled bagging is placed to
prevent sand entering while the mold is being rammed. This is
removed before the mold is poured.
The timbers are sawed off flush with the floor line, a cord
being used to give the proper alignment. This will give more
accurate results than any attempt at measuring the timbers
and sawing them off before placing. The pit thus prepared,
is for a pattern four feet six inches deep. It can be used for a
smaller pattern by simply filling the pit to a greater or less
depth with sand. Referring now to Figs. 23-27, the pattern is
placed on the floor in the position in which it is desired to
pour it and its outline traced in the sand. This indicates the
amount of space required for the pattern, which is then re-
moved and the pit excavated to a sufficient depth to permit
MOLDING A DRAW-BENCH FRAME IN THE PIT
52 FOUNDRY PRACTICE
molding the pattern, a deeper hole being dug at one end to
accommodate the projection on the pattern. The cinder bed is
placed, covered with newspapers, and the gas pipes put in
position. On top of the cinder bed, molding sand is rammed
to conform to the line F of the pattern, Fig. 26. The pattern
is then placed in the pit and leveled to the proper height with
wedges F, Fig. 30.
The portion of the pattern DD, Fig. 26, is removable.
This is removed and the remaining portion of the pattern is
weighted at the ends, and facing sand tucked under the edges
of the pattern. The construction of the pattern is such, that
this work can be done both from the inside and the outside,
while the weights hold the pattern in place. The wedges F
are removed as they are reached in this operation. Gate cores
are placed at the ends of the pattern and also upright gates.
Facing sand is laid up against the side of the pattern and black
sand is shoveled in around it to a depth of about five inches
and is then firmly rammed, first with the peen and then
with the butt of the rammer. Inasmuch as these first ram-
mings of sand receive the greatest side strain from the melted
iron when the mold is filled, this portion of the operation must
be carefully done. The facing sand, lying loose at the top and
adjoining the pattern, is scratched away and when the core-
prints C, Fig. 26, are reached, the pins which hold them to the
side of the pattern are removed. These pins are usually made
of three-sixteenths-inch wire, one end of which is turned over
and extended through the core-print into the pattern.
The outside being rammed up, the inside of the pattern
next receives attention. Facing sand is laid against the sides
of the pattern and bl$.ck sand is rammed inside. When the
sand has reached the proper height, five-eighths-inch iron
rods are driven down in the green-sand core, formed inside
the pattern, as shown at G, Fig. 30. The pattern is faced and
sand rammed up in it until it is within three-quarters of an
inch of the top, when the sweep D, Fig. 27, is used to true the
facing sand in the last three-quarters of an inch. The green-
sand core is vented, care being taken that the vent-wire passes
MOLDING A DRAW-BENCH FRAME IN THE PIT
53
through the newspapers or straw into the cinder
vents are then filled with sand at the top and the
top of the mold is made up with the
fingers. The covering boards forming
the top of the pattern are then re-
placed and the joint is made level
with the upper surface of the pattern.
The joint being made, parting sand
is dusted on, the cope is placed,
rapped down, staked, and then hoisted
off. Attention is here called to the
manner in which the cope is barred
through the center as shown in
Fig- 31.
Facing sand is next spread over
the pattern and the joint, after which
the cope, first being wet down or
clay-washed, is lowered into place.
Gate-sticks and gaggers are set, black
sand is riddled into the cope and
tucked in between the bars and pat-
tern. Sand is then shoveled into the
cope to a depth of about five inches
and rammed with the peen of the
rammer. Enough rammings of sand
are added to fill the cope level full.
The final ramming of sand is butted
with the rammer and the excess sand
cleaned off. In ramming up the cope,
the space between the lines of chucks,
CC, Fig. 31, is not rammed up with
sand, but is left open and the cope
well vented.
The gate-sticks are now removed
and the cope hoisted off. The joint is
brushed off and the mold is vented
all around the pattern at a dis-
bed
face
, The
at the
54 FOUNDRY PRACTICE
tance of about one and one-quarter inches from the edge of
the pattern after the latter has been boshed. The pattern
is now rapped and drawn, the gate-sticks removed, and the
mold finished with trowel, slicker, and lifter, and wherever
square corners of sand have been left on the inside of the mold
by the pattern they are rounded off to form fillets in the cast-
ing. This is a point which should always be remembered, for
unless a fillet be placed in the corner of a casting, strains will
be set up when the casting cools and it will have a tendency to
break through the corner.
Referring to Fig. 27, at A will be noted a partition extend-
ing the length of the casting formed by a corresponding space
in the mold. As the green-sand core C is struck off level at
the line of pattern B, this core extends only partially into
the pattern. The balance of the space is occupied by dry-
sand cores hung from the cope. These are shown at E and
straddle the green-sand core, leaving a space between them
and the green-sand core into which the iron flows to form the
partition F.
In order to obtain the right thickness of metal on the sides
of the casting, pieces of board, of the same thickness as the
casting is to be, are placed over the green-sand core, after
which the cores E are lowered into position on these boards.
After they are correctly placed, the cope, Fig. 29, is lowered
over the mold, being guided to place by the stakes B, driven
into the floor. Hook bolts are passed through the openings
A, Fig. 31, and attached to staples provided for the purpose
at B in the cores. Gate-sticks are placed at O where the gas
is to escape from the cores and wedges are driven in between
the bars of the cope and the top of the cores to insure the cope
bearing solidly on the cores in order to hold them in position
to give the proper thickness of metal when the mold is poured.
The spaces between the bars XX at either end of the cope,
and between chucks C C, left open when the cope was ram-
med up, are now rammed with black sand and the gate-sticks
forming vents are drawn. The clamps H, Fig. 31, are now laid
in position as shown and by means of the slotted bars D,
MOLDING A DRAW-BENCH FRAME IN THE PIT
55
56 FOUNDRY PRACTICE
slipped over the hook bolts to the cores, previously mentioned ;
the cores are firmly held in position by screwing the nuts on
the bolt down on the slotted bar. The cope is next hoisted
as is shown in Fig. 29 with the cores hanging from it.
The mold is examined, the boards on top of the green-sand
core are removed, the name-plate core is placed, and the cores
X, Fig. 30, set in position. Necessary repairs to the mold are
made and its entire surface is given a coat of silver lead. Gates
are cut to connect the upright gates in the cope with those in
the floor. The cope is then finally lowered and held down with
binders which span the pit. Blocks of wood are placed on the
cope underneath the binders, after which the bolts /, Fig. 27,
are hooked into the eye-bolts in the floor, the tops being set in
the slots in the ends of the binders, when by screwing down the
nuts, the binders are made to bear firmly on the cope. Care
should be taken in tightening the binders as the nuts at the
end will exert considerable leverage and crush the mold if
screwed down too far.
Runner boxes, shown in Fig. 27, at the ends of the cope, are
placed and runners built as indicated in Fig. 31. In order to
avoid any great head on the casting, due to excessive height
of the runner boxes, the flow-off D is built, which conveys any
excess of iron to a basin in the floor. Gases escape from the
mold through the pipes Q, Fig. 30, and through the gates lead-
ing from the cores. These gases are lighted as soon as they
begin to flow.
Eye-bolts, timbers, and vent-pipes are all kept below the
floor level in this type of mold, so that they will be out of the
way. When access is needed to them, they can easily be
reached by a slight amount of digging.
In order to compare the foregoing method of molding
with the ordinary way of molding in a flask, consider what
would be done with the same pattern in a flask. It would be
placed on the mold-board, cope side down, with a drag around
it as in Fig. 32. The pattern would be faced with facing sand
on the outside and the sand rammed in alongside the pattern
as in molding any plain pattern, until the top of the pattern
MOLDING A DRAW-BENCH FRAME IN THE PIT
57
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FOUNDRY PRACTICE
is reached. The upright gates B and the inlet gates D would
then be placed as shown, the inside of the pattern cleaned out,
faced, and the green-sand core
formed, rods being placed as
before and the core vented.
The remainder of the drag then
would be rammed up, the sand
struck off, and the bottom-
board rubbed to a bearing. The
bottom-board would be lifted
off, channelways formed in the
bottom of the drag by striking
it with the strike, edge down,
after which the molder would
then vent the drag all over.
The channelways conduct the
gas from the vents to the edge
of the mold. The bottom-
board would next be replaced
and clamped and the drag
rolled over. After the joint is
made, the cope is made exactly
as before, the principal differ-
ence being that the cope is
guided by pins on the flask
instead of stakes in the floor.
Fig. 33 shows the mold closed
and clamped and ready for
pouring.
MOLDING A GAP-PRESS FRAME
In Figs. 34-37 are shown the
patterns of a gap-press frame,
which can be molded in the
same pit used for the patterns
described above. A pit is dug
MOLDING A GAP-PRESS FRAME 59
between the upright posts, deeper than the pattern, and
the sand and cinders riddled and separated. When the
hole has a depth of about 10 inches greater than the depth
of the pattern, a cinder bed about three inches thick is made
and gas pipes provided for carrying gas away from the
bottom of the mold when it is poured. A timber D, Fig. 36,
is placed as shown. This is used later for holding the chaplets
supporting the core. Molding sand is then rammed up over
the cinder bed, newspapers first having been placed on it, and
shaped to conform to the under side of the pattern as nearly as
possible. The pattern is then placed, being blocked and
wedged to its proper position and weighted to hold it in place
while sand is being rammed under it. The parting of the
pattern is at A, Fig. 35, and that part of the pattern below the
parting is bedded in the pit as shown in Fig. 36. The core-print
for the main core is at B, Fig. 35, and a flat iron plate is placed
under this print to support the weight of the heavy main core.
A slab core is set so as to bear against the face of the feet, as
they must be fairly true and also carry a heavy strain due to
the weight of the finished casting. Sand is rammed underneath
and facing is tucked under the pattern, the wedges and blocks
being removed as they are reached and replaced with firmly
rammed sand. When the pattern is finally resting on a bed
of sand, the stakes AA, Fig. 37, are driven and the pattern
lifted from the pit. The entire face of the mold is well vented,
the vents extending down into the cinder bed. The face of
the mold is then made up with the fingers and finished as far
as possible, after which the pattern is replaced and rapped
down to a solid bearing. The stakes are now removed, facing
sand laid against the pattern, and black sand is rammed solid-
ly around it, struck off, and the joint made. The joint being
made, parting sand is dusted on the joint, and the cope half of
the pattern placed on the drag. The cope, Fig. 38, is lowered
over the pattern and staked in place with stakes X, after which
it is lifted and wet down or clay-washed. The pattern is then
coveted with facing sand, which is laid up against any portion
to which it does not adhere readily and it is also spread over
6o
FOUNDRY PRACTICE
the joint. A slab core is placed against the foot, this core being
arranged with a staple which will permit it to be wired to the
cope. .Gate-sticks and risers are placed and long-stem gaggers
set in position. As the pattern is heavy, it is necessary to
provide some means of supporting it in the cope, since it might
Fio-39 BjU
THE FINISHED Fio.35
CASTING THE PATTERN
FiQ.34
THE PATTERN
FIGS. 34-39. — MOLDING A GAP-PRESS FRAME.
fall out when the cope is lifted. Accordingly, wood screws,
with eyes in the end, and extending through the cope into
the pattern are provided. After the pattern is covered with
facing sand, black sand, to a depth of about two inches, is
shoveled in and rammed with short iron hand rammers. In
MOLDING A GAP-PRESS FRAME 6 1
many large copes, such as this, the bars are stopped off some
distance above the patterns and the sand is shoveled in and
rammed with these rammers instead of being tucked in by
hand as is the case with smaller patterns. The black sand is
now filled in, in several rammings, until the top of the foot
is reached. A riser for a flow-off is placed on top of the foot
as it is the highest part of the mold. If gas pockets in a mold,
it always does so at the highest point, and the provision of a
flow-off to enable some of the iron to run away from this
point, will produce a casting sound and free from blow-holes.
After placing the riser, sand is filled in the flask and rammed
until the cope is filled. The top is then cleaned of loose sand,
well vented, and the core at the foot properly secured. Gate-
sticks and risers are removed and the cope lifted off.
The cope is set up on one side and the wedges and rods in
the eye-bolts, holding the pattern in the cope, are removed.
The holes left by them are filled up and the cope rolled over
on its back. The pattern is drawn and the cope finished and
given a coat of silver lead, which is rubbed on with the hand on
the heavier parts and brushed on with a camel's-hair brush on
the lighter. Channelways and gates are cut in the cope, both
to conduct the iron to the mold and to act as cleaners.
Before the drag portion of the pattern is drawn, the screws,
holding the pattern to the base, are removed, freeing the base
from the main part of the pattern. In the corner formed by the
foot of the bracket, iron rods five-eighths inch diameter, are
driven to support the sand when the iron flows around this
corner, which is well vented down to the cinder bed. After this
is done, the foot portion of the pattern is drawn and the mold
finished. When finishing the drag and cope, large-headed nails
are pushed into the face of the mold, around the jaw, and also
around the edges of the base. This is to prevent the heavier
parts of the casting from scabbing when the iron is poured.
When finishing the cope and blacking it with lead, this black-
ing is omitted from that part of the mold forming thin portions
of the casting, as there is a liability to cold-shutting the iron
with a heavy facing like lead. A lighter facing, with less sea-
62 FOUNDRY PRACTICE
coal, is used on these portions. The mold being finished, it is
gated and nails are pushed down into the sand in front of the
gates, to keep the face of the mold from being cut by the iron
flowing into it. At one end of the mold there is no core-print
for the main core. Consequently, it must be held up by chap-
lets. Accordingly, these are cut to length, sharpened on one
end, and driven through the sand in the floor, into the timber
D, Fig. 36, and allowed to extend above the face of the mold
a distance equal to the thickness of the casting, as shown at
F, Fig. 36. The main core / is then set, one end resting in the
core-print, the other being held up by the chaplet. At the end,
resting in the core-print, provision is made for gas to escape
through suitable vents in the mold. Cores K and L are next
set and then the shaft core, one end of which rests in the core
K, while the other is held up by a chaplet G in the core-print.
The cope is rolled back and the gate-stick placed in the
gate hole. The runner B, Fig. 38, is built and an iron ring
placed around the riser C. Two pieces of pig iron are placed on
each side of the gate-stick, forming the flow-off D. Pieces of
clay one inch diameter, and a little higher than the thickness
of the casting, are formed and set on the cores at the points at
which it is desired that the chaplets shall be placed. The
cope is closed on the mold, and is then immediately removed
and examined and repaired if necessary. It frequently hap-
pens in closing the cope over the cores that parts of the
cope are broken. In order to see that the cope bears prop-
erly on the cores, flour or white sand is placed on such parts
as may be doubtful of bearing properly. These will leave
a mark on the dark sand of the mold on the removal of the
cope. It being found that the cope bears as desired on the
joint and cores, the vent-wire is run up through the cope,
and chaplets are set at the points where the pieces of clay
have marked the mold. The stems of the chaplets are made
long enough, so that when they are pushed up through the
holes in the cope made with the vent-wire they will extend
about a quarter of an inch above the top of the cope and
still leave in the mold a length of chaplet equal to the thick-
MOLDING A GAP-PRESS FRAME 63
ness of the casting. The chaplets are held from falling down
by pieces of soft clay squeezed around the top of the stem
projecting through the cope.
The vent-wire is also used to form outlets through the cope
for the gas driven off from the cores. Paste is placed on the
edges of the cores so that the iron cannot "fin" over them,
and thus enter the vents and prevent the escape of gases which
would then back into the mold and ruin the casting. It is
advisable, before placing the cope temporarily, to arrange
pieces of thin rope or belt lacing from the vent openings in the
cores to the outside of the mold. These should be covered with
sand and be below the joints. When the mold is finally closed,
and just before pouring, these ropes or belt lacings should be
pulled out, thus leaving a clear vent from the core. If clay
be filled in around the rope or lacing before sand is filled in
around them, it will be impossible for iron to enter these vents,
even should it overflow the cores. In places where the cope
does not bear as it should, the sand in the floor is built up or
parting sand is filled in on the joint. With very large castings,
what is termed a clay worm — a roll of common fire clay about
fourteen inches long — is laid at the back of the gate. This
being soft, it is easily flattened by the weight of the cope when
it is finally closed and prevents the iron straining out the
back of the pouring gate at the joint.
The cope is now finally closed and the riser C covered so
that nothing will drop into the mold. Binders A, Fig. 38, are
placed on top of the cope as shown, blocks of hard wood or
iron being placed between the binders and the edge of the cope.
The binders are held down by hook bolts engaging with the
eye-bolts in the floor as before. In order to keep the main
core from rising when iron is poured in the mold, the binders
E are passed underneath the binders A , being held by wedges.
Wedges G are pushed in between these binders and the top
of the chaplets.
A certain disadvantage in pouring is encountered in that
the jaw portion, which must be the strongest part of the cast-
ing, is heavy, while the lightest part is the leg. The iron must
64 FOUNDRY PRACTICE
be poured hot enough to run to all the light parts of the cast-
ing, including the leg, and this is too hot to give the best
results with the heavier portions.
Let us consider molding the same pattern in a flask. The
drag portion of the pattern is placed on the mold-board and
a slab core placed against the foot, while an iron plate is laid
on top of the core-print. The drag of the flask is set around the
pattern which is then covered with facing sand and successive
layers of facing sand around the pattern of the leg. The flask
is filled up with rammings of black sand and struck off.
Bottom-boards are rubbed to a bearing, the drag vented, and
the bottom-boards replaced. The clamps are placed in posi-
tion and the drag rolled over. The cope is then finished as
before.
Still another method exists of bedding which must be
practiced with many different styles of patterns. The pattern
is blocked and wedged to the proper height in the hole and
black or heap sand is tucked and rammed under it, the block-
ing and wedges being removed as reached. When the pattern
has been rammed completely on its under surface, it is staked
and removed and the sand bed below it well vented down to the
cinders. The entire face of the mold is covered with facing
sand to a depth of three-quarters inch and the pattern replaced
and rapped down to ram the facing sand into the bed of black
sand. The vents in the black sand take care of the gas from
the facing sand of which the face of the mold is made.
CHAPTER VI
MOLDING COLUMNS
CAST-IRON columns are still used to a certain extent to
support the floors of buildings and also for ornamental pur-
poses on the fronts. The illustrations, Figs. 40-42, show the
pattern and method of molding a rectangular ornamental col-
umn. The pattern is made with separate side pieces A to
which are attached pieces of moulding to give an ornamental
finish. These are pinned on to the side pieces so that they may
be removed during the process of molding. The pattern itself
is made solid and is shown at B. In molding, the floor is used
as a drag, the pit being prepared as described in Chapter V.
The pattern is placed in the pit and leveled and a facing
sand, comprising one part seacoal to fourteen parts molding
sand, is laid up against the pattern. Black sand from the
heap is rammed firmly against the facing sand. As each suc-
cessive ramming of sand is laid in the mold, the facing sand
is firmly rammed against the pattern with a hand rammer and
fresh facing placed against the pattern. As the sand in the
mold rises to the point at which the pieces of moulding a are
pinned to the pattern, the pins holding the moulding are with-
drawn, and it is supported by the sand. The facing of the
pattern and the ramming of black sand is then continued
until the floor line is reached where the joint is made. The
cope is now placed in position and rapped down to insure its
bearing solidly on the sand. If there is but a small amount of
sand around the pattern and there is danger of the mold being
crushed in when securing, the cope, pieces of board are placed
under the cope and on the sides near the center. In this case
pieces of plank are nailed to the sides of the cope and stakes are
driven against them into the floor to act as guides when the
cope is lifted on or off; otherwise stakes C, Fig. 42, are used
5 65
66
FOUNDRY PRACTICE
for this purpose. The cope is then lifted off and clay washed or
wet down ; the pattern is brushed off, parting sand placed on
the joint and facing sand riddled over the pattern, except at
its center. The facing sand is left off the pattern at the center
as it has a cooling effect on the iron which, in this case, will
be poured from the ends of the mold. Were seacoal facing
to be used at the point where the flow from opposite directions
COPE CLOSED ON AND SECURED
FIG. 42
FIGS. 40-42. — MOLDING AN ORNAMENTAL BUILDING COLUMN IN THE SAND.
meets, there would be the liability of a cold shut forming and
thus destroying the casting. In place of the seacoal facing
at this point, a mixture of old and new sand is used.
The cope is now replaced, and gate-sticks D and E set to
form the pouring gates and risers. Gaggers are set and the
sand shoveled in to the proper depth for tucking the bars.
Extreme care must be used in this operation in castings of this
character, since any soft spots left in the mold will form lumps
on the casting and destroy their value for ornamental purposes.
After tucking the bars, the cope is rammed up, vented in the
usual way, the cope hoisted off, turned over on its back and
MOLDING COLUMNS 67
finished. The joint is brushed off and the pattern drawn.
The pieces of moulding a remain in the sand when the pattern
is drawn, and they now are drawn inward into the mold and
lifted out. Should these pieces be of any considerable depth,
thus leaving a considerable body of sand hanging over them,
the mold is nailed on the upper surface of the cavity left by
these pieces.
The side pieces A are now placed in the mold, one on either
side, and the center or green-sand core built. These side pieces
are the same thickness as the casting is required to be. A
mixture consisting of one-half old sand and one-half new sand
is tempered and the side pieces faced with it. Black sand is
rammed firmly against this facing until a height of about six
inches below the top of the casting is reached. The sides of the
core are then vented and two channelways of cinders are
formed, extending the length of the green-sand core into the
body of sand around the mold. In order to do this, the joint
must be broken up somewhat. Pieces of pipe are placed to
bring the vent from the cinder beds to the outside of the mold
as described in Chapter V. The cinders used should be,
roughly, five-eighths inch diameter and should not come closer
than four inches to the side of the mold. After tamping them
with the rammer, paper is placed over them, it also being kept
back four inches from the edge of the mold. Should the paper
be allowed to extend to the edge, iron would find its way into
the sand through the crack formed by the paper, and raise the
face of the mold.
The sand is now rammed on top of the paper to within a
short distance of the top of the side pieces, when it is struck off
with a sweep running on the side pieces. These latter extend
above the surface so that the sweeps will not bear on the joint
when used. The whole surface is then vented down to the
cinder beds. The surface of the mold must be soft enough for
the gas to escape easily and allow the melted iron to lie quietly
on it. The casting being very thin, will be scabbed and in-
jured should the iron boil while covering this green-sand core.
Making the face of this core is usually done by hand. In order
68 FOUNDRY PRACTICE
to form it to the proper height to give the correct thickness,
the sweep G is first used. The first sweep used left the sand
about three-quarters of an inch below the final face of the core.
The same mixture of sand which was used to face the inside of
the side pieces is now used to make up the upper face of the
center. This sand is pressed lightly down in place by hand
or it is thrown in handfuls down on the surface. The sweep
G is then used to true the sand from / to /, Fig. 42. At point
/, a recessed panel X is formed and sweep H is used to sweep
the sand out to a greater depth at the center of the core, where
this panel is to come. This sweep is used from J to K after
which the sweep G is used to complete the surface from K to
M. The top of the center is now finished and the side pieces
drawn, fillets first being formed on the edges. The mold is
then blackened over its entire surface, except at the center,
with plumbago. A slight coating of talc is then dusted over
the entire surface to assist the flow of iron through the mold.
Gates are next cut for pouring, being shown by the dotted
lines R, Fig. 42, and also gates to the risers. Flour or white
sand is placed on the joint and the cope is lowered into position.
The cope is then raised and the mold examined to see if the
cope bears solidly as will be evidenced by marks in the white
sand or flour, necessary repairs are made, pouring basins and
heads or flow-offs from risers are built, and the cope is lowered
into place. The cope may be secured either by means of
binders as described in Chapter V, or it may be weighted
down. Iron for a casting of this character must be poured
sharp, that is, extremely hot.
A point which has been omitted in the description of the
making of the mold is the provision of a camber in the pattern
in order that the casting shall come straight when cooled. As
the sides of the casting are thin, when the melted iron is poured
the lower part of the thin side fills quickly and sets hard before
the top of the casting is set. This almost instant cooling of
the sides, combined with the later cooling of the top, causes the
shrinkage in the sides and top to be unequal. The shrinkage
of the top tends to draw the ends upward and thus give a bent
MOLDING COLUMNS 69
casting, or to crack the casting if the moulding on the sides
has been left off or if the iron is not especially soft. If the sides
are heavier than the plate forming the top of the casting, the
casting will cool at about the same rate in all parts and thus
avoid bending. There are one or two methods of avoiding
this bending of the casting. One is to make the pattern with a
slight camber in it, the ends being at a lower level than the
center. Another method is to force the ends of the pattern
down in the mold, below the level of the center, so that, with
either method, the mold itself is curved in the opposite direc-
tion to that in which the casting would curve in cooling. The
same shrinkage effects will occur with the mold made in this
manner, but the casting originally being curved in the opposite
direction, the shrinkage in cooling will pull it straight.
By using a solid pattern and ramming it up to get the ex-
terior surface first and then making the center by means of side
pieces as described, the pattern is easier to mold and castings
of the desired thickness are more likely to be obtained. The
side pieces should be provided with straps and eye-bolts for
drawing them out of the sand as shown in the illustration.
There is but little chance to rap them while drawing, and they
are usually drawn by means of a hook in the eye-bolt, the
other end of the hook being attached to a lever. While bearing
down on the lever, the hook or top of the eye-bolt is rapped
slightly.
MOLDING A ROUND COLUMN
In many foundries it has been the custom to use split pat-
terns in molding round columns, drawing one-half of the
pattern from the drag and the other from the cope. Other
foundrymen prefer to use the solid pattern. In molding, the
pattern would be laid in a frame, the drag being placed on top
in the usual manner, rammed up, rolled over, and the joint
made. The cope would then be rammed up and the pat-
tern rapped through the cope, thus avoiding a seam showing
on the casting. Another method would be to bed the pattern
in the flopr, if only a few were to be made, and to stake the
FOUNDRY PRACTICE
cope in position as in molding the ornamental column described
earlier in this chapter. Fig. 43 shows a column pattern placed
on a board as described with the drag around it ready to be
rammed up and rolled over.
Round columns are frequently provided with brackets to
support I-beams. The column shown in Fig. 43 has such a
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FlG. 44. SIDE VIEW OF MOLD OF COLUMN WITH BRACKETS IN COPE AND DRAG.
IT TT
FIGS. 43-45. — MOLDING COLUMNS.
bracket which will be molded in the drag, while Fig. 44 shows
a column with brackets to be molded in both cope and drag.
This latter column illustrates some special devices adopted in
molding. For instance, it will be noted that the bracket B
extends to the top of the cope. A head of iron of greater depth
than this is required in order to insure the filling of the mold
of the bracket. To make the cope of the requisite depth re-
quired to provide this head, and also to provide the necessary
thickness of sand over the pattern, would entail unnecessary
expense and also render the flask more difficult to handle. It
MOLDING COLUMNS 71
would also necessitate a greater amount of time to ram up
the deeper cope. In order to avoid these features, the cope is
simply boxed over at the bracket and at each end of the flask
where the pouring gates are located.
In the author's opinion, the cheapest manner of molding
round columns, when there are a number to be made, is to
make a solid pattern and use a drag of the required length,
width, and depth. The drag should be placed on the molding-
board and leveled with the joint side up. Sand from the heap
is rammed to a point very near the joint, but so formed as to
leave a trough through the center. The sweep F, Fig. 45, is
then used and the sand is swept out to a depth of about three-
quarters of an inch greater than the half diameter of the pat-
tern. Facing sand, mixed according to the thickness of the
column, is then spread on the surface left by the sweep and
the sweep G, raised from the joint of the flask about one-
quarter inch, is used to form the facing to the shape of the
pattern. The pattern, if free of brackets, is then laid in the
trough so formed and rapped down until the block of wood H,
which is used as a gauge, rests on the top of the pattern and the
joint of the flask. If a bracket is to be made on the lower side
of the casting, sand is dug out of the trough where the bracket
is to be formed, and after the pattern is placed in position and
rapped down, facing sand is laid around the bracket and sand
rammed in against it and against the pattern where needed.
The same gauge that was used to set the pattern is now used
as a sweep to sweep the sand from each side of the pattern at
the joint. The joint is vented, after which the cope is placed
and rammed up with gate-sticks and risers in their proper
places. The pattern is rapped through the cope, a gate-stick
having been placed over a hole in the pattern, provided for this
purpose. The rapping bar is entered through this hole, which,
after the removal of the bar, is filled up. The cope bracket is
pinned to the cope side of the pattern and when the cope is
hoisted off, the bracket is found in it. In ramming up the cope,
the spaces / and / between the ends of the flask and the first
bar are not rammed up. The gate-sticks are set between the
72 FOUNDRY PRACTICE '
next two bars as at K. The runner boxes D, which are usually
free from the cope, are not rammed up with the cope, but later
after the mold is closed.
After the cope is rammed up, it is rolled over and the
bracket has the sand secured around it, usually by means of
spikes, and the bracket pattern is drawn. It is frequently ad-
visable to ram a dry-sand core in the mold against the face of
the bracket which is to be used as a seat for the I-beam. After
the pattern is drawn, the face of the mold is felt and any soft
spots filled up with a pipe slicker. The cope is then given a
coat of silver lead and the chaplets for holding down the cores
are placed as described in Chapter XIV. The joint of the drag
being brushed off, a channel is formed alongside the drag which
is dampened with the bosh. A vent-wire is bent and run from
this channel under the pattern, thus venting under the pat-
tern and alongside of it to the side of the flask. As the sides
were previously vented toward the bottom-board, before the
joint was made, the escape of gases from the drag is thus pro-
vided for. The mold is now finished and blacked.
In gating round columns, the gates are made on the ends,
alongside the core on both sides of the mold. The iron fills
the column poured in this manner with slacker iron than when
the mold is gated along the sides. The mold being finished,
the core is calipered and also the pattern. One-half the dif-
ference in diameter between the two is the distance which
chaplets must project above the surface of the mold in order
to support the cores in the proper position. In selecting the
chaplets, it should be remembered that with a large body of
iron flowing into the mold, a much larger diameter is required
than for smaller cores. For a thickness of casting of one and
one-half inches in the column, we would use a chaplet with a
stem about one-half inch diameter. Using a lighter chaplet
will probably permit the core to settle as the chaplet would
soften under the influence of hot iron and the weight of the
core would cause it to crush and thus permit the core to settle.
On the other hand, chaplets used in the cope must be stiff
enough to withstand the pressure of the core being floated
MOLDING COLUMNS 73
upward by the entering iron. The chaplets are driven clear
through the drag, into the bottom-board, which they should
enter for a distance of about three-eighths of an inch. The
number of chaplets to be placed in the cope and drag depends
on the size and general arrangement of the cores. No fixed
rule can be given except that it is better to have too many
rather than too few chaplets.
It is much easier with a long column, to make and set the
core in two pieces rather than in one. The cores are butted
together at the center of the mold, one end resting in a core-
print at either end, the other end of each piece being supported
at the middle of the mold by chaplets. To prevent 'the cores
shifting sidewise, due to iron entering one side of the mold
more rapidly than the other, chaplets are placed on either
side of the cores at the ends where they are butted together.
These chaplets are wedged in place by a wedge driven between
the end of the chaplet and the side of the flask. After placing
the chaplets, flour or sand is arranged on the joint to afford a
tell-tale as to whether the cope bears on the cores or on the
joint. In the ends of the flask at the joint are holes through
which are shoved short rods into the vent holes in the end of
the column cores, as shown at 0, Fig. 44. Sand is then rammed
in the spaces / and /, after which the rod O is removed, leaving
a clear hole from the vent of the core to the outside of the mold.
Two or more vent holes are sometines left in the core, depend-
ing on its size, and as many vent rods are used as there are
holes in the core. It is advisable to put a little paste on the
ends of the cores before closing the mold in order to exclude
iron which might find its way over the cores and thus stop
the vent hole.
The pouring boxes D and E are next placed and pouring
basins P built. These boxes are fastened by driving a nail a
short distance into the cope. In securing the cope, clamps are
used and binders are placed to hold the core down through
the agency of the chaplets, wedges being driven between the
ends of the chaplets and the binders which are clamped across
the top of the flask.
74 FOUNDRY PRACTICE
The iron used in pouring should be cooled until it is quite
dull for the larger and thicker columns, and it is advisable to
feed the larger sizes of columns through the riser on the bracket
to avoid shrinkage. Columns seldom shrink the full allowance
— one-eighth inch to the foot — and for that reason column
patterns are usually made with a smaller shrinkage allowance.
It is important that the same iron mixture be used in pouring
all the columns of a given lot, particularly ornamental
columns; otherwise there will be a difference in the shrinkage,
resulting in columns of varying lengths.
When molding columns of the following approximate di-
mensions— fourteen feet long, six inches wide, and sixteen
inches deep, with a thickness of one-half to five-eighths inch
— it is best to mold them on edge to avoid troubles due to
the shrinkage curving the column in cooling. In many cases,
castings with heavy parts must have these parts uncovered
in order to permit them cooling more rapidly. The entire
casting is then cooled more nearly at a uniform rate and
warping is thereby avoided.
The pattern for a fluted column is usually made in quarters,
and the two quarters of each half are hinged together, where a
space comes between the flute and the out-
side, as shown in Fig. 46. A piece of flat iron
is let into the joint side to hold the quarters
apart and in this way form one-half of the
pattern. The two halves are pinned together.
TERNFOR A FLUTED In moldmg» the coPe and drag are molded as
COLUMN. a plain pattern. To draw the pattern, the
screws holding the pieces of flat iron in place are removed
and the two quarters closed together, sufficient material being
cut away from each quarter to form a V-shaped opening the
entire length of each half of the pattern. After closing together
the pattern can be lifted out of the mold.
The method of making cores for columns is described in
Chapter XIII.
CHAPTER VII
MOLDING WITH SWEEPS
THE expense of pattern work for certain classes of castings
of a regular form may be avoided by the use of a sweep. Such
castings as circular boiler fronts, tank heads, pulley rims, and
similarly shaped castings can easily be molded by this method.
In addition, certain irregular-shaped castings may be partially
swept out in green-sand molds, the balance of the mold being
finished by means of pattern pieces. The sweep consists of a
board, one edge of which is shaped to correspond with the
surface of the casting and, on drawing it across the sand, it
leaves a surface in the mold of the desired shape to make the
casting.
In Figs. 47-50, the method of molding a ribbed tank cover,
by means of sweeps, is illustrated. The casting is a circular
piece of dished cross-section with four ears, slotted to receive
bolts, placed at equal intervals around its circumference. In
molding it, two or three sweeps are used, according to the ideas
of the molder, and no pattern work is necessary excepting for
the four ears and for the ribs on the under side of the dished
portion.
In making the mold for this casting, the first operation is
to set the spindle seat in the floor. The spindle seat consists
of a socket for the spindle of the sweep, and is mounted on
four cross arms, extending horizontally from the body of the
socket. A hole is dug in the floor of such depth that the top of
the spindle seat will come level with the floor line when the
spindle seat is leveled in it. The spindle is placed in the seat
and by means of spirit level is plumbed until it is truly vertical,
wedges being driven under one leg or the other of the spindle
seat, to throw the spindle in the necessary direction to bring it
vertical. Sand is then rammed around the spindle seat until
75
76 FOUNDRY PRACTICE
the hole in the floor is filled. The sand around the spindle is
then swept off level by means of the sweep. This is a plain
piece of board about four inches wide and of any desired length
and with a beveled lower edge. Attached to one end, by means
of bolts, is a finger which fits snugly over the spindle, being
FIG. 48 SETTING SPINDLE SEAT
FIGS. 47-50. — SWEEPING A RIBBED COVER PLATE MOLD.
fastened thereto, and permits the sweep and the spindle to
be revolved. The sand being rammed down around the
spindle, the sweep is revolved and sweeps off any surplus
sand, leaving a level and true bed of sand.
The sweep finger is then removed from the spindle and a
bottom-board with a hole in the center, lowered over the
MOLDING WITH SWEEPS 77
spindle, or the spindle may be removed from the seat, the
bottom-board placed in position, and the spindle re-inserted
in the seat through the hole in the bottom-board. The drag of
the flask is then placed on the bottom-board with the joint up
and is wedged up a short distance by means of wedges set from
the inside of the flask. The sweep for forming the cope side of
the mold is bolted to the sweep finger and leveled. The end
of the sweep is allowed to rest on a trowel laid on the joint of
the drag while it is being leveled so that on removing the
trowel, the sweep has a clearance from the drag of the thickness
of the trowel. In certain cases a guard is placed around the
spindle to prevent sand from passing through the hole in the
bottom-board. Such a guard is shown at G.
Cinders are next spread over the bottom-board and covered
with paper, after which the drag is rammed full of sand. When
it has reached the proper height, the sweep is revolved, tracing
in the sand a circular cavity of the exact shape of the bottom
of the sweep. The sand should be rammed in the drag as hard
as possible preparatory to this operation. When it has been
struck off, after sweeping, it is slicked and parting sand is
dusted over the joint, and sometimes over the face formed by
the sweep. Instead of parting sand, paper is sometimes laid
over the swept surface, being first wet in order to make it con-
form to the exact shape of the mold. The use of paper makes
a very clean parting, whereas, if parting sand is dusted on, it
must later be brushed off which not only tends to make a rough
surface on the casting, but, if not thoroughly removed, is liable
to be washed off when the casting is poured and make dirt in
the casting.
The ribs which are to be cast in the cope and for which
patterns are required, are placed as shown at / in the plan of
the cope, Fig. 50, being held in place by a few nails pushed into
the sand alongside of them. The spindle is then removed and
the green-sand core / having been formed, a bunch of waste is
placed in the hole left by the spindle. The cope of the flask is
then placed in position, gaggers set, and the cope rammed up as
for any ordinary mold, the patterns for the ears first being
78 FOUNDRY PRACTICE
placed in position. After venting, the cope is turned over, the
ribs and ear patterns drawn, and the edges, where the ribs
unite with the body of the casting, filleted. The gates are
prepared as desired and the cope is blackened with plumbago.
The next operation is to sweep out the drag. It will be
remembered that in sweeping out the drag first, what was
known as the cope sweep was used. This was for the purpose
of forming a recess the exact size of the projection of sand
desired in the cope. In order to give thickness to the casting,
the drag must be swept out to a greater depth than was done
by the cope sweep. The drag sweep used is of exactly the same
shape as the cope sweep, but is as much deeper than it as the
casting is thick. The drag sweep is bolted to the sweep finger,
the sand is dug out from over the bunch of waste, and the waste
removed from the spindle hole, after which the spindle is set. A
gutter is dug from the spindle to the outside of the flask of suffi-
cient depth to permit the sweep to rest on the trowel on the
joint. The sand is dug up to about three-quarters inch below
the edge of the sweep, the sweep is revolved, and the surplus
sand removed. The drag is thoroughly vented down to the
cinder bed, after which facing sand, properly tempered and
riddled, is thrown, a handful at a time, on the face of the mold
where it will stick. The entire face of the mold is covered in
this manner, the sweep being revolved as the sand is thrown,
in order to form a surface of the desired shape. The face is
examined for soft spots which are repaired as found and the
spindle is removed. The mold is finished, blackened, gated,
and made ready for pouring in exactly the same manner as
any other mold.
It may be well at this point to call attention to some things
that should be borne in mind in sweeping molds. We have de-
scribed above the method of sweeping a comparatively light
casting. If instead the casting should weigh several tons
rather than a couple of hundred pounds, the operations of
molding would be the same, but the greater amount of metal
would bring considerably greater strain on the face of the mold,
particularly on the drag, and certain precautions must be ob-
MOLDING WITH SWEEPS 79
served to take care of this. After ramming up the cope as
above described, the drag would be dug out in the same manner
as for the lighter casting. The sweep is made so that it can be
lowered three-quarters of an inch below what is to be the face
of the mold or a third sweep is made, which will sweep out the
sand to this depth. After digging out the sand from the drag,
in the manner described, black sand is solidly rammed on the
face to the line of this third sweep or to the edge of the sweep
lowered below the level of the face. The surface thus formed is
thoroughly vented, after which facing sand is thrown on as
was done for the lighter casting, and the face of the mold is
finally finished.
The object of using this third sweep or its equivalent, and
making a solid face on which facing sand is built, is to provide
an evenly rammed surface for the mold. If there is any dif-
ference in the strength of the mold, in different portions, the
casting will be distorted. If the hard-rammed sand is left
uneven when digging off the face and the facing sand simply
thrown down on it as described, the molten iron filling the mold
will soon discover the point at which this facing sand is the
deepest and at this spot will cause the sand to give. In other
places, where the sand was not cut away to the same depth,
the facing will be harder and, therefore, the surface of the cast-
ing will be found to be uneven, being at the proper level over
the hard portions and having projections at those points where
the facing sand was deepest and therefore soft. It is evident,
therefore, that by ramming the surface at a depth of three-
quarters of an inch below the face of the mold, and then
building the face of the mold on this surface, the pressure of the
molten metal is resisted evenly over the entire surface of the
mold and a casting with a true surface is the result. The lack
of care in making this firm under-surface, is often responsible
for the failure to obtain good results with swept up molds.
Oftentimes, patterns molded by bedding them in the floor
or a flask, may have a portion of the mold made by a sweep
and the balance made by placing the pattern on it and tucking
the sand under those parts of the pattern which are irregular
80 FOUNDRY PRACTICE
in shape. In this way, the pounding of the pattern into the
bed is avoided. To illustrate this method of molding, we will
consider the case of a tank bottom, eight feet long, five feet
wide, and five-eighths inch thick, which is to be bedded in a
flask. A bed of sand is first made on the floor where the center
of the flask will rest, being made one foot wide and a trifle
longer than the flask. This is made three inch thick and is
trodden down firmly and is struck off with a straight edge.
On this a bottom-board is placed and the drag set, being
raised about five-eighths of an inch from the bottom-board by
means of wedges driven between them from the inside of the
flask. The bottom-board is then wedged up on one side until
it has an inclination of about five-sixteenths inch in two feet.
Cinders are next spread over the surface of the bottom-board
and covered with paper, after which straight-edges G, Figs.
51 and 52, are placed and raised to the desired height by means
of bricks and wedges H, or they may be made of sufficient
depth to rest directly on the bottom-board. They are leveled
and secured at the desired height and sand rammed in around
them to prevent their movement sideways. Black sand is
then rammed over the cinders until it is about level with the
top of the straight-edges. The sweep / is used with the notched
side down, the bottom of the sweep being notched so that
the edge / is five-eighths inch below the edge of the straight-
edge, to sweep out the sand between the straight-edges to that
depth. The bed of sand is then thoroughly vented down to
the cinder bed, after which a mixture of seacoal facing, in the
ratio of one seacoal and fourteen sand, thoroughly tempered
and riddled, is spread on the bed between the straight-edges,
until its surface is slightly above the straight-edge. The sweep
with the straight side down is then used, a block of wood one-
eighth inch thick being placed under 'each edge, and the sand
swept level. The blocks are removed, and one man holding an
end of the sweep on the straight-edge, a man on the other end
strikes the straight-edge a blow with the opposite end. The
sweep is moved gradually across the width of the mold, the
sand being pounded down in this way, first by the man at one
MOLDING WITH SWEEPS 8 1
end and then by the man at the other. This process will ram
the sand solidly, and a casting weighing many tons can be
poured on it without danger of rough spots being formed, due
to soft places in the mold. The bed being made, the pattern
is placed on it, weighted down, and sand rammed around the
edges. The joint is made and the cope rammed up, the gates
being set so that hot iron shall flow into the mold up to the
last moment of pouring.
It will be recollected that, at the beginning of operations,
we wedged the bottom-board so that one side of the flask was
higher than the other. This was done so that the iron, in
FIGS. 51-52. — MOLDING A TANK COVER PLATE WITH A SWEEP.
pouring, would fill the lower side of the mold first and rise
along the face of the mold as it fills. If the mold were to be
level, the iron would cover the entire lower surface of the mold
before it reached the upper surface. The lower portion of the
mold would require covering with liquid iron immediately or
cold shuts would result which might ruin the casting. By
causing the iron to flow into the mold from the higher side, this
trouble will be avoided and a slacker iron can be used. A slight
coating of talc over the entire face of the mold will assist in the
rapid flow of the iron.
We will now consider the case of a pattern which is to be
molded in part with a sweep and the remainder tucked up.
Referring to Fig. 53, the method of molding the face of the
6
82
FOUNDRY PRACTICE
segment of a large built-up fly-wheel is shown. In molding
these segments, it is desired to have the face as nearly as
possible on the same circle as the finished wheel, leaving merely
enough stock for finishing. Two cast-iron guides A are ar-
ranged to rest on timbers -B in the flask and using a similar
sweep to that described in the operation of making the tank
FIG. 53. — MOLDING SEGMENT OF BUILT-UP FLY-WHEEL.
bottom, a bed is made on which the pattern is to rest, the sweep
being guided by the guides A. After the bed is made, it is
vented to the cinder bed which has previously been made at
the bottom of the flask and, on top of this bed, a face is built
of facing sand on which the pattern is placed. In gating
this mold, the pouring gates must be further apart for large-
diameter wheels, say thirty feet, than for smaller wheels of
/F
FIG. 54. — MOLDING A FORMER FOR SHEET-METAL WORK WITHOUT A
PATTERN.
ten or fifteen feet diameter. With the smaller wheels, the iron
flowing in and being given a quick turn due to the smaller di-
ameter, will be given a whirling motion and will thereby cut the
face of the mold, producing a scabbed casting, unless the mold
is of the proper hardness.
Fig. 54 shows the method of making the mold, known as
a former for sheet-metal work, without a pattern. Two boards
MOLDING WITH SWEEPS 83
with the size of the inside of the former cut in them as shown at
A are set in ends of the flask and sand rammed firmly between
them and swept off level with the top of the inside of the guides
A . The pieces F, shown by the cross-hatching, that were sawed
out from the guides along the line A , are then replaced and
sand rammed between these pieces and the ends of the flask.
Damp parting sand is slicked on to the steeper parts of the
face of the mold and dry sand dusted on the flat portion. The
cope is now placed on the drag and rammed up and removed.
The end pieces F are now removed and the sand dug out be-
tween the guides. A sweep notched somewhat deeper than
the thickness of casting desired as shown by the distance
between the lines A D is used to strike the sand off along the
line D, the sand being firmly rammed and vented. The face
of the mold is built up to the line B, a sweep notched a
distance equal to AB being used. The mold is finished and
gated in the usual manner.
CHAPTER VIII
MOLDING CAR-WHEELS
CAST-IRON car-wheels having a chilled tread are cast in
molds formed partly of molding sand and partly of cast-iron.
The pattern used in forming the mold is what is termed a solid
pattern, being made in one piece and having on it core-prints.
The flask in which the wheel is molded and cast consists
of three parts: The drag in which the flange side of the
wheel is molded, the wheel being poured flange side down;
on top of the drag, a cheek or chill of cast-iron is placed to
form the tread and part of the flange; on top of the chill
rests the cope in which the face of the wheel is molded.
Over the center of this is a raised part in which the pouring
basin is built. The flask rests on a perforated iron bottom-
board through which the gases escape from the drag. The
entire flask is of cast-iron and the cope is provided with radial
bars of the shape of pattern to hold the sand in the cope.
The cast-iron chill is chambered and connected to a water
supply for cooling the chill if required. The raised part of the
cope is provided with ears to take the tops of chaplets which
hold down the lightening cores around the hub of the wheel.
Oftentimes, before the wheels are molded the chill part of
the flask is oiled in order to prevent it sweating, or gathering
dampness from the warm sand. If this is carelessly done, or if
the chill is warm, the oil may find its way to the bottom of the
chill, leaving dry spots on the face on which moisture may
condense and thus crack or make a bad place on the tread of
the wheel. To avoid this, sometimes lead is mixed with the
oil, or, instead of oil, lampblack and shellac are mixed, first
killing the lampblack with alcohol. The chills are coated with
this mixture, as one would black a pattern.
In molding, the pattern is placed in the chill portion of the
84
MOLDING CAR-WHEELS 85
flask with the flange side up, the face of the wheel sliding down
in the chill a distance equal to the width of the tread. The
flange of the wheel rests in a part of the chill which is formed
to receive it. The drag is placed over the chill and the pattern
is covered with a mixture of facing sand, consisting of ten
parts of old molding sand from the heap, two parts of new
molding sand, and one part seacoal. This mixture is riddled
into the drag through a number six sieve, and the facing is
laid up against the ribs and evened off to a depth of five-
eighths inch over the pattern. The drag is then shoveled full
of sand and peened around the edge of the flask, trodden over
and butted off. The sand is next struck off flush with the top
of the drag and about three-quarters of an inch of loose
molding sand is thrown over the drag, after which it is vented
and the bottom-board rubbed to a bearing. The bottom-board
is then clamped to the flask and by means of a yoke, which
is hooked to the trunnions on the chill, the flask is raised and
rolled over. It is then lowered on to two rails. Care should be
taken that these rails are level and at the same height, as it is
important that a car-wheel mold should fill evenly with iron
in order to avoid the chill cracking the wheel.
After the gate-sticks are set to form pouring gates, facing
sand is riddled over the pattern and heap sand is shoveled in
until the cope is filled flush with the tops of the bars. The sand
is then peened between the bars, after which the cope is heaped
full of sand which is trodden down and then butted off. The
pouring basin is built and the sand scraped from above the
bars of the cope, and the cope is vented all over and the gate-
sticks removed. Cope and chill are then bolted together and
hoisted by means of the yoke, leaving the pattern in the drag.
The cope is finished, blackened with silver lead, and the
chaplets set to hold down the ring or lightening core. The chill
is given a coating of lard oil, or of shellac and lampblack, or
some one of the various mixtures made for application to chills.
The pattern is then drawn from the drag, which is finished
and blackened with silver lead, and a vent- wire is run down
through the core-prints to the bottom-board, after which one
86
FOUNDRY PRACTICE
of the ring cores shown in Fig. 55 is placed with the three pro-
jections in the prints in the drag. The center core is next set.
Usually the sand is first cut up to form a ring around the vent
hole so that the core may press down on it and thus prevent the
iron from running under the core into the vent hole. Before
TOP OF MOLD
SIDE OF MOLD
FIG. 55. — CAR-WHEEL MOLD AND CHILL.
setting the core, a vent is made through the drag to the bot-
tom-board.
The cope and chill are next rolled over on the trunnions and
lowered, chill down, on the drag, and the parts of the flask
are clamped together. After the cope is closed, the chaplets
are moved up and down to see that they bear properly on the
top of the core they are to hold down. A wedge is placed
between the top of the chaplet and the pouring basin part of
the cope.
MOLDING CAR- WHEELS 87
After the wheels are poured, they are allowed to stand,
usually until the molder has poured six, after which they are
shaken out of the mold, hoisted out of the sand by grasping
the rim of the wheel with a pair of tongs, and the wheel is
moved by a hot-wheel train to the annealing pits. The heads
are broken off with a ram and the center cores taken out. A
crane, arranged to handle two wheels at a time by means of
two pair of tongs, grasps the wheels in the center and moves
them over the proper annealing pit in which sixteen wheels
are placed at one time and annealed by their own heat. The
wheels remain in the pit four days, being taken out on the
fifth day.
In pouring car-wheel molds, the iron can be poured either
too hot or too cold and it is necessary that the mold fill evenly,
otherwise chill cracks may result. Pouring the iron too hot
will cause a variation in the depth of chill and it will also cause
internal strains which are lessened or partly avoided when
the iron is poured at the proper temperature, which, however,
can only be learned by experience. The iron poured into the
mold and running against the face of the chill is hardened on
the tread of the wheel by being cooled rapidly, producing, as we
find on breaking the wheel, a hard white surface which is about
three-quarters of an inch deep, becoming mottled toward the
inside. From the mottling, what are called legs or veins,
extend into the gray-iron portion of the casting.
While the pig iron used in the manufacture of car-wheels
is usually number three, or three and one-half charcoal iron,
mixed with a certain percentage of old car-wheels, occasionally
steel scrap or coke iron is introduced in the mixture. The
Chicago* Milwaukee and St. Paul Railroad adds one pound
of eighty per cent ferromanganese to the quantity of iron
required to pour one wheel, in order to deepen and toughen
the chill. This is added to the iron in the pouring ladle.
In the past it has been considered that the greater the
amount of coke iron used in the mixture, the more distinct
was the line of demarkation between the chill and the gray
iron in the casting. The wheel in running would constantly
88 FOUNDRY PRACTICE
strike on one spot in passing from rail to rail and the shock
would finally cause the chilled part to separate from the gray-
iron center on account of the mottling and legging not being
sufficient to properly hold the two parts together. The gray
iron would finally crumble out and leave a hole in the wheel.
When in use the application of the brake to the wheel
causes the generation of heat. To determine the ability of
the wheel to stand up under the application of the brake, the
following test is made : From a number of wheels one is selected
and placed on a green-sand bed with the flange of the wheel
down. A dam of molding sand is built around it, leaving a
space of about one and one-eighth inches between the dam and
wheel. Into this space molten iron is poured, being taken from
the cupola under the specifications of the Master Car Builders'
Association, and poured into the channelway in two places.
The wheel is left for a specified time, after which it is removed
and examined, and from the action of this test wheel under
treatment, the lot of wheels may be accepted or rejected. This
test is known as the thermal test.
A second test, to determine the strength of the wheel, is
made by dropping a two-hundred-pound weight a distance of
nine feet on the center of a 625-pound wheel, the wheel
being placed flange down on an anvil supporting only the rim.
The wheel must sustain ten such blows to be accepted. A
675-pound wheel must sustain twelve blows, with a drop to
the weight of ten feet, while a 725-pound wheel must sus-
tain twelve blows from a height of twelve feet.
Formerly car- wheel foundries were equipped with jib cranes
around which the wheels were molded and poured. The iron
was brought to the floors in wheel ladles which were hoisted
by a crane for pouring into the molds. With this arrangement
of circular floors much space was necessarily unoccupied.
The more modern wheel foundries have adopted what is known
as the straight-line system which reduces the unoccupied space
to a minimum. Typical straight-line plants are those of the
Chicago, Milwaukee and St. Paul Railroad at Milwaukee, Wis.,
and that of the Dixon Car Wheel Foundry, Houston, Texas.
MOLDING CAR-WHEELS 89
At the Milwaukee plant, the wheel flasks are arranged in
straight lines across the foundry, resting on. two rails, spaced
twelve feet centers. The cupolas deliver to large reservoir
ladles which are electrically tipped. In front of the reservoir
ladles is a track extending the length of the foundry, on which
two ladle trains are electrically operated from in front of the
ladles to opposite ends of the foundry. The movement of the
ladle trains and the tipping of the reservoir ladle is controlled
from a pulpit at the cupola. Each car in the ladle train carries
two ladles, which can be lifted from the car at the various
pouring floors by means of overhead trolley hoists over each
floor. The molds are poured from the ladles suspended from
the trolleys.
After pouring six wheels, the men begin to shake them out
of the molds and to deliver them by means of the overhead
trolleys to the hot-wheel cars on the hot-wheel tracks extend-
ing the length of the foundry to the annealing pits where the
pouring heads are broken from the wheels and the center
cores knocked out.
In addition to car-wheels, many different styles of castings
are produced in molds made partly of molding sand and partly
of iron. Certain cotton-machinery castings are made in iron
molds in order that the wearing surfaces will be chilled and
thus have a harder skin as the chilling of the hot iron hardens
it, due to the quick cooling. The common gray-iron casting,
however, is not hardened to any great depth by pouring it
against an iron surface, if the casting is of any great thickness.
In order to obtain a chilled surface of any depth it is necessary
to have an iron of such chemical analysis as will be affected
by the chill forming a portion of the mold. See Chapter XXIII
for analyses of irons for use in chilled castings.
CHAPTER IX
SKIN-DRIED MOLDS
THE skin-dried mold is made of green sand with a facing
composed of varying mixtures of sand and flour and after
completion the surface is dried by heat to a depth ranging from
one-half inch to several inches. Thus the skin-dried mold
occupies a place midway between the green-sand mold and
the dry-sand mold. The class of castings which are poured in
skin-dried molds, will include locomotive cylinders and station-
ary engine frames and cylinders. Later in this chapter we
will consider the making of a skin-dried mold for a Tangye
engine frame.
The molds are dried in several different manners. The
smaller molds may be placed in an oven and baked until the
surface has been dried to the required depth. In the natural-
gas belt, heat is applied to the mold by means of a portable
gas torch, and, the gas being under pressure, the flame may be
directed against any portion or into a deep pocket of the mold
as desired. Where gas is not available, the oil torch is fre-
quently used for this purpose, providing compressed air is sup-
plied to the foundry. The oil torch has the special advantage of
regulation of the flame; thus an intensely hot blue flame may be
used or a moderately hot large yellow flame, or any flame be-
tween these two extremes. Either crude or kerosene oil may be
used, depending on the air pressure available. Sixty-five pounds
per square inch is required for this work with crude oil while
but twenty pounds is necessary with kerosene. In using the
oil torch, some experience is necessary to obtain the best
results. Too sharp and too quick a heat applied to the face of
the mold, may cause the sand to blister and fall. Heat should
be applied gradually and its intensity slowly increased as the
mold dries out. After a time, a heat of considerable intensity
90
SKIN-DRIED MOLDS QI
may be applied without danger of burning the face of the
mold.
Where neither natural gas nor the oil torch is available, fire
baskets may be used for drying the mold. These are baskets
made of iron in which is built a fire of charcoal or gas coke. The
fire is built in them outside the mold and, when it is well alight,
the basket is lowered a little at a time until it is at the proper
distance from the bottom of the mold. If lowered too close to
the face of the mold immediately, the mold will be damaged
and a great deal of patching necessitated. When the mold is
partly dried, the process can be hurried by building a moderate
fire, and covering the mold.
The sand mixtures used to form the face of the mold vary
with the locality. Either fire sand or ground silica rock is
added to the facing mixture, depending on the kind of work.
If neither is available, the facing mixtures should contain
lake or hill sand. The addition of a highly refractory and
coarser sand, to the ordinary molding sand, not only produces
a more porous-faced mold through which steam will escape
while the face of the mold is being dried, but it also assists the
molding sand in resisting the action of metal. The body of a
skin-dried mold should be well vented to carry off the steam
and gases generated in drying. Large green-sand hanging cores
are often skin-dried and scabbing thereby avoided.
MOLDING AN ENGINE BED IN A SKIN-DRIED MOLD
Fig. 56 shows an engine frame of the Tangye type which
can be cast to advantage in a skin-dried mold. As there will
be considerable side strain in pouring a casting of this character,
necessitating a heavy flask and considerable special rigging, the
mold will be made in a pit. The pit is prepared as described in
Chapter V, and, when ready, the pattern is leveled in position
by means of wedges and sand is rammed to within a few inches
of the backbone A of the pattern, Fig. 57. Facing sand is
then tucked and rammed below and around the sides of the
backbone and continued under the remainder of the bed.
92 FOUNDRY PRACTICE
When enough is in place to hold the pattern in position, the
pattern is lifted from the pit and the surfaces already finished
are well vented down to the cinder bed, the sides and edges
of the backbone are nailed, and the face is finished. The
pattern is then replaced and is faced and rammed up with
black sand to a point where the iron plate supporting the main
core can be placed under the core-print. This plate should
extend some distance on either side of the core-print into the
sand as shown in the detail Fig. 58. After these plates are
placed, facing and ramming are continued until the saijd is
high enough to permit placing the gate cores B, Fig. 57,
between the jaws C C of the pattern. These are bedded in the
sand and a cinder bed D placed over them, a vent pipe being
inserted in the cinder bed for the escape of gas. Pouring gate
cores F and upright gate-sticks G are placed at the end of the
pattern. Iron rings are set around these to re-enforce them to
resist the strain generated in the sand while pouring. When
the sand has reached the round portion of the pattern, it is
vented below the pattern and the vents are covered with
cinders which, in turn, are covered with paper. The pattern
is faced and sand rammed in until it has reached the floor line.
Referring now to the detail Fig. 58, the method of inserting rods
to strengthen the face of the mold is shown. These rods should
extend to within about two inches of the face of the mold, there
being four layers of rods set in a pattern of this depth. A
cinder bed extending beyond the end of the cope is built along-
side each edge of the pattern at C, Fig. 58, a short distance
below the floor line. From this cinder bed vents are made
with a large vent-wire down to the lower cinder bed as shown.
In placing these cinder beds, they are well rammed with the
butt of the rammer in order to assist in resisting the side strain
when the mold is poured.
The inside of the pattern is a succession of deep pockets of
sand to form the cope side and, in order to lift out these pockets
of sand from the pattern, skeletons or grids are made to con-
form to the face of the pattern as shown in Fig. 57. These grids
are secured to the cope by bolts /. The cope is lowered into
MOLDING AN ENGINE BED
93
94
FOUNDRY PRACTICE
place, being made wide enough to rest on upright timbers
which extend up from the binders in the pit bottom. It is
guided by stakes driven into the sand and the bolts / for hold-
ing the grids are then placed. The cope is next removed to-
gether with the skeleton, and parting sand is dusted on the
joint and facing sand is placed inside the pattern to a depth
five-eighths inch. The skeletons are then lowered into place
FIG. 58. — MOLD OF END OF PATTERN.
and rapped down. Gaggers are set in the skeletons exactly
as though these were the barred cope flask, and on top of each
skeleton pieces of joist are set to come up level to the top of
the pattern.
A water pocket is to be formed in the casting underneath
the jaws C C by means of the core K. On this core are four
prints over each of which the gas pipe / is set extending to
the top of the cope. These gas pipes are rammed up in the
cope with the sand. The inside of the pattern is faced and
backed with black sand which is rammed to the point where
the green-sand core extends under the ribs A, Fig. 59, also
shown at L, Fig. 57. This rib extends into the inside of the
cope and causes an overhanging core to extend all around the
pattern. The inside of this flange being faced, five-eighths inch
rods are laid from the body of the hanging sand on the cope
side to the sand under the flange, to support it. This sand is
MOLDING AN ENGINE BED 95
vented, the vents being brought out four inches away from
the pattern and the vents covered with cinders, as shown at
M. We now have a body of sand covering the skeletons and
forming the inside of the pattern. A long channel is scooped
out in the center of each pocket and these are vented to this
channel which is then covered with cinders and filled with
sand up to the floor level. The joint is made, parting sand
dusted on, and the cope flask replaced. The bolts / are at-
tached to the flask, the pipes / and the gate-sticks set to the
cinder beds, and the joists in the pockets are wedged down to
hold the skeletons firmly in position. The cope is gaggered
and rammed with successive rammings of sand in the usual
fashion. The cope is hoisted off with the pockets of sand,
forming the inside pattern, suspended from it. It is lowered
on to trestles and the sides propped up with pieces of joist
to insure it against springing on account of the weight of sand
suspended from it. The flanges A, Fig. 59, are made loose and
are drawn out of the mold with the cope. They are now re-
moved from the sand and the cope is finished, after which it is
skin-dried to a depth of an inch and a half. When finishing
the cope, the edges of the pockets are nailed wherever there is
any liability of the cope cutting on account of the flow of iron.
A gas or oil flame is used for drying, care being taken to direct
the flame into the pockets in the cope formed by the various
ribs.
The pattern in the floor is next boshed, rapped, and drawn
from the sand. The pieces D, Fig. 58, are loose and are re-
moved from the sand after the main portion of the pattern is
drawn. The various edges, where there is a liability to wash-
ing, are nailed as is also the face of the mold near the gate.
The mold is then sprayed with molasses water and skin-dried
with fire baskets, as described earlier in the chapter.
The main core is made in two halves, the core-print being
formed by a loose piece in the core box. The two halves of
the core are bolted together with the bolts R, but before this
is done, the core S, which is made in a special core box, is
bolted to the upper half of the main core by the bolt T. The
96 FOUNDRY PRACTICE
vent from this core is led to the vent of the main core. Each
half of the main core is made on a solid cast-iron core arbor
which takes the strain due to the heavy weight of the core.
The bottom of the core is rodded as shown at U to hold it to
the arbors. This is not required with the upper half which
is not suspended. The cores forming the openings in the side
of the bed E and C, Fig. 56, are first placed, after which the
main core is set. A special stop-off piece B, Fig. 59, is used to
form the side of the mold at that point and, after it is placed,
a bed of cinders W, Fig. 57, is made and vented with the pipe
X. A spud or piece of timber is set on either end of the core
arbor, being cut off level with the floor. Sand is now stopped
in over the end of the core at B, the regular facing mixture
being used against the stop-off piece, backed up with black
sand rammed firmly against it. The stop-off core Y at the
opposite end of the mold is placed as shown, cinders and the
vent pipe for venting the core are laid in, and black sand ram-
med in back of it. After the core Y is set, the joint between
it and the sides of the mold is filled in and dried. The core K,
forming the water box between the jaws of the pattern, is now
placed in the cope. This core is made with a staple in each
round core-print, over which, it will be recollected, the gas pipes
/ were set, and rammed into the cope. Wires are inserted
through these staples and threaded through the gas pipes and
drawn tight to bring the core against the chaplets A B. The
wires are then fastened to a rod at the upper end of the gas pipe
and this rod is wedged up to hold the core in position against
the chaplets. The pipes J also act as vents to the core. The
edges of the pipe are covered with paste and a small amount
is placed inside the pipes to prevent iron entering. Vent-wires
are inserted in the pipe, after which they are filled with sand
and the vent-wire withdrawn.
The bolt cores D, Fig. 56, are set in the prints and the shelf
core, Fig. 59, C, is placed, after which the cope is tried on. In
Fig. 56 prints are shown for the bolt cores on the cope side of
the pattern. The author considers this poor practice and
recommends having the cope side flush, so that the cope will
MOLDING AN ENGINE BED
97
98 FOUNDRY PRACTICE
bear on the top of the cores which should be steadied with
nails set alongside the cores. This will avoid pulling 'down
part of the cope when lifting it after trying on the pattern.
The name-plate core is next set, after which the cope is once
more tried on, and, every thing being satisfactory, the joint is
pasted wherever the casting comes near the side of the cope,
and the mold finally closed.
It will be observed that the pouring gates are outside the
cope, as this makes a shorter cope and one easier to handle.
The upright gates, it will be remembered, were ringed and
rammed up with facing sand which is vented to permit the
escape of gas from the gates.
Binders are now placed across the top of the cope and it
is fastened firmly to the floor by means of the hook bolts shown
connecting with the eye-bolts with the binders in the pit. One
binder is placed across the spud G H in the cope, which is
wedged down to hold the end of the main core in position.
The spud at the opposite end is wedged down below the end
of the flask. The facing sand is next scraped away from the
upright pouring gates, where dry, and replaced with fresh
sand. Runner boxes are placed in position and runners built
to pour the casting from each end, cores being placed in the
bottom of each runner box for the iron to fall on as it is poured.
Heavy risers were placed on either side of the pattern in 'the
cope for feeder heads and these are built out above the cope
in order to give a greater head. Pieces of oiled paper are
placed in the vent pipe to be lighted when pouring for purpose
of igniting the escaping gases. Holes are dug at the ends of
the mold, back of the runners, to permit the lip of the ladle
in pouring to be as close as possible to the runner. In pour-
ing, the ladle at the left which feeds the deepest part of the
casting, is first started and afterward the ladle at the right.
The mold is filled so that the iron flows up in the risers to
nearly the top of the cope, and pouring is stopped when the
iron shows a tendency to rise above this point in the riser.
They are kept covered until the escaping gas indicates that
the mold is nearly filled, and the iron remaining in the run-
MOLDING AN ENGINE BED 99
ners is then depended on to completely fill the mold. To
provide against the emergency of iron overflowing the top of
the cope and finding its way into the vents, flow-offs are pro-
vided. The casting should be churned for some considerable
time and the iron fed to the risers during the operation must
be extremely hot. The direction of flow of the molten iron
filling the mold is shown by arrows in the gates.
Shortly after the mold is filled, the iron will become set
in the pouring gates and the runners may then be broken
away and broken up while hot. When the casting has cooled
somewhat, the binders are removed as is also the rod holding
the water core in place. The nuts holding the skeletons are
removed, the cope is hoisted, and the sand knocked out and
allowed to fall on top of the casting, which will require about
two days to cool off sufficiently to permit its being lifted from
the sand.
CHAPTER X
DRY-SAND MOLDS
DRY-SAND molds are used for intricate castings in which
the walls must be of a positive thickness or in which large
bodies of metal must remain fluid for a considerable period of
time. Dry-sand molds are molds made of a special mixture of
rather coarse sand which are afterward dried or baked in an
oven. Molds treated in this fashion possess great rigidity and
will stand rather severe usage. After being baked, they may
be poured in any position without damage to the mold. Dry-
sand molds are principally used for steam- and gas-engine
cylinders, pump, air compressor and hydraulic cylinders,
printing-press cylinders and rolls, rolling mill rolls, anvil
blocks, engine beds, and similar heavy castings. The following
mixtures are given by West1 as suitable sands for the different
classes of castings: —
Large spur gears: 12 pails of lake sand, 12 pails strong
loam sand, 4 pails molding sand, I to 10 pails of coke dust, ij^
pails of flour; wet with water.
Large bevel wheels: one part molding sand, one part Jersey
sand, one part seacoal to 16 parts of sand mixture; wet with
thin claywash.
Engine cylinders: 6 pails molding sand, i>£ pails of lake
or bank sand, 30 parts sand mixture to one part of flour; wet
with claywash.
Another mixture for cylinders is 4 parts of fair loam, one
part of lake sand, one part coke dust or seacoal to 14 parts
sand mixture; wet with claywash according to the clayeyness
of the loam. The backing used with this facing is 5 parts loam
and I part lake sand ; wet with claywash. A good mixture for
ordinary work is: i part molding sand, I part bank sand; wet
l" American Foundry Practice," p. 353.
DRY-SAND MOLDS IOI
with claywash and use I part of flour to 30 parts of mixture
or I part blacking to 20 parts of mixture.
A mixture with a clay loam for cylinder castings is as
follows: 6 parts strong loam sand, 6 parts lake sand, 2 parts
old dry sand, flour I to 40, seacoal I to 14; wet with water.
A mixture used for rolling mill rolls: 2 parts old dry sand, I
part baked sand, seacoal I to 12, flour I to 18; make as wet as
can be worked with claywash.
The author has had good results with a dry sand composed
of equal parts of coarse molding sand and coarse New Jersey
fire sand. Flour or rye meal is added to this mixture in the
proportion of I part flour to 14 parts mixture. The mass is
mixed thoroughly and then dampened with molasses water
made of I part molasses and 16 parts water. If fire sand is not
available, ground silica rock may be substituted.
In molding, the pattern is faced with one of the above
mixtures and the facing is backed up with what has become a
burnt mixture of the facing wet with clay water, or with com-
mon black sand. The mold itself is usually made in the same
manner as a green-sand mold. The flask, however, especially
for large castings, is somewhat different, being made of iron
with slotted holes in the side as shown in Fig. 64. These holes
are for the purpose of venting the mold, five-sixteenths inch
vent rods being inserted through them, extending into the
mold to within a short distance of the pattern.
A typical dry-sand job is the molding of a Corliss engine
cylinder, the various operations being shown in Figs. 60-69.
When pouring such cylinders, they are usually poured with
the steam ports vertical in order to give cleaner and sounder
valve seats than would be obtained were the molds poured in
any other position. In molding, the pattern A, Fig. 62, is
placed on the mold-board with the drag around it, joint side
down. Gate-sticks B forming upright pouring gates are set
and held the proper distance away from the cylinder pattern
by the sprue C. The pattern is faced with the dry-sand
mixture, which is backed up with old sand, wet with clay
water. The gate-sticks are faced and the outside of the pattern
102 FOUNDRY PRACTICE
faced and rammed up with successive rammings of sand, vent
rods being introduced through the slotted holes as the flask
is filled, and afterward withdrawn, leaving vents throughout
the mold.
When the top of the steam and exhaust chests on the
pattern are reached, deep pockets will be formed by the exten-
sions of the chest above the round of the barrel. In these are
placed rods D, Fig. 63, which have been claywashed, to
support these pockets. The sand is vented around the rods.
A similar procedure is followed when the wrist-plate seat E
is encountered. On reaching the main core-print, an iron
plate is laid on the print and rammed in the mold to support
the heavy center core. Facing sand is covered over the pattern
and heap sand rammed in, in successive rammings, until the
flask is filled. The remaining operations are carried out as
they would be for any green-sand mold.
After the joint is made and the cope placed in position,
with the gate-sticks and gaggers set, the cope is rammed up
with vent rods in the side. On top of each port post, a large
plug of the same size as the top of the core-print is placed and
rammed up and, on each end flange of the cylinder, a riser is
placed to serve as a flow-off. Screws for securing the cope
half of the pattern in the flask are inserted, the cope is faced,
and heap sand shoveled in to fill the flask and rammed up.
Bars are shoved through the eyes of the screw-eyes screwed
into the pattern and wedged in place and the cope is lifted
off. The screw-eyes are removed and the holes left by them
are stopped up, after which the joint is made and the pattern
is boshed with molasses water, it then being rapped and drawn.
Usually, in making the joint, the corners are nailed and
sometimes the entire joint around the edge of the pattern is
nailed, since there are but few bars used in the cope of a dry-
sand mold.
In finishing a dry-sand mold, breaks at the corners should
be repaired by first placing nails to secure the sand, after which
the broken sand should be replaced with the fingers, and
shaved to the shape of the mold as closely as possible. Should
DRY-SAND MOLDS 1 03
wet mud be laid on these breaks with a trowel, it will scab off
when the mold is poured and injure the casting. After the
mold is finished and before it is baked, blacking is applied.
The blacking is mixed to about the consistency of cream and
applied evenly over the entire surface of the mold with the
swab. After it has set for a few moments, it is slicked with the
trowel which is held at a slight angle to the surface. If the
trowel is allowed to lie flat against the surface when the black-
ing is slicked, a part of the face of the mold will follow the
trowel when it is lifted. Larger molds are best blacked green,
that is before baking, while the smaller sizes are more satis-
factory if blacked after drying. After blacking a green mold,
it should be brushed over with molasses water to smooth the
blacking and give a smooth surface to the casting. The gate
is cut and the mold placed in a proper oven for baking, the
oven used being one adapted for core work.
Referring to Figs. 68 and 69, the method of making the
cores for the exhaust chambers is shown. In making this
core, the iron plate A is placed on trestles and over this four
smaller plates B are set, with dryers at each end. The skeleton
or grid D is laid on these plates with the part which is to go in
the dryer in place. The skeleton core box E is placed in posi-
tion and core sand tucked under the skeleton and rammed
around it. Iron rods, of at least one-quarter inch diameter,
are inserted through holes in the end of the core box and rest
on the vent rods lying in the post part of the core box at F.
The core box is then rammed full and swept off on top with
the sweep G. The core is hollowed to form the proper thick-
ness of the cylinder barrel by means of the round surface H
on the sweep. The ports / are next rammed up. Pieces of
wire of the proper length, inserted in the post part of the core
box, support the sand forming the core for the port at /. The
mixture used in making this portion of the core usually has
seacoal added in order to leave a clean port in the casting.
Nails are placed along the top edge of the core and it is vented
in the same manner as a mold. The top is slicked lightly and
the vent rods withdrawn. The screws / are removed and the
104
FOUNDRY PRACTICE
portion K lifted off, leaving exposed the end of the core. The
holes left by the vent rods are then filled with paste to prevent
iron working into them later. The screws L are withdrawn
FlQ.69. TOP OF EXHAUST CORE BOX.
L
Eia.62. END OF PATTERN IN MW_ FlO.68. SIDE VIEW OF PATTERN IN DRAG „
FlG.ae. RUNNER AND FLOWOFF BUILT, SIDE VIEW.
FIG.67. READY FOR POURING.
FIGS. 60-69. — MOLDING A CORLISS ENGINE CYLINDER IN DRY SAND.
and the sides M removed as is also the stop piece N. The
object of this piece is to determine the proper length of the
core and it can be set at any desired point in the core
DRY- SAND MOLDS 1 05
box. There now only remains portion O of the core box
to be removed and the core remains in the dryer C and on
the plates B. The core is then finished all over and, if
of large size, is blackened before being dried. The steam-
chest core is made in one piece with the post and port at
each end.
The mold, when baked, is placed in position for pouring.
The drag is examined and, if properly dried, is cleaned out and
the steam-chest core tried in. The vent hole in the bottom of
the post is stopped to prevent iron working under the core and
rising in the vents. This vent should be left open until the
core is ready for use, as it is then possible to make sure that
all vents are open. The exhaust-chest core is set after the
steam-chest core. This core is in two pieces and a partition
is formed in the middle of the exhaust chest. Consequently
each core has but a single post at one end to support it and it
must be supported at the opposite end by chaplets. The barrel
center or main core is now placed by means of the crane and
is set in between the port cores as shown in Fig. 65.
When the ports of the exhaust-chest core were made, staples
were set in the back of the core where the center of the nozzle
cores were to come. Wires are twisted and passed through
the staples and holes in the center of the nozzle cores T, Fig. 65,
and the exhaust-chest core is drawn tightly against the nozzle
core by passing the wire through the side of the flask at U,
Fig. 64, and twisting it around a rod which is then wedged out
from the side of the flask. A vent is arranged to bring the
gas from the nozzle cores, this being cut usually while the mold
is green. Flour is next placed on the joint of the mold and
chaplets set on the exhaust-chest cores, after which the cope is
tried on.
It will be recollected that when the cope was rammed, a
large plug was rammed up on top of each post core-print.
When the cope is hoisted, a man looks through each of these
holes and guides the tops of the posts of the chest cores into
their proper print. This operation requires four men, while
two more are necessary to guide the flask itself until it reaches
106 FOUNDRY PRACTICE
the long guide pins on the flask. When the cope is lowered to a
bearing it is clamped with a few clamps which are immediately
removed and the cope once more lifted off, after which the
mold and cores are examined to see that no portion is crushed
by reason of the cope bearing too hard on the drag. It being
determined that the mold bears satisfactorily, as shown by
the flour on the joint, a line of thick paste is laid along the
joint adjoining the edge of the flask and over the ends of the
nozzle cores to prevent iron flowing into the vents. After the
mold has been finally closed, the pouring basin is built and
flow-off channels arranged from the risers.
When building the pouring basin of green sand it is usual
to place a dry-sand core at the bottom of the basin at the point
where the iron will fall from the lip of the ladle, since iron
falling on green sand may wash the bottom of the basin into
the mold with the first rush of iron. After the pouring basin
is filled and the gates are choked, there is little danger of dirt
entering with the iron. It is also usual to make that portion
of the basin, into which the iron is poured, somewhat deeper
than the basin at the entrance to the gate.
The clamps are tightened on the flask while the paste on
the joint is still green, and iron plates with a hole in them are
set over the top of the post cores, the holes in the plates co-
inciding with the vent holes in the cores. Waste is tucked
around the plates to prevent sand from falling into the mold
and a rod of the proper length is set on top of the plate, as
shown at V, Fig. 66. A piece of pipe W is connected with the
hole and sand is rammed around the pipe and rod and a binder
X clamped across them by means of clamps A B. A wedge is
driven between the binder and the rod V to hold the chest cores
down. Gases escaping from the vent reach the air through
the pipes W. Both drag and cope of the flask are provided
with chipping pieces which cause a space to be left between the
two at the joint when the mold is closed. Molding sand wet
with molasses water is rammed in these spaces to prevent iron
from breaking out when the mold is poured. A space is also
left around the barrel core in order that when setting the core,
DRY-SAND MOLDS 1 07
it may be raised or lowered to give the right thickness of cylin-
der walls. In placing this core, paste was placed just inside of
the edge of the flask, which dried quickly due to the warmth of
the core. Before finally closing the cope, the top of the barrel
core should be covered with a thick paste, immediately adjoin-
ing the end next to the flask. Thus with a reasonably tight
fit for the center core, the paste will prevent any damp sand
rammed between the core and mold from finding its way into
the mold. The space around the core should be rammed with
sand and the core barrel held down by wedges between it and
the flange of the flask on the cope side. After the sand is
rammed in, a plate C, Fig. 67, is rubbed to a bearing, pegs of
iron D are inserted in the holes in the iron core barrel, and
wedges E placed between the pegs and the plate. This insures
against iron finding its way out around the core barrel. The
method of building flow-off troughs is shown at F, Figs. 66
and 67. The runner box is next set and weighted with pig
iron. This is the common practice, although the author
recommends using a runner box with flanges on the lower
edge by means of which it may be either clamped or bolted to
the flask.
Cylinders molded in the manner described above, may
weigh anything from a couple of hundred pounds to several
tons, and the flask and other rigging must be in proportion
to the weight of cylinder to be cast. Flasks for this work must
be rigid as there is considerable strain brought on them from
the molten iron in the mold and it is better to have a flask
heavier than necessary than one which is so light that there is
danger of its springing when the mold is poured. The heat of
the iron must be in proportion to the size of the mold which is
to be poured. A slack, dirty iron will seldom produce a satis-
factory cylinder, while a heavy cylinder poured with hot iron
is liable to be equally unsatisfactory. No general rule can
be given to cover this point nor can one be given to govern the
rate at which the iron should be poured. If iron is poured too
slowly in a large cylinder, cold shuts may result, while too rapid
pouring may wash certain portions of the mold away and
IO8 FOUNDRY PRACTICE
produce defective castings. Experience is necessary to obtain
the best results in these two respects.
Cylinders of this character are usually poured at the
bottom and as near as prudent to the exhaust-chest post, as
imperfections can be repaired on the exhaust side which would
be impossible to remedy on the steam side. As there is usually
more room around this post core, iron entering at this point
has a better chance to float the dirt to the top of the cope,
and it is customary to allow an extra amount of metal for
finishing in order to take care of the dirt which may rise in
these posts. Oftentimes, considerable excess metal is cast
here to act as a shrinkhead or feeder. When pouring begins,
the vents should be lighted and, when the mold is filled, a
certain amount of iron should be allowed to flow through some
of them. This is done to flow out any gas generated in the
mold which may cause the iron to kick away from the surface,
and it will thereby be enabled to lie more closely to the mold
and thus give a better casting. If the cylinder is at all large,
it should be churned at the flow-offs and it may also require
churning on- the port posts.
When pouring cylinders of slide-valve engines, the iron is
usually made to enter at the lowest point so that the incoming
iron will flow into the iron already in the mold and thus
restrain the dirt from entering. These cylinders are cast with
the valve seat down and a sounder and cleaner seat is thereby
obtained, providing the mold has been properly made.
MOLDING PRINTING-PRESS CYLINDERS IN DRY SAND
Printing-press cylinders are molded in dry-sand molds and
afford an interesting illustration of the use of sectional flasks.
The flasks are of iron, circular, and as many are used superim-
posed upon one another as are necessary to give a flask of the
requisite height. This class of work is interesting in that the
same pattern may be used for cylinders of different lengths,
the pattern being made of sufficient length to answer for the
longest casting required. On account of the height of the
DRY-SAND MOLDS IOQ
completed mold in this class of work, it is usually convenient
to make the mold in the pit in which the mold is poured.
The pattern used is shown in Fig. 70 and the completed
mold with the cores in place is shown in Fig. 71. The sections
of the flask are short cylinders with a flange at the top and
bottom, accurately machined so that when the various sections
are set one on the other, the mold will stand true and vertical.
A lip B, Fig. 71, is cast on the interior of each section to retain
the sand which is rammed in the flask. Each section is pro-
vided with a pair of trunnions C set in a boss D which is pinned
to the flask with loose pins. Provision is made for bolting the
various sections of the flask together at the flanges and holes
are drilled in the circumference to act as vents to the mold.
Referring now to Fig. 70, the operation of commencing a
mold is shown. An iron bottom-board G is bolted to the first
section of the flask and is placed on a solid bearing in the pit.
Heap sand is shoveled into the bottom of the flask and when
this is at the proper height, facing sand is rammed over it and
the bottom end of the pattern is bedded into it. The facing
sand used is a mixture of old and new sand mixed in the pro-
portions of one part old sand, one part .fire sand, and one part
coarse molding sand. With this is mixed flour in the propor-
tion of one part flour and fourteen parts sand mixture. This
is wet down with molasses water.
When the lower part of the flask is rammed full, a second
section is placed on the first and as there is but little space
between the pattern and the edge of the flask, it is rammed
full with facing sand. A joint is made at the top of this section
and the operation repeated until four of these parts are ram-
med up, when a parting is made. The remaining sections are
then placed and rammed up as before until the last section is
reached. In this section a shrink head is formed by cutting
the sand back to the line H, Fig. 7 1 . The pattern is drawn and
the mold finished, and, if of large size, is blacked before being
placed in the oven to bake.
In making cylinders up to sixteen inches diameter not more
than two sections of the flask are rammed up together, and in
HO FOUNDRY PRACTICE
case of the smaller sizes, but one, before partings are made as
they are finished, blacked and the cores set more easily.
The core box for making the cores used in this mold is
shown in Fig. 72. The core projects on one side as shown at A
in order to cut a slot in the casting. The hub and arms of the
cylinder are at the bottom of the core box. Three gate-sticks
are set as shown between the arms in order to provide vents.
These must be accurately placed as, when the cores are set in
the mold, one above the other, these vents must form one
continuous channel from top to bottom of the built-up core.
Rods are set down through the core to strengthen it and three
staples are inserted between the arms, for use in handling the
core when it is placed. The first core to be set in the mold is
made by ramming the box full of core sand and striking it off
level with the top. A plate is clamped on top, the core box is
rolled over, the clamps removed, and the box rapped. What is
now the toj^of the core box is pinned to the sides. The pins
are removed and the top lifted off. The sides of the box are
split at B, being held together with clamps C. These are
knocked off and the sides removed. The gate-sticks forming
the vents are drawn and the core is left on the plate to be
finished, blacked, and dried in the oven. In making the sec-
tions of the core above the first one, the upper part of the hub is
formed in the bottom of the core as it sets in the mold, by using
section E, Fig. 73, in the top of the core box before it is rolled
over on the plate. The hub formed is filled with black sand
which is removed after the core is baked and the space left by
it is blacked.
The mold having been baked, the first section of the
flask is placed in the pouring pit, resting on the binder as
shown in Fig. 71, and is carefully leveled. The first section of
core is set in this drag and is also leveled. This core is
set in core-print at the bottom of Fig. 70, and is accurately
centered. Around the vent holes and also around the vent in
the center core, is placed a putty worm. The second section is
placed on top of the first and the putty being soft is flattened
out between the two cores and forms a dam which will prevent
DRY-SAND MOLDS
III
FIGS. 70-74. — MOLDING A PRINTING-PRESS CYLINDER.
112 FOUNDRY PRACTICE
iron working into the vents in the cores. Each succeeding core
is set in this manner, being leveled as set. The cores being in
place, the various sections of the mold are set around the core.
On top of the cores is placed a clay worm and over this the
plate /. Two blocks of wood are set on the edges of the flask,
across which the top binder K is laid. This binder and that at
the lower edge of the mold are held together by the stirrup
R. Wedges driven between the upper binder and the plate
/ hold down the center cores. The runner N is set on top of
the mold, this being of dry sand and set as shown. Gates in
the bottom of this runner allow iron to flow into the mold all
around its circumference. The mold itself is left open at the
top, rendering it easy to observe when the mold is filled and to
stop pouring at the proper time. This style of runner box is
used for many different types of castings. It is one of the best
methods of getting clean iron into the mold, as dirt in the iron
tends always to rise to the surface. The iron from the runner
flows from the bottom and therefore is the cleanest iron, the
dirt remaining on the surface and adhering to the sides of the
runner.
The hubs encased in the cores are the last parts of the cast-
ing to cool. For this reason the casting, if it is to cool evenly,
must be left in the mold for a considerable period of time and
when removed must be kept out of drafts until the casting has
attained the temperature of the atmosphere, otherwise cracks
may be found in various portions, particularly in the edges
where the casting was stopped off by the projections on the
core.
Fig. 75 shows a type cylinder with the cores set in sec-
tions as in the first cylinder. The hubs, however, are not tied
together as in the first case owing to some peculiarity of manu-
facture. The pattern used is solid and, being of small diameter,
the sections of the flask are rammed up one at a time, and
parted at A, B, C, D and E for convenience in finishing, black-
ing, and setting the cores F. In closing the cores over the flask,
the center cores are first set as before and sections of the mold
closed around them. After the first section is in place, the
DRY-SAND MOLDS
remaining sections are closed two at a time, a certain amount of
clearance being left between the cores in the sides of the mold
and the center core. After the cores have been set and the
flask completely closed, a gage is run down among the cores
FIG. 76 CASTING
WHEN CORE PRINTS
I REMOVED
FIG. 77 ROLL MOLD WITH CORE
FIG. 78 ROLL FLASK TYPE CYLINDER MOLD FIG. 75
FIGS. 75-80. — CASTING TYPE CYLINDERS AND ROLLS.
in the mold to insure that they are correctly placed. The mold
is poured with the same kind of a runner as before and the
same rules should be observed in pouring.
Another style of roll largely used is shown in Fig. 76, while
114 FOUNDRY PRACTICE
adjoining it, Fig. 77, is the section of the mold for it with the
core in place. The smaller sizes of these rolls are usually
molded on their side in an iron flask, but when poured, the
mold is set on end. Occasionally such molds are molded in
green sands, but cleaner and sounder castings are obtained by
the use of dry-sand molds in this work. The core shown is a
loam core (see Chapter XI) and is fastened in the mold at
the bottom by a rod passed through a hole in the gas-pipe
forming the arbor on which the core is built, the rod being
secured in the flask. The core thus has a chance to expand
upward when heated by contact with the molten iron. After
closing the mold, it is set upright and plumbed to insure its
being truly vertical. The various details of runner, gates, etc.,
are shown in the illustration.
While many printing-press rolls are poured in the manner
described above, that is, from the top, many rolls for different
purposes are poured at the bottom. In this case, the flask
Fig. 78 is used. This flask has a projection on the front in
which a gate can be made, through which iron may be poured
to enter the mold at the bottom. When the flask is plumbed,
the iron, entering the mold at the bottom, rises around the core
evenly, thus setting up no uneven strain on any side of the
core. For molding solid rolls, square flasks are sometimes used,
the gates being set in the corners of the flask and staggered
somewhat in the various sections to prevent the iron having a
straight drop the entire length of the mold. A sprue is cut
from the gate in one flask section to that in the next to afford
a continuous passageway for the iron. It is best to set a gate
in the opposite corner to that down which the iron is poured
and to allow this second gate to fill, since, when the roll is
cooling, the side on which the gate is, through which the iron
was poured, keeps that side of the roll the hottest and thereby
often warps the roll in cooling, if but one gate has been used.
By placing gates in opposite corners, both sides of the roll are
kept equally hot and warping is avoided.
Many foundries use whirl gates in pouring solid rolls (see
page 24) to force the dirt to the center of the casting, whence
DRY-SAND MOLDS 115
it will rise in a shrinkhead or riser. In making short rolls it
is often more economical to make the mold in a core rather
than in sand and to pour it on end. Thus a frame is made and
the roll pattern molded in the frame to form a drag, and a
second frame is used to form a cope. A pouring gate is
arranged down the side and into the bottom of the mold to-
gether with a riser for churning. The second or cope frame is
gaggered and rodded. The pattern is lifted with the top
frame when it is removed, thus helping to hold the sand in
place. If a core is to be used through the center, it is placed
in the lower half and the top half closed on it. If the riser for
churning is arranged to be one-half in each core forming the
mold, it will be easy to see when the cores are properly matched.
Planks or plates are clamped on each side of the core to hold
the two halves together and it is placed in a hole dug in the
floor and sand rammed around it.
Long rolls of small diameter with a shaft in them, are best
poured in an inclined position, the iron entering at the bottom
and covering the lower end of the shaft first. If bubbling or
boiling occurs as the iron flows over the shaft, the bubble will
follow along the shaft and enter a riser placed at its high corner,
thereby insuring sound metal in the main casting. Such a
shaft which is to be cast into a casting should be tinned in
order to flux the iron on it. Instead of placing the mold in an
inclined position for long rolls, some foundrymen favor the
use of a large number of gates on the mold in order to fill it
quickly with hot iron, claiming thereby to obtain a sounder
casting with the core held more easily in the center, the iron
covering it quickly and burning it more nearly alike at all
points and exerting an even pressure under the core. Light
rolls for leather and cotton machinery are often poured in
this manner and good results obtained.
CHAPTER XI
LOAM MOLDING
MANY of the larger and heavier castings are made in what
are known as loam molds, as this class of mold is usually swept
up and requires less pattern work than any other class of mold.
A loam mold consists essentially of a brick backing built up
on cast-iron plates, the surface of the bricks being covered
with loam which is swept to the proper size and shape to form
the finished mold. The loam is baked on the bricks after the
mold has been finished. Castings weighing many tons are
poured in this type of mold and include engine cylinders,
fly-wheels, and similar heavy castings.
In making a loam mold, certain equipment is necessary
and, in order that the student may understand the making of
this equipment, we will assume that for the mold which we are
about to consider there is none of it immediately available and
that it is necessary to make it in the foundry before actual
molding is begun. We will discuss the making of the mold
shown in Figs. 82 to 85, which is for a large cylinder. Before
commencing operations, the entire construction of the mold
must be planned in advance, and provision made for tearing
away and breaking down certain portions of the mold as soon
as poured in order to allow the casting to shrink while cooling.
Green-sand molds will crush under the shrinkage of a casting,
but a loam mold, being stiffened with brickwork and iron
plates, will not yield and the casting will thereby be rup-
tured in shrinking unless the mold is broken down sufficiently
to permit shrinkage.
The cylindrical casting which we are to consider is seven
feet diameter and six feet long. It is provided with flanges
extending five inches from the walls of the cylinder, each flange
two and three-quarters inches thick. The walls of the cylin-
116
LOAM MOLDING 117
der are two and one-quarter inches thick. As there is no equip-
ment at hand for the making of this mold in loam, it is neces-
sary for the molder to provide himself with a spindle seat,
bricks, sweeps, sweep fingers, carrying plates, etc. A sketch
has been provided showing the size and shape of the casting.
A rough pattern of the spindle seat, Fig. 90, is made and a
casting taken therefrom. The spindle, to which the sweeps are
to be fastened, is formed of a piece of cold-rolled shafting, two
and three-eighths inches diameter, one end of which is tapered
for a length of one foot down to one and three-eighths inches
diameter. A number of collars, fitted with set screws, are
made to fit snugly on the spindle. As the spindle is a tall one,
it is advisable to make provision for supporting it at the top by
braces to the wall as shown in Fig. 83. The spindle may be
made either to revolve in the seat or to be fixed. In the latter
case, the sweeps are held at the proper height on the spindle
by collars set-screwed to the shaft below them. The brace is
so constructed that it may be swung up out of the way when
not in use, or to permit the lowering over the spindle of a
collar. The bracing is so arranged that the spindle cannot
move in any direction.
The brace for the top of the spindle is lowered into position
and stayed in place with ropes and blocking. The spindle
seat is molded in the floor directly under the center of the
collar on the brace, its position being determined by* a plumb
line, a fire brick being placed under the center of the hub.
A finger pattern for the sweep finger B has been made and
castings from it finished and bored out to the size of the
spindle. One of these fingers is placed on the spindle, which is
then set in the spindle-seat mold with the end resting on the
fire brick. The tapered end of the spindle having previously
been blackened, slack iron is poured into the mold, which is
poured open. After the seat casting has set, it is covered with
sand and left until the next morning, when a plank is bolted
to the sweep finger and the spindle turned in the seat. Later,
when the seat Jias cooled, the spindle is removed and the seat
is properly set in the sand for beginning molding operations.
118 FOUNDRY PRACTICE
Before the mold proper can be constructed, the plates on
which the mold is to be built, and which in some cases are to
form portions of the mold, must be cast. The first plate to be
made is the bottom or drag plate. A sand heap is leveled
under one of the cranes and a bed made on it. A block of
FIG. 81. — MOLDING THE DRAG PLATE AND CARRYING PLATE.
wood is bedded at the center and with a pair of trammels two
circles A and B, Fig. 81, representing respectively the outside
and inside diameter of the plate, are traced on the face of the
bed. A piece of plank C, of somewhat greatef thickness than
the plate, has one edge formed to a section of the outer circle,
LOAM MOLDING 1 19
and a similar plank E is cut to form a section of the inner
circle. These two pieces of plank are successively moved
around the circumference of the circle traced in the sand, and
sand is rammed up against them and struck off flush with the
top of the plank. We thus have formed in the sand bed a
depression of the same size and shape as the desired drag plate,
but of somewhat greater depth. As the plate must be handled
by the crane it is necessary to cast on it four lugs D, which
quarter the circle. These lugs are formed by placing a block
of wood of the desired size and shape against the segment C
at the proper points on the circle and ramming sand around it.
A flow-off gate is cut in the sand forming the exterior circle
around the mold at the desired height above the bottom of the
mold to form the proper thickness of plate, in this case two
and one-half inches. When the mold is poured, any excess
iron will run off through this gate and maintain the thickness
of the plate at the desired point. Dry-sand cores are placed
to form holes in each of the four lugs D and weighted down.
A pouring basin / is formed and a screen built to protect the
molders from the heat when pouring the mold. The heat in
this case will be intense as there will be a considerable number
of square feet of iron radiating heat at 2,300 deg. F. The
screen is formed by rods / driven in the sand, against which
are placed bottom-boards or iron plates held in place by other
rods driven in front of them. It is advisable to construct a
second pouring basin on the opposite side of the mold from
the first and pour into it a small ladle of iron at the same time
that the larger basin is poured.
A cope plate is also to be made, which is similar in shape and
size to the bottom plate, with the exception that pouring gates
must be provided through which the cylinder mold is poured.
The cope-plate mold is made in the same manner as was the
bottom plate, but, after the sand has been built up around the
outside and inside circles, a third circle is struck in the sand to
locate the pouring gates. On this circle cores C, Fig. 81, of one
inch greater diameter than the pouring gates are set. Some
foundrymen prefer instead of cores to use pieces of coke as H ,
I2O FOUNDRY PRACTICE
claiming it makes a rough hole which will hold the loam around
the pouring gates better than the core. As the under side of
the cope plate must be faced with loam, teeth must be cast on
this face to hold the loam when it is swept on. These teeth
are formed by the print M, consisting of a block of wood
with the teeth formed on it, the face of the mold being printed
all over with this block, as shown at K. The finished cope ring
is shown in Fig. 87.
The cheek ring and carrying plates, Figs. 88 and 89, are
molded and cast in the same manner as the cope plate, teeth
being made in the under side to hold the loam. The carrying
plates, simply being required to support the overhang of the
flange of the cylinder, are made only five-eighths inch thick.
After molding the carrying plates, a number of small cores
are set across the plates so as to form a weak spot at either
side enabling the plate to be easily broken at the proper time.
The uses of these various plates will be explained as they are
reached in the construction of the mold. The brick used for
backing the mold are common red brick, the softer brick being
preferred as they are more porous and will hold the loam
better than the harder brick.
The loam mixture to be used consists of New Jersey fire
sand, a sand of light yellowish color, of coarse texture nearly
approaching gravel, and having a fairly high fusing point, a
coarse molding sand, white pine sawdust and for bond dried
and ground Jersey fire clay of high plasticity. These are mixed
in the proportions: four parts fire sand, one part molding sand,
one part fire clay, and one part sawdust wet with water. The
sawdust is used to make a porous open mixture which will
permit the easy escape of gases when the mold is poured. This
loam is thoroughly mixed with a hoe and wet until it is of the
proper consistency for easy handling in the mold.
The various plates having been made, the spindle seat is
set in the floor and the spindle plumbed in it. The spindle is
then removed and the bottom plate lowered over the seat,
being permitted to rest on timbers as shown in Fig. 82. The
spindle is then replaced and a finger A bolted to it and the plate
LOAM MOLDING 121
leveled by means of the sweep, which has been previously
leveled by means of a spirit-level. The molder next places a
brick on the plate and raises the sweep C to a sufficient height
to permit the brick to be laid in mortar on the bottom plate
and to provide room for the loam which is to be swept on the
brick. The mortar used is formed of sand and clay wet to the
consistency of mortar. Bricks are now laid on the bottom
plate to form the seating as shown in Fig. 82, being kept five-
eighths of an inch below the edge of the sweep. After the seat-
ing has been built the bricks are covered with the loam mixture
and trued off with the sweep. The sweep is cleaned off and
the loam allowed to set, after which it is given a coating of slip
consisting of four parts of molding sand and one part of fire
sand wet with molasses water. The slip closes the pores of
the coarse sand and gives a smooth surface to the mold. It is
allowed to dry after which it is blackened. The seating is
made with a slight slant at D to provide clearance at the part-
ing of the cheek. The seating is sometimes dried by bolting an
arm to the spindle and hanging from it a fire basket which is
swung around over the seating, or at other times by means of
an oil burner when compressed air is available. If there is
plenty of time, the seating may be allowed to air-dry until
hard enough to carry its load, the molder meantime sweeping
loam on the carrying plates. In drying the seating by means
of heat, it should be remembered that molding sand and mo-
lasses water mixtures will burn very quickly and care must be
exercised.
After the seating is dry, it is covered with oiled newspapers
in lieu of parting sand in a green-sand mold, the spindle having
first been removed. Instead of the newspapers powdered
charcoal mixed with water is sometimes used. The faces D
and E of the seating are covered with loam, after which the
cheek plate F, Fig. 83, is lowered, pricker side down, on the
seating and loam is tucked between the seating and the plate
on the line D, Fig. 82, and the plate leveled. The spindle is
then replaced and a second finger A, Fig. 83, is attached to
it, sweep C then being bolted to fingers A and B. Attached to
122
FOUNDRY PRACTICE
sweep C are a number of loose fingers which are removed as
the work progresses. This sweep as a whole forms the inside
of the cheek, \vhich in turn forms the outside of the casting.
FIQ.82. SWEEPING THE SEATING.
FIGS. 82-90. — MOLDING A CYLINDER IN LOAM.
of
It is carefully plumbed in order to insure the casting
the same diameter at the top and bottom. .
Referring now to Fig. 83, at the lower end of the sweep is
finger D to form the circle for the outside of the lower flange.
Bricks E are bedded in the mud on cheek ring F, being set low
LOAM MOLDING 123
enough to permit loam to be laid between their upper surface
and the finger D, and by swinging the sweep around the circle
the outside circumference of the flange is formed. The bricks
are loamed and built up to the level of the top of the flange.
The loam is then covered with slip and finished to receive the
carrying plate, after which it is allowed to dry and become
set, since it must bear the weight of the brickwork on the
carrying plate and if soft when the brickwork is built the
carrying plate will settle and thereby decrease the thickness
of the flange.
One of the carrying plates having previously been covered
with loam on the pricker side, is baked in the core oven. After
the loam is hard, this plate is lowered on top of the brickwork
of the mold already built and centered from the spindle. Its
position is shown at G, Fig. 83. The cheek is next bricked up,
as shown at H, the various courses being tied together and set
back far enough from the sweep to permit loam to be swept
on later. The brick work is carried to a point where it is
necessary to set the carrying plate /, which is to carry the
portion of the mold which overhangs the vertical brickwork H.
This plate is set in loam mud, pricker side up, and the brick-
work is continued upward on it to the thickness of the top
flange. Loam is then swept on top of the brick on the carrying
plate and on the brick around the flange. Some molders will,
at this point, loam the entire face of the brickwork already
built, but usually only the part forming the flange is done at
this time. The loam is allowed to set, after which the finger
K is removed and the carrying plate L which is to form the
top of the upper flange is placed, having previously been
loamed as was plate G. The brickwork is then continued a
short distance above this plate to form a shrinkhead, being
kept back a short distance in order to give a shrinkhead of
greater thickness than the casting. The interior face of the
brickwork is now cleaned off and the surface loamed, the brick
being dampened if necessary. Loaming is performed by the
molder throwing loam against the surface by the handful and
truing it off with the sweep. It is evident that the loam must
124 FOUNDRY PRACTICE
be worked to a -proper consistency, for if too stiff it will not
adhere to the brick and if too soft it will sag. After truing, the
loam surface is coated with slip, usually by brushing it on with
a molder's soft brush, after which the slip is floated off with the
sweep. Sweep and spindle are now removed and the loam
and slip allowed to set, after which blacking is applied to the
entire surface with a swab, and slicked off with a trowel, being
finally finished with a camel's-hair brush and molasses water.
By means of the cross, shown in Fig. 86, which is attached
to the crane, the cheek is lifted off, parting from the seating at
M and TV. Slings from the four extremities of the cross are
passed under the four lugs on the cheek plate, the slings being
kept as close to the outside as possible. The cheek is then low-
ered on the carriage of the core oven, and, as the loam on the
under side of the cheek ring is not dry, the ring is blocked up
under the lugs. The cheek is then placed in the core oven and
baked hard.
The spindle is now replaced and the center built. When
constructing the center it should be borne in mind that the
casting will shrink about one-eighth inch per foot, or in the
present case, where the circumference of the casting is about
twenty-two feet, two and three-quarter inches. Provision
must therefore be made for the brickwork to crush as this
shrinkage takes place, otherwise the casting will be ruptured.
There is therefore provided a number of loam bricks, that is
bricks formed of the loam mixture used in the mold, and a
vertical row of these is built into the center. The fingers A
and B, Fig. 84, being replaced on the spindle, the sweep C is
bolted to them and plumbed, the inner edge being set the re-
quired distance from the center to give the desired inside
diameter of the casting.
The location of the loam bricks is shown at D in Fig. 84.
Oftentimes when strength is desired in the cheek a double
thickness of brick is used, in which case but a single thickness
may be used in the center. The cheek is required to resist an
outward bursting pressure in pouring and a stronger construc-
tion than for the center is necessary for it. Both cheek and
LOAM MOLDING 125
center must be built so that they will be rigid while the mold
is being poured, but the center must be so constructed that it
will give when the casting has set and is contracting.
After bricking up, the center is loamed and finished as was
the cheek. It is then dried either in the core oven or by means
of a fire basket or an oil flame. The covering or cope plate is
then prepared by sweeping loam on the pricker side, after which
a circle is described in the loam to mark the location of the
pouring gates, which were filled with loam when the plate was
prepared. While the mold is drying, the curbing, consisting of
sheets of boiler plate formed in a circle, is prepared. These
circles are made in halves and for the mold under consideration
three are required. If the mold is to be poured in a pit, how-
ever, no curbing is necessary. The diameter of the curbing is
such that it will completely encircle the mold outside of the
lugs on the various plates.
The center being dried, it is placed level on a sand bed
either on the floor or in a pit as desired and the cheek ring
lowered over it to its place on the seating. Before removing
the cheek from the seating for drying, notches were cut in
both the cheek ring and bottom plate to locate them with
reference to each other, and in replacing the cheek these
notches are matched so that in the assembled mold the various
parts have the same relation to each other that they had when
first built. The covering plate is then set, being located in its
proper position by measurement and by looking through the
pouring gates. Sometimes a seating is swept in the cheek to
locate the cover plate, but in a mold of the kind under con-
sideration this is usually unnecessary. The cross is now set on
the cover plate as shown in Fig. 86 resting on blocking, on
either side of the pouring gates as shown in Fig. 85. A curb
of boiler iron is set against the inner set of blocks, after which
slings are passed over the ends of the cross and under the lugs
on the bottom plate and wedged up, thus tying the mold to-
gether. Wads of cotton waste are inserted in the gate holes
to prevent any dirt from falling into the mold and the first
section of curbing / is set. Sand is rammed between this curb-
126 FOUNDRY PRACTICE
ing and the brickwork, a compressed-air rammer being used,
if it is available. The ramming should be done uniformly,
preferably by a number of men all around the mold, so that
the brickwork will not be strained unevenly. After the sand
has been rammed a short distance above the first carrying
plate, straw is laid against the brickwork and sand rammed
around it, the straw forming a vent. The second curb is ram-
med as was the first, but when the third and upper curb is
placed considerable care must be exercised in ramming sand
under the overhang and up to the top of the covering plate.
The wads of waste are removed from the pouring gates and
gate-sticks are inserted. The overhang is vented with a vent-
wire and the vents adjoining the curb are brought, by means of
cinders or straw, to a point where a gate-stick may be rammed
in the sand to form a vent from the cinders or straw, after
which sand is rammed to the top of the curbing and the runner
built as shown in Fig. 86. A riser may be formed through one
of the gate holes as shown, but usually castings of this charac-
ter are poured without a riser, as it is easy to tell when the
mold is full by the action of the iron in the runner.
The casting being poured, the iron in the runner is broken
as soon as it has set and steps are immediately taken to
provide for the shrinkage of the casting. The two top sections
of curbing are unbolted and taken apart. At the same time
another workman with a long chisel is cutting through the
strips of loam brick built into the center so that the latter
may crush as the casting contracts. As soon as the curbing is
removed, the wedges holding down the cross are knocked out
and the slings removed from it. The sand is cleared from
under the overhanging plate forming the upper flange of the
casting, and with chisel-pointed bars the bricks are pried out
from under this plate at the points where the rows of small
cores were set when it was made in order to provide a weak
spot where the plate could be easily broken. The plate is
broken with a sledge and the two halves pulled out from the
mold or a course of brick is removed from under the plate,
which enables the casting to contract in a vertical direction
LOAM MOLDING 127
without danger of breaking off the upper flange. These same
plates may be used in a second similar mold if desired, by
bolting them together across the break, or by sweeping them
up separately in the mold.
In loam molds of this character, plates of different shapes
are cast and loamed and then used to carry overhanging parts
where the flanges or other overhang is too wide to be carried
by bricks. Cores also are often used for the same purpose,
especially where it is necessary to cut the mold away to permit
shrinkage of the casting. Loam work is sometimes considered
expensive, but in many cases castings can be made in loam
much more cheaply than in green or dry sand when the cost
of pattern work, flasks, and necessary rigging is considered.
Where a great many castings are made in loam the work is
necessarily done much more cheaply than in foundries where
loam work is of comparatively infrequent occurrence.
In molding certain classes of castings in loam a skeleton is
often furnished with some solid parts attached to it, patterns
being furnished for these parts. A portion of the mold may be
swept and a portion bricked up against solid parts of the pat-
tern. Thus the barrel of a steam cylinder may be swept and
the steam and exhaust chests formed by solid patterns, the
brickwork being carried against these parts. In this case the
steam and exhaust chests will be tied together at the top and
bottom by the flanges of the cylinder and by the wrist-plate
stand and any parts formed on the barrel of the cylinder. The
seating is swept and the parts that are to form the lower end
of the cylinder are bricked and loamed, after which the pat-
tern parts are set and the cheek plate arranged on the seating
as in the mold previously described. The cheek is bricked up
and the pattern being well greased or oiled, the rounding por-
tion of the cylinder is built up to it, after which loam is placed
against the pattern. Bricks are then dipped in water, rubbed
in the loam, and laid against the loam on the pattern, and loam
mud grouted in between the various bricks. The sides of the
cylinder are continued upward and, to strengthen the brick-
work, iron plates are built in at intervals. The outside ends
128 FOUNDRY PRACTICE
are built last, as they have to be removed to allow the setting
of the chest cores. After the cheek is built it is hoisted off and
the center built as in the first mold considered. Instead of
patterns, skeletons, which are guides on which sweeps are used
to form the faces desired, may be bricked in.
In casting large fly-wheels for engines, if there are many to
be made, the wheel may be hoisted out of the mold, leaving a
bricked-up rim in good shape for a second pouring, only the
loam face requiring repairs. If the loam is so injured that it
is not possible to repair it, it is carefully removed, the face of
the brick cleaned with a wire brush and dampened, and the
proper thickness of loam swept on. Thus the time of bricking
up is saved. While it was formerly customary to make the
face of large pulleys in loam, they are now often made in green
sand or with cores.
Figs. 91-99 show the method of constructing the centers
of loam molds for heavy balance wheels and heavy gears. The
bottom plate is shown in Fig. 91, the cope plate being similar,
with the exception that cored holes are provided for risers.
The cover plate for the hub and arm core box are shown in
Figs. 92 and 93 respectively. Fig. 94 shows grids which are
used to strengthen the arm core, while Fig. 95 illustrates a core
box for forming the gear teeth.
The method of sweeping the seating is illustrated in Fig.
96. If the lower part of the hub is to be formed by means of
a core, this is placed at the center and bedded down with a
spindle rising through the core-print. If it is to be swept up in
loam this operation is performed when the seating is swept.
After the seating has set, the gage, Fig. 97, is used to set the
sweep A, Fig. 98, by which the center is formed. The brick-
work is swept to the proper height and the cores A and B, Fig.
100, which form the arms are placed. They are kept back a
sufficient distance to allow the sweep to pass them. The
corners are usually rubbed off to permit the loam to adhere
later. The brickwork, Fig. 99 F, is built in between the arm
cores, being set so that a coating of loam can be swept over
the face. As the tops of the cores are reached, they are bricked
LOAM MOLDING
129
over, the bricks being laid in a mixture of loam mud with quite
open joints. When learning the bricks they should not be dry
and better results will be obtained if the bricks are rubbed
with loam before they are laid. After learning, a coating of
slip is brushed on, after which the face of the mold is blackened
FlS.91. BOTTOM AND TOP PLATE
' OF COPE AND DRAO.
FJG.S9. GENERAL VIEW OF MOLD. TO?
FIGS. 91-100. — MOLDING A FLY-WHEEL IN LOAM.
and the whole center thoroughly dried. While drying the
center, the covering plates should be loamed and the cores for
forming the teeth made.
Before proceeding further, let us examine the arm cores,
which are shown at B in Fig. 100. These are made with
grids to stiffen them, and in many cases the grids are provided
9
130 FOUNDRY PRACTICE
with ears which project beyond the edge of the core. When
the two halves of the core are dry they are bolted together by
means of these ears, thus forming a pipe through which the
metal flows from the hub, where it is poured, to the rim.
The center being dried is replaced as shown in Fig. 98,
the portion B of the sweep being removed and replaced with
the piece D. The inner edges of the tooth cores are set against
this piece as it is revolved around the spindle. As it is ex-
tremely important that the center be replaced after drying
in the exact position in which it was made, guides must be
provided to insure its being returned to this position. It is bet-
ter to dry the center in place, even if it is inconvenient, rather
than to remove it and dry it in the oven. The tooth cores
being in place, a wall of brickwork is built up back of them and
dried out sufficiently hard to support the covering plate, which
is placed as shown in Figs. 99 and 100, and is held in place by
stirrups or slings / wedged in place. The center core is set in
the core-print, the under side being covered with paste to
prevent iron working under it. The hub plate covering the
center of the mold is arranged with holes for pouring gates
and risers and, after loaming, is set. This is provided with a
beveled edge which guides it to place in a beveled seating swept
in the mold. It is covered with paste where it bears on the
center core. After bolting this plate in place as shown, gate-
sticks are placed, the curbing set, and sand rammed between it
and the mold. The runner is then made as shown at L and
iron balls, each provided with a handle, are placed over each
gate. In pouring the runner is rilled with iron, after which
these balls are lifted and the iron permitted to flow into the
mold from the bottom of the pool in the runner. As dirt will
rise to the surface of the iron, this practice insures that only
clean iron will enter the mold.
After the mold has been poured and the iron set, usually
the next day, the center covering plate should be removed and
the core dug out. The brickwork should then be removed from
between the arm cores, although these will crush sufficiently to
prevent breaking of the arms as the casting shrinks in cooling.
LOAM MOLDING 131
When building brickwork for loam molds in which a large
amount of metal is to be poured, the brickwork is built solidly
around the mold with cinders laid in between the bricks to
provide vents. It is necessary to have a solid structure to
resist the pressure of the metal and this would be impossible
were the bricks to be laid with rather open joints as is done in
smaller molds. It is also necessary, however, that the mold be
thoroughly vented and this is accomplished by the cinders
which are laid in between two layers of loam mortar between
each course of brick. In building the cheek of a loam mold it is
advisable to lay whole brick on the outside and small pieces on
the inside against the loam, thus providing a large number of
joints close to the mold to act as vents. Conversely, in build-
ing the center the small pieces of brick should be laid on the
outside and the whole brick on the inside of the center.
Loam molds are especially susceptible to buckles and scabs.
A scab is formed by a portion of the loam scaling from the
face of the mold, leaving a cavity which forms a rough irregular
projection on the casting. The loam which scales off fre-
quently lodges against some other portion of the mold and
thus forms a cavity in the casting. The cause of this scaling
is usually the failure to properly clean the face of the brick
before loam is applied. It is also frequently caused by the
use of brick which have been used for a considerable period
and have become burned hard. The loam adheres with
difficulty to the glazed surface thus formed. Another cause
of scaling, especially over flanges, is the failure of the molder to
properly dry out the deep bed of loam, steam thus being gen-
erated when the casting is poured which forces the loam from
the face of the mold in escaping. A buckle is formed by steam
being generated as above, but not in sufficient quantity to
rupture the loam. It may, however, expand and force the
loam outward a short distance from the surface of the mold
and thus make a depression in the casting.
132 FOUNDRY PRACTICE
LOAM MIXTURES
It is practically impossible to lay down any fixed rules for
the mixing of loam, as requirements for different classes of
work vary greatly, as do the qualities of the material obtain-
able in different parts of the country. However, the following
mixtures used by the writer have given satisfaction: —
1 . One part coarse Jersey molding sand
Two parts coarse Jersey fire sand
One part white pine sawdust mixed with seven parts of the above
mixture. Mix with a thick clay wash formed of clay of high plas-
ticity.
2. Four parts fire sand
One part Jersey molding sand
One part ground clay
One part white pine sawdust
Wet with water, mix well, and allow to stand for two days, after which
it should be again mixed before using.
3. Mixture for a ten-ton cylinder mold.
One part Jersey molding sand
Four parts Jersey fire sand
One part of rye meal to twenty parts of the sand mixture wet with sour
beer.
4. Mixture for a three-ton cylinder mold.
One part Millville (New Jersey) gravel
One part coarse molding sand
Mix with water.
5. Mixture for slip.
Four parts coarse molding sand
One part fire sand
Wet with molasses water and pass through a fine riddle.
SWEEPING LOAM CORES
The illustration Fig. 101 shows how a loam core may be
swept up on a gas-pipe arbor, being built around a hay rope
center. This core is one that vents easily and the gas escapes
freely from one end to the other. A horse A B with semi-
circular notches in the upper surface is used as shown. A gas-
pipe arbor is placed in corresponding notches at either end of
LOAM MOLDING
133
the horse, a crank being set-screwed to one end of the arbor.
Numerous holes are bored at intervals in the gas-pipe to allow
the escape of gases from the core to the interior of the pipe.
Hay rope which may be either twisted by the molder or pur-
chased from a foundry supply house is wound on the arbor,
a thin cast-iron plate F being set at the middle point of the
arbor to prevent the hay rope being forced up toward the end
of the core by the pressure of the iron
when the mold is poured. The hay
rope is wound firmly on the arbor, but
without sufficient strain to break it,
to approximately the shape of the
t±3
FIG. 101. — SWEEPING A LOAM CORE.
finished core E. After the rope has been wound on, coarse,
clayey loam is rubbed well into the rope, a good way being to
revolve the arbor and with a round piece of iron rub the loam
into the rope. After this is done, loam should be applied
thickly to the core and swept off to the proper size and shape
by revolving the core against the sweep or strike G, which has
a beveled edge and is used with the beveled side up. The core
is then dried, after which it is replaced on the horse and once
more revolved, this time a brick being rubbed lightly on its
face in order to roughen it for the coat of slip which is swept
on the surface. The core is then blackened and dried once
more in the oven. The same mixtures of loam and slip are
used in these loam cores as in loam molds described above.
CHAPTER XII
MOLDS FOR STEEL CASTINGS
THE subject of steel castings requires an entire book in
itself, as it involves not only questions of molding but also
those of steel melting and making, including open-hearth
furnace and Bessemer converter practice. The author pro-
poses in this book to treat only of the problems of making
molds for steel castings and for further information regarding
the entire subject the reader is referred to the excellent work,
"Open Hearth Steel Castings," l by W. M. Carr, and also to
the splendid papers, "Converter vs. Small Open Hearth,"2
by the same author.
Steel is a more difficult metal to cast than iron as the
shrinkage is greater, being about one-quarter inch per foot as
compared to one-eighth inch per foot for cast-iron. It also has
a shorter period of fluidity and expels a greater quantity of gas.
Molds for steel castings are made in much the same manner as
for iron castings of similar size and shape. Two principal
differences are noted, however, the first being the quality of
the sand used, and the second the number and size of shrink-
heads and risers.
Molds for steel castings are made of a mixture of silica
sand and silica clay, a highly refractory mixture. This is
necessary as the temperature of the molten steel ranges from
2,900 to 3,000 degrees Fahr. Molding sand of this character
requires the addition of a certain amount of bonding material
to cause it to hold together while the mold is being made,
finished, and baked. Silica clay is used for this purpose, being
added to the sand after drying and grinding. After mixing
together the mass is wet with molasses water and tempered.
1 The Penton Publishing Co., Cleveland.
2 The Foundry, Nov. and Dec., 1907, Jan., 1908.
134
MOLDS FOR STEEL CASTINGS 135
Mr. Carr, in "Open Hearth Steel Castings," gives the follow-
ing typical analysis of a molding sand for steel castings:
Silica 98.5 %
Alumina 1 .40%
Iron oxide o . 06%
Lime o . 20%
Magnesia o. 16%
Combined water o. 14%
Alkalies 0.25%
The color is often white or slightly tinged with yellow.
Color is not necessarily a guide to the quality of molding sand
but is an indication. In the same work is given a typical
composition of fire clay for use with the above sand :
Silica
60
to 66
Alumina
25
. to 20
Iron oxide
0
tO 2
o
to I
o
to i
Alkalies. .
. . o
tO 2
Combined water 7.50 to 10.50%
Mr. Carr also says, "The value of fire clay depends largely
upon a low content of alkalies and a freedom from carbonates
of lime. Oxide of iron has a strong fluxing effect, but its
presence below three per cent is harmless." In a certain steel
works, the face of the molds for steel castings is made from the
following mixture:
Silica fire clay One part
Crushed silica rock Five parts
Silica sand Eleven parts
Dampen with molasses water.
This mixture is used for molding castings for heavy miter
gears and other castings weighing up to 1,500 pounds. For
smaller castings the same facing mixture is used, but is adul-
terated with burned sand from the heat.
The mold for a steel casting is rammed up and the pattern
drawn in the usual manner. Flat surfaces, however, if of any
136 FOUNDRY PRACTICE
considerable extent, are nailed after finishing by pushing
shingle nails into the surface, leaving the heads flush with the
face of the mold. The nails will prevent the face of the mold
from being scabbed or cut by the fluid steel washing over it
when the mold is filling. A coating of ground quartz, ground
to the fineness of flour and mixed with molasses water, is
applied to the face of the mold with a swab or a soft brush.
The mold should then be placed in an oven and baked. After
baking the molds are closed and clamped for pouring in the
usual fashion, excepting that the steel, instead of being poured
over the lip of the ladle as is the case with iron castings, is
poured through a gate in the bottom of the ladle, thus prevent-
ing the slag floating on top of the steel from entering the mold,
and giving a cleaner and sounder casting.
On account of the great shrinkage of steel in cooling from
the liquid to the solid state, risers of liberal proportions must
be provided over all the relatively massive portions of the
casting, to act as reservoirs of steel to supply the casting with
liquid metal as it shrinks in the mold. Should these not be of
ample size and quantity, cavities will result in the finished
casting.
Molds for steel castings must also be made with provisions
for crushing wherever pockets are formed in the casting in
order to take care of the great shrinkage. The baked mold of
silica sand is an extremely rigid structure, which will offer
great resistance to crushing, and unless provision is made to
relieve this rigidity as the casting cools, it will crack the cast-
ing at the corners of the pockets, or if the casting is heavy
enough to prevent cracking, undesirable shrinkage strains will
be set up in it which will have a weakening effect. It is there-
fore advisable to construct in the pocket of sand a pocket of
cinders which may be formed by placing a box in the center
of the sand pocket which is withdrawn after the mold has been
rammed and the cavity filled with cinders, after which the
mold is completed. Provision, of course, must be made for
venting this pocket by one of the methods previously described.
With this construction the sand will be crushed into the cinder
MOLDS FOR STEEL CASTINGS 137
pocket, as the casting cools, and thus prevent all strains on
the latter. Another method of providing for shrinkage is to
construct the mold so that certain portions of it will break
down easily, as the casting cools and contracts. The more
porous that either mold or core can be made for a steel casting
and yet resist the action and pressure of the molten metal, the
easier the gas can escape and also the easier will the mold
crush and thus prevent shrinkage strains and afford sound
castings.
Another feature which must be borne in mind in making
steel castings is that when one part of a casting is light, and
another part adjoining it relatively heavy, the light part will
draw metal from the heavier part as the former shrinks in
cooling. Provision must be made by means of an ample
shrinkhead to make up the deficiency of metal in the heavy
part, caused by this action.
In making cores for steel castings it should also be borne
in mind that while the same binder may be used for a core
for a steel casting as for an iron one, the sand used must have
a much higher fusing point for steel than for iron. While the
sand which will give satisfactory results to the iron casting
may be strong enough to resist the heat of the steel so far as
the shape of the casting is concerned, yet it may fuse and ad-
here to the casting, making it difficult to remove from the in-
terior of the cored surface. Cores for steel castings are rodded
and vented the same as for iron castings.
CHAPTER XIII
DRY-SAND CORES
CAVITIES in castings are formed by cores which are made
either of green sand, as described in previous chapters on
molding, or of dry sand, mixed with a binder and baked in an
oven to render them hard and to fix their shape. Cores are
usually made in a core box of wood or metal, the interior of
which is hollowed to the shape of the exterior of the core. As
considerable gas is generated when the cores are surrounded
with hot metal in pouring the mold, they must be well vented
to permit the escape of this gas. The cores are set in the
mold, their location being determined by core-prints on the
pattern. The iron entering the mold fills it and flowing around
the cores is/ormed in the desired shape with cavities or hollow
places the exact shape of the cores. Typical dry-sand cores
are shown in Fig. 102, and Fig. 103 shows the core box for
making core No. 12 together with the method of inserting rods
in the core for strengthening it. We will later in this chapter
discuss the various operations of core making, but we will now
consider the various mixtures from which cores are made.
In the various parts of the country, the core sands used vary
as regards their chemical analyses and range from a very fine
sand to a coarse gravel. For very small cores, coarse molding
sand may be wet with molasses water, but core sand, as the
term is generally understood, is a very different material from
ordinary molding sand. In the first place, molding sand has
bond and cohesion while core sand has none. For making small
cores, a sharp, angular-grained sand is preferred, although
a round-grained sand with high permeability and a large
amount of porosity will give good results if a good binder is
used to hold it together. The fine sand used in small cores will
withstand the heat of the metal in small castings, but, under
the influence of the greater amount of heat, continued for a
138
DRY- SAND CORES 139
considerable period in larger castings, the fine sand will be
burned and the core crumbled. Thus in core making, as in
molding, coarser sand must be used as the casting increases
in size, the coarser sands usually having greater resistance to
fusion. Another reason for the use of coarser sands with large
castings, is that a greater amount of gas is generated from the
larger body of metal and more provision must be made for its
escape. The larger sands, being more porous, furnish this
provision.
Inasmuch as good core sand has no bond whatever, and
water added to it would not cause it, after baking, to retain a
shape to which it might be molded, it is necessary to add to
the sand some material to act as a binder. The binder not
only will hold the core sand in shape during and after molding,
so that it may be removed from the core box and placed on an
iron plate for baking, but, under the influence of heat, will bind
the separate grains of sand together in a firm, hard mass, which
will preserve its form when set in the mold and resist the
action of the hot metal. When the core is removed from the
casting it should leave square corners, and hold in it the exact
shape of the core when it was set in the mold.
There are a variety of core binders on the market, and there
are others in common use in foundries, the principal ingredi-
ents being wheat flour, rye meal, powdered rosin, and linseed
oil. Dry and liquid core binders must be obtained from
foundry supply houses or from manufacturers. For a core
which is to be made and set in the mold a short time before
pouring, a mixture of New England hill sand and flour can be
used, mixed in the proportions of one part flour to sixteen parts
sand. This should be tempered with water and riddled
through a No. 8 sieve to remove lumps. These cores will
absorb dampness somewhat rapidly and, if the cores are to
remain in the mold for any length of time, a mixture of
eighteen parts sand to one part flour wet with a mixture of
one part molasses and sixteen parts water must be used. This
will produce a harder, firmer core than before, which will resist
the dampness of the mold for a longer period.
140 FOUNDRY PRACTICE
If a core is desired which will resist moisture still longer,
one part linseed oil to fifty parts sand, passed through a mixing
machine, will give good results. By increasing the oil to one
part in thirty-five still better results are obtained. Hill sand
contains matter which is not found in lake or river sands and
these last will absorb binder and produce cores with a smaller
quantity than the hill sand. When tempering the sand for use,
if it is made too damp the cores will swell and be ruined when
baked in the oven. On the other hand, the core must be
sufficiently wet with oil or molasses water to bake right. The
degree of wetness necessary is impossible of description and
can be learned only by experience.
For small cores for brass or composition castings, a fine
sharp sand is necessary. For the cores in Fig. 102, fine New
England hill sand, or lake sand of Pennsylvania may be used.
New Jersey sands usually have a slight amount of bond and
the finer sands require a smaller amount of binder than usual.
One part flour or rye meal added to sixteen parts of any of
the above sands has been a common mixture for many years
in all parts of the country. The amount of sand is increased
or diminished as the cores increase or decrease in size. The
sand is wet with a mixture of one part molasses and sixteen
parts water, and after the cores are molded they are baked to
a deep brown color.
Since the introduction of dry and liquid core binders,
eighteen parts sharp core sand and eighteen parts old or burned
core sand, mixed with one part of binder and wet with mo-
lasses water will give good results for large-size cores. For
pump and small engine castings, a mixture of twenty-five parts
sharp sand and twenty-five parts burned sand and one part
linseed oil, thoroughly mixed in a mixing machine, will make
excellent cores. For making a core for a large engine barrel, a
mixture of four parts coarse New Jersey fire sand and two
parts of coarse molding sand to which is added flour in the
proportion of one part flour to twelve parts sand should be
well riddled and wet with molasses water and thoroughly
tempered.
DRY-SAND CORES 141
A word regarding the qualities of the various sands will not
be amiss at this point. The New England hill sand is large-
grained quartzite. It resembles the lake sand largely, although
hill sand contains a certain amount of alumina while lake sand
is a clear wash sand. These sands may be largely used for
small cores, but to withstand high heat for any length of time,
they must be mixed with a refractory sand as ground silica
rock or New Jersey fire sand. River sands are dredged from
the bottoms of rivers. In the western part of New York is
found a sand which resembles hill sand or river sand, but it is
mixed with slate which fuses the sand and renders it hard to
remove from castings. New Jersey sands differ from all other
in being more refractory. They may be obtained in many
different grades of fineness and are especially suited to large
cores in heavy bodies of metal.
In regard to binders many experiments have been con-
ducted to determine if a portion of the old core sand could be
used, but it was found that flour and rye meal would not give
satisfactory results when used as a binder in cores made partly
of old sand.
It was found that a core binder having a pitch or tar body
would permit the use of a large percentage of old core sand and
thus effect a saving. In order that a core binder should be
considered good, it must not only bind the core sand in the
green state but bind it still better when baked, so that the
cores will hold their corners and be blackened if necessary, in
order that the core will stand the intense heat and separate
easily from the casting when it is cool, especially in the corners
and in other portions hard to reach.
For core-making machines, flour has proved an unsatis-
factory binder as it gums the machine and the cores stick. It
has been found that by using an oil binder the sand could be
easily passed through the tube of the machine and satisfactory
cores made.
In making a core of the simpler form, such as shown at i,
2, 3, or 4, Fig. 102, a core box of wood or metal is tucked or
rammed full of sand of the proper mixture and the sand leveled
I42
FOUNDRY PRACTICE
off flush with the top of the box. The box is then covered
with an iron plate called a core plate, and rolled over so that
the plate is underneath. The box is rapped to free it from the
sand core and is then carefully lifted, leaving the core on the
plate. Plate and core are then placed in an oven and baked.
The other cores shown in Fig. 102 are more complicated,
although the general method of making them is the same. In
FIG. 102. — TYPICAL CORES.
order to form a core of the desired shape it is often necessary
to make it in a number of pieces and afterward fasten these
together by various means according to the size and character
of the core. For instance, core 7 is made in halves, each half
requiring a special box. After drying, the two halves are
cemented together with paste, the joint between the two being
the line X. The side view of this core is shown at 8.
As the sands and binder of which the cores are made, give
off large quantities of gas when the molds are poured, great
care must be exercised, especially with the larger cores, in
providing ample vent channels for the escape of this gas.
These channels are arranged to lead the gas from all parts
DRY-SAND CORES 143
of the core to a main vent whence they are conducted into
vent channels in the sand forming the mold itself. If the cores
are improperly vented the gases generated will be imprisoned
and may burst the core with disastrous effects on the casting.
Consider core u. After the core box is filled with sand and
rammed, it is slicked level with the top, and a channel is cut
lengthwise in each half of the core. From this channel, holes
are formed, leading to the deeper parts of the core to conduct
the gases to this main vent. The two halves of the core are
cemented together, the paste being laid entirely around the
edge of one half with the exception of the space immediately
over the end of the main vent. The paste must not be allowed
to get into the vent and close it, or the gas will be imprisoned
in the core. After the two halves are cemented together, a
mixture of fine molding sand and molasses water, known in the
foundry as slurry, is rubbed on the joint between the two
halves in order to smooth it and avoid making a seam on the
interior of the casting. This operation is known as slurrying
the cores. Referring to the remaining cores shown in Fig. 102,
cores Nos. 9, n, 13, 14, and 15 are made in halves and after-
ward pasted together. Special attention is called to core 9 as
it illustrates the practice adopted where it is impossible to
bring the main vent out at the end of the core. This is often
the case where iron is flowed over the ends of the cores and it
is necessary to bring the vent to the most convenient point
for the escape of gases. In the core under consideration, the
main vent is brought out of the core at 20. The iron flows
around the greater portion of the core. That portion on which
the numbers are inscribed forms the print resting in the core-
print on the mold. At XX are seen two staples through which
wire may be threaded to hold the core in place when it is sus-
pended from the cope.
While cores may be of any shape, the position they occupy
in the mold may subject them to heavy strain and their pro-
portions at times may be such that the heavier part must be
supported by a light portion. Such a case is core 12. With a
core of this character, rods are set in the core when it is made to
144
FOUNDRY PRACTICE
strengthen it. The core box for this core is shown in Fig. 103
at A. At B is shown the opposite half of this core box partially
filled with sand mixture, with the strengthening rods set in
position to support the various parts of the core. These rods
are covered either with claywash or paste, to make the sand
adhere to them and bake hard on them. C is the. completed
FIG. 103.— CORE Box, SHOWING METHOD OF RODDING AND VENTING
CORE.
core, being identical with that shown at 12, Fig. 102. At D
is the finished casting showing the cavities formed by the
cores C.
The size of the strengthening rods is increased with the
size of the core, and with the larger sizes the rods will not
suffice and resort must be had to grids or skeletons of cast-iron
made to conform with the shape of the core. These are either
used alone or in connection with rods. When making these
grids, it should be borne in mind that iron shrinks one-eighth
of an inch per foot when passing from the molten to the solid
state, and in using heavy, strong grids in cores, these must not
be allowed to approach close to the sides or ends of the cores,
lest the iron in the casting in shrinking bind on the grid which
tends to expand with the heat, and thus be cracked or broken.
In making these grids, a bed of molding sand is usually made
in the floor and the core box laid on the bed and its outline
DRY-SAND CORES 145
traced ; after which the shape of grid necessary to fit the inside
of the box is cut out of the sand. Grids for heavy engine cast-
ings, and the like, require patterns and in some foundries a
special floor is reserved for the molding of grids.
In order to allow the larger sizes of cores to be compressed
by the shrinking of the casting, pockets are formed of coke or
cinders in the core which is made strong enough to resist the
strains of pouring and yet sufficiently weak to compress with
the shrinkage of the casting. These compression pockets also
act as vents to carry gas from the core and often have vents
from more distant parts led to them by means of wax tapers.
Wax tapers are made of a thread coated with wax or
paraffine similar to a candle. They are laid in the core wher-
ever desired and sand rammed around them. When the core is
baked in the oven, the wax melts and is absorbed by the sand,
leaving a hole in the core, through which the gas escapes
from the surrounding sand. By the use of wax tapers, vents
can be made in the core wherever desired with but little trouble
and expense. Wax tapers are used in such cores as locomotive
cylinder ports and others in which it would ordinarily be diffi-
cult to lead a vent around a corner. They are also used to a
considerable extent in very thin cores and their use is becoming
quite general.
Many cores do not require rodding. Among these are
what are ordinarily termed stock cores, which are generally
round and of different diameters. These are made up in
quantities of varying length and are cut off to the length re-
quired. When used in a vertical position, they seldom require
to be strengthened with rods; but when set horizontally, rods
are required if the cores are of any length in order to prevent
them breaking or springing when the mold is poured. When
set in pulleys, it is usually best to rod the core as there is a
considerable length exposed to iron.
Often cores of irregular shape, when made in quantities,
are baked in what are known as core dryers. This is simply a
cast-iron box of the same shape as the core in which the core
is placed when it is removed from the core box, instead of
1 46 FOUNDRY PRACTICE
being set on a core plate. The advantage of the core dryer is,
that there is no possibility of the core losing its shape, while
drying.
In recent years, the importance of mixing the different
binders with the core sand has been appreciated, and mixing
machinery has been generally introduced in the larger foun-
dries. In these machines, oil is fed to the mixture automatic-
ally in the desired proportions, to give the best result. The
importance of preparing the sand for use has long been recog-
nized in foreign countries and much attention has been given
to it.
Closely allied to molding machines, are machines for
making cores. In fact, the development of the molding
machine, increasing as it did the output of foundries, de-
manded better facilities for furnishing cores in the quantities
required than were possible with the ordinary hand equipment
of the core room. The machines most commonly used are for
the purpose of forming stock cores, and consist of a screw which
forces the core mixture through a tube of the proper diameter
to form the core. The length of the tube has a direct influence
on the quality of the core, the hardness of the finished core
being increased as the length of the tube is increased. Cores
often come from the machine too hard for the purpose desired
and the fault can be remedied by shortening the tube; the
machines are also arranged to make triangular, octagonal, and
elliptical cores with satisfactory results. The machines form
a vent hole through the center and, if desired, insert a rod
lengthwise of the core to strengthen it. The core comes from
the machine perfectly straight and is delivered on a plate with
grooves in it to keep the core in shape. Liquid core binders are
generally used with machines and cores up to eight inches
diameter can be made in certain types. The sand used is as
a rule new sand, only a small amount of burnt core sand being
added. This is mixed with oil in the proportions of forty or
fifty parts of sand to one of oil.
The use of machines for making stock cores has enabled
their length to be increased to about eighteen inches instead
DRY-SAND CORE'S 147
of twelve as formerly. It has also enabled more perfect cores
to be secured. Formerly, round cores were made in half
boxes and the halves pasted together. Now they are either
made in whole boxes or by machine. Cores made in halves
and pasted together are slightly elliptical in cross section and
therefcre not as good as the machine-made cores.
Cores, after molding, are baked in any one of the standard
core ovens which are on the market. These ovens are heated
by gas, oil, or coke, as may be most convenient. Core
ovens for the larger-size cores are provided with tracks on
which flat cars, or cars carrying racks on which the cores are
placed, may be run into the oven for baking. In certain types
of core oven, the door is in one piece and slides upward, being
counterbalanced. In others it is in the form of a roller
curtain. In the smaller types, the doors are hung on hinges.
The core ovens of the Dickson Car Wheel Co., Houston,
Texas, represent good practice. The cores in dryers are placed
on racks on a large carriage which is run into one of three
ovens by means of a transfer table. The floor of the oven
consists of iron plates, cast with two-inch holes in them. The
fire box is located back in the oven below the level of the oven
floor. Heat from the fire is drawn under the floor and passes
up through holes in the plate as well as from plates into the
core oven. About two hours and a half are required to dry a
car load of cores.
The even distribution of heat in core ovens has been given
considerable attention. Unevenly distributed heat causes
considerable annoyance, to say nothing of giving poor results
in baking cores. In many ovens it has been necessary to set
the cores as high up in the oven as possible in order to dry
them, and in handling large cores this has caused much trouble
and loss of time. At the foundry of the Allis-Chalmers Co.,
the large ovens are fired at the back in a specially built fire
box and the heat drawn through an opening in the back of the
oven. Special flues are arranged to draw the heat to various
parts of the oven as desired. Other designs include fire pots
placed in the corner of the oven and lowered as close as possible
148 FOUNDRY PRACTICE
to the floor. In still other ovens a series of flues are run under
the floor and, in most of the larger ovens, flues are provided to
carry off the steam from the core. These are closed at a certain
stage and the heat confined to the oven.
While the greater number of cores used are made in more
or less expensive boxes, or by machines, it is sometimes
desirable to make a core as cheaply as possible, few being
required. For such cases core boxes often are made separable
FiG.104-CORE BOX FOR Fia.105-CORE BOX FOR
AN INEXPENSIVE CORE A COVER CORE
CORE BOX FOR A COVER CORE FOR A PULLEY
FIGS. 104-106.
at two diagonally opposite corners, and having no top or bot-
tom, as shown in Fig. 104. In use the box is placed on a core
plate, being held together by the core-maker and filled with
core sand. After slicking off with the trowel, the box is
removed, leaving the core on the plate.
Again cores known as "cake cores" or "cover cores"
are called for, these being used as "covering cores. " They are
made in a box consisting of a frame, of the required size and
depth on the inside, as Fig. 105. Sometimes these cores require
rodding to strengthen them, and often they are made of a
strong mixture, and kept on hand. If for covering the rim of a
pulley and shaped as shown in Fig. 106, they are given a coat
of blacking on one side, and the larger cores are vented from
the opposite side. These cores are used blackened side down.
DRY-SAND CORES 149
Some cores are swept by means of guides and sweeps. Thus
a cylinder core of considerable size may be swept in either of
these ways.
Fig. 107 shows a barrel or center core made in this manner.
The straight edge A, Fig. 108, is clamped to the core plate B,
and the core arbor D is placed in position, being raised on the
core plate one inch as seen at C, Fig. in. Cinders or molding
sand E, Fig. 108, are placed as shown and the core-sand mix-
ture is rammed around -the arbor until it is as high as the top
of the arbor. Rods F, Fig. 108, are driven down alongside the
arbor to hold the sand which is to hang below the arbor.
Sometimes these arbors are cast with prongs extending below
the backbone O of the core arbor to hold the hanging sand to
the arbor, but arbors can also be used without them, and the
sand can be held as above. Care should be used that the rods
do not come high enough to interfere with the passing of the
sweep over them when the core is swept. At times, if there is
a large body of sand hanging, these rods are bent to a hook
shape and used as a gagger C, Fig. no, one end being hooked
under the arm of the backbone, and the other end coming near
the top of the core as it is swept forms an inverted gagger, so
that the sand is held firmly to the arbor. False ends, cut from
boards, shown at A and B, Fig. 1 10, are now set on edge on the
ends of the arbor at F and G, Fig. 108, and the sand is rammed
over the arbor between these ends. The sweep A, Fig. 109, is
used to shape the core, the part C pressing against the inside
edge E of straight-edge D, as the sweep is moved lengthways of
the core. The core is well vented down to the cinders E, Fig.
108, the vent holes are filled, and core trued with the strike,
and finished with the trowel. It is usually blacked while green
and the blacking slicked.
If the core is long, one or two gate-sticks are set over the
hole H, Fig. 108, to form an opening. When the lower half
is dried and rolled over, the top half is dried, after which the
upper half is rubbed on the lower half and the core brought to
size. If molding sand has been used to form the channels for
the vent, it is now removed. The core, when found to caliper
150 FOUNDRY PRACTICE
the right diameter, is pasted together, and the joint is slurried
as were the smaller cores. In addition, a long core is bolted
together in the center as well as at the ends.
The top half of the core is made exactly as the lower half
was, but as it is not rolled over, there is no hanging sand, and
no rodding is required. In rolling over the lower half of a large
core, a bed of molding sand usually is made on the floor and
the core rolled over on it. In doing so care must be exercised
that the edge is not broken. If cinders are used for the vent,
they are left as rammed up in the core as they form a porous
mass through which the gas escapes easily.
When the core is bolted together in the center, the heads
of the bolts are covered with the core-sand mixture, and in
order to hold this sand in the hole formed, spikes are driven
into the sides. These places are blackened over and the core
placed in the oven to dry the paste and blacking. If the nole
in the center of the halves is large, it is well to put cinders at
the bottom of the core so that the gases will escape through
them from this portion. When filling in the sand it should
be vented down to the cinders; as, in order to have a sound,
clean cylinder barrel, it is important that the center core be
thoroughly dry and well vented.
Another method of venting a core is to have holes in the
end pieces, as D, Fig. no, and when the core sand is rammed
high enough three-eighths inch rods are placed through these
holes, extending about eight inches beyond the ends of the
core. When the half of the core is finished the rods are with-
drawn, leaving vent holes near the surface, but still so far down
that the iron cannot enter them. In some foundries these
ends, Fig. no, are made of cast-iron and are arranged to be
bolted to the core plate. When such is the case, the arbor D,
Fig. 108, is claywashed and placed on the plate, and ends, Fig.
no, bolted to the plate. The ends A and B have slots to ac-
commodate the arbor. The sand is rammed up to the proper
height on the arbor, hook rods or gaggers being used as in the
first case, or when the sand has been rammed high enough,
straight rods may be driven down between the arms on the
DRY-SAND CORES
FIG. 107
a
FIGS. 107-112. — SWEEPING CORES ON AN ARBOR.
152
FOUNDRY PRACTICE
arbor. Rods to form vents are run through the holes in the
ends A and B, these rods extending beyond the core. The sand
is rammed above the ends over the vent-rods and is then swept
off level by the sweep E, Fig. 112, using the ends as guides.
The half core is then finished, and the strike laid down flat
over each vent-rod, and rod drawn out, thus keeping the rod
FIG. 113. — MAKING A FORMED CORE BY MEANS OF A STRICKLE.
from breaking out through the sand sideways. The ends are
then removed.
The finished half core is seen at A , Fig. 1 1 1 , resting on the
core plate B, with the core arbor C projecting from it. In
order to hoist the core up with the plate, holes D are cored in
the plate.
It will be seen in sweeping cores that by having a core plate
arranged in this way, formed cores of different diameters may
be swept by having the plate ends of proper size, and having
the outline of the core wished made in the sweep or strike,
at times called strickles, as shown at A and B, Fig. 113.
In many of the large foundries making steam-engine cast-
ings, it is the custom to sweep up the center or barrel core on
DRY-SAND CORES
153
large core barrels made of cast-iron, thus effecting a saving of
core sand, labor, and time of drying. Some of these barrels
are cast in halves, and when the two have been covered with
the core-sand mixture and dried, they are bolted together. Fig.
1 15 shows one-half of the core barrel A resting on core plate C,
with removable ends B bolted to the core plate. An end is
FlG. 114 THE FINISHED CORE
FIGS. 114-118. — BARREL CORES MADE ON CORE BARREL WITH HORNS.
shown, Fig.'n6, and D, Fig. 117, with horns for holding the
sand to the barrel, and between the horns are the holes
through the barrel E for bringing the vent to the inside of
the barrel. In use, the core barrel is first given a coating of
claywash, and is placed on core plate C, Fig. 115, and the
ends B are bolted to the barrel or plate.
A mixture is made of four parts of coarse New Jersey fire
sand, and two parts of coarse molding sand, to which is added
flour in the proportion of one flour to twelve of sand, and after
the mixture has been well mixed and riddled, it is wet with
molasses water in the proportion of one part molasses to six-
teen parts water, and thoroughly tempered. The core-maker
then uses it by placing double handfuls of the mixture on the
154 FOUNDRY PRACTICE
core barrel, and with his fingers pressing it down in between
the horns. In some cases a bench rammer is used to ram it
down on the core barrel, depending on the length of the horns.
The sweep, Fig. 118, is then used to true the core to the size
wished. In passing it over the core the first and second time,
places will be found requiring attention and hand work to
made them solid. This is done and the sweep passed over the
core until it is of tha right size, when the core is blackened
and slicked. This half is placed in the oven or on a carriage
and the ends B removed to be used in sweeping another
half.
When the bottom half is dry, a piece of shafting is run
through the holes in the ends, and this half is turned on the
bar F, Fig. 117, and the joint is pasted. The top half having
some of the sand scraped away at the joint to bevel it, it is
placed on the lower half and the two bolted together at G
and C, Fig. 117. If the core is of too great length to trust the
ends alone to hold, it is bolted together at H, Fig. 115.
The joint is next filled and pasted, the joint blackened, and
the core dried in the oven. When the core is in use in the mold,
the barrel expands and allowance must be made for this, as
the cylinder is shrinking at the same time, and the horns may
bind on the inside of the cylinder, rendering it difficult to
remove the core barrel.
In making cores for small castings when there is but a small
amount of iron surrounding the core which is made of fine
sand, the casting soon cools and the core is easily rapped out,
leaving usually a smooth enough hole for ordinary purposes
in the casting. But as the cores increase in size and the
amount of metal surrounding them increases in thickness and
weight, causing burning of the core, it becomes necessary to
protect the face of the core to prevent the iron from burning it,
or in some cases from destroying its face and producing a rough
casting. This is done by coating the core with a coat of black-
ing. This may be silver lead, wet with molasses water, or the
same lead wet with clay water. Red New Jersey fire-clay is
generally used in the clay water, but blue clay, as found in
DRY-SAND CORES 155
many parts of the United States, will answer if sufficiently
refractory. The blacking protects the core from the intense
heat of the iron, so that when the casting is cleaned, the sand is
easily freed from it and the casting is found to be of the shape
of the core set in the mold. See Chapter XXII, relative to
facing materials.
CHAPTER XIV
SETTING CORES AND USING CHAPLETS
CAVITIES in castings are formed by means of cores of green
or dry sand, the dry-sand cores being made as described in
Chapter XIII. The dry-sand cores are set in the mold in core-
prints formed by projections on the pattern which locate the
cores accurately in regard to the rest of the mold. As the
pressure of the iron in filling the molds would tend to float the
core to the top of the mold, it must be held down by chaplets,
as shown in Figs. 120 to 125. If the core is long or if the casting
is of such shape that the core is supported by the core-print
at only one end, it is necessary to use chaplets to support it
at the opposite end or at various points along its length. In
Fig. 119 are illustrated various forms of chaplets, each one of
which has its special uses and is adapted to various classes of
work.
The chaplets A to Fare formed of perforated sheet tin, and
will resist a heavier crushing stress than would be imagined.
The chaplet A with one flat and one concave side is used to
support a round core above a flat surface, or vice versa.
Chaplet B, with one concave and one convex surface, is used
with a round core in a cylindrical mold. The chaplet C is
similar to the one shown at F and is used in situations similar
to those requiring B, but, having four side walls and being
larger, will resist a greater crushing stress. Chaplets D and E
are used either over or under cores for holding them down or
supporting them, E being used in the heavier classes of work.
These chaplets are used on the lighter classes of castings,
although they can be used on rather heavy work if desired, the
thickness of metal of which they are formed being varied to
suit the requirements of the case. The chaplet shown at H
is what is known as a water back or front chaplet and is used to
156
SETTING CORES AND USING CHAPLETS 157
FIG. 119. — TYPES OF CHAPLETS.
158 FOUNDRY PRACTICE
hold the cores in the water backs of stoves. It is made of
material to which the iron will readily flux when poured.
Chaplets /, /, K, L, and M are used on the heavier classes
of work both to hold cores down, to support them in the mold
and to prevent their moving sideways. They are used in con-
nection with castings weighing many tons and in various
combinations with one another. Chaplets G and / are the
most commonly used types. They are composed of a head
with a shank or stem which may be either pointed as shown at
M or blunt. They are usually provided with serrations V,
near the head, which will prevent the chaplet in any way
from being driven or working out of the casting if by any
chance the metal of the chaplet does not fuse with that of the
casting when the mold is poured. If the chaplets G or I are
to be used to support the core, the stem is pointed and driven
through the drag into the bottom-board about a quarter of an
inch. Chaplet G is formed of a stem with a flat head riveted to
it, while chaplet / is made in one piece by upsetting the stem to
form the head. Chaplet L is formed with a pin projecting
above the head, which may be inserted in holes in the plate of
a chaplet similar to K, which has shoulders on the stem to
prevent the plate from sliding up on it under the pressure of
the entering metal. The stem of the chaplet L is projected
through the sand of the mold and either driven into the
bottom-board or wedged against the binder, as will be de-
scribed later, and thus transmits the pressure on chaplet K
to the flask. P is a forged chaplet used in situations similar to
those in which K is used. Larger heads may be desired than
are possible on forged chaplets and, by using double-ended
stems similar to those used in chaplet K and plates of different
sizes as N, a chaplet of any desired size and shape may be made.
It is advisable, in foundries doing a general class of work, to
keep on hand a supply of these stems and plates. / and O are
small double-ended chaplets used for the same purpose as K,
while R, S, and T are chaplets of small size, pressed out of tin,
which are convenient for nailing on the side of a mold and to
place between, over, or under small cores.
SETTING CORES AND USING CHAPLETS 159
Chaplets used in steam-, water-, gas-, and air-cylinder cast-
ings are always tinned where they come in contact with the
molten iron, the tin acting as a flux and causing the chaplet
to unite with the metal of the casting and thus form a joint
which will not leak under pressure.
Referring now to Figs. 120-122, we have respectively an
end section, a plan, and a sectional plan of a cylindrical mold
with a cylindrical core, which illustrate the method of placing
the core and using the chaplet. Assume the pattern to be ten
inches diameter and the core to have a diameter of eight inches,
the thickness of the wall of the casting thus being one inch.
A gauge A or B is made, with the notch C cut one inch deep
and sufficiently wide to fit over the edge of the chaplet. The
thickness of sand being ascertained by pushing the vent-wire
through the mold where the chaplet is to be set, there is added
to this length the thickness of metal of the casting plus one-
quarter inch which the chaplet will be driven into the bottom-
board, and the stem is cut off to the proper length and pointed.
The chaplet is then driven down through the sand into the
bottom-board and the head allowed to project one inch above
the surface of the mold, this height being determined by the
notch in the gages A or B. The bottom of the notch is set
against the head of the chaplet and the top of the notch should
rest on the surface of the mold. The moid in question is for a
column eight feet long. The core-prints at either end of the
mold are six inches long and, therefore, the core is cut off to a
length of nine feet. To prevent sagging, it is supported at the
middle by a chaplet placed in the mold as described above.
To prevent the core from moving sideways, chaplets G are
placed on either side of the core as shown, a channel being cut
in the sand at the joint and a wedge driven between the flask
and the blunt end of the stem, which is cut about three-eighths
inch short of the distance between the core and the inside of
the flask. Side chaplets and wedges are then covered with
sand and the joint left in its former condition.
The thickness of sand in the cope over the pattern is then
ascertained, and to it is added the thickness of metal in the
l6O FOUNDRY PRACTICE
casting. A chaplet is cut off to this length and the end of the
stem left blunt. A large vent-wire is used to make a hole
through the sand at the spot where the chaplet is to be placed,
and after the chaplet has been inserted in this hole it is held
in position by pinching the sand around it at the top of the
cope, after which the cope is closed on the drag. The molder
then moves the chaplet up and down to make sure that it
bears on the core, after which strips of wood / are laid on the
edge of the flask and a binder / laid across the cope over the
top of the chaplet. The binder / is fastened to binder K
under the bottom-board and the two held together with rod
bolts L. A wedge O is then driven firmly between the binder
and the top of the chaplet to hold the latter tightly against the
core, but not so firmly as to drive the latter into the core.
The wedge should not be driven until after the binders have
been tightened; otherwise the chaplet might be driven into
the core or force it down lower than desired.
The chaplet E, Fig. 120, is purposely shown set in the wrong
position in order to illustrate a common fault in setting chap-
lets, which must be avoided. Unless the stem of the chaplet is
driven truly vertical through the sand, the chaplet will bear
on a single point and when the strain due to the pouring of
the mold comes on it, it will either bend or be forced into the
core. In any event the core will rise more or less in the mold
and render the casting thinner on that side than it should be.
It is necessary that the chaplet have a firm bearing on the core
and, to do this, it must stand vertical.
Fig. 123 illustrates the use of several different types of
chaplets. At A is a double-ended chaplet resting on a piece of
a baked core set in the sand in the drag, placed there for the
special purpose of holding it. At B is a single-end, long-stem
pointed chaplet, such as we have just described. In the cope,
at C, is a chaplet set correctly, while at D is a similar one set
incorrectly. Instead of binders and bolts, clamps are used for
securing the cores. Strips of wood E are laid on the edge of
the flask and over them a bar or piece of wood / passing over
the tops of the chaplets. The clamp G is placed to hold these
SETTING CORES AND USING CHAPLETS l6l
SECTIONAL PLAN OF MOLD
Fro. 122
MOLD FOR A QUARTER TURN
PIPE ELBOW
FIG. 125
FIGS. 120-125. — SETTING CHAPLETS.
1 62 FOUNDRY PRACTICE
bars E and the bottom-board F together, the clamp being
wedged in place by the wedge H. Wedges / are inserted
between the top of the chaplets and the bar /. This core does
not require any side chaplets. It will be observed that, this
mold being quite deep in the cope, there will be a considerable
lifting tendency due to the high head of metal. The bar 7
must, therefore, be made heavy enough to resist any tendency
to spring; otherwise the core will lift and iron may enter the
vent.
Figs. 124 and 125 show the mold for a quarter-turn pipe
elbow. After the cope has been made, an iron bar B with a
lug A projecting from its side is placed in the top of the cope
at the point where the chaplet is to be placed, the stem of the
chaplet coming under this lug. The stem of the chaplet is cut
to such a length that it will fit snugly against this lug and pro-
ject into the mold the proper distance to give the necessary
thickness of metal, or the stem may be cut short and a wedge
C driven between the bar B and the chaplet.
CHAPTER XV
GATES AND GATING
As many castings required from a single pattern are small,
it obviously would be poor economy to mold each casting
separately. It would not improve matters much to have a
number of similar patterns separate from each other and mold
them all in the same flask. The general practice in foundries,
when many similar small castings are to be made, is to string
them on a gate, as it is termed. Saddlery, shelf hardware,
and small machine parts are made in this fashion. This
method is indispensable in the making of castings for inter-
changeable machinery, as castings can be made truer to pattern
when they are gated than when they are molded singly.
The process of gating is as follows: A single master pattern
is made with an allowance, perhaps, for finishing. From this
master pattern are made the requisite number of castings to
fill a flask. These castings are finished to the pattern size
and are then attached to a gate as shown at A, B, C, D, and
£, Fig. 126. They are arranged, according to the shape of the
casting, in such a manner as to permit the greatest possible
number to be placed in a flask, and they are also attached to
the gate in the best method for pouring.
When ready for use, a match-board is made of plaster of Par-
is or of litharge and sand mixed with linseed oil. This match-
board in appearance resembles the green-sand match-board
made in the upset, shown in Fig. 9. The match-board corre-
sponds to the cope as the pattern is placed on it, cope side
down, when molding is begun. The drag is rammed up over
the match-board exactly as in any other pattern, pockets
being secured with nails or soldiers in the usual manner. As a
rule, however, patterns which are gated in this fashion, are
so arranged that they may have the sand riddled on them and
164
FOUNDRY PRACTICE
be rammed up without any other work. After rolling over the
drag, parting sand is dusted on as soon as the match is lifted.
Should the match be any the worse for wear, a thin layer of
sand may adhere to the pattern. The gate should then be
rapped slightly to jar this sand loose, after which it may be
blown away with the bellows. As a rule, however, it is better
FIG. 126. — METHODS OF GATING PATTERNS.
to have a new match-board made than to work with one with
which this procedure is necessary.
A small hole is left at the center of the gate, being clearly
shown in the illustration. The gate-stick is set in this hole and
the cope is then rammed and struck off. The gate-stick is
withdrawn, but, before lifting off the cope, the molder places
a bar through the gate-hole in the pattern and raps it gently,
thus jarring the pattern loose in the cope and drag at the same
time. By doing this, the pattern is jarred an equal amount
in both cope and drag and the finished casting will be found to
be without evidence of a seam or parting at the joint. In
order that it may be possible to jar a pattern in this manner,
GATES AND GATING 165
the cope and drag must be tight, that is, they must have no
motion with relation to each other, due to the pins on the flask
being loose in the pin-holes. The gate of patterns is then
drawn from the drag without further rapping. This is usually
done by screwing a drawpeg in the rapping hole, or if the pat-
terns are gated many times, pins are provided in the pattern
for this purpose. Gates of patterns are seldom boshed in the
drag as, on the drag side, steady-pins, shown at G, Fig. 126,
are provided. These are round pins of small diameter, extend-
ing below the deepest part of the pattern to guide it wrhen the
pattern is drawn from the sand and thus avoid breaking the
sand and altering the shape of the casting. The object of ar-
ranging the pattern on gates is to have the pattern, when
drawn, leave a perfect mold, as there must be no stopping to
repair broken molds if the maximum output and quality of
castings is to be obtained. Patterns are gated usually for
machine work, in which case they are arranged so that they
can be attached to a vibrator in which compressed air is used
for rapping; a greater output is thereby obtained.
Patterns are often gated on 'match-plates as shown in Fig.
127. Where there are many castings to be made, half of the
pattern is mounted on one side of the plate and half on the
other, for the cope and drag respectively. The plate itself is
usually of cast-iron planed to one-quarter inch thickness. In
mounting the patterns, they are, wherever possible, finished
and the two halves are drilled through so that they will match
as desired. One-half of the pattern is then placed in the desired
position on the match-plate and used as a jig for drilling the
match-plate. The other half of the pattern is attached to
the opposite side of the plate and, the holes in the plate and
the two halves of the pattern being aligned, the two halves of
the pattern will correspond exactly in position writh each other.
The halves of the pattern are fastened to the match-plate by
pins extending through the pattern and the plate. The gate
is also attached to the drag side of the plate as shown at D in
Fig. 127. The patterns on either side of the match-plates
A and B in this illustration are alike, although this is not
1 66
FOUNDRY PRACTICE
necessarily a characteristic of match-plate patterns. For
instance, the pattern C differs on the two sides of the plate.
In molding with match-plates, the cope of the flask is
placed directly on the bench, joint side up. The match-plate
is set on the cope and the drag on the match-plate, the pins
of the drag extending through tight holes in the match-plate.
The arrangement of the flask and match-plate is shown at C,
Fig. 127. The drag is rammed up first, the bottom-board
FIG. 127. — GATING PATTERNS ON MATCH-PLATES.
rubbed to a bearing, and the entire flask rolled over. The
gate-stick or gate-pin is set, the cope rammed up, struck off,
and the gate-pin removed. The match-plate is rapped and the
cope removed, being guided off the pattern by the flask pins.
The match-plate is next removed, it also being guided by the
flask pins. Rapping the match-plate jars the sand alike in
cope and drag.
In foundries where compressed air is used, the air is usually
piped to the benches, so that in hand molding compressed
air may be used for vibrating all match-plate patterns, it
being possible to attach vibrators to any match-plate. Match-
plates also are commonly used on molding machines. It is
possible, by using match-plates, to increase the output of a
foundry to a remarkable extent when compared with single-
pattern molding handled one-half a pattern at a time. In
GATES AND GATING 1 67
making match-plates, it is usually best to cast the match-plate
with the patterns on it at the same time.
The process of casting the match-plate, with patterns on it,
is as follows: Consider the match-plate A, Fig. 128. The
patterns, ten in number, are split through the center, forming
a cope and drag half for each pattern. The drag halves are
placed on the mold-board in the position shown, joint side
down, and the drag is made and rolled over. The joint is
carefully made, and the cope is rammed up, the gate-stick
being set far enough away from the patterns to allow for mak-
ing a plate around them and gating into it. The cope is lifted
off and carefully finished, as much parting sand being removed
as possible. An upset or frame, of the thickness that is desired
for the match-plate, and of the same size as the flask with
which it is to be used, is placed on the joint of the flask and
around the patterns, and a frame, the size and shape of the
match-plate desired, is placed. This is shown at B. The sand
is then cut and roughed between the frames B and the sides
and ends of the upset, which has been placed on the joint of
the drag C. This keeps in position the sand that is built on
the top of the sand joint, between the drag and the frame B.
This sand is piled on by hand and struck off level with the top
of the upset on the joint of flask C, and the frame B forming
the match-plate, is then drawn from the drag.
The process consists essentially in molding the patterns in
the flask and, after drawing them from the cope and drag, of
deepening the drag by adding one-quarter of an inch of sand
at the joint. A mold of this character naturally requires
greater care in finishing than an ordinary mold, inas-
much as it is to form a casting, which will be used as a
master pattern, and any imperfections in this casting will
be repeated many times over in the castings made from it as
a pattern. In pouring this mold, one side is usually raised
slightly as shown, by the wedge K, so that the iron entering
the mold may fill one side first and flow up over the face of
the drag a little at a time. With this arrangement, hot iron
is always flowing down to meet the iron rising along the face
1 68 FOUNDRY PRACTICE
of the mold, and sharper castings are the result. Certain
shapes of castings are made better by permitting the iron to
flow in at the lower side of the mold and using a higher head
to force it up over the face of the mold as soon as possible.
Further details regarding gating and mounting patterns on
match-plates are given in Chapter XIX, on molding machines.
TYPES OF GATES
In addition to the arrangement of patterns, as described
above, the term "gating" is also applied to the method of lead-
ing iron into the mold. The arrangement of the gate is impor-
tant, as on it often depends whether or not a clean, sound
casting will be obtained. Fig. 129, I and 2 show the plan and
sectional elevation of a gate, arranged to clean the iron as it
flows into the mold and to prevent impurities in the casting.
Referring to the plan, a set gate is placed at either corner of
the pattern, being set in position when the pattern is first
laid on the mold-board. A short distance behind the set gate,
are placed the two skim gates A , which are provided with core-
prints for skim cores. The gate-stick is placed in the cope at B,
and when the cope is lifted from the drag the gate C is placed
in the cope. This extends from the gate B to each of the skim
gates and a channel is cut in the drag under the skim gate,
the sand being softened where the iron is to drop in it. The
channel is cut still further to connect the skim gate A with
the set gate and a core is set in the skim gate, being marked
"skim core" in the plan. The action of these various gates
is as follows: Iron being poured fast enough to fill or "choke "
the gate B, fills the gate C, which assists in restraining any
dirt in the iron. The iron entering gate A, shown in the plan,
and flowing underneath the core, is skimmed by the core and
the dirt is still further restrained. The round part of the
set gate continues this action and the iron, flowing through a
deep thin channel into the mold, has but little chance to carry
dirt or scoria with it into the mold. As dirt or scoria in iron
has a tendency to rise to the surface, the molder can, by
GATES AND GATING
I69
TOP VIEW OF JOINT,
'
^E
::>
-0
1
1
SIDE OF FLASK RAISED FOR POURING.
FIG. 128. — CASTING A MATCH-PLATE AND PATTERNS.
170 FOUNDRY PRACTICE
contriving his gates to present pockets or skimming arrange-
ments similar to the one described above, prevent a large
amount of these impurities from passing into the mold with
the iron. An arrangement sometimes used is similar to that
just described, with the exception that the skim gates are
omitted, the set gates being depended on to dam the iron
and thus hold back the scoria. It is, however, necessary to
keep the gate B choked, inasmuch as the scoria, being more
fluid than the iron, will flow along the surface of it if it is given
a chance to enter the cross gate, and thus get into the mold.
As a general rule, a shallow, wide gate will permit more
impurities to enter the mold than will a deep, narrow one.
The arrangement of the gates, shown in plan and elevation
in Fig. 129, i and 2, is shown in perspective at 3, and the
course of the iron can be traced through it. Many styles of
skim gates are on the market, some of them being patented.
A peg gate is shown in Fig. 129, at 4 and 5. This consists of
a basin cut in the cope, from which a number of small upright
gates extend down through the cope to a basin cut in the drag,
whence a wide gate allows the iron to enter the mold. Fig.
129, 6, shows a gate commonly used where it is not necessary
that the iron be kept particularly clean. This is mostly used
for such castings as building plates and general rough work.
It consists simply of the upright gate and a channel cut from
the bottom of this gate to the mold.
The horn gate is shown at 7. The uses of this gate are many.
In pouring small gears, it is used to bring the iron into the
mold, either over or under the teeth of the gear, as described
in Chapter II, and it is also used as a skim gate. As shown
in the illustration, the iron flows down the upright gate and
then through cross gates in either direction to the horn gates,
whence it enters the mold. As the iron flows down the semi-
circular portion below the mold, the upper surface of the gate
acts as a dam. The tendency of the dirt in the iron will be
to flow with it until the gate is filled at the bottom, and then
to back up in that portion of the horn gate adjacent to the
cross gate, thus permitting clean iron only to enter the mold.
GATES AND GATING
171
The flat gate used by stove and sink molders is illustrated in
Fig. 129 at 9. This type of gate is used for pouring thin
castings, such as stove tops and bottoms and similar classes
L
of work. On sinks, a number of these gates are used at one
time. As the thin castings cover a large surface, it is diffi-
cult to cut a thick enough gate in the thin edge of the casting
172 FOUNDRY PRACTICE
to properly fill the mold and at the same time one which will
break away from the casting, when cool, without breaking
with it a portion of the casting itself. Gates of this character
are also used with molds of cast-iron hollow-ware and with
building facers. They may be made of any desired width
but are narrow, not exceeding three thirty-seconds of an inch
at the point where they adjoin the casting. In pouring with
this type of gate, the iron is not poured directly into it, but
is allowed to strike at about the point marked A,
In molds where it is desirable that the iron enter near the
bottom, such as molds for steam cylinders, the type of gate
shown in Fig. 129, at 10 and n, is used. In making this gate,
two upright gates are laid in the drag, four or five inches from
the pattern, and between these and the pattern, the gates C
are placed. When ramming up the cope, two upright gates,
somewhat offset from those in the drag, are made, the relative
position of the two being shown at D and E. These are
connected by the channel G cut in the drag and a pouring basin
is cut in the top of the cope so that both gates E will be filled
at the same time.
In pouring rolls and large, round, solid castings, whirl gates
are used to give the iron entering the mold a whirling tend-
ency and thus throw any dirt in it toward the center, where it
can work out of the casting by means of a riser on top of the
casting. The whirl gate is usually made by causing the metal
to enter the mold at the circumference of the casting and at
a tangent to it.
The gating of a mold is a matter that must be left largely
to the judgment of the molder, depending on the character
of the mold, as many considerations enter this subject. The
temperature of the iron has considerable influence on the gat-
ing, since hot iron will flow faster than cool iron. The rapidity
with which the mold must be filled, depending on the char-
acter of castings, must also be considered. In certain types
of mold, the iron must enter at different places in order to
fill all parts of the mold properly. Castings wnich have both
heavy and light parts must often have separate gate? of
GATES AND GATING 173
different sizes leading to the parts of different weights. Where
a wide plate is to be cast, a gate may be cut across the entire
end of the casting, or along one side, and from this gate a num-
ber of ingates or sprues cut from it to the casting, so that the
iron will cover the entire surface of the mold rapidly.
In pouring some large molds with peg gates, from a basin,
it is customary to use iron balls with handles, dipped in thick
blacking and dried, to stop off each peg gate, one ball being
placed over each gate, when building the green-sand runner.
The iron is poured into the basin and first one ball and then
another is lifted to permit the iron to flow down through the
gates as desired. In this way the dirt is held in the basin,
clean iron flowing into the mold from the bottom of the basin.
CHAPTER XVI
RISERS, SHRINKHEADS, AND FEEDING HEADS
A RISER is a hole cut in the cope of a mold to permit the
iron to rise above the highest point of the casting. It serves a
number of purposes. It enables the molder to see when the
mold is filled and thus warns him when to stop pouring to
avoid straining the casting. It may be used to avoid pocket-
ing gas in a high part of the mold by being placed on this high
point of the casting. It may be used as a. flow-off , being placed
at the highest part of the casting. If metal is permitted to rise
and flow out of the mold, through this flow-off, a softer casting
will be produced, at the point where the riser is attached,
than would be the case were the metal permitted to simply
rise up and fill the mold. A riser placed near thin parts of
castings at the joints of molds, connected to these thin parts
by a gate, the iron being allowed to flow through these gates
into the riser, will often insure castings more nearly true to
the shape of the pattern than would be the case were the riser
omitted.
Large risers are used for shrinkheads or feeding heads.
Large bodies of iron, while solidifying, require a certain amount
of molten iron to be fed to them in order that the casting may
entirely fill the mold, inasmuch as iron shrinks when solidifying.
Feeding heads or large risers are provided with large gates
between the riser and the casting. The gate must be of such
size that the iron in it will not become solid before the casting
solidifies. It is essential that the iron be permitted to flow
freely from the feeder head to supply all deficiencies due to the
shrinkage of the iron in the mold.
Castings, up to a certain size, may be fed from feeder heads
by gravity, if the feeder or shrinkhead is properly propor-
tioned. With larger castings, a gravity feed would require
174
RISERS, SHRINKHEADS, AND FEEDING HEADS 175
a basin at the top of the riser of inconvenient size and to avoid
this and use a smaller riser, which may be easily broken from
the casting, pumping or churning is resorted to. The molder
will place on top of the casting, or at times alongside of it,
a riser of sufficient diameter to permit the entrance of an iron
rod. This riser is connected with the mold proper by a larger
gate. After the mold has been poured, the iron rod is inserted
in the riser and moved up and down and around the sides of
the riser. Molten iron is poured into the ris,er constantly,
and, by means of the rod, the hot iron is kept in motion in
the riser and gate and prevented from solidifying until after
the casting itself has set or frozen. As the casting shrinks in
solidifying, it draws on the liquid in the riser for sufficient iron
to make up the shrinkage and fill the mold completely. The
operation above described is known as churning or pumping.
When the pumping rod is first pushed down into the riser, care
should be taken not to allow it to come in contact with the
sand forming the bottom of the mold, and thus tear up the sand
which might find its way back into the mold and thus spoil
the casting. In moving the iron around in the riser, the
opening kept clear should be as large as possible. The churn-
ing rod should be struck every few moments with a short bar
of iron to prevent a ball of iron from forming on it at the point
where it enters the riser. If the casting is of such size that a
considerable time is required for churning, extra churning rods
should be provided for use when the ball forms, as it will do
eventually. The churning rods should be heated before use
to prevent their freezing the riser when they are inserted in
it. As the riser is to furnish hot metal to the rest of the cast-
ing, it must be kept hot longer than any other portion. In
churning large castings, it is advisable to fill the top of the
churning head with powdered charcoal to exclude the air
from the surface of the iron.
CHAPTER XVII
TREATMENT OF CASTINGS WHILE COOLING
OFTEN castings which have been molded and poured cor-
rectly are found to be warped and distorted on their removal
from the sand. This may be due either to improper design or
to improper treatment of the casting before it is removed from
the sand. If a heavy part of the casting immediately adjoins
a light part, the latter will solidify first and the heavy portion,
cooling later, will shrink and tend to draw away from the
lighter portion. If the casting does not rupture in this
operation, strains may be set up which will warp the casting
out of shape and thus render it worthless. This contingency
may often be avoided by exposing the heavier part of the
casting to the air, thus making it cool more rapidly while the
cooling of the lighter portion is retarded, the entire casting
thus becoming solid at about the same time. Shrinkage
strains are thereby avoided and the casting is removed from
the sand true to pattern. The cooling of the lighter parts is
retarded often by covering them deeply with sand at the same
time that the heavier parts are exposed to the air.
Oftentimes it can be predicted from the shape of the pattern
the method in which it will cool and the extent to which it will
be distorted if allowed to cool normally. This distortion can
be avoided and the effects of unequal cooling counteracted by
distorting the pattern in the opposite direction an amount
equal to that distortion it would assume in normal cooling.
Thus, in casting columns, the pattern is made with the ends
relatively lower than the middle portion. The mold is made
with the middle of the column higher than the ends which cool
last. They are thus thrown up as the casting cools and if the
right amount of camber has been given to the pattern the
column will be perfectly straight when cold. The same
176
TREATMENT OF CASTINGS WHILE COOLING 177
method is followed in casting the copings for the top of brick
walls. Cornice work for buildings is usually molded with a
camber in the same manner. The castings are usually made
with lips at the edges, for bolting together, combined with
moldings. The lips on the edges of the plates are often on
opposite sides of each edge, and the pattern is arranged on the
mold-board crooked in the opposite direction from which it will
crook when cooling. Thus one edge will be crooked in one
direction and the other in the opposite direction and when the
casting is cold these edges will be straight and parallel. Lathe
beds, up to fourteen feet in length, are molded with a camber,
as the ends tend to rise in cooling. A lathe bed thirty feet
long, however, is so heavy that the casting in shrinking will
not lift the ends and therefore these beds are cast with the
center down.
Many castings of different lengths must be kept covered at
the ends in cooling while the sand is dug away from them at the
center. Often if a casting is of such size and shape that it must
be left overnight in the sand it is advisable to dig the sand
away from around the gates. This is to permit the casting to
shrink while cooling without being held by the gates, and
thereby having a piece at or near the gates torn out or a crack
started due to the rigidity of the structure held in one position
by the gates.
In certain classes of work it is not sufficient to retard the
cooling of the thin parts. An artificial supply of heat must
be provided. Such a case is the casting for a disk crank of a
stationary engine which consists of an engine crank surrounded
by a web, the crank and counterbalance being hidden on
the inside by a plate. This casting is molded with the plate
face down and the pockets of sand to form the crank and
counterbalance are lifted out with the cope. After pouring,
the cope is lifted as soon as possible and the sand dug out of
these pockets, leaving only enough sand in them to protect the
casting. Molten iron is then poured into these pockets or pig
beds and covered with sand, after which the cores in the hub
and crank-pin hole are dug out. Thus the thinner portions
178 FOUNDRY PRACTICE
are continuously supplied with heat until the entire casting
has cooled uniformly. If this precaution is not adopted, the
crank disk will either be found cracked when it is taken from
the sand or strains will be set up which will cause the disk
to fail when it is forced on the engine shaft by hydraulic
pressure.
Castings of U-shaped section should be gated together at
the top, as in cooling the tendency is for the bow to cool first
and thus draw the legs of the casting apart, which tendency is
resisted by the gates, which cool first. If it is impossible to
gate the casting in this manner, the bow portion should be
uncovered at the earliest possible moment while the legs of the
U should be kept covered and their cooling retarded.
Pulleys for power transmission, with thin rims, should have
the center core removed as soon as the metal has set, especially
if the pulley is of large diameter. Often a pulley that is re-
quired in a hurry is removed from the sand while the hub is still
red-hot. This condition of affairs will cause a heavy strain
on the arms and will frequently pull them from the rim. To
avoid this condition the sand is dug away from the cope over
the hub as soon as possible and water poured into the hole
formed by the core. The rim and arms are kept covered and
the heat retained in them as long as possible. Large fly-wheels
and balance-wheels are often cast with the hubs split by means
of cores, the rim being cast solid. As the rim contracts the
two parts of the hub are forced together and cracking of the
arms and rim is avoided. Conversely to the above cases, if
the rim is heavy and the center comparatively light the rim
must be uncovered and cooled more rapidly than the center.
Plates cool first at the edges and frequently are found
checked. This condition can be cured by removing the cope
as soon as the casting has solidified, knocking the sand from
the cope down on the casting and cutting channels in it diago-
nally across the plate from opposite corners, thus permitting
the center to cool in advance of the edges.
Where castings are made with heavy rigid cores in them
they may be ruptured by shrinking on these cores. Thus,
TREATMENT OF CASTINGS WHILE COOLING 179
jacketed cylinders having light jacket walls and heavy barrels
must have the cores removed promptly to prevent the barrel
cracking away from the jacket. Cored cylinders frequently
have internal strains set up in them by shrinking on the cores,
and when the first roughing cut is made on them in the ma-
chine-shop these strains are relieved and warp the casting,
which as a result must be annealed.
In situations where a circle of iron of one thickness has
another circle of greater thickness cast inside it, there is con-
siderable danger of cracking owing to the thicker circle cooling
last and pulling away from the lighter outside one. To offset
this tendency considerable ingenuity is sometimes required.
Usually there is one particular spot in castings of this character
which always gives trouble and, in a certain case, this was
obviated by placing a chill at a particularly heavy part and
chilling the iron as it was poured so that it cooled relatively
faster than at the other portions of the casting.
In loam molds, provision for shrinkage is made by inserting
in the mold loam bricks which crush under the contraction of
the metal, and also by the insertion of iron plates in the mold
which can be pulled out as soon as the casting is poured and
thus provide ample space in which the metal may shrink.
The larger the casting and the faster the cooling, the greater
is the relative contraction, and this must be borne in mind
when making the mold, in order that proper provision may be
made for taking care of this contraction.
After the casting has been removed from the sand, care
must be exercised in its treatment until it has cooled down to
room temperature. A large casting which may be exposed to a
chilling draft on one side, such as might come from a door
communicating with outdoors in the winter time, would cool
more rapidly on that side than on the other and thus crack
just as surely as it would in the mold had no provision been
made for crushing the cores. Printing-press cylinders exposed
to unequal temperatures on opposite sides are especially liable
to warping.
The composition of the iron of which the casting is com-
I8O FOUNDRY PRACTICE
posed also has an influence on its treatment after pouring.
Light castings of machine parts are usually removed from the
sand immediately after the mold is poured. These castings
are high in silicon and lowin sulphur, manganese, and combined
carbon. A coating of sand frequently adheres to such castings
in proportion to the thickness, protecting them from the air.
However, if air does come in contact with the casting, the
high silicon and the high graphitic carbon content prevent the
formation of a hard scale. On the other hand, if the sulphur
and manganese contents are high the reverse will be true and
a hard scale will form on the castings if the air is permitted to
strike them before they have cooled to room temperature. It
is therefore advisable to leave them in the sand until they are
cold, especially if they are to be machined later. Should it be
necessary for any reason whatever to remove them from the
sand promptly they should be poured with iron of a silicon
content about twenty points higher than ordinarily.
The thinner the wall of the casting to be machined the
greater is the danger of removing it from the sand too quickly
and of forming on the surface of it a hard scale. When un-
covering such castings, to equalize the cooling, a small amount
of sand should be allowed to remain on surfaces which are to
be machined. This will prevent direct contact with the air
and thus avoid scale and yet will permit the rapid escape of
heat.
Castings which are found to be crooked on removal from
the sand may be straightened by heating them to a red heat
and then weighting them so that the casting will be bent in
the opposite direction. Lathe beds and similar castings may
be treated in this manner, the ends being placed on solid bear-
ings, the casting arching upward and being heated at the
center until it is red hot, after which it is weighted and allowed
to cool. Many times castings may be straightened by peen-
ing on the hollow side, thus closing the grain of the iron and
forcing the ends down.
CHAPTER XVIII
CLEANING CASTINGS
FOR cleaning castings from the sand which adheres to them
after pouring, three general methods are in use : rattling them
in a tumbling barrel, pickling, and sand blasting. In rattling,
the castings are placed together in a horizontal barrel which
is revolved and the castings fall over and over and against one
another, and the sand and scale are gradually pounded from
the surface. This method, however, produces a hard skin on
the surface of the casting which renders it more difficult to
machine, and pickling in sulphuric, muriatic, or hydrofluoric
acid is more generally resorted to for castings which are later
to be subjected to machine processes. Sand blasting consists
in directing against the casting, by means of air under a pres-
sure of from sixty to one hundred pounds per square inch, a
jet of sharp sand which abrades not only the burned sand but
also the hard surface of the casting.
In rattling, the castings are placed in the barrel until it is
nearly full, together with "stars" or "picks," which are small,
irregularly shaped pieces of hard iron, and the barrel closed
and revolved. The castings falling on each other and on the
"stars" knock from the surface all the burned sand and scale
and polish each other. In rattling together such castings as
legs for machines it is advisable to pack the castings in with
blocks of wood to hold them apart and allow the "stars" to
do the abrading and polishing when the barrel is revolved.
Heavy castings of this character are liable to become broken
if placed in the barrel loose. If the barrel is not well filled with
castings it is advisable to fill the remainder of the space with
blocks of wood if the castings are of light character.
For many purposes rattling is insufficient to clean the
casting properly. If a casting has been made in raw sand with-
181
1 82 FOUNDRY PRACTICE
out any facing, the sand will apparently be burned on it.
Rattling will not remove this burned sand properly and pickling
is necessary. The pickling bath is placed in a stone or wooden
trough and may consist of sulphuric acid diluted in the propor-
tions of one part acid to seven parts water, or of muriatic acid
and water, or one part of hydrofluoric acid to twenty parts of
water. The castings should remain in the pickling bath
about twelve hours and then should be well washed with clear
water. As much of the sand as possible should be removed
from them before placing them in the bath. Gears are cleaned
best by first subjecting them to a sand blast, which loosens the
sand in the corners of the teeth, and then pickling them.
The following information concerning the use of hydro-
fluoric acid is given in a pamphlet issued by the General
Chemical Company. "Until quite recently castings have been
cleaned either by mechanical means or by dilute sulphuric
acid. Sulphuric acid loosens the sand by dissolving the iron
from under it. On the other hand hydrofluoric acid dissolves
the sand itself, and therefore acts morfe promptly, takes much
less acid, and does not cause a loss of iron. For cleaning cast-
ings that are to be galvanized, tinned, enameled, nickel-plated,
or painted, hydrofluoric acid is vastly superior to sulphuric or
muriatic acid because it leaves a purer metallic surface and
does not rust the plating or work through the paint. Hydro-
fluoric acid dissolves more readily than sulphuric or muriatic
acid, the ordinary rust and magnetic (black) oxide that forms
on the surface of heated iron. The strength at which the acid
is used varies with the kind of iron to be cleaned and the time
in which it is to be finished, but generally it is used in the
proportions of one gallon of acid to twenty or twenty-five
gallons of water. The acid should be poured into the water
and well stirred. Such a solution will clean ordinary castings
in from one-half hour to one hour. If used of half this strength
— one gallon of acid to fifty gallons of water — it will take
several hours. Hydrofluoric acid is used cold, but should be
kept above the freezing point. The bath can be used re-
peatedly by adding about one-third the original quantity of
CLEANING CASTINGS 183
acid before charging again with iron. If it is desired to keep
the iron bright it should be washed with water at about
200° Fahr. immediately after coming out of the acid so as
to dry quickly. By this means all trace of the acid is eradi-
cated and all chance of corrosion or tarnish resulting is ob-
viated. If washed with cold water the casting will remain
wet for some time and rust. A little lime may be added to
the wash water. For immersing and removing castings from
the bath, wooden boxes with holes in the sides have been used
with good results. By this means the sand is retained at
the bottom of the boxes and is removed with the castings, thus
saving the strength of the acid when not in use. Spent, weak
acids should be discarded and the tanks cleaned every month.
In removing stoppers from vessels containing the acid, care
should be exercised, as sometimes gas is generated from the
action of the acid on the lead in which it is enclosed which
may cause some of the acid to be thrown out if the corks are re-
moved hastily. The acid is neither explosive nor inflammable.
As strong acid will cause inflammation wherever it comes in
contact with the skin it should be handled as carefully as other
acids. Rubber gloves are the best protection, but if acid has
splashed on the skin it should be washed off with water and
diluted borax or sal soda solution, or with aqua ammonia
which will prevent injury,"
CHAPTER XIX
MOLDING MACHINES
WHERE there are a number of molds to be made from one
pattern, it is frequently advisable to use a molding machine
for this purpose. Molding machines are made in a number
of varieties, each designed for some specific purpose. Thus we
have the power squeezer and the hand squeezer, the split-pattern
squeezer, the jarring machine, also known as a jolt rammer, and
the roll-over machines, which are made to operate entirely by
hand, or to use power for rolling over and drawing the pattern,
the ramming being done by hand, or to use power both for
ramming and for rolling over and pattern drawing. Each
machine has its particular field in which it will do better work
than one of the other types.
Where the ramming time is a large factor in the time
required to make the mold, one of the squeezer machines or
jarring machines is advisable. However, if the mold is such
that the finishing time is the largest factor, a machine which
will draw the pattern should be adopted. This brings us to
the split-pattern machine which, however, is limited in its
application to patterns which can be split on a true plane
and molded one-half in the cope and the other half in the drag,
or to one of the roll-over machines operated either by hand
or by power. In selecting the machine to save ramming time
the character of the mold to be made is the chief considera-
tion. As the squeezer machine packs the sand to the density
required for the mold by pressure applied at the outside sur-
face of the mold, it is not well adapted to molds having deep
bodies of sand, since in this case the sand will have the greatest
density at the outer surface instead of against the pattern as is
required. On the other hand, the jarring machine in which
the sand itself forms the ramming medium is well adapted to
molds in which there are large pockets of hanging sand.
184
MOLDING MACHINES 185
Having thus considered the general properties of molding
machines, we will now consider each type in detail. First in
the list is the hand squeezer. This consists simply of a frame
carrying a yoke, a plate on which the mold-board is set and
which can be elevated toward the yoke by means of a hand
lever operated by the molder. The flask is placed on the
mold-board with the pattern in it in the proper position and
sand is riddled over the pattern until it is covered. Sand
from the heap is then shoveled in and struck off flush with the
top of the flask, a bottom-board fitting within the flask is
placed on top of the mold and the whole contrivance elevated
against the yoke by means of the hand lever. This operation
compresses the sand in the flask to the required density and
the mold is then lowered to the original position, turned over,
and the pattern drawn. It may be drawn either in the usual
manner by means of a draw-nail which is rapped by the
molder, or the pattern may be mounted in a vibrator frame as
described later and vibrated by means of compressed air
while it is being drawn. This latter method gives much the
better molds.
Power Squeezers. — Of much greater capacity and scope
is the power squeezing machine shown in Fig. 130. This is
a machine designed especially for molding light snap-flask
work. It consists of a yoke carried between two uprights,
the yoke being adjustable to suit varying depths of flasks;
a power cylinder for elevating the table of the machine on
which the mold-board and the flask are mounted; a lever for
controlling the admission of air to the power cylinder, and a
connection for operating the vibrator by compressed air.
The yoke in the type of machine illustrated is mounted on
trunnions enabling it to be swung back out of the way for
placing and removing the flasks and the molds on the table.
The patterns are usually mounted in vibrator frames or on
match-plates to render the operation of drawing them easy
and accurate. Machines of this character require about four
cubic feet of free air per minute for their, operation.
The operation of making the mold on this machine with
1 86 FOUNDRY PRACTICE
the patterns mounted on a vibrator frame is as follows: A hard-
sand match is formed, on which patterns mounted in a vibrator
frame are set. This match is placed on the table of the
machine and the drag portion of the flask set in position and
sand riddled over the pattern until the latter is covered.
Sand is then shoveled in until the flask is filled, the excess
sand being struck off with the bottom-board, which is next
placed over the flask and the yoke of the machine is drawn
forward to its vertical position. Air is then admitted to the
power cylinder and the table elevated, thus squeezing the
sand in the flask against the yoke. The air is exhausted from
the cylinder and the mold lowered to its original position,
the half-flask pattern and hard-sand match then being rolled
over. The match is next removed, after which parting sand
is shaken on the mold and the cope half of the flask put in
place, filled with sand, and squeezed in the same manner as
the drag. This completes the ramming operations and the
sprue is cut with a brass tube used as a sprue cutter.
The vibrator is now started and the molder grasping the
cope by its handles lifts it from the drag. The snap flasks
used with these machines have accurately fitted pins of con-
siderable length which act as guides when the pattern is drawn,
the vibrator frames or match-plates having ears which fit
closely to these pins, thus being guided vertically upward
from the mold. After the cope has been lifted off and set aside,
the vibrator is once more started and the pattern is drawn by
lifting the vibrator frame in its guides. The pattern being
drawn, the mold may be closed, the snap flask removed, and
the mold set on the floor ready for pouring.
To make hard-sand match to use with the vibrator frame,
the latter is put in the cope flask and rammed up. The part-
ing is made in green sand and lycopodium is dusted on the
parting between the green sand and the preparation forming
the match. The match frame which is beveled to hold the
match in place is set over the pattern and clamped firmly so
that it cannot move during the ramming operation. The
portion of the pattern projecting into the frame is rammed
MOLDING MACHINES
FIG. 130. — POWER SQUEEZER MOLDING MACHINE.
1 88 FOUNDRY PRACTICE
up exactly as would be done for bench molding, with sand
made up of fifteen pounds of new burnt molding sand, riddled
through a No. 30 sieve, into which has been kneaded a mix-
ture of one quart of boiled linseed oil and four ounces of
litharge. The match and the green-sand half-mold are rolled
over and the cope taken off. The pattern is drawn and any
parts of the match which may have broken in drawing are
mended, after which the match is dried in a warm place for
about twelve hours when it may be coated with thin shellac.
Instead of using a hard-sand match, aluminum match-plates,
with the patterns cast one-half on either side of the plate,
may be used, especially if the patterns have an irregular part-
ing and exceptionally good castings are required. The ad-
vantage of these aluminum match-plates is that the whole mold
may be squeezed at one operation and, furthermore, there is
no possibility of the cope and drag shifting in relation to one
another. To make an aluminum match-plate, a mold of the
patterns is made in a flask large enough to accommodate the
size of plate necessary. Master patterns should be used which
have been made with the proper allowance for shrinkage and
finish. Great care should be taken in making this mold in
order to avoid any unnecessary finishing in the plate. Strips
of wood the thickness of the plate required are placed on the
parting of the drag before the mold is closed and a false part-
ing of sand built up to the level of these strips. The strips
are then removed, the mold is closed and poured, after which
the plate may be finished with a wire brush or scraper. After
attaching suitable handles and guides to the ends, the plate is
ready for use.
To make a mold by means of this plate, the flask is put
together on the table of the machine with the plate between
the two halves, the drag side being uppermost. Parting
sand is dusted on the plate and the drag filled with sand, the
first portion being riddled in until the patterns are covered.
The bottom-board, being used first to strike off excess sand, is
placed in position, after which the flask is rolled over, the cope
filled with sand, and the mold squeezed. The cope is then
MOLDING MACHINES 189
lifted off, the vibrator being used, after which the pattern
plate is also lifted. The sprues having been cut before lifting
the cope, the mold may now be closed ready for pouring.
Instead of the two methods above described, paraffine
boards may be used for mounting the pattern where there are
not a great number of molds to be made from one set of pat-
terns. They are especially desirable in flat-back work or for
split-pattern work. The paraffine board is usually made of
oak and is boiled in paraffine for forty-eight hours to prevent
it warping in contact with damp sand. It is mounted in a
vibrator frame and the patterns fastened to it by means of
wood screws, having first been located in position by means of
dowel pins. Where castings are to be made from split-pat-
terns in large quantities, a three-sixteenths inch steel plate
may be used. The patterns are mounted one-half on each
side of the plate and the entire mold is squeezed at one time
as is the case with aluminum match-plates. In mounting the
patterns, the corresponding halves should be finished together
so that they will match at the parting. A hole should be
drilled and slightly countersunk before the two halves are
separated. After separation, one half should be laid in the
desired position on the steel plate and used as a jig in drilling
the latter. After the drilling is completed the corresponding
half-patterns should be placed on the opposite side of the plate
and the two parts riveted to the plate by means of a brass rod
inserted through the drilled holes and riveted into the counter-
sink.
The illustration, Fig. 131, shows the method of suspending
patterns in a vibrator frame. A carrier of sheet brass one-
eighth inch in thickness is soldered or sweated to the pattern,
being attached to the runners if possible. Carriers are then
rigidly fastened to the vibrator frame by first inserting them in
a slot in the frame and drilling two three-sixteenths-inch holes
through both frame and carrier and fastening them together
by means of a snugly fitting brass pin. The pattern is next
placed in the vibrator frame and holes drilled in the carriers
on the pattern. The carriers on the pattern and those in the
190 FOUNDRY PRACTICE
frame come together, and the carriers in the frame are drilled
to correspond with holes already drilled in the carriers on the
pattern. The slot in the vibrator frame should then be filled
with wax to prevent the mold from crumbling at the edges.
The vibrator is simply a small compressed-air hammer
striking a large number of blows of uniform intensity per
minute, the head of this hammer being attached to the vibrator
frame or match-plate to communicate the blows of the hammer
to the pattern. The blows are such that the size of the mold
is not enlarged to any extent, but they simply overcome the
friction of the pattern against the sand, and enable the drawing
of a pattern which has no draft.
Split-Pattern Machines. — Fig. 132 illustrates a special
type of molding machine adapted for split- pattern work. It
is especially adapted to patterns which are symmetrical, in
which case both cope and drag may be molded from one
pattern plate containing a double set of half-patterns, those
on one side of the mold in the cope matching those on the
opposite side in the drag. In using this machine it is cus-
tomary to make as many drag portions of the molds as may be
required, placing them on the floor in position for pouring, after
which the copes are formed and closed on the drags. If cores
are required in the mold, they are, of course, set before the
copes are made. It will be observed that the machine is
similar in appearance to the power squeezer described above.
It is, however, provided with an arrangement for drawing the
pattern either by hand or power and also either by raising
the mold away from the pattern or by drawing the latter down
through a stripping plate.
To make a mold on this machine, the patterns, which are
mounted on a steel plate, are set on the table of the machine,
the flask placed around them, being accurately located by
means of dowel pins on the machine, and it is filled with sand
and squeezed in the usual manner. After squeezing, the mold
is lowered to its original position and the vibrator started.
The operator then presses down on a pattern-drawing lever,
if a hand-draft machine, or admits air to the drawing cylinder,
MOLDING MACHINES
FIG. 131. — I, Mounting Patterns in a Vibrator Frame; 2, Hard-Sand
Match for Same Patterns; 3, Cope of Mold Made from these Patterns;
4, Drag of Mold.
I Q2 FOUNDRY PRACTICE
if a power-drawing machine, which elevates the outer portion
of the table on which the flask is carried clear of the patterns,
when the half-mold may be removed from the machine and set
on the floor. The operation of making copes and drags on
this machine is similar, except that in the case of copes
the location of the sprue is indicated by a button on the
bottom board which' marks a depression in the sand where the
gate is to be cut by means of the sprue cutter. When used
with a stripping '' plate, the patterns are drawn downward
through the stripping plate, the mold remaining stationary.
The illustration, Fig. 133, shows the method of stooling
patterns molded on this type of machine where there are large
bodies of hanging sand which would be liable to drop when the
pattern is drawn. Such bodies are those forming the green-
sand cores of the stuffing boxes in the illustration. A hole is
cut in the pattern plate the exact size of the green-sand core
or through the pattern and pattern plate according to the
requirements of the case. A stool, made usually of cold-rolled
steel and of the exact size of the core, is attached to a stool
plate underneath and in exact alignment with the holes in the
pattern plate. When the mold is elevated to draw the pattern
the steel plate rises with the tables of the machine and the
stools support the hanging green-sand cores as shown until
they are entirely clear of the pattern.
The mounting of the two halves of a symmetrical pattern
for use in a split-pattern machine is a job requiring considerable
care and great accuracy. The recommended method is the
use of a transfer plate. The first operation is to make a
pattern plate for the machine and drill in it two dowel holes
located on the center line of the plate. The halves of the
various patterns are doweled together before finishing, after
which they are numbered and separated. The halves without
dowel pins are arranged on one side of the pattern plate and
used as jigs to drill that side of the plate. A transfer plate
somewhat wider than half the width of the pattern plate is
next made by first drilling holes to match the center-line holes
of the pattern plate. Transfer and pattern plates are now
MOLDING MACHINES
193
FIG. 132. — SPLIT-PATTERN MOLDING MACHINE.
194
FOUNDRY PRACTICE
fastened together, being located with reference to each other
by means of dowel pins in the center-line holes. Using the
pattern plate as a jig, holes are drilled in the transfer plate
to correspond with those drilled in the pattern plate, after
which the transfer plate is turned over, not around, so that
what was its upper surface is now its lower one and it is once
FIG. 133. — STOOLING PATTERNS ON A SPLIT-PATTERN MACHINE.
more placed on the pattern plate, the dowels inserted in the
center-line holes, and it is used as a jig to drill the holes in the
undrilled side of the pattern plate. The two sets of holes in
the pattern plate will thus be symmetrical around the center
line, and when the half-patterns are doweled to this plate
molds made from them will match perfectly.
Jarring Machines. — For large deep work in which the
ramming time is of considerable importance, or for large cores,
the jarring machine is of especial importance. This machine
MOLDING MACHINES IQ5
requires heavy flasks and large quantities of sand. It consists
essentially of a table of massive construction which may be
elevated any desired distance by means of air pressure and
then suddenly dropped. The pattern, flask and sand are
carried on this table, which when it is dropped falls more
rapidly than do the former. The inertia of the sand and
flask striking the table after the latter has come to rest causes
the sand to be firmly packed in the mold. The density to
which the sand can be packed varies with the length of drop
and the efficiency of the machine increases with the drop and
decreases with the dead weight handled over and above the
weight of the sand. The machine, to secure best results, must
be solidly constructed in the table, and in operation there must
be no movement between the pattern, sand, and flask which
will tend to pull the sand apart or to fracture the sand into
various layers. Badly fitted pattern boards or patterns which
are too light for their work, flasks which are crooked, or a light
table on the machine will tend to cause such fractures. In
ramming a mold on this type of machine it is only necessary
to place the pattern in position, set the flask around it, riddle
sand over the pattern, and open the air valve. After the
table has been given a sufficient number of strokes to ram the
sand to the proper density, the mold may be removed and
finished by any of the approved methods.
The latest development in connection with the jarring
machine is the shockless jarring-machine, a cross section of
which is shown in Fig. 134. This is a machine in which the
impact of the mold on the table is absorbed within the machine
itself instead of being transmitted to the foundation and thence
to the surrounding floors and buildings. One great disad-
vantage of the plain jarring machine is, that in ramming large
molds, involving heavy masses of sand, vibrations are set up
for a considerable distance around the machine and these
vibrations are not only disagreeable to the workers but may
also shake down the sand in completed molds, thus doing con-
siderable damage. These vibrations in the case of the machine
under consideration are eliminated by means oi an anvil
196
FOUNDRY PRACTICE
mounted in a cylinder and supported on long helical steel
springs. The table is elevated by compressed air admitted
to the jarring cylinder to raise the table. At a predetermined
point in the table movement, the air is automatically cut off,
and expanding, raises the table still further. The air from the
jarring cylinder exhausts into the anvil cylinder and the jarring
table falls by gravity. At the same time, the anvil being re-
FIG. 134. — SHOCKLESS JARRING MACHINE SET UP IN PIT.
lieved of a considerable portion of its load, is thrown upward
by its supporting springs to meet the falling table. The
velocity with which it rises is increased by the air expanded
from the jarring cylinder into the anvil cylinder. The anvil
and the table are brought to rest by their impact upon each
other, giving great ramming effect upon the sand but without
giving vibration to the surrounding floors, the vibrations being
absorbed by the springs and air under the anvil. Machines
MOLDING MACHINES 197
of this character are built to ram molds weighing as much
as 50,000- pounds.
Roll-over Machines. — A roll-over machine in which the
pattern, flask, and mold are rolled over and the pattern drawn
by hand is shown in Fig. 135. The great advantage of the
roll-over machine is that it is portable and follows up the sand
pile as it is consumed, leaving behind it completed molds as is
FIG. 135. — PLAIN HAND ROLL-OVER MACHINE.
done in hand molding. It is especially valuable for making
intricate molds from straight patterns with little or no draft,
and avoids entirely any patching or finishing of molds. A
typical pattern molded on a roll-over machine is a grate-bar
pattern forming about one hundred and fifty deep green-sand
cores. This would be a most difficult mold to make and draw
by hand and the time required for finishing would be no small
item. However, with the roll-over machine, patching and fin-
ishing of the mold is the exception and the output of such a ma-
chine on work of this character far exceeds that of hand molding.
The machine consists essentially of a frame on which the
mold-board with the patterns is attached. This frame is
carried on trunnions, which in turn are supported on sliding
198 FOUNDRY PRACTICE
frames mounted on accurately machined guides. The frame
can be revolved about these trunnions through a half-circle in
order to roll the mold over and bring it in position for drawing
the pattern. This latter operation is accomplished by means
of a lifting lever which raises the frame with the mold-board
and pattern attached vertically upward, it being guided by
the sliding frames working on the guides before mentioned,
thus enabling parallel patterns to be drawn without the aid
of draft. Should by any chance any portion of the mold
become broken in drawing the pattern, the guides enable the
patterns to be replaced in the mold with exactness, after which
the mold can be mended much more quickly and satisfactorily
than otherwise.
In molding with this machine, the pattern board is placed
on the hinged frame and clamped to it. The flask is then
placed on the pattern board, its location being determined by
pins on the latter. The flask is then filled and rammed as
in floor or bench molding and the mold struck off. The bottom-
board is then next rubbed on the mold and clamped to the
pattern board. The hinged frame is then rolled over until the
bottom-board rests on the equalizing cradle. The pattern-
drawing lever is next drawn down until the stops on the
hinged frame engage the stops on the frame of the machine
and the flask is allowed to settle by gravity on the cradle.
The clamps are then released and the vibrator started, after
which the pattern is drawn by lifting the pattern board clear of
the mold by means of a pattern-drawing lever, the frame and
pattern board being guided vertically upward by means of a
guide on the machine. As soon as the pattern is clear of the
mold, it is rolled back to its original position, a new flask placed
on the machine, and the operations repeated. An advantage of
this type of machine is that it can be kept at work continuously,
as the completed mold can be removed by a couple of laborers
at their convenience while the molder is ramming up the new
mold. The occupation of the cradle by the completed mold
does not interfere in the least with the operations of the molder
in making a second mold.
MOLDING MACHINES
199
When the molds to be made on this type of machine
become of large size, it is beyond the ability of the molder and
his helper to roll over the heavy flask full of sand by hand, or
to withdraw the pattern by hand. In such cases a power
cylinder operated by compressed air is added, as shown in
FIG. 136. — POWER ROLL-OVER AND POWER DRAFT MOLDING MACHINE.
Fig. 136, to perform these operations. Otherwise the making
of the molds is carried on exactly as before. A still further
development of this type of machine is the addition of a
jarring machine to the power roll-over attachment, for ram-
ming the molds. This combination givec a machine of the
2OO
FOUNDRY PRACTICE
TABLE I — DESCRIPTION' OF OPERATION MOLDING DRAG AND COPE
(PART OF PLOW)
Flask 13" x 17". 4" Drag, \\" Cope. Hand Molding at Bench
Detailed Instructions
Element Time
per Piece Hand
Mold
1 I Preparation
2 I
3 i
4 Pick up hard-sand match and put on bench I 0.04
5 Pick up pattern and put on hard-sand match o . 04
6 Pick up drag and put in place o . 07
7 Shake parting on pattern 0.08
8 Pick up riddle and put on flask o . 02
9 Fill riddle with sand, one shovel full 0.04
10 Riddle sand on pattern 0.08
11 ! Fill drag with sand (three shovels full) 0.08
12 Peen around edge of drag and butt ram some.1
(With shovel butt.) | o. 10
13 j Put two more shovels full in drag 0.06
14 i Butt ram o . 30
15 j Strike mold off with bar, %Xi X3& in. long o. 10
1 6 j Pick up bottom-board and place in position 0.08
1 7 : Roll mold over o . 08
1 8 Remove hard-sand match 0.07
19 Blow sand off mold (with bellows) o . 07
20 Repeat operations 6 to 10 inclusive for cope o. 29
21 Fill cope with sand, 4 shovels full o. 10
22 Repeat operations 12 to 15 inclusive for cope 0.56
23 Mark sprue hole. (With cope board.) 0.05
24 (Cut sprue hole 0.12
25 Rap pattern. Spike going through sprue hole into
pattern o . 49
26 Round sprue | o.io
27 Remove cope mold . ' o . 09
28 Blow pattern off with bellows | o . 09
29 Draw pattern from mold by hand I °-45
30 Patch up mold. (With slick.) j o . 30
3 1 Close mold 0.12
32 i Remove snap flask from mold o . 07
33 Remove mold to floor o . 07
4.20
I Number four riddle
Weight of shovel. ... ...... .'.".' .' . ... . . . . . "5 Ibs.
Weight of sand 16 Ibs.
Total weight 21 Ibs.
MOLDING MACHINES
201
TABLE II — DESCRIPTION OF OPERATION MOLDING DRAG AND COPE
(PART OF PLOW)
Flask 13" x 17". 4" Drag, 4!" Cope. Power Squeezer
Detailed Instructions
Element Time
per Piece Mach.
Mold.
Preparation
Pick up hard-sand match and put on table of
machine 0 . 04
Pick up pattern and put on hard-sand match 0.04
Pick up drag and put in place o . <
Shake parting on pattern o . <
Pick up riddle and put on flask o . 02
Fill riddle with sand o . <
Riddle sand on pattern o .
Fill up drag (three shovels full.) 0.08
Peen around edge of drag. (Butt of shovel.) .... 0.05
Strike off with board and put in place 0.07
Bring yoke over and squeeze (sixty Ibs. pressure.).. . 0.06
Roll mold over. (On table.) . 0.08
Start vibrator and remove hard-sand match o . 03
Blow off with compressed air 0.05
Repeat operations from 7 to 1 1 inclusive for cope. . o. 29
Fill up cope, four shovels o. 10
Repeat operations 13, 14, and 15 for cope o. 18
Remove cope board o . 03
Blow mold off with compressed air o . 05
Cut sprue hole o . 08
Start vibrator and lift cope 0.12
Blow mold off with compressed air o . 05
Start vibrator and draw pattern o. 10
Close mold 0.12
Remove flask o . 07
Stop off carrier o . 06
Place mold on floor o . 06
2.10
Number four riddle
Weight of shovel 5 Ibs.
Weight of sand 16 Ibs.
Total weight 21 Ibs.
2O2 FOUNDRY PRACTICE
highest efficiency and one which saves in not only the ramming
but the finishing time, and which has an output far in excess of
anything possible by other means. It, however, is adapted
for situations where there are a vast number of heavy and
complicated castings of similar size and shape to be made.
When to Use a Molding Machine. — The question of
whether or not the use of a molding machine would pay can
be decided accurately only by means of a detailed time-study
of the various operations of making a mqld by hand and by
machine. This time-study would show the amount of time
saved by the machine and it is then simply a question of
whether there are sufficient castings to be made from a given
pattern, the total saving on which would aggregate a sufficient
amount of time to warrant the expense of the machine. It
should be borne in mind in this connection that a molding
machine can usually be run by lower-priced men than are
required for making molds by hand. An instance of a time-
study on hand molding and on machine molding of the same
pattern was given by Mr. Wilfred Lewis, in a lecture before
the Franklin Institute in April, 1911. With his permission,
the author presents these time-studies together with Mr.
Lewis's comments thereon. (See pages 200-201).
In the tables the time given for each individual operation
is in hundredths of a minute. By carefully timing, with a
stop-watch, each operation of making a mold, it can quickly
be observed what motions are unnecessary and by comparing
the time study of the hand mold with that of the machine
mold, it is easily determined the amount that can be saved
by one method as compared with the other. In the two tables
presented, the time for molding a part of a plow in a flask 13 by
17 inches, with a 4-inch drag and a 4^-inch cope, both by
machine and by hand is given. Comparing these two tables,
it will be seen that items 4 to 1 1 [the item numbers here
refer to the table of hand molding] must be done in the same
way and will consume the same amount of time, 0.05 minute,
whether the mold is made by hand or by machine. Item 12
must be done more thoroughly and consumes more time in
MOLDING MACHINES 2O3
hand molding, and item 13 is not required at all in machine
molding. Item 14, butt-ramming, 0.30 minute, is equivalent
to squeezing by power but consumes five times the time.
Item 15, striking off, is performed after ramming, and requires
0.03 minute longer than striking off the unrammed sand on
the machine. Item 16 is not required in machine molding.
Item 17, rolling over, is the same in both cases. Items 18 and
19 require 0.14 minute, compared with 0.08 minute when
compressed air is used on the power machine. Items 20 and 21
are identical for hand or power molding. Item 22 requires
0.56 minute against 0.18 by power. Item 23 is not performed
by power as a separate operation and item 24 is the same in
both cases. Rapping the pattern, item 25, requires 0.48
minute as compared to 0.12 minute, consumed in starting the
vibrator and lifting the cope at one operation on the machine.
Item 26 is the same in both cases. Item 27, removing the
cope requires 0.69 minute. Item 28, to blow off the pattern,
requires 0.04 minute longer with bellows than with compressed
air and drawing the pattern, item 29, requires 0.35 minute
longer in hand molding than by machine. Item 30, patching,
requiring 0.30 minute is not called for, in machine work.
Items 31, 32, and 33 are the same in both cases, and in mold-
ing with the machine an additional operation, stopping off
the carriers, 0.06 minute is required. The total time required
for making a mold by hand is 4.20 minutes, whereas the
machine will do it in 2.10 minutes or exactly one-half the
time. Should a vibrator be used on the patterns in making
the mold by hand, the total molding time will be consider-
ably reduced, but still enough in excess of the machine time
to warrant the installation of machines, provided the cast-
ing is to be made in sufficient quantities. Similar studies
to the above, if made on any class of molding, will soon tell
the best method of work. Time studies may also be applied
to two different methods of hand molding or two different
methods of machine molding to ascertain which is the most
economical.
CHAPTER XX
MENDING BROKEN CASTINGS
CASTINGS are frequently broken in service or they may have
some portion defective when made. Unless the break is a
very bad one or the defective portion of wide extent it is
possible to repair the casting by one of a number of methods.
Up to comparatively recent times the only method of making
such repairs was by means of the process of burning. More
recently, however, the Thermit process and the oxy-acetylene
flame have placed in the hands of the foundrymen new tools
of high efficiency.
The process of burning a casting is shown in Fig. 137.
Assume that a casting with a small projecting arm D has had
this arm broken as shown. The two parts are bedded into
the floor and a parting made exactly as would be done
in ramming up a pattern. A shallow cope is set over the
broken casting and its position fixed by means of stakes, after
which parting sand is riddled on the joint and two gate-sticks
set, one a little longer than the other, on either side of the break.
The cope is then rammed up and lifted off and the small
broken part rapped and drawn from the mold. The broken
end is then ground off for a distance of about one-quarter
inch and the surface nicked all over with a chisel. This piece
is now returned to its place in the mold and a sprue is cut
between the two vertical gates leading to the space between
the broken ends of the arm. The cope is then replaced, the
gate-sticks withdrawn, and by means of snap-flask weights A,
a deep pouring basin is built above the smaller gate B and an
outflow H is built over the larger gate G, this outflow leading
to a large basin /.
The theory of burning broken castings involves the flowing
through the break of very hot iron which will eventually fuse
204
MENDING BROKEN CASTINGS
•^eights
2O5
Keadj focburnJnj
FIG. 137. — MENDING A BROKEN CASTING BY BURNING.
2O6 FOUNDRY PRACTICE
the ends of the broken casting, and then allowing the casting
to cool together with the iron which has been poured through
the break. The broken parts and the fresh iron will then
be found to have solidified in a firm homogeneous mass. The
surplus iron around the break is chipped off and the repaired
casting is as serviceable as one that has never been broken.
The inflowing gate is made considerably smaller than the out-
flow in order that the iron may flow freely through the break.
Should it be retarded in its flow it is liable to chill and fail
to melt the ends of the broken casting, in which case a hard
glazed surface would be formed which would be more difficult
of repair than the original break. It is also important that
the pouring basin be at a considerable elevation above the
outflow gate in order that there may be a high head to cause
the iron to flow rapidly through the break. Care must be
taken that the ends of the break are given a sharp jagged
surface as the molten iron will not fuse a smooth surface so
readily.
If the casting is of such shape that it cannot be readily
removed from the sand as in the case just described, grooves
may be cut through the break by a milling machine or chisel
and after the sprues are cut the sand is carefully blown from
these grooves and the cope replaced and the operation pro-
ceeds as before. If a portion of a casting of cylindrical section
is lost, it can be repaired by bedding the casting in the sand and
making a cylindrical mold above the broken portion, the
mold being made of sufficient depth to allow for a shrink-
head, after which a sufficient quantity of iron is allowed to
flow through the mold to fuse the end of the casting and it is
then permitted to solidify.
It is not possible to repair breaks of every character by
this method. The burning on of a corner or an arm is usually
accomplished with but little trouble. To burn metal into a
hole in the centre of a casting, particularly if the latter be thin,
is a more difficult proposition. The actual burning operation
is accomplished easily, but trouble is encountered when the
repair cools. The unequal shrinkage of the liquid metal and
MENDING BROKEN CASTINGS 2O7
the moderately heated solid casting surrounding it renders it
difficult to make a perfect joint between the two parts and
the new metal frequently pulls away from the old. This
trouble may sometimes be remedied by preheating the metal
of the casting up to about 400° Fahr. before burning, and
placing the repaired casting in an oven of this temperature
as soon as the burn is made, and cooling it gradually.
Another method of burning is to surround the break with
dry-sand cores about an inch above the casting, an outlet being
cut in the core so that hot iron can be poured directly on the
break and flow off over a notch cut in the core. From one
hundred to one hundred and fifty pounds of very hot iron is
poured in a thin stream on the break and around the place to
be mended. By means of a small rod the action of the iron is
ascertained. This method is usually practiced on flat surfaces.
The iron used in repairing breaks in this manner must
be extremely soft, especially if the casting is to be ma-
chined later. The higher the combined carbon in the iron
the harder will be the burned spot. The iron in the cast-
ing itself affects to some extent the quality of the iron in
the break.
Thermit Welding. — The introduction of the Thermit
process has rendered possible the repair of broken castings
which was impossible under the older method. Thermit is a
mixture of fine aluminum filings and iron oxide, which, when
set on fire, gives a temperature of about 5,000° Fahr., the alumi-
num uniting with the oxygen of the iron oxide. There is thus
formed a very pure iron and a slag consisting principally of
aluminum oxide. If this is allowed to flow on a casting the
intense heat will melt the casting wherever the mixture comes
in contact with it and, on cooling, the iron from the Thermit
will unite with the iron of the casting and form a homogeneous
uniform mass. It is this feature that is taken advantage of
in the making of repairs to broken castings by means of
Thermit. A typical repair by this method is that of a loco-
motive driving-wheel with broken spokes. The wheel is laid
on the floor and the broken parts are placed as nearly in their
2O8 FOUNDRY PRACTICE
original position as possible with a small space left between
them at the break. A mold is formed around the break, the
parts of which are heated with an oil burner. After they have
been brought to the proper temperature the funnel containing
Thermit is placed over the part to be repaired, a steel plug
being inserted at the bottom of the funnel. A special ignition
powder is set on top of the Thermit and lighted and after
the combustion of the Thermit is complete the plug is pushed
up into the funnel and the iron which has been formed by the
combustion of the Thermit is allowed to flow down over the
break, the slag flowing into a 'basin made to receive it. Repairs
made by this method are extremely strong, frequently being
of greater strength than the original casting.1
Oxy-acetylene Welding. — Welding by means of the
oxy-acetylene flame has been successfully used in the repair
of many difficult castings. Acetylene gas when burned in a
blow-pipe with oxygen gives the highest temperature known
excepting the electric arc, approximating 6,000° Fahr. This
flame can be regulated so that it may be drawn down to a fine
point which localizes the heat generated by it to a very limited
area. It is this fact that makes possible its use in the repair
of castings. The broken parts are brought together and a
groove is chipped along the break, the sides of the grooves hav-
ing an angle of about forty-five degrees from the vertical. The
oxy-acetylene flame is played on this groove until the metal in
it is fused. A soft iron wire is then melted by placing its end
in the groove and allowing the flame from the oxy-acetylene
torch to play upon it, when it unites with the metal fused from
the casting. On cooling the break will be found to be repaired
quite perfectly and the strength of the repaired joint will
approximate from 85 to 100 per cent, of the strength of the
original casting. Considerable care is required in the manipu-
lation of this process and detailed directions are given for the
use of the apparatus by the makers. These directions would
1The use of Thermit is covered by United States and foreign
patents and complete directions for its use should be obtained from the
owners of the American rights, the Goldschmitt Thermit Co., New York.
MENDING BROKEN CASTINGS 2O9
be out of place here and the reader is advised to consult with
the manufacturers of this apparatus before attempting to
make use of this process. The leading manufacturers of this
apparatus are the Davis-Bournonville Company, New York,
The Nelson Goodyear Company, New York, and the Linde
Air Products Company, Buffalo.
14
CHAPTER XXI
MOLDING TOOLS
THE tools most commonly used by molders are shown in
the illustrations Figs. 138 and 139.
The shovel is used for cutting up the sand heap and for
filling the flask.
The water pail is used for supplying water to wet down the
sand for tempering and also for wetting the swab or bosh on
the floor molding.
The riddle is a sieve used for sifting the sand on to the
surfaces of the pattern when starting a mold. The size of the
riddle is given by the number of meshes to the running inch.
Thus, a No. 8 riddle has eight meshes to the inch and a No.
4 riddle, four. The particular riddle used depends on the
character of casting to be made, the finer castings with con-
siderable detail on their surface requiring finer sand and, there-
fore, a finer riddle.
Rammers, used for pounding the sand around the pattern
in the flask, are, for the heavier class of castings, made of iron,
although sometimes they are made with a wooden handle
with a cast-iron butt at one end and a cast-iron peen at the
other end. The small rammers used in bench work are usually
made of maple, although sometimes they are made of cast-iron.
The strike is used to scrape the extra sand not wanted from
the top of the cope or drag and also for leveling the loose sand
placed in the bottom of the larger drags before placing the
bottom-board. It is usually a thin strip of bar iron, two to
three inches wide.
Clamps, used for holding together the cope and drag of
the completed mold or for clamping together the mold-board
and the bottom-board on either side of the drag when the latter
is rolled over, are of many styles and sizes. They are shown
MOLDING TOOLS 211
at 6, 7, and 8 of Fig. 138. They are made of either wrought-
iron or cast-iron and are wedged on the flask by means of the
wooden wedges 10. The wedges for side-floor use are usually
of soft wood and for the heavier work either of hard wood or
iron.
The bellows, 11, are used to blow parting sand from the
pattern and also to blow loose sand and dirt from the mold.
Gaggers are L-shaped pieces of wrought or cast iron. They
are shown at 12, Fig. 138, and are used to hold up deep pockets
of sand in the mold, which, if unsupported, would fall of their
own weight. The gaggers are clay-washed and the friction
of them against the body of the sand is sufficient to prevent
them falling on account of the weight of sand on the pocket
they are supporting.
Soldiers are sticks of wood of varying thickness, used for
much the same purposes as gaggers. In certain places, they
will hold up sand better than gaggers and can be used in
pockets in many places where gaggers would be impracticable.
Trowels, shown at 14, 15, and 16, Fig. 139, are of many
different styles and sizes to suit the individual taste of the
molo!er. In floor work, the trowel is used for making the joint
on a mold, and it is used in all classes of work for finishing,
smoothing, and slicking the flat surfaces of the mold.
Vent-wires are shown at 17, 18, and 19, being steel wires,
upset on one end and having a handle on the other. They
are used to perforate the mold to permit the escape of gases
from it when the casting is poured. They are also used. to
form holes for gas to escape from cores in the mold to the
outside of the mold.
The bosh or swab, 20, is made of hemp, teazled out to a
point at one end and bound with twine at the other to hold it
together. It is used to flow a small amount of water around
the edge of the pattern in the sand, before the pattern is
rapped for drawing from the mold. The bosh will hold con-
siderable water and the amount which it delivers to the sand
can be regulated by the pressure the molder applies when
squeezing it. Boshes are also used to apply wet blacking to
212 FOUNDRY PRACTICE
dry-sand molds when they are to be blacked green, that is
before the mold is dried, and the blacking slicked.
The soft brush, 21, is used to brush off the pattern and
the joint of the mold. The hard brush, 51, is used to spread
beeswax or tallow on metal patterns and to brush and clean
out between the teeth of gears and similar patterns.
The rapping and clamping bar, 22, is usually a bar of steel
from three-quarters to seven-eighths inch diameter and two
feet long. It is pointed at one end to enter rapping
plates in a pattern and is flattened and turned up at the
other end for convenience in tightening clamps on a flask.
For rapping large patterns, the size of the bar is of course
increased.
Draw-screws, 23, 24, and 25, are eye-bolts threaded on one
end. They are used for drawing large wooden patterns from
the sand, being screwed into holes, left for that purpose, in
the pattern. They are also used for drawing metal patterns.
The draw-spike, 26 and 27, is a piece of steel, sharpened at
one end for driving into a wooden pattern to rap and draw it.
It is principally used in bench work for drawing small patterns.
Lifters, 28, 29, 30, are used for clearing of loose sand deep
places in molds. They are of different lengths and sizes, one
end being turned at right angles to the stem, this portion
being termed the heel. The straight, flattened portion is
known as the blade. The blade and heel are also used to
slick the sides of the mold where they cannot be reached in
finishing by the trowel or slicker. The heel is also used to
slick the bottom of deep places after the sand has been re-
moved.
Slickers, 31, 32, and 33, are formed with blades of varying
widths, with the other end of the tool turned to form a heel
somewhat similar to the lifter. It is used for lifting loose sand
in shallow parts of the mold and for slicking down when patch-
ing broken edges. The blade is used to build sand on, to
form corners to the proper shape. This tool is used more by
molders than any other except the trowel.
Corner tools, 34, are used to slick the corners of molds
MOLDING TOOLS 213
where a slicker or the heel of a lifter will not do satisfactory
work. Corner tools are made with different angles for special
work, being usually formed of cast-iron by the molders and
polished.
Bead slickers, 35 and 36, are of special shapes and sizes.
They are used to slick what are termed beads or hollow places
in a mold. They are usually made of steel or composition
metal and seldom of cast-iron.
Flange tools, 37, are used for slicking flanges on pipes or
cylinders. The rounded ends of the flange tool are made of
different radii for use on different flanges. They are usually
made of steel.
Spoon slickers, 38 and 39, have spoon-shaped ends and
are used to slick rounding surfaces in a mold. They are
usually made with one end larger than the other.
Pipe tools, 40 and 41, are used to slick pipe molds in the
plain rounding part. Some are made as in the illustration
and others are formed more in the shape of a spoon. They are
also used on any cylindrical work for facing the interior of
cylindrical surfaces. They are usually of cast-iron with a
handle set vertically in the center.
Hub tools, 43, 44, 45, and 46, are used in any cylindrical
portion of a mold, such as hubs of pulleys or other portions
which are too small to permit use of a pipe slicker. One end
is turned at right angles for use in lifting sand from the bottom
of the hub in order to slick it. The back of the heel being
rounded, the hub tool can be brought in close to the edge of
the mold for finishing. They are made of steel or composi-
tion metal.
The double- ender , 47, comprises a slicker at one end and a
spoon slicker at the other. They are usually made to the
molder's order and are used by bench molders on small molds.
The earner s-hair brush, 48, is used to brush dry blacking
on the face of the mold.
The wooden gate-pin, 49, sometimes called a sprue, is a
round tapered pin used to form the gate extending through the
cope into which iron is poured into the mold. They are of
214
FOUNDRY PRACTICE
1
FIG. 138. — MOLDER'S TOOLS.
i, Shovel; 2. riddle or sieve; 3. iron rammer; 4. tool box; 5. strike; 6-8 clamps; 9. hand
mer; 10. wedges; n, bellows; 12, gaggers- 13, soldiers; 55-56, calipers, 57. cul
MOLDING TOOLS
FIG. 139. — MOLDER'S TOOLS.
14-16, Trowels; 17-19, vent-wires; 20, bosh or swab; 21, soft brush; 22. rapping or
clamping bar; 23-25, draw-screws; 26-27, draw-spikes; 28-30, lifters; 31-32, slickers;
34, corner tool; 35-36, bead slickers; 37, flange tool; 38-39, spoon slickers; 40-41, pipe tools;
42, button tool; 43—46, hub tools; 47, double-ender; 48, camel's-hair brush; 49, wooden
gate-pin; 50, rapping iron; 51, hard brush; 52, spring draw-nail, 53, 54. sprue cu.ters.
2l6 FOUNDRY PRACTICE
the size required by the class of mold, and occasionally may
be square or octagonal in cross section.
The rapping iron, 50, is used to rap or jar gated patterns
in the mold. It is commonly used in connection with the rap-
ping bar, 22, which is entered through the hole in the cope
made by the gate-stick. The bar entering a hole in the striking
gate on which the patterns are soldered, it is struck with the
rapping iron to jar the pattern at the same time in both the
cope and drag.
The spring draw-nail, 52, is used for drawing small patterns.
It consists of two pointed rods, joined together with a spring,
which forces the points outward. It is used for drawing small
patterns by inserting the points of the two rods in a hole in the
pattern, the points being pressed together; on releasing the
points, they spread apart and give sufficient grip on the pattern
to draw it.
The gate or sprue cutter, 53, is a piece of sheet brass bent
to a semicircle on one edge. It is used to cut the channel in
the drag from the hole left by the gate-stick to the mold.
Another form of sprue cutter is shown at 54, being a
cylindrical metal tube used to cut the gate in the cope when
the gate-stick has not been used.
Calipers are more used by the core-maker than the molder.
The molder uses them to verify the sizes of cores in order to
make the proper size of core-print and also to obtain the length
of smaller cores. The calipers in this case are set at the
proper length and the core filed to fit. This is important in
dry-sand work, since, as there is no give to a dry-sand mold, it
will be crushed if the core is too large when the mold is closed.
Cutting nippers, 57, are used to cut the smaller wires in
core-making to the desired length.
The monkey wrench is used to screw down rod bolts to
hold binders with which the mold is fastened and also to
tighten bolts in iron flasks.
CHAPTER XXII
MOLDING SANDS
MOLDING sand is a sand possessing those qualities which
enable it to be tempered and formed to definite shapes which
it will retain when molten metal is poured in it, and which has
the requisite chemical composition to enable it to resist fusion
from the heat of the molten metal. Molding sand must also
have sufficient permeability to permit the free escape of gases
from the mold while it is filling with metal, without scabbing
or otherwise injuring the surface of the mold. The sand also
should be capable of being retempered and used for successive
molds without the addition of new sand to provide bond.
Molding sand is found in large deposits in the United
States in the states of New York, New Jersey, Ohio, Indiana,
Illinois, Missouri, and Kentucky. It is also found in smaller
deposits in Michigan, Wisconsin, Connecticut, and Massa-
chusetts. The characteristics of the sands from these different
localities vary and they are not all suited to every grade of
work. Combinations or mixtures of sands from one locality
with those from another, will often give a desired grade and
quality of molding sand when none of the component sands is
suitable.
The principal requirements of a good molding sand are:
resistance to fusion; bond; permeability and porosity. An
excess of lime — one per cent or more — will lower the power of
the sand to resist fusion. If present as a silicate, it will com-
bine with the silica and alumina of the sand under the influence
of the heat of the molten iron, and will vitrify and form a scale
on the casting. Permeability, or ability to permit the passage
through it of gases formed in the mold while filling with metal,
is one of the most important qualities of molding sand. There
is a difference between permeability and porosity. The
217
218 FOUNDRY PRACTICE
porosity of a sand is the ratio of voids or pore spaces to the
total volume of the sand, while the permeability depends on
the area of the passage ways through the sand formed by these
voids. Air fills the pores in the mold, and this when heated
during the pouring of the metal, expands. The sand must
have sufficient cohesion or bond to resist the pressure due to
this expansion, and it also must have sufficient permeability
to permit the escape of the contained air and of the gases
generated in pouring. The greater the ease with which the
air and gases escape, the less need there is for a strong bond.
In green sand, more or less water is contained in the mold
which is converted into steam in casting, and this also must
escape. If these various fluids cannot escape easily through
the mold or core, blow holes are formed and the casting is
injured. A molding sand, therefore, must not only have
cohesion between its particles to withstand certain strains,
but it must at the same time possess the desired permeability.1
The experiments of King2 show that the finer-grained
sands, even when the grains are approximately the same size,
have greater pore space than the coarser sands when both are
equally tamped. The average pore space of seven samples
of No. 100 quartz sand 3 was 36.6 per cent., while that of three
samples of No. 20 sand was 33.9 per cent. The same experi-
ments show that sharp, angular sands have a greater pore
space than rounded sands of the same size, indicating ap-
parently the greater difficulty of making angular grains pack
well. It was also found that the smallest pore space was
obtained when two sands of rounded grains, but of quite
dissimilar diameters, were mixed in about equal proportions
by weight. The theoretical minimum pore space of sand with
spherical grains is 25.95 Per cent., and only once in these ex-
1 Annual Report of the State Geologist of New Jersey, 1904, page
199. Report on molding sands.
2 Nineteenth Annual Report of the Director of the U. S. Geological
Survey, II., pages 209-215.
3 Sand retained on a sieve with 100 meshes to the inch but passing
an 8o-mesh sieve.
MOLDING SANDS 219
periments did the pore space fall below this minimum. From
these experiments, the conclusions can be drawn that (A)
pore space can be reduced by tamping, but the theoretical
minimum can be reached but rarely; (B) under equal treat-
ment, mixed sands of different grain diameters give lower
pore space than do sands of uniform grain, the degree of
rounding being the same; (C) angular sands have more pore
space than rounded sands, other things being equal; (D) the
least pore space may be expected when the round grains are
about equally divided between large and small with no in-
termediate sizes. It is evident that the closer the packing
of the grains, the less the permeability, and, other things being
equal, coarse sands are more permeable than fine, and angular
sands more so than rounded.
Chemical analysis, while determining the amount of bond
in the sand, and also its resistance to fusion, does not deter-
mine whether or not a good casting can be produced with a
certain sand. Microscopic tests are also necessary, as these
will reveal the shapes of the grains of sand, whether the grains
are flattened, rounded, or angular which in turn determines
how closely the mold can be rammed and still permit the gases,
generated in pouring, to escape. A sharp angular grain is of
the utmost importance, since with this grain the sand can be
firmly rammed around the pattern and yet give a porous and
permeable mold. With a strong open sand, a poor molder
will often make a better casting than will a good molder using
a sand lacking in permeability. A molding sand with grains
nearly round, while making a good mold, requires more atten-
tion than the other.
If heavy castings are to be made, the sand must withstand
a high degree of heat for a considerable period and, to resist
fusion, a sand containing more silica and less bond is required.
The refractoriness of sand depends upon its silica content, but
the bond decreases as the silica increases. When the sand avail-
able for large castings is considered too close in texture to have
sufficient permeability and refractoriness, silica sand or ground
silica rock is sometimes added to open up the molding sand.
220
FOUNDRY PRACTICE
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MOLDING SANDS
221
The table herewith has been derived from the reports of
various State Geologists. It indicates the chemical composi-
tion of various grades of molding sand together with the uses
to which they are best adapted.
TABLE II shows the analyses of molding sand from
different parts of the United States. Of these Nos. I and 2 are
stove-plate sands, while 3 and 4 are used for general work.
TABLE II
i
Per Cent
2
Per Cent
3
Per Cent
4
Per Cent
Silica
79.36
79.38
84.40
85.04
Alumina
9^6
9 38
7 SO
5 90
Ferric oxide
3.18
3 98
2.52
3.18
Lime
0.44
i .40
O.O6
0.06
Magnesia
0.27
0.54
O.2I
0.14
Potash
2.19
i. 80
I .29
1.65
Soda
I 54
i 04
O 6s
o 83
Titanic oxide
o 34
o 44
o 44
0.78
Water . . .
2 O2
2.50
1.49
i .57
Moisture
0.74
0.80
1.76
i. it
The following analysis of a sand with an angular grain
formation will prove a good sand for stove-plate work. For
light bench castings, however, it should have more bond.
TABLE III
Per Cent
Silica 80.98
Alumina 9 . 50
Oxide of iron 3 . 90
Lime o . 60
The following analyses of molding sands are from the joint
report of B. H. Hamilton and H. B. Kummel, on "Molding
Sands of New Jersey."
222 FOUNDRY PRACTICE
TABLE IV
UNUSED No. i ALBANY SAND
Per Cent
Silica (Si02) 80.88
Alumina (A12 O3). . . )
Iron oxide (Fe2O3) J I4'°3
Lime (CaCO3) i .32
Combined water 2 . 54
Specific gravity 2 . 65
Pore space 43 . 3
Tensile strength 4.31 Ib. per sq. in.
Pan, 80; clay adhering, 5.5; fineness, 95.00.
ALBANY STOVE-PLATE SAND
Pan, 77; clay adhering, I + ; fineness, 95; specific
gravity, 2.65; pore space, 41.55 per cent.
NEW JERSEY MOLDING SANDS
I. Sand for brass molding and light malleable castings —
pan, 84.5; clay adhering, 2.5; fineness, 95.2; pore space, 43
per cent.
II. Stove-plate sand — pan, 71.36; clay adhering, 0.565;
fineness, 88.4; pore space, 37 per cent.
III. General foundry work — pan, 11.5; clay adhering,
3.0; fineness 72.2; pore space, 37 per cent.
IV. Heavy castings — pan, 13.89; fineness, 72.2; specific
gravity, 2.633; pore space, 37 per cent.
V. Lumberton Loam No. II — pan, 44.42; clay adhering,
10.27; fineness, 85; pore space, 47.4 per cent.
COXSACKIE (N. Y.) No. 2 SAND
Pan, 52.52; clay adhering, 5.0; fineness, 83.9; pore space,
33 per cent.
The character of casting to be made governs the selection
of the molding sand to be used. Small, thin castings for
MOLDING SANDS 22$
ornamental work, having on their surfaces a series of lines, de-
pressions, and projections, require a very fine-grained molding
sand. A coarse sand, used in this connection, will not only
refuse to reproduce the design but will leave rough surfaces
and imperfect lines on small castings. For molding very
fine castings in bronze, what is known as French sand is
necessary. See analyses in Table I.
In the United States a sand known as Windsor Locks
(Conn.) is used in making castings for chandelier and similar
fine composition work. A sand used for bronze, brass, or
other composition castings is not subjected to as high a tem-
perature as that used in iron casting, owing to the lower
melting point of the composition metals, and, therefore, cast-
ings may be permitted to remain in the mold until cooled. For
brass and small iron castings, a grade of sand known as No.
oo Albany sand is frequently used instead of Windsor Locks
sand. Among these classes of castings are toys, shelf hard-
ware of the lighter kind, small novelties, name-plates, and small
gears. Sands of similar texture to these two are found in
Kentucky, Ohio, and Indiana.
For somewhat heavier castings, in general bench work,
No. o Albany sand is used. The most commonly used sand
in the Eastern States is No. I Albany sand. It may be used
for nearly all kinds of castings, both brass and iron and for
castings of considerable size. When used for composition or
brass castings, it is made somewhat drier than when used for
iron, as composition metals will not lie quietly against a damp
surface and a scabbed face will result. For boiler fronts,
cab brackets for locomotives, and general light castings on
bench or side-floor work, cotton and woolen machinery castings
and small tool castings, highly permeable sand should be used.
No. 2 Albany sand, or sand of a similar grade, is largely used
for side-floor work alid for some of the heavier castings molded
under a crane. It may be used for castings weighing several
tons. As much depends on the skill of the molder as on the
sand when making molds for castings whose weight is measured
in tons. A scabbed casting may often result from improper
224 FOUNDRY PRACTICE
venting of the mold, especially where the iron remains in a
molten state for any length of time after pouring. The sand
is often blamed for poor results whereas they rightly should be
traced to the ignorance of the molder in regard to vents and
passageways through which gas may escape from the mold.
Lathe beds, locomotive and small-engine castings, made in
green sand, may be molded in a sand of similar analysis to that
of Coxsackie No. 2. Albany sand No. 3, or Albany sand No. 4,
are quite similar to this Coxsackie No. 2 sand, although it is
somewhat coarser. They are used for printing-press frames,
planer beds and tables, drop-press beds, shear frames, beds for
stone crushers, engine beds, and the heavier machine-tool
castings. It is also used as a component in mixtures for skin-
dried and dry-sand molds and for core-sand mixtures.
As the sand becomes coarser, its bonding properties which
give cohesion decrease, and the silica content, which aids in
resisting fusion, increases. Many castings molded in green
sand remain in a liquid state for a considerable period after
pouring. They also require churning, pumping, or feeding with
hot iron, during which period the sand is constantly absorbing
heat from the casting. Hence, the resistance to fusion must
be great and also the cohesiveness to prevent the sand crum-
bling under the intense heat to which it is subjected. It is there-
fore evident that the selection of the proper grade of molding
sand for making any given class of castings, requires a knowl-
edge of chemical analysis and of the granular formation.
While any of the larger foundry-supply houses, as The S. Ober-
mayer Co., Whitehead Bros., or J. W. Paxson & Co., will supply
a good grade of sand for any given class of castings, the foun-
dryman should have a general knowledge of the properties of
molding sand in order to obtain the best results with the
different classes of castings which he is required to make.
In making castings with a very smooth surface, a sand
that has been previously used will give a better surface than
a new sand, fresh from storage. It is presumed, of course, that
the used sand has sufficient strength, molding sand becoming
"rotten" or weakened by constant use. If it is necessary to
MOLDING SANDS 225
use new sand, it is advisable to first spread it on the floor and
then flow molten iron over it to burn it. The following day,
some of the old sand from the heap should be mixed with this
sand and used as a facing on the mold.
Molding sand, as it comes from the pit where it is mined,
contains a certain amount of vegetable or animal life. The
sand must be burned to get rid of this. As an instance of what
may happen in an unburned sand, the case of a large mold
which remained unpoured for a number of days after finishing
may be cited. This mold was made of new sand and on being
opened, prior to pouring, it was found that a number of plants
were sprouting from the face of the mold. Considerable time
was lost and no little expense incurred in going over the face
of the mold to repair the damage caused. The importance of
properly preparing molding sand, to prevent occurrences of
this character, is becoming recognized and machinery is now
on the market for such purposes.
Molding sand, after being used a certain length of time,
loses its bond or cohesion. Every time a casting is removed
from the mold, a certain amount of sand adheres to it and
is thereby lost. New sand is added to the sand heap, not only
to make up for this loss, but to restore the bond to the older
sand. New molding sand is of a yellowish or reddish yellow
appearance, ranging to a deep reddish brown due to the
presence of oxide of iron. Molding sand which has been used
gradually assumes a deep black color, due to the presence of
the seacoal facing which is burned into the sand.
When the sand heap becomes very black in color, mechani-
cal tests should be applied and, if found lacking in strength,
the sand should be renewed. A mold made of sand of low
strength is liable to have the face washed from it by the in-
flowing iron or, in closing the mold, a portion of the sand is
liable to drop.
Foundrymen have many methods of testing the physical
quality of molding sands. For instance, a foundryman will
take a handful of tempered sand, squeeze it in his hand to form
an elongated mass. He then suspends it by one end from
15
226 FOUNDRY PRACTICE
between his thumb and forefinger. If it breaks off from its
own weight, it is not considered a strong sand. If, however,
it hangs together, thus indicating strength, there may be an
excessive amount of clay present. Therefore, a small portion
is wet and rubbed between the thumb and forefinger, the
amount of clay being judged from the stickiness of the sand
as shown in this operation. Frequently, an open mold is made
of the sand under consideration and after feeling it to deter-
mine the hardness, iron is poured on it and its action observed.
The test gives a very close estimate of the value of the sand.
While these different tests have their value to the experienced
foundrymen, they are not in any case equal to a microscopic
and chemical examination of the sand. Generally, if a sand in
use in a foundry is satisfactory to those in charge of the prac-
tical operations, it is unwise to change, as there is considerable
liability of many castings being lost before the molders become
accustomed to the new sand.
The report of the Board of Geological Survey of the State
of Wisconsin, in 1907, says regarding molding sands: "Un-
fortunately no standard method of examination or testing
has been adopted by the foundrymen, much as this is to be
desired. A few buy their sand on the basis of composition;
others specify sands of a certain texture or both texture and
composition may be considered. The majority of foundry-
men, however, depend upon the judgment of their foreman
who, in many cases, uses empirical methods for determining
the value of the material. If the fears expressed by many
foundrymen are well founded, the time may not be far distant
when the supply of high-grade sands will be exhausted and the
production of artificial materials, by the admixture of sand
and clay, will be necessary."
Preparation of Sand for Molding.— After the flasks in
which the previous day's castings were made have been
shaken out and the castings removed from the sand, the sand
is wet down. The molder or his helper do this with a pail of
water, throwing the pail around in a circular path and tipping
it so that the water will fly over the edge on one side and form
MOLDING SANDS 22 7
a thin sheet covering quite an area. This operation is con-
tinued until, in the judgment of the molder, the sand is
sufficiently damp. If, in molding on the previous day, the
sand has shown insufficient strength, new molding sand is at
this point added to the heap, it being spread over the entire
surface. The sand is then "cut over" with the shovel. As
each shovelful of sand is thrown, a twist is given to the shovel
to spread the sand as much as possible. Lumps are broken
up with the flat or under side of the shovel. Any dry portions,
which are encountered in cutting the sand, are moistened, care
being taken to avoid making the sand too wet. An excess of
moisture in the sand will cause the metal in the mold to bubble
or "kick," whereas sand that is too dry will crumble when the
pattern is drawn. It is difficult, if not impossible, to describe
a properly tempered sand, which is determined by the sense of
touch of the molder. This can be acquired only by experience.
As sand may remain in a flask for some little time after
the mold has been poured, it may bake hard in the flask.
When the mold is shaken out, the sand will be found to have
formed in a mass of large and small lumps. These must be
broken up before water is applied, otherwise moisture will
not soak in when the sand is wet down. The effect of not
breaking these lumps becomes evident when molding. If one
of these lumps is broken up while sand is being riddled over
the pattern, a small shower of dry sand will fall into the mold
and will fail to cohere to the tempered sand. The result will
be a rough, a broken casting. The more thoroughly sand is
tempered and cut over, the more easily it will be worked by
the molder.
Information regarding the molding sands, fire sands, and
fire-clay of various States, can be obtained from the State
Geologists and Mineralogists. The more important reports
on these subjects are as follows:
Pennsylvania. "Report of Topographic and Geologic
Survey Commission, 1906-1908." "Annual Report of the
Secretary of Internal Affairs, Pennsylvania, Part III, Indus-
trial Statistics, 1907."
228 FOUNDRY PRACTICE
Wisconsin. "Bulletin 15. The Clays of Wisconsin and
Their Uses."
Michigan. "Report of the State Board Geological Sur-
vey, 1907."
New Jersey. "Report of the Geological Survey of New
Jersey, 1904."
New York. "Clay Industries of New York, 1895." H.
Ries. "Clays of New York; Their Properties and Uses." H.
Ries. "Mining and Quarry Industry of New York." D. H.
Newland, 1905, 1906. "Mining and Quarry Industry of New
York, 1906, July, 1907." "Mining and Quarry Industry of
New York." D. H. Newland, 1907, 1908.
Missouri. "Missouri Geological Survey Report. Sand
and Clays." Wheeler.
FACING MATERIALS
For forming the surface of molds, it is often necessary to
use a different material from molding sand. There are many
facings on the market, the more common ones being seacoal,
plumbago, powdered charcoal, talc, and gashouse carbon.
Seacoal. — Seacoal is a facing made from bituminous coal.
It obtained its name from the fact that coal was formerly
brought to London by sea, and became known as seacoal in
contradistinction to coal brought in overland. The name has
clung to it, although in a strict sense it is meaningless.
Most of the seacoal facing manufactured in this country is
made from coal mined in Westmoreland County, Pa. A good
gas coal is required for manufacturing first-class seacoal facing,
as it must contain a high percentage of volatile matter, with
a low percentage of ash and other impurities. The writer
is indebted to the S. Obermayer Co. for the following in-
formation regarding seacoal : Coal of approximately the fol-
lowing analysis is used: Fixed carbon, 60.52 per cent.; water,
1.37 per cent.; volatile matter, 34.75 per cent.; sulphur, 0.678
per cent.; ash, 21.675 Per cent. The coal is prepared by being
ground, screened, and bolted to the degree of fineness desired.
For use in molds for the heavier castings, most foundrymen
MOLDING SANDS 22Q
prefer it ground to what is termed "gunpowder." This grade
is also used on medium crane, and heavy side-floor work. The
finest ground and bolted seacoal facing is used on light work
where intricate designs are traced on the face of the pattern.
Seacoal is used in the foundry, mixed with molding sand in
different proportions according to the class of castings to be
made.
For castings one-quarter of an inch thick it is used mixed in
the proportions of one part of seacoal and twelve parts of sand,
depending somewhat on how sharp the iron is to be poured,
and with lesser amounts of sand to one part of seacoal for
the heavier castings.
For castings one-eighth of an inch thick, as for certain
classes of cotton machinery and in the teeth of fine gears which
are hard to free from sand with pickle, it is mixed in the propor-
tion of one part seacoal to twenty parts of sand, while on car-
wheels it is used one of seacoal to nine of sand. It often is
used in front of a gate where there is supposed to be danger
of iron cutting the mold as it enters.
One part of seacoal to five parts coarse molding sand is
about as strong as it can be used. It is well tore member,
when using strong seacoal facing sand, to use the vent-wire
freely, as, the stronger the facing, the more gas there is to
escape.
In mixing seacoal facing for green-sand work, the sand
should be used as dry as possible, and when the proper propor-
tion of seacoal has been added to the sand, it should be
shoveled over in order to mix it thoroughly, and then riddled.
If flour is to be added to the mixture it is added at the same
time as the seacoal. The mass is wet down and turned over in
order to mix it, and is tramped to force the component parts
together, and to break up the lumps. It is next passed through
a No. 8 sieve. For some of the larger castings a little flour is
added, say, one part flour to twenty- five parts sand for a mold
that is to be skin-dried, and one of flour to thirty- two of sand
where it is not skin-dried, this usually being done when a
poorer grade of molding sand is used which is deficient in bond.
23O FOUNDRY PRACTICE
When mixing the seacoal and sand it is well to remember
that if mixed too strong, or if too much seacoal is used in pro-
portion to the amount of sand, the casting will be "veined"
or "mapped."
Seacoal is not used generally to produce an especially
smooth surface on castings, although, if a little lead be used
with seacoal facing, there will be produced a fairly smooth
casting.
Plumbago. — Among the many facings used in the foundry
to give the castings a clean, bright surface, and to prevent
the sand from burning on to the face of the casting, there is
no greater favorite than the facing known as plumbago; silver
lead and Ceylon lead stand high. There are large quantities
of Ceylon lead used in the manufacture of foundry facings, and
the richer they are in it, the better the results obtained. The
pure material gives the smooth surface desired in machinery
castings, it being applied after the mold is faced with the sea-
coal facing.
Ceylon lead or graphite is "native carbon in hexagonal
crystals, also foliated or granular masses, of black color and
metallic luster, and so soft as to leave a trace on paper." It
is often called plumbago or black lead. Ceylon graphite of
high grade for facing purposes should analyze about as follows:
moisture, 1.20 per cent.; alumina, 3.06 per cent.; silica, 16.14
per cent.; oxide of iron, 5.90 per cent.; lime, 0.90 per cent.;
graphitic carbon, 72.80 per cent.
The bulk of Ceylon graphite imported for foundry facings
runs between 50 to 60 per cent graphitic carbon. For thin
castings the lead is usually placed in a bag which is shaken
over the mold, the lead passing through and falling lightly on
the face of the mold until enough has been applied to give the
desired result. After it has been brushed with a camel's-hair
brush, the mold is blown out with the bellows to remove any
lead not adhering to the face of the mold.
In molds for very thin castings the lead at times cannot be
brushed on. In such cases a little charcoal is dusted on top of
the mold and the pattern is printed back, the charcoal keeping
MOLDING SANDS 23!
the lead from sticking to.the pattern and spoiling the face of
the mold. Or it may be dusted on and blown off as the con-
dition and form of mold may require. Thicker castings,
however, require the aid of seacoal facing. With such molds,
the lead is sometimes brushed on with a camel's-hair brush,
light, quick strokes being used. Again, on the heavier cast-
ings it may be rubbed on with the hand and then lightly
brushed off; also it is often slicked on with the trowel and
slicker.
For blacking dry-sand molds lead is sometimes wet with
molasses water, and brushed on, and the heavier castings are
usually blackened with a mixture made to the consistency of
cream and laid on with a swab. After the blacking has been
allowed to set, the face of the mold is slicked all over with tools,
and then lightly brushed with molasses water to give it a
finishing smoothness. It is also used in the same way for
blacking cores.
On loam molds, it is advisable to boil and add a little com-
mon starch to the blacking mixture, and to slick the blacking
green on the face of the mold. The starch will prevent the
blacking from flaking off in thin sheets. Clay water is some-
times used instead of starch.
German lead is sticky on green-sand molds when used alone
and requires a coating of charcoal over it to prevent it from
adhering to the tool. It is largely used for mixture with
other blackings, to make a wet blacking for dry-sand and loam
molds. It will peel heavy castings when used properly.
Mexican and Austrian leads, or graphite, are used by many
in place of Ceylon lead, as they are much cheaper, but do not
work as nicely on the heavier class of castings, or give them
the attractive color or surface that Ceylon lead does. They do
not resist heat and protect the mold like Ceylon lead.
Blackstone and Valley Falls lead, also called Rhode Island
facing, is a carbonaceous mineral which is neither coal nor lead,
but when ground fine and applied to the face of a mold is
capable of protecting it from the intense heat of the molten
metal. It is naturally sticky and, if shaken on to the face of a
232 FOUNDRY PRACTICE
mold through a bag and slicked, requires a coating of charcoal
to prevent it from sticking to the tools. It was, and is still,
used to some extent as a facing for stove-plate molds, by being
shaken on to the mold through a bag, after which a coating of
charcoal is shaken on top of it and the pattern replaced. This
is called "printing back the pattern." It is also used with
other blackings to make wet blacking, for dry-sand and loam
work.
Lehigh blacking consists of Lehigh coal ground fine and
is used to mix with other blackings to make wet blacking
for dry-sand and loam work.
Coke blacking is coke ground fine for mixing with other
blackings for making wet blacking.
Charcoal blacking or powdered charcoal is used on green-sand
molds over other blackings which would stick to tools. It is
used in stove-plate work when printing back to prevent other
blackings from sticking to the patterns. It may be used as a
facing for dusting on very light work, but it requires something
to cause it to adhere to the face of the mold. For this reason
it is used in place of parting sand at times, to part molds in
making very light castings. It is used, too, in mixtures of
wet blacking to keep the tools from sticking to the blacking
and to allow the blacking to be slicked, which could not be
done if charcoal were not used.
Talc or soapstone, sometimes called white plumbago, is
used in mixtures of blacking for cores and for dry-sand work.
It will give a coating capable of resisting a high degree of heat,
and when shaken on the face of a mold after the mold has been
given a coating of lead, or other blacking, the iron will run
on it farther and smoother than it will without it. In this
way cold shuts may be avoided. Castings made in molds
in which it has been used show something of a cream color
when coming from the sand, instead of the handsome blue
shade shown when Ceylon lead is used.
Gashouse carbon facing is carbon taken from the gas retorts
and ground. It is one of the best facings for mixing with
others for wet blacking for cores, dry-sand, and loam molds.
MOLDING SANDS 233
Fire sand is a highly refractory silica sand used in making
molds for iron and steel. In the foundry it is used to mix with
coarse molding sand to form mixtures for making dry-sand and
loam work and to make mixtures for facing molds of cylinders
for steam- and gas-engines. Of the larger sizes, hydraulic and
pump cylinders, rolls and castings requiring to be sound and
clean, or to have a positive thickness of walls or where on ac-
count of the weight or for some special reason it may be con-
sidered safer to make the casting in dry rather than in green
sand.
As a base to work from there may be used seven parts
good coarse molding sand and seven parts coarse New Jersey
fire sand mixed, to which is added one part flour and after the
whole has been thoroughly mixed it should be wet with mo-
lasses water mixed in the proportion of one part molasses to
fourteen or sixteen parts water.
The mixture is varied according to the quality and grade
of sands and flour for the grade of work. This sand is also
mixed with other sands for making large cores where the cores
are to be subjected to intense heat from large bodies of metal.
It is also used for making the hearth for reverberatory fur-
naces, being wet with claywash or mixed with ground clay
dry, and then wet. It is also valuable for forming mixtures
for daubing large ladles, or in lining large cupolas.
CHAPTER XXIII
IRON AND ITS COMPOSITION
IRON, the metal most generally used in the foundry, is one
of the chemical elements. The iron of commerce, however,
is not pure metal, but is a compound of iron with various
metalloids such as carbon, silicon, phosphorus, sulphur, man-
ganese, etc. Each of these exercises an important influence
on the structure of the iron, the latter principally through their
action on the carbon, which is, without doubt, the most im-
portant element entering into the iron. The percentage of
carbon in the iron determines its grade and also whether it
comes under the classification of iron or steel. These points
will be discussed in more detail later.
The iron of commerce when examined under the microscope
has a structure closely allied to granite in appearance. It is
composed of two definite substances, known to the metal-
lurgists respectively as ferrite and cementite. The former is
pure metallic iron and is soft, weak, and very ductile. The
latter is a chemical compound of iron and carbon, is harder
than glass and very brittle. It, however, has great strength
to resist gradually applied pressure. The relative proportion
of ferrite and cementite in any given iron determines its grade.
Carbon. — The total amount of carbon in cast-iron ranges
from 3 to 4 per cent. It exists in the iron in three states,
namely : combined carbon which is the carbon in the carbide
of iron forming the cementite; free carbon, also known as
graphitic carbon, which exists in the form of small flakes of
pure carbon entangled in the crystals of ferrite and cementite;
and tempering graphite carbon into which combined carbon is
gradually changed by the prolonged application of heat. This
last is relatively unimportant compared to the other two.
The combined carbon has the effect of increasing the hard- -
234
IRON AND ITS COMPOSITION 235
ness, shrinkage, and brittleness of cast-iron. The strength of
the iron increases with the amount of combined carbon up to
about i per cent of the latter. Above i per cent, combined
carbon tends to decrease the strength of the metal.
The graphitic carbon tends to soften and weaken the iron
if present in quantities of over 3 per cent. If the iron contains
i per cent or more of combined carbon, being at the same time
low in graphitic carbon, any additions of the latter will in-
crease the strength of the casting. The amount of graphitic
carbon in a casting is increased with the size of the casting,
and it is also increased when the casting is held a long time in
the mold at high temperature; in other words, when it is
cooled slowly. This is due to the action of the combined
carbon changing to temper graphite as explained above.
Silicon. — The tendency of silicon in cast-iron is to soften
the casting. It acts by changing combined carbon into
graphitic carbon and also by counteracting the effect of any
sulphur which may be present and which exercises a harden-
ing effect upon the iron. The silicon also may act to increase
the strength of the iron when the latter is high in combined
carbon, as it tends to reduce brittleness. If, however, the
addition of silicon is such as to reduce the combined carbon to
below i per cent it will seriously weaken the iron. If present
in quantities over 3.5 per cent it changes the character of the
iron entirely, the iron becoming silvery in color instead of gray
and also becoming brittle and weak. Manganese present in
the iron will, like sulphur, react with the silicon and decrease
the effect of the latter on the iron.
Sulphur. — Sulphur present in the iron reacts with the
carbon present to form combined carbon and thereby increases
the hardness, brittleness, and shrinkage of the casting. In ad-
dition to r'ts action on the carbon it also has in itself a weaken-
ing effect on the iron. On account of its effect on the shrink-
age, patterns which are made for use with iron high in sulphur
must have a greater shrinkage allowance than the usual one-
eighth inch per foot, otherwise the casting will be smaller than
desired. The sulphur should never be permitted to increase
236 FOUNDRY PRACTICE
beyond o.i per cent, as any excess of this amount will render
the iron brittle and weak unless other elements are present in
sufficient quantity to counteract it. The iron will be danger-
ously brittle even with such a low quantity as 0.06 per cent
sulphur if the amount of silicon present is less than I per cent.
Phosphorus. — The general effect of phosphorus is to in-
crease the fluidity of the iron. In small quantities, say below
0.7 per cent, it has but little effect on the strength of the iron,
but if present in quantities of I per cent or more the effect is
decidedly weakening. Like silicon it acts to increase the soft-
ness of the iron and also to decrease the shrinkage. On account
of its increasing the fluidity of the iron, it is a desirable element
when thin castings such as stove plates are to be made, as the
iron will flow freely to all parts of the mold before cooling. It
is also valuable in ornamental castings of thin section which
have on their surface fine lines and sharp projections. The
iron containing phosphorus will flow freely into these lines
and projections and reproduce the pattern perfectly. /
Manganese. — Manganese when present in quantities of
2 per cent or more increases the hardness of the iron. When
present in small quantities, say 0.5. per cent or less, it tends to
counteract the effect of the sulphur present and thus acts as
a softener. In quantities of from 0.5 per cent to 2.0 per cent
it changes graphitic carbon to combined carbon and thus acts
as a hardener. A peculiar property of manganese, and one
wherein it differs from most of the other constituents of iron,
is that it will combine with iron chemically in almost all pro-
portions. In quantities of 10 to 30 per cent in the iron it
forms spiegeleisen and when present in quantities of over 50
per cent the alloy is known as ferro-manganese. These alloys
are used as additions to iron and steel in the ladle after they
have been melted in the cupola or other furnace to make up
deficiencies in the metal and to act as softeners or to toughen
the metal as the case may require. Manganese also acts to
increase shrinkage. While ordinary pig iron usually contains
not over 4 per cent of carbon, this quantity can be increased
in the presence of manganese, which increases the solubility of
IRON AND ITS COMPOSITION 237
carbon in iron. The property of manganese to toughen and
harden cast-iron is taken advantage of in the casting of chilled
rolls, on which a hard surface is desired. It is added in quan-
tities of about i per cent. It must not be permitted to exceed
0.4 per cent if softness is required in the finished casting.
Another effect of manganese is to decrease the magnetism of
iron and it must therefore be avoided in castings for electrical
machinery, as iron with 25 per cent manganese is totally de-
void of magnetism.
Miscellaneous Impurities. — Other metals often encoun-
tered in iron are as follows: Aluminum in quantities of from
0.2 to i .o per cent will increase the softness and strength of
white iron. Added to gray iron it softens and weakens it.
Vanadium, in quantities of 0.15 per cent, will increase the
strength of iron, acting as deoxidizer and also alloying with the
iron. Titanium, when added in quantities of 2 to 3 per cent
of a titanium-iron alloy containing 10 per cent titanium, will
increase the strength of the iron from 20 to 30 per cent. Its
action is to combine with any oxygen or nitrogen present in
the metal and thus purify it. The titanium oxide or nitride
passes off and no titanium remains in the metal. After the
metal has been totally deoxidized, further additions of tita-
nium have no effect. Aluminum, vanadium, and titanium are
all added to the iron in the ladle after melting, in the form of
alloys of these metals with iron. Copper when present in
quantities of o.i to i.o per cent closes the grain of cast-iron,
but has no particular effect as regards brittleness.
GRADING OF PIG IRON
Up to quite recent times, pig iron was graded by the foun-
drymen and blast-furnace operators largely according to the
appearance of the fracture obtained when a pig was broken.
As the appearance of the fracture depends on the relative
quantities of graphitic and combined carbon present, this
method gave a fairly close approximation to the quality of the
iron. In more recent years, however, grading by fracture has
FOUNDRY PRACTICE
been largely superseded by the method of grading by analysis.
The designations of pig iron according to grade vary in dif-
ferent sections of the country. Thus in Pennsylvania and
eastern parts of the United States grades are known as Nos.
i and 2 Foundry, Gray Forge No. 3, Mottled No. 4, White
No. 5. Intermediate grades are designated by the addition
of the letter X to the grade of the higher number. Thus an
intermediate grade between Nos. 2 and 3 would be known as
No. 3X. The following table from Kent's "Mechanical
Engineers' Pocket-Book," eighth edition, page 414, gives the
analyses of the five standard grades of northern foundry and
mill pig iron :
TABLE V. — ANALYSES OF FOUNDRY IRONS
No. i
No. 2
No. 3
No. 4
No. 48
No. S
Iron
Per Cent
92 37
Per Cent
Q2 31
Per Cent
Q4. 66
Per Cent
Q4. 4.8
Per Cent
Q4. 08
Per Cent
94 68
Graphitic carbon
Combined carbon. . . .
Silicon
Phosphorus
3.52
0.13
2-44
i .25
2.99
0-37
2.52
I. 08
2.50
1-52
0.72
0.26
2. 02
I.98
0.56
o 19
2.02
1-43
0.92
o 04
3-83
0.41
o 04
Sulphur
o 02
o 02
o 08
o 04.
o 02
Manganese
o 28
o 72
° 34
o 67
2 O2
o 98
The characteristics of the above irons are given in the same
work as follows:
No. I Gray. — A large, dark, open-grained iron, softest of
all the numbers and used exclusively in the foundry. Tensile
strength low. Elastic limit low, fracture rough, turns soft
and tough.
No. 2 Gray. — A mixed, large and small, dark grain, harder
than No. I, and used exclusively in the foundry. Tensile
strength and elastic limit higher than No. i. Fracture less
rough than No. i. Turns harder, less tough, and more brittle
than No. i.
No. 3 Gray. — Small, gray, close grain, harder than No. 2,
used either in the rolling mill or foundry. Tensile strength
IRON AND ITS COMPOSITION 239
and elastic limit higher than No. 2. Turns less hard, less
tough, and more brittle than No. 2.
No. 4 Mottled. — White background dotted closely with
small black spots of graphitic carbon. Little or no grain.
Used exclusively in the rolling mill. Tensile strength and
elastic limit lower than No. 3. Turns with difficulty, less
tough and more brittle than No. 3. The manganese in the No.
46 pig iron replaces part of the combined carbon, making the
iron harder and closing the grain, notwithstanding the lower
combined carbon.
No. 5 White. — Smooth, white fracture, no grain. Used
exclusively in the rolling mill. Tensile strength and elastic
limit lower than No. 4. Too hard to turn and more brittle
than No. 4.
For making chilled castings a special grade of iron is re-
quired, one which has a gray fracture when cooled slowly, but
which when cast against a chill will show white iron for a cer-
tain depth on the side which was rapidly cooled by reason
of its contact with the iron chill. See the analyses of chilled
castings, Table VIII, pages 242-3.
SPECIFICATIONS FOR FOUNDRY PIG IRON
In May, 1909, the American Foundrymen's Association
adopted standard specifications for foundry pig iron and rec-
ommended that all pig iron for foundry use be bought by
analysis. It recommended sampling each carload of iron,
taking therefrom one-half of a sand-cast pig or one machine-
cast pig for every four tons in the car. Drillings should be
taken fron these pigs to represent as nearly as possible the
composition of the pig as cast and an equal quantity of the
drillings from each pig should be mixed to form the sample
for analysis. When the elements are specified, the following
percentages and variations are to be used. Opposite each
percentage of the different elements a syllable has been
affixed so that buyers by combining these syllables can form a
code word for telegraphic use.
240
FOUNDRY PRACTICE
TABLE VI
SILICON
SULPHUR
TOTAL CARBON
MANGANESE
PHOSPHORUS
Per Cent
Code
(Max.)
Code
(Min.)
Code
Per Cent
Code
Per Cent
Code
0.04
Sa
3.00
Ca
O.20
Ma
O.2O
Pa
1. 00
La
0.05
Se
3-20
Ce
0.40
Me
0.40
Pe
1.50
Le
0.06
Si
3-40
Ci
0.60
Mi
0.60
Pi
2.OO
Li
O.O/
So
3-60
Co
0.80
Mo
0.80
Po
2.50
Lo
0.08
Su
3-8o
Cu
1. 00
Mu
1. 00
Pu
3-oo
Lu
O.OQ
Sy
1-25
My
1-25
Py
0.10
Sh
1.50
Mh
1.50
Ph
Percentages of any element specified one-half way between
the above are designated by the addition of the letter x to the
next lower symbol. Thus Lex means 1.75 silicon. The
allowed variations are silicon 0.25, phosphorus 0.20, manganese
0.20. The percentages of phosphorus and manganese may be
used as maximum or minimum figures when so specified. An
example of the use of the above code is as follows : Li-si-pa-ma
represents an iron of the following analysis — Silicon 2.00,
sulphur 0.06, phosphorus 0.20, manganese 0.20. For market
quotations, an iron of 2 per cent silicon with a variation of
0.25 per cent either way and maximum sulphur content of
0.05 is taken as the base and the following table may then be
- TABLE VII
Sul-
phur
Silicon
2.25
B+2C
I.OO
B-3C
3.25
B+6C
3.00
B+SC
2-75
B+4C
2.50
B+3C
2.OO
B + C
1-75
B
1.50
B-iC
1-25
B-2C
0.04
0.05
B+sC
B+4C
B+3C
B+2C
B+iC
B
B-iC
B-2C
B-3C
B-4C
0.06
B+4C
B+3C
B+2C
B+iC
B
B-iC
B-2C
B-3C
B-4C
B-5C
0.07
B+3C
B+2C
B+iC
B
B-iC
B-2C
B-3C
B-4C
B-5C
B-6C
0.08
B+2C
B+iC
B
B-iC
B-2C
B-3C
B-4C
B-sC
B-6C
B-7C
0.05
B+iC
B
B-iC
B-2C
B-3C
B-4C
B-sC
B-6C
B-7C
B-8C
O.IO
B
B-iC
B-2C
B-3C
B-4C
B-sC
B-6C
B-7C
B-8C
B-9C
IRON AND ITS COMPOSITION 24!
filled out as part of a contract. In this table B or base
represents the agreed price for a pig of 2 per cent silicon and
of lower sulphur content than 0.05. C is a constant differen-
tial to be determined at the time the contract is made.
ANALYSES OF CASTINGS
A committee of the American Society for Testing Materials
in 1908 recommended that the sulphur in light gray-iron
castings be not allowed to exceed 0.08 per cent; in medium
castings not over o.io per cent; in heavy castings not over
0.12 per cent. A light casting is one which has no section over
one-half inch thick and a heavy casting has no section less
than two inches thick. The same society in 1905 specified
for metal in cast-iron pipe four grades of pig iron as follows:
No. I, silicon 2.75, sulphur 0.035; No. 2, silicon 2.25, sulphur
0.045; No. 3, silicon 1.75, sulphur 0.055; No. 4, silicon 1.25,
sulphur 0.065. A variation of 10 per cent either way in the
silicon is permitted and of o.oi per cent in the sulphur above
the standard is allowed.
In June, 1910, the American Foundrymen's Association
published a report by Dr. John Jermain Porter, showing
tentative standards or probable best analyses of a large
variety of iron castings. This report was abridged in tabular
form as reproduced below in Industrial Engineering in August,
1910. The definitions of light and heavy castings conform
to those given in the above paragraph. The most desirable
percentage of silicon depends largely on the exact thickness of
the casting and the practice followed in shaking out. The
effect of purifying alloys and the use of steel scrap were not
considered in compiling the report. In many cases a wide
range of compositions is permissible and compatible with the
best results, and in such cases the question of cost will be the
first element to be considered. The sources of information in
compiling this table were published works, replies to inquiries
sent to members of the association, and private notes of
Dr. Porter.
16
242
FOUNDRY PRACTICE
TABLE VIII. — ANALYSES OF CASTINGS
"Class of Casting
Si
Per Cent
s
Per Cent
p
Per Cent
Mn
Per Cent
C
(Comb.)
Per Cent
c
(Total)
Per Cent
Acid-resisting castings (stills,
1.00-2.00
2.00-2.50
0.05-*
0.06-0.08
0.40-*
0.60-0.80
1.00-1.50
0.60-0.80
3.00-3.50
Agricultural machinery, ordi-
nary
Agricultural machinery, very
thin
Annealing boxes, etc
Automobile castings
Balls for ball mills
Boiler castings
Car castings, gray iron
Chilled castings
Chills
.40-1.60
•75-2.25
.00-1.25
.00-2.50
.50-2.25
•7S-I.2S
0.06-
0.08-
0.08-
'0.06-
0.08-
0.08-0.10
O.2O-
O.40-O.50
O.20-
O.2O-
0.40-0.60
O.2O-0.4
0.60-1.00
0.60-0.80
0.60-1.00
0.60-1.00
0.60-1.00
0.80-1.20
::::::::
.80-1.00
0.08-0.10
O.2O-O.4
0.80-1 20
Cutting tools, chilled
Cylinders:
Air and ammonia
.00-1.25
.00-1.75
.75-2.00
.00-1.75
0.08-
0.09-
0.08-
0.08-
O.2O-O.4
O.30-0.5
0.4O-O.5
O.20-O.4O
0.60-0.80
0.70-0.90
0.60-0.80
0.70-0.90
O.'ss'-o'.os
3.00-3.30
3.00-3.25
3.00-3.30
low
low •
low
Hydraulic, medium
Locomotive
Steam-engine, heavy
Steam-engine, medium
Dies, drop-hammer
Diamond polishing wheelsf. . . .
Electrical machinery (frames,
bases, spiders) , large
Electrical machinery, small. . .
Engine castings:
.20-1.60
.00-1.50
.00-1.25
.25-1.75
.25-1.50
2.70
.00-2.50
.50-3.00
0.09-
0.08-0.10
O.IO-
0.09-
0.07-
0.063
0.08-
0.08-
0.30-0.50
O.3O-O.50
O.20-O.4O
0.30-0.50
0.20-
O.3O
O.5O-O.8O
0.50-0.80
0.70-0.90
0.80-1.00
0.80-1.00
0.70-0.90
0.60-0.80
0.44
0.30-0.40
0.30-0.40
"i.o'o"
0.20-0.30
0.20-0.30
low
2.97
low
low
Fly-wheels
Fly-wheels, automobile
Frames
Pillow blocks
.50-2.25
.25-2.50
.25-2.00
.50-1.75
0.08-
0.07-
0.09-
0.08-
0.40-0.60
O.4O-O.5O
O.3O-O.5O
O.40-O.5O
0.50-0.70
0.50-0.70
0.60-1.00
0.60-0.80
Piston rings
Fire pots and furnace castings.
Grate bars
Grinding machinery, chilled
.50-2.00
.00-2.50
.00-2.50
•50-0.75
.00-1.25
.00-1.25
0.08-
0.06-
0.06-
0.15-0.20
0.06-
0.06-
0.08-
0.30-0.50
O.20-
O.2O-
0.20-0.40
O.2O-O.30
O.2O-O.30
0.40-0.60
0.60-1.00
0.60-1.00
1.50-2.00
0.80-1.00
0.30-
low
low
low
Gun-carriages
Gun iron
Hardware,, (light) and hollow
0.80-1.00
low
low
Heat-resistant iron (retorts) . . .
Ingot molds and stools
Locomotive castings, heavy. . .
Locomotive castings, light. . . .
Machinery castings, heavy ....
Machinery castings, medium . .
• Machinery castings, light
Friction clutches
Gears, heavy
Gears, medium
Gears, small
Pulleys, heavy
Pulleys, light
Shaft collars and couplings . .
Shaft hangers
Ornamental work
Permanent molds
Permanent mold castings
.25-2.50
.25-1.50
.25-1.50
.50-2.00
.00-1.50
.50-2.00
.00-2.50
.75-2.00
.00-1.50
.50-2.00
.00-2.50
.75-2.25
.25-2.75
.75-2.00
.50-2.00
.25-2.75
.00-2.25
.50-3.00
0.06-
0.06-
0.08-
0.08-
O.IO-
0.00-
0.08-
0.08-0.10
0.80-0.10
0.00-
0.08-
0.09-
0.08-
0.08-
0.08-
0.08-
0.07-
0.06-
O.2O-
O.2O-
0.30-0.50
O.4O-0.6O
O.3O-O.5O
0.40-0.60
O.5O-O.7O
O.3O-
0.30-0.50
0.40-0.60
O.5O-O.7O
O.5O-O.7O
0.60-0.80
O.4O-O.5O
0.40-0.50
O.6O-I.OO
0.20-0.40
0.60-1.00
0.60-1.00
0.70-0.90
0.60-0.80
0.80-1.00
0.60-0.80
0.50-0.70
0.50-0.70
0.80-1.00
0.70-0.90
0.60-0.80
0.60-0.80
0.50-0.70
0.60-0.80
0.60-0.80
0.50-0.70
0.60-1.00
0.40-
0.30-
low
' ' low ' '
::::::::
' ' low ' '
low
* Affixed hyphens indicate that the percentages present should be under those given.
IRON AND ITS COMPOSITION
TABLE VIII. — ANALYSES OF CASTINGS — Continued
243
Class of Casting
Si
Per Cent
S
Per Cent
P
Per Cent
Mn
Per Cent
C
(Comb.)
Per Cent
(ToteO
Per Cent
Piano plates
Pipe
.00-2.25
.50-2.00
•7S-2.SO
•50-1.75
.75-1.25
0.07-
O.IO-
0.08-
0.08-
0.08-
0.40-0.60
.50-0.80
.50-0.80
.20-0.40
.20-0.30
0.60-0.80
0.60-0.80
0.60-0.80
0.70-0.90
0.80-1.00
........
Pipe fittings
Pipe fittings for superheated
steam lines
Plow points, chilled
low
Propeller wheels
Pv.mps, hand
.00-1.75
.00-2.25
.00-2.25
.50-2.25
.00-1.25
.60-0.80
0.75
.00-2.30
.75-2.00
.75-2.25
.25-2.75
• 25-1.75
O.IO-
0.08-
0.08-
0.08-
0.08-
0.06-0.08
0.03
0.08-
0.07-
0.09-
0.08-
0.09-
20-0.40 0.60-1.00
60-0.80 0.50-0.70
60-0.80 0.50-0.70
40-0 .60 o .60-0 .80
20-0.300. 80-1.00
20-0.40 i. oo-i. 20
0.25 0.66
60-1.000. 50-0. 70
0.30- 0.70-0.90
50-0. 80 p. 60-0. 80
60-0.90(0.60-0.80
20-0.40(0.80-1 .00
0.50-0.60
low
Railroad castings
Rolling mill machinery:
Housings
Rolls, chilled
Rolls, unchilled (sand-cast)t
Scales
Slag car castings
Soil pipe and fittings
Stove plate
Valves, large
low
3-00-3.25
4.10
1.20
' ' low ' '
Water heaters
Wheels, large
Wheels, small.
.00-2.25
.50-2.00
.75-2.00
.50-0.90
0.08-
0.09-
0.08-
0.15-0.25
30-0.50
30-0.40
40-0.50
20-0.70
0.60-0.80
0.60-0.80
0.50-0.70
0.17-0.50
2.90
2.50
t But one or two analyses available — no suggestion made.
Mr. W. J. Keep in the Trans. A. S. M. E., Vol. XXIX,
writes as follows regarding the analyses of iron for various
classes of service :
Hard Iron for Heavy Work.— Castings for compressor
cylinder-valves, high-pressure work, etc. Chemical composi-
tion: Silicon i. 20 to 1.50, sulphur under 0.09 per cent, phos-
phorus 0.35 to 0.60 per cent, manganese 0.50 to 0.80 per cent.
Medium Iron for General Work. — Castings for low-
pressure cylinders, gears, pinions, etc. Chemical composi-
tion: Silicon 1.50 to 2.00 per cent, sulphur under 0.08 per cent,
phosphorus 0.35 to 0.60 per cent, manganese 0.50 to 0.80 per
cent.
Soft Iron. — For general car and railway castings, pulleys,
small castings, and agricultural work. Chemical composition:
Silicon 2. 20 to 2.80 per cent (with less, the castings are hard,
and with more they are too weak). For large castings, 2.40
per cent is a good average. Sulphur under .085 per cent,
phosphorus, under 0.70, manganese under 0.70 per cent.
244
FOUNDRY PRACTICE
Iron for Frictional Wear. — Castings for brake shoes,
friction clutches, etc. Chemical composition: Silicon 2.00 to
2.50 per cent, sulphur under 0.15 per cent, phosphorus under
0.70 per cent, manganese under 0.70 per cent. The addition
of spiegeleisen increases hardness.
The method of calculating the mixtures of the various
brands of pig iron available for cupola charges to obtain the
analyses as given in the above notes and table will be explained
in Chapter XXIV.
SHRINKAGE OF CAST-IRON
The common allowance for shrinkage of cast-iron in cooling
from the liquid to the solid state is one-eighth inch per foot.
As has been shown above, however, the percentage of the
various elements alloyed with the iron has an important effect
on the shrinkage. Mr. Keep says: "The measure of shrinkage
is practically equivalent to a chemical analysis of the silicon.
It tells whether more or less silicon is needed to bring the qual-
ity of the casting to an accepted standard of excellence." Mr.
Keep published in the Trans. A. S. M. E. the following
table showing the variation in shrinkage with the size of bar
on which his experiments were made and with the variation
in the silicon contents of the iron. See also the Appendix,
page 317.
TABLE IX.— SHRINKAGE OF CAST-IRON
SILICON
SIZE OF SQUARE BARS
Shrinkage, Inch, per Foot
Per Cent
y3 inch
i inch
2 inch
3 inch
4 inch
I .OO
0.178
0.158
0.129
O. 112
O.IO2
1.50
0.166
0.145
O.II6
0.099
0.088
2.00
0-154
0-133
0.104
0.086
0.074
2.50
0.142
O. 121
0.091
0.072
0.060
3.00
0.130
0.109
0.078
0.058
0.046
3-50
O.II8
0.097
0.065
0.045
0.032
CHAPTER XXIV
THE CUPOLA AND ITS OPERATION
FOR melting iron for foundry use two types of furnaces are
commonly used, the cupola and reverberatory or "air" furnace.
Of these the cupola is the most widely used, although the
reverberatory furnace is becoming very popular for certain
classes of work. There are many different cupolas on the
market which vary only in details of design. In principle
they are all alike. A typical cupola is shown in Fig. 140. As
will be observed it is a straight shaft furnace open at the top
and bottom, lined with fire-brick, provided with a door at about
the middle of its height through which the charge is introduced
and with tuyeres near the bottom through which air is blown to
consume the fuel which is charged to melt the iron. The open-
ing at the bottom is closed by hinged cast-iron doors which are
dropped at the end of the day's run in order to permit the un-
consumed fuel and the residue of iron in the cupola to fall out
and be removed. Molten iron is taken out through a hole at
the bottom and slag is removed through a hole in the opposite
side and at a slightly higher level than the iron tap-hole.
The cupola is encircled near its base by a chamber, known as
the wind-box, communicating with the tuyeres. The fan or
pressure blower furnishing air to the cupola delivers it to this
wind-box whence it finds its way through the tuyeres into the
cupola. It is in the arrangement of the tuyeres that the
various cupolas of different makers differ principally from
each other. It would be out of place in a book of this char-
acter to enter into a discussion of the various details of con-
struction of different cupolas and the reader is referred to the
catalogues of the various foundry-supply houses for informa-
tion on this subject.
Taking up the construction in detail of the cupola shown in
245
246 FOUNDRY PRACTICE
Fig. 140, the shell A is formed of separate rings of boiler plate
riveted together with angles E riveted to the interior at in-
tervals to support the fire-brick lining L. The shell is carried
on a cast-iron bed-plate ring B, which is in turn supported by
the cast-iron legs 5. The opening in this ring is closed by
a pair of hinged drop-doors, which when closed are held in
place by a rod, or spud, wedged between them and the floor.
At F is seen the wind-box encircling the cupola communicating
with the tuyeres H and /. At G is the blast-pipe connecting
the fan or blower with the wind-box. At C is the breast built
around the tap-hoi^ T through which iron is removed from
the cupola, 'it flowing through a spout R. The slag-hole and
spout are shown at W. Iron and fuel are introduced into the
cupola through the charging door D, and in practice this door
is usually at the level of the second floor of the foundry or a
platform is built around it. Cleaning doors are built on
either side of the wind-box to permit the removal of any slag
or iron which may flow through the tuyeres into it. Opposite
each tuyere a peep-hole P is provided, which is covered when
not in use by a swinging cast-iron cover. By using these
peep-holes the melter can ascertain in a measure how the cupola
is operating. The tuyeres are of cast-iron and flare inward
as shown in the plan, Fig. 141.
The height of the tuyeres above the bed plate varies
according to the class of work done in the foundry. The
number of rows of tuyeres also ranges from one to three. Thus
stove-plate work does not require a great depth of iron to be
maintained in the basin, as the space between the bottom of
the cupola and the tuyeres is known. Consequently, the
tuyeres can be set at a lower level than in a cupola melting
iron for heavy engine castings where a great volume of metal
may be required at one time. The advantage of using two or
more rows of tuyeres is that gases may be distilled from the
fuel and escape without coming in contact with air blown
through the lower row. They must, however, pass through
air blown through the upper tuyeres and thus become com-
pletely consumed. The double row of tuyeres, therefore,
THE CUPOLA AND ITS OPERATION
247
248
FOUNDRY PRACTICE
renders possible economical operation and quick melting, inas-
much as no fuel is wasted. When running small heats the
upper row of tuyeres may be shut off by means of a damper.
Also if the cupola is melting more rapidly than is desired, the
upper tuyeres may be shut off and the amount of air furnished
the cupola may be diminished by means of a damper in the
blast-pipe. Thus the melting rate of the cupola is always
under control of the melter. An arrangement is also provided
FIG. 141. — SECTIONAL PLAN OF CUPOLA THROUGH LOWER TUYERES.
whereby iron rising too high in the basin before tapping will
run through a spout into the wind-box where it will melt a lead
plug and fall to the floor, thus giving warning that the cupola
should be tapped.
Cupolas may use either coke or anthracite coal for fuel,
coke being the most generally used. In preparing the cupol?
the bottom doors are closed and a sand bottom, usually com-
posed of gangway sweepings or similar material, is built on
them. This is tempered the same as molding sand and
rammed down as in molding, being rammed harder at the
THE CUPOLA AND ITS OPERATION 249
bottom than at the surface. It is inclined toward the tap-hole
so that the tendency will be for all iron to drain out. The fire
in the cupola may be lighted either with wood or by means of a
gas or oil burner. In the former case shavings are laid on the
bottom with enough wood over them to insure thorough ig-
nition of the coke. A bed charge of coke is placed in the cupola
before any iron is charged and this is of considerably greater
weight than the subsequent charges of coke which are charged
alternately with charges of iron. A portion of this bed charge
is laid on the wood and after it is thoroughly ignited the re-
mainder of it is introduced into the cupola, only enough being
reserved to level off the top of the bed charge before intro-
ducing iron.
When the coke is to be ignited by means of a gas or oil
burner a space is left in front of the breast opening and one or
two channel ways are formed, leading nearly to the back of
the cupola, by pieces of coke laid end to end, through which
the flames of a burner will pass. The channels are covered
with pieces of coke, and one-half to one-third of the bed charge
placed. The burner is then laid in the spout of the cupola
and kept back from the breast opening a distance of about
four inches. It is lighted and regulated so that the flame at
the burner will be blue, changing to purple tipped with yellow.
It is kept on until the coke is thoroughly ignited, usually a
period of thirty minutes with the oil burner and somewhat
less with the gas. On its removal, the breast is built as will be
described later and the blast turned on to thoroughly ignite
the entire charge of coke on the bed. When the blast is put
on, the remainder of the bed charge is introduced into the
cupola with the exception of enough reserved to level it before
charging the iron.
When the fire is visible through the coke, as viewed from
the charging door, and the bed charge is leveled, charging
should begin, as the fire should not be permitted to
burn red hot. If the coke appears to be burning more
freely on one side than on the other some of the coke reserved
for leveling is thrown on that side and the peep-holes opened
25O FOUNDRY PRACTICE
or closed to force the air to the side which has burned the least.
The more evenly the coke is burned the better will the cupola
melt and the better will be the grade of iron obtained for the
mold.
The breast is now built in and the tap-hole formed. Three
different methods of doing this are in general use. When the
shavings and wood used to fire the cupola have burned away
the coke will settle down on the sand bottom in front of the
breast opening. Any coke that may have fallen into the open-
ing is removed and a tapered iron pin is laid in the tap spout,
small end in, projecting into the cupola. With small pieces
of coke a wall is built in front of the burning coke and in front
of this wall the same mixture of fire-clay mud that is used for
lining the cupola (see page 258) is rammed, after which the iron
pin is withdrawn, leaving a tap-hole in the breast. The wall of
coke soon ignites and dries out the breast. The second
method consists in building the wall of coke as before, leaving
quite a space in front of it. Wet shavings are forced against
the coke, after which the pin is placed and the fire-clay breast
rammed up as before. The third method utilizes a board with
a notch in its lower edge which fits over the tap-hole pin and
which is laid against the wall of coke. The breast is built
against this board. Instead of fire-clay mud, some melters
will use for the breast a mixture of molding sand wet with
claywash, while others make use of any natural loam which
may be found in the vicinity.
The breast being in, it must be ascertained that the top of
the bed charge is at the correct height. Every cupola has a
melting zone above the tuyeres where it is the hottest, this
zone being known as the melting zone. In a cupola which has
been running for some time, this melting zone is easily ascer-
tained by the condition of the lining which will be burned
away to a certain extent as shown in Fig. 142. A rod with one
end bent to a right angle to hang on the edge of the charging
door may be provided, its length being such that it will drop
in the cupola to the highest point of the melting zone. The
bed charge should then be brought up to the lower end of this
THE CUPOLA AND ITS OPERATION
251
FIG. 142. — CUPOLA CHARGING ARRANGEMENT. Also shows effect of wear
on lining.
252 FOUNDRY PRACTICE
rod. The use of a small amount of coke in the bed charge will
lower the melting zone and a large amount will raise it. With
a new cupola some experimenting is necessary to ascertain the
proper height at which best results will be obtained before the
amount of bed charge and its height are definitely determined.
The quality of the iron melted will be influenced by this, as
scrap will -melt earlier than heavy pig iron, and if a large pro-
portion of the former material is used the melting zone should
be somewhat lower than if the bulk of the charge is pig iron.
The quality of the melted iron is usually better with a high bed
than with a low one. With a new cupola it is advisable to be
on the safe side and start with a high bed, say twenty- two
inches above the upper tuyeres, and by examination of the
lining the following morning determine whether or not the
amount of the bed charge should be reduced.
The bed charge of coke having been brought to the right
height, iron is introduced on it. The amount of the first
charge of iron varies with different melters, ranging all the
way from two and one-half pounds of iron per pound of coke
in the bed charge to four pounds of iron per pound of coke.
The amount of iron charged depends also on the total amount
of iron to be melted in the heat and this also governs the size
of the subsequent charges of iron and coke. Assume that our
first charge of coke was I ,500 pounds. On this will be
charged 4,500 pounds of irorT On this charge of iron will be
placed 256 pounds of coke and on the coke a charge of_2.,5OO
pounds of iron. This ratio of coke and iron is maintained
throughout the remainder of the heat. The arrangement of
the various charges of coke and iron is shown in Fig. 143. We
will later discuss the question of varying the size and weight of
the charges of coke and iron, with their effect on the operation
of the cupola.
In charging with iron, the pig iron is usually placed in the
cupola first, and on top of this the scrap. The scrap being free
from scale usually melts more rapidly than the pig iron, and
the pig iron being charged so as to reach the melting zone first,
the two are usually melted at about the same time. The
THE CUPOLA AND ITS OPERATION
253
charging of coke and iron alternately continues until the cupola
is filled to the desired height or the amount of iron needed for
the heat has been charged. If the cupola will not hold enough
iron for the heat, after it has been filled to the level of the
FIG. 143. — CUPOLA CHARGING ARRANGEMENTS. Also shows arrangement
of coke and iron charges.
charging door, subsequent charges are added as the bed settles,
due to iron being withdrawn through the tap-hole and the coke
burning away. If heavy scrap is used it is generally charged
254 FOUNDRY PRACTICE
with the second lot of iron, a little coke being mixed with it to
assist in its rapid melting.
A certain amount of slag is required in cupolas to prevent
the iron from being burned away by the action of the blast.
It is also necessary to prevent the molten iron in the basin from
being decarbonized. Frequently the coke will contain suffi-
cient impurities to form slag enough to protect the iron, but
with clean iron and fuel slag will not form in sufficient quanti-
ties in small heats. It is therefore necessary to introduce a
material to form slag; and limestone, marble dust or fluor-spar,
or any other material containing lime, should be charged with
the iron, commencing at about the fifth charge and using
approximately sixty pounds of limestone per ton of iron. The
particular amount, however, depends on local conditions, being
governed by the analysis of the fuel and iron and also by its
effect on the lining. Sufficient slagging material must be
added to insure the slag being sharply fluid, and yet any excess
of limestone will attack the fire-brick lining of the cupola and
will also influence to a certain extent the quality of the iron
melted. If marble dust is used, six pounds per ton of iron will
usually give a good slag of sufficient quantity.
Certain foundrymen do not slag their cupolas, these being
larger than are necessary to give the amount of iron needed at
any one time. However, if the cupola is to be driven to the
limit of its capacity, slagging is absolutely essential. If the
quantity of slag formed is not too great, it may be allowed to
remain in the cupola until the end of the heat. As it rests on
top of the iron in the basin none of it will run out of the tap-
hole unless the level of the iron is lowered to below the upper
edge of the tap-hole. However, if it is necessary to use a
considerable quantity of slagging material, provision must be
made to remove it through the slag-hole continuously. If
allowed to accumulate, it may bridge or scaffold above the
tuyeres and give trouble in the operation of the cupola.
The cupola being charged, it will be well to allow it to
stand for about half an hour before the blast is put on. The
lower charges will then be heated to such an extent that when
THE CUPOLA AND ITS OPERATION 255
the blast is put on melting begins rapidly and evenly and con-
tinues at a uniform rate throughout the heat. The blast
being put on, iron shortly begins to run sluggishly from the tap-
hole which has been left open. It becomes hotter and hotter
until finally it is perfectly fluid. The melter then closes the tap-
hole with a bod of fire-clay and allows the iron to accumulate
in the basin until there is a sufficient quantity to pour the first
lot of molds. Should the tap-hole be closed as soon as the iron
began to flow, the iron might cool in the bottom of the cupola
and harden in front of the tap-hole, making it extremely diffi-
cult to tap the cupola later. In tapping the cupola care must
be taken that the tap-hole be kept free of slag and iron, and
also that while boding up, or closing the tap-hole with clay,
parts of each bod are not left around the tap-hole each time,
thus building it out from the breast. If this care is not
taken, it will eventually become difficult or impossible to bod
up the cupola, and the iron will run out until the cupola is
empty.
The clay to form the bods for the tap-hole should be one
that will not bake too hard, else it will require a tapping bar and
a sledge to drive the bod out of the hole when it is desired to
tap the cupola. The clay used should be one that will bake
hard enough to hold the iron, yet one which will break com-
paratively easily. If the clay alone bakes too hard, white-pine
sawdust, seacoal, or similar material may be added to it. The
tapping-bar must be kept clean and pointed, which can be
accomplished by holding the end in the stream of iron flowing
from the cupola. Before making the hole in the breast, the
clay on the breast around the bod should be slightly cleaned
with the point of the tap-rod, which will prevent trouble due
to the bods building out on the breast. In closing the tap-hole
the rod with the bod of clay on the end should be held above
the stream of iron, and the bod forced down. If it is attempted
to force the bod up through the iron, it is liable to be washed
from the rod, which may cause serious trouble before it can
be replaced.
After the cupola is in operation, the pouring-spout should
256 FOUNDRY PRACTICE
be observed closely to ascertain when it is necessary to open
the slag-hole. When nearly all the iron has run from the basin
during a given tap, a small quantity of slag may appear on
the surface of the iron as it flows down the spout. This is
evidence that by the time the basin has filled with iron for the
next tap a considerable quantity of slag will have accumulated
on top of the iron. Shortly before the next tap, therefore, the
slag-hole, which has been closed with a bod of molding sand and
molasses water, is opened and the slag permitted to escape.
After the slag has once commenced to run freely, the slag-hole
will take care of itself, the slag rising on top of the iron as it
collects in the basin, and flowing out through the slag-hole
whenever it rises to that level.
It is customary to charge a few hundred pounds more of
iron into the cupola than are required to pour all the molds,
as the last iron out of the cupola always has more or less slag
on it, which would render defective castings which later must
be machined. Consequently the last castings to be poured
should be those of a rough character requiring no machining.
If all the castings are to be of a good character the iron cannot
be totally drained from the cupola for them and the last few
hundred pounds are run into ingot molds or pig beds. When
all the iron has been drained from the cupola, the spud is
knocked from beneath the bottom doors or pulled out by
means of a compressed air attachment, and the coke in the
cupola falls to the floor. In most large foundries a series of
iron hooks are placed under the cupola, points upward, so that
the mass of coke may be pulled from under the cupola by means
of a chain and a compressed air hoist, thus tearing the mass
apart and distributing it so that it can be readily quenched
by a stream from a hose and considerable coke thereby saved.
It is absolutely essential that the spot on which the mass from
the cupola drops be perfectly dry. Otherwise there will be a
generation of steam which in expanding will throw the red-hot
coke in all directions, burning the workmen and doing damage
to the building. Occasionally, when the drop takes place,
all the material above the tuyeres does not come with it, being
THE CUPOLA AND ITS OPERATION 257
scaffolded in the cupola. However, as the coke burns away
during the night this material will fall, although occasionally
it has to be poked down by means of bars inserted through the
peep-holes in the tuyeres or broken down by pigs of iron thrown
through the charging door. This latter occurrence happens
most often when the cupola is not slagged.
The following day the lining of the cupola should be in-
spected and repaired before it is charged for that day's run.
Cupolas are built with either a single or double lining, the first
consisting of a lining of heavy cupola blocks of fire-brick, the
second of two rows of fire-brick one inside the other. The
advantage of the double lining is that it is considered to give
greater protection to the shell, while the single lining permits
relining to be accomplished more quickly than does the double
lining. It, however, requires more careful watching than the
other and may, if not attended to, break through at a time
when the cupola is in operation, which will be evidenced by the
shell becoming red hot opposite the hole in the lining. If
possible, this spot should be cooled by a plentiful application
of cold water to the shell and the cupola kept in operation until
the heat is finished. However, if the red spot shows a ten-
dency to enlarge, the blast should be shut off and the bottom
dropped. It is sometimes possible to repair temporarily a
break in the lining while the cupola is in operation by throwing
in fire-brick and fire-clay mud through the charging door im-
mediately above the place where the hot spot shows. These
will fuse and find their way into the break and repair it suffi-
ciently to finish the heat. Wetting down of the shell should
continue nevertheless until the heat is ended.
The care of the lining and the method of charging have
much to do with the life of the cupola. The fact that the lining
burns out rapidly is not necessarily an indictment against the
brick of which it is composed, but may indicate lack of care on
the part of the melter. In lining the cupola for the first time,
a space of about five-eighths inch should be left between the
back of the brick and the shell of the cupola, and grouting —
a thick claywash — poured in behind them. The fire-brick
17
258 FOUNDRY PRACTICE
composing the lining are set in a thick claywash, termed butter.
The brick should be laid as closely together as possible and the
rows buttered together. The brick are grouted at the back to
avoid chipping where they come against rivets in the shell, and
they must be carefully fitted around the tuyeres and lining
shelves. Otherwise they are laid up in regular rows, with broken
joints. The lining below the level of the charging door is
considerably thicker than it is above, as this portion of it not
only has to resist the more intense heat but also the abrasion
of the fuel and iron. Frequently the lining above the charging
door is composed simply of common red brick of good quality.
After the lining is completed it should be thoroughly dried out
by a fire built in the bottom of the cupola.
A lining built as above must be repaired after each heat
with a mud composed of sand and clay wet with water,
all foreign matter which may be clinging to the lining being
first removed with a pick or chisel, care being taken not to
break away the surface of the lining if it can be avoided. The
mud is applied by throwing it in handfuls against worn spots
in the lining and afterward smoothing it with a trowel so as
to conform as closely as possible with the original shape of the
lining. The slag-hole is formed by placing a gate-stick at the
proper point and daubing mud around it, afterward removing
the stick and filling the opening with a mixture of sand and
molasses water. The cupola lining will require but little re-
pairing during the first few heats, but after a long period of
operation holes of considerable size may be burned in it and
these should be filled with small pieces of fire-brick and the mud
laid in around them. The space to be repaired in a cupola
usually extends some three or four feet above the tuyeres as
shown in Fig. 142, and also in Fig. 144, the latter illustrating
the method of making certain classes of repairs. When the
variety of clay available for lining repairs is of poor quality,
a large quantity of sand of high fusion should be mixed with
it to render it more refractory. If the fusing point of the clay
is low, the mud repair may melt and run down and choke the
tuyeres as shown in Fig. 144. Again, the daubing may become
THE CUPOLA AND ITS OPERATION
259
broken away and permit the charge to enter in back of it as
shown in the same illustration, finally breaking the lining away
and scaffolding the cupola. When this occurs the iron melts
slowly, as the charge cannot work its way down to the melting
zone and it is necessary to drop the bottom and thus lose the
LINING MELTII
RUNNING DOV
TUYERE
INING CRACKING
>M BRICK. COKE FOLLOWING
IN BETWEEN, AND
THROWING CHARGES.
PROPER WAY TO REPAIR BADLY
FIG. 144. — FAILURES OF CUPOLA LININGS AND CORRECT AND INCORRECT
METHODS OF MAKING REPAIRS.
heat. The proper method of making extensive repairs to the
lining is also shown in this illustration.
A great deal of useful information regarding the operation
of the cupola is given by Bradley Stoughton in an article in
The Foundry in October, 1907. Mr. Stoughton divides the
cupola into four zones: (i) The crucible zone or hearth extend-
ing from the bottom of the cupola to the tuyeres. (2) The tuyere
rone where the blast comes in contact with and burns the
red-hot coke. This is the zone of combustion. Its upper
limit depends on the blast pressure, and the higher the pres-
sure the greater will be the height of the zone. The top of the
zone should never be allowed to go 15 to 24 inches above the
tuyeres. (3) The melting zone where all melting takes place.
It is situated immediately above the tuyere zone and the lower
part of it overlaps the latter. Iron of the charge should begin
to melt as soon as it enters the melting zone and should finish
melting at a point about seven inches lower down, the iron
and coke sinking as the latter burns away. Each charge of
iron should enter the melting zone just before the last previous
charge is completely melted at the bottom. (4) The stack ex-
260 FOUNDRY PRACTICE
tending from the melting zone to the level of the charging door.
Its function is to contain the material, permitting it to absorb
heat and thus prepare itself for the action at the lower level.
The blast pressure should depend on the size of the cupola,
but present practice favors a pressure of not over one pound
per square inch, diminishing to one-half pound in the smaller
sizes of cupolas. As one pound of coke requires about sixty
cubic feet of air for burning it, the size of the blower necessary
may be calculated. Makers of blowers advocate pressures
and volumes too high for good cupola practice. If the pressures
and volumes advocated by them are adopted unqualifiedly,
the melting zone will be raised and the iron oxidized, due to its
greater drop to the hearth through the incoming blast.
Melting should begin within fifteen minutes of the time
that the blast is put on. If it takes longer than this the bed
charge of coke has been made too high and coke is wasted.
The first layer of iron should be completely melted in eight to
ten minutes. The thickness of the various layers of coke should
be such that the next layer of iron should enter the melting
zone just as the previous one is melted. If the layers of coke
are made thicker than this, coke is wasted. If the iron layer
is too thick the last of the layer will melt near the tuyeres and
will oxidize excessively and be cold. The fact that the iron
layers are too thick may be noted by the iron running first hot
and then cold from the cupola spout.
It is important to watch the flames from the stack. Too
great a volume of blast is indicated by a "cutting" or oxidizing
flame, and also by the projection of sparks from the slag-hole.
If the layers of iron and coke are too thin, there will be two
charges of iron in the melting zone at one time. This will be
made evident by the iron flowing more freely from the cupola
spout at one time than another. If very hot iron is desired
the coke layers must be made thicker, with a consequent
diminution in the rate of melting.
Concerning the absorption of sulphur by the iron from the
fuel, Mr. Stoughton says that the absorption will range from
0.020 to 0.035 Per cent and that pig-iron with a sulphur con-
THE CUPOLA AND ITS OPERATION 26l
tent of 0.08 per cent will give castings in which the sulphur
will range from o.io to 0.115 per cent. The sulphur will be
higher in the first iron to come down than in the iron ob-
tained at the middle of the heat because of the extra amount of
coke in the bed charge. The iron obtained at the end of the
heat will also be higher in sulphur because of the greater loss of
metal at the end of the run due to better oxidizing condi-
tions and consequently greater concentration of the metal.
Silicon to the extent of 0.25 to 0.40 per cent may be burned out
of the iron in its passage through the cupola. An allow-
ance must be made for this in calculating the character of the
charge.
In this same article, Mr. Stoughton published a table of
comparative cupola practice which is reproduced below.
Commenting on this table, Mr. Stoughton says that a mixture
of coal and coke, or an inferior coke gives slow melting and a
poor fuel ratio. The next striking evidence from the table are
the figures given by the relation of the tuyere area to the
speed of melting. If an average iron is melted in cupolas
whose area is less than 6.56 times the tuyere area, we have
a melting speed of 22.56 pounds per minute. For lesser
proportional tuyere areas the figure is 18.57 pounds. Slow
melting in cupola No. 8 is evidently due to the low height of
the stack, which caused the iron to reach the melting zone
before it was sufficiently preheated. A large proportional
tuyere area means that the blast passes through the tuyeres
with less resistance and with lower velocity. An important
figure in the table is the relation between the speed of melting
and the height of the charging door above the tuyeres, divided
by the diameter of the cupola. The average melting speed
where this ratio is over 2.5 is 24.12 pounds per minute.
When the ratio is under 2.5, the melting speed drops to 19.15
pounds per minute. An exception to this rule is shown by
cupolas Nos. 6 and 3. Cupola No. 6 melts faster due to its
larger proportional tuyere area, while cupola No. 3 melts
slower due to its lower proportional tuyere area. The average
speed of melting with cupolas of more than 12 ounces blast
262
FOUNDRY PRACTICE
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THE CUPOLA AND ITS OPERATION
263
pressure is 20.75 pounds per minute, while the rate with less
than 12 ounces is 21.53. .The divergence here is not great
enough to establish a rule, but it is sufficient to discredit the
theory that a high blast pressure necessarily gives fast melting.
This last statement is apparently borne out by an article
by Mr. W. B. Snow, published in The Foundry in August,
1908. Mr. Snow gives a table showing the record of capacity
and the blast pressure of a number of cupolas as follows:
TABLE XI. — CAPACITY AND BLAST PRESSURE OF CUPOLAS
Diameter of lining,
in
44
44
47
49
54
54
54
60
60
60
74
Tons per hour
6.7
7-3
8.4
9-1
7-7
8.8
10.2
12.4
14.8
13.8
13-0
Pressure, oz. per sq.
in
12.9
16.4
I7-S
II.8
13-6
II. O
20.8
15.5
16.8
12.6
8.7
Mr. Snow says that for a given cupola and blower the
melting rate increases with the square root of the pressure.
Thus a cupola which melts nine tons per hour with a pressure
of 10 ounces will melt about ten tons with a pressure of
12.5 ounces and n tons with 15 ounces. The power re-
quired varies as the cube of the melting rate, so for n tons
(n •*• 9)3 = 1.82 times as much power will be required as
for 9 tons. Thus large cupolas and blowers using light pres-
sures have a distinct advantage.
The ratio of iron to fuel in the cupola is shown by a series
of tables in the eighth edition of Kent's "Mechanical
Engineers' Pocket-Book," page 1227. These are taken from
the charging list of several stove foundries.
TABLE XII
Bed of fuel, coke 1,500 Ib.
First charge of iron 5,ooo Ib.
All other charges of iron
First and second charges of coke, each .
Four next charges of coke, each
Six next charges of coke, each
Nineteen next charges of coke, each. . .
[ ,000 Ib.
200 Ib.
150 Ib.
120 Ib.
100 Ib.
264 FOUNDRY PRACTICE
Thus for a melt of 18 tons, 5,120 pounds of coke are re-
quired, giving a melting ratio of 7 to i. If the amount of iron
melted is increased to 24 tons, the melting ratio of 8 pounds
of iron to one of coke is obtained.
TABLE XIII
Bed of fuel, coke 1,600 Ib.
First charge of iron 1 ,800 Ib.
First charge of fuel 150 Ib.
All other charges of iron, each 1,000 Ib.
Second and third charges of fuel, each 130 Ib.
All other charges of fuel, each 100 Ib.
For an 1 8-ton melt, 5,060 pounds of coke are needed, the
melting ratio thus being 7.1 pounds of iron to one pound of
coke.
TABLE XIV
Bed charge of coke 1,600 Ib.
First charge of iron 4,000 Ib.
First and second charges of coke, each 200 Ib.
All other charges of iron, each 2,000 Ib.
All other charges of coke, each 150 Ib.
Thus 4,100 pounds of coke will be required to melt 18 tons
of iron, giving a melting ratio of 8.5 to I.
TABLE XV
Bed charge of fuel, coke 1,800 Ib.
First charge of iron 5>6oo Ib.
All charges of coke, each 200 Ib.
All charges of iron, each 2,900 Ib.
The melting ratio in a melt of 18 tons is 9.4 pounds of iron
to one pound of coke, 3,900 pounds of fuel being used.
TABLE XVI
Bed of fuel, coal 1,900 Ib.
First charge of iron 5,ooo Ib.
First charge of coal 200 Ib.
All other charges of iron, each 2,000 Ib.
All other charges of coal, each 175 Ib.
THE CUPOLA AND ITS OPERATION 265
The melting ratio in a melt of 18 tons is 7.7 pounds of iron
to one pound of coal, 4,700 pounds of coal being used.
Calculating Cupola Mixtures. — To produce uniformly
good castings, materials must be uniform and all supplies in-
cluding pig iron, coke, etc., should be analyzed and their com-
position determined. By calculating charges which have been
put into the cupola, and comparing these calculations with
the analyses of good castings made from these charges,
melting losses and changes in composition of the iron
occurring in the cupola, can be ascertained. After the
melting factor has thus been determined, proper mixtures
can be made and the cupola can be studied to still further
improve the quality of its output. What follows in regard
to this subject is abstracted from a lecture by Dr. Richard
Moldenke, before the students of the Case School of Applied
Science.
If the analysis of a series of good boiler castings shows that
they should contain about 1 .90 per cent silicon, not over 0.05
per cent sulphur, and not over 0.40 per cent phosphorus, the
carbon and the manganese being those of normal irons, then
the mixture must contain the silicon wanted, plus that burned
out during the melting (about 0.25 per cent). The sulphur
of the mixture must be at least o.oi per cent lower, as this
amount is always added by unavoidable contact with the fuel.
The phosphorus need be but slightly lower, as the melting acts
somewhat in the way of concentration, the bulk of the heat
becoming 4 to 7 per cent smaller, which percentage is called
the melting loss.
In calculating mixtures we must deal with the following
elements: Pig iron, scraps of various kinds, the fuel, and the
limestone flux. The pig iron may have been cast either in the
sand bed of the blast furnace or in chill molds, and it may be
either charcoal, coke, or anthracite iron, depending on the fuel
with which it is smelted. Furthermore, it may be either
cold-blast or warm-blast charcoal pig iron. The order of ex-
cellence is from the finest cold-blast charcoal iron down to the
poorest cinder-made, hot-blast coke iron. Cupola mixtures
266 FOUNDRY PRACTICE
may contain only one variety or can be built up from twenty-
three pig-iron ingredients.
The scrap used may be either made in the foundry or
bought. The former is simply the bad castings, the gates
and sprues of previous melts, and we should know all about it.
The bought scrap, however, will often upset all calculations as
to quality, when used in too great a quantity. In addition
we may add steel scrap to strengthen castings and then malle-
able scrap, wrought-iron scrap, cast-iron borings, steel borings,
etc.
The chemical composition is the basis of all preparations
and mixtures for building up a heat for castings. The prep-
aration of a mixture begins when the pig iron is received in the
foundry yard. The metal should be piled in such a way that
the foundryman may be sure of uniform material when he uses
it. This is best done by spreading the first car-load of a given
composition in a long row of pigs. The next car-load goes on
top of this and so on till the pile is man high. Another pile is
then commenced. By drawing from the end of the first pile,
an average of all the car-loads thus stacked is obtained and one
analysis will do for many car-loads of pig iron. In this way
one can use specifications to an advantage, for, with a given
class of work, such as miscellaneous car castings, it is possible
to specify, say, four grades of iron containing, respectively,
silicon contents of 1.75, 2.00, 2.25, and 2.50. Of the two
extremes, but little will be wanted, but the bulk will be 2.25
silicon iron. Now by placing all car-loads with less than ten
points of silicon below that required on the next lower pile,
a satisfactory arrangement is obtained and one can build up
a mixture at the desk and be sure that it will work out right.
In general, the more scrap used, the cheaper the mixture,
but also the greater the melting loss. A good mean is usually
60 per cent pig and 40 per cent scrap. This is for general
jobbing castings, as special classes of work often require pig
iron only. In calculating a mixture, suppose that the limit
for silicon be 2.15 per cent in the castings, then the 0.25 per
cent lost in melting added to this will g.ive us a requirement
THE CUPOLA AND ITS OPERATION 267
of 2.40 per cent silicon in the mixture. Assume the cupola
to be charged in 4,ooo-pound layers of metal with the coke-to-
iron ratio one to eight. Of these 4,000 pounds of metal which
should, at 2.40 per cent silicon contain 96 pounds of silicon,
the pig iron is to form 60 per cent of the charge or 2,400
pounds, and 40 per cent or 1,600 pounds should be scrap.
Scrap usually contains less silicon than the castings of the
particular class from which the scrap originated and, therefore,
for our purpose, the scrap may be considered to contain 2.00
per cent silicon, or 32 pounds. The pig iron must contain the
other 64 pounds and hence must have an approximate silicon
content of 2.65. This example, which by the way is of soft
machine castings of medium size, shows that the yard must
contain irons of higher silicon contents than those given above.
They should run in this case 2.00, 2.25, 2.50, and 2.75 per cent.
We note that with pig irons averaging 2.65 per cent silicon
desired, the mixture will be from irons between the 2.50 and
the 2.75 limits. A simple trial calculation shows that 2,000
pounds of the 2.75 mixture and 400 pounds of the 2.50 silicon
iron will give the proper results. The mixture table is as
follows :
1,600 lb. scrap, 2.00 per cent Si 32.0 Ib. Si.
2,000 lb. pig iron, say Warwick, 2.75 per cent Si. ... 55.0 lb. Si.
400 lb. pig iron, say Clifton, 2.50 per cent Si. ... 10.0 lb. Si.
4,000 Average 2.40 97.0
It is advisable to have in the foundry yard a quantity of
iron containing 4.00 to 5.00 per cent silicon to correct a sudden
tendency downward of the silicon in the mixture as the result
of an improper working of the cupola or furnace. This also
enables us to use lower silicon and therefore cheaper irons
in the mixture. However, this is not conducive to the best
results which are obtained by putting into the cupola a§ nearly
as possible what is desired to obtain from it.
In charging steel scrap, this must be selected from boiler-
plate, structural material, or steel castings if obtainable. It
268 FOUNDRY PRACTICE
must be neither too thick nor too thin, otherwise an irregular
melting will result. Twenty-five per cent is a good amount
to use for very strong work. It can be increased to 40.00 per
cent if desired, but anything above 25.00 percent will take up
so much carbon from the fuel that the value as a reducer of
the total carbon is gone. Where much steel is used, from 2.00
to 4.00 per cent of ferro-manganese should be put in the ladle,
as the added steel raises the melting point of the metal and the
ferro-manganese is able to act as a deoxidizer which is im-
possible with the low temperatures of ordinary gray iron.
Sulphur must be kept low or there will be trouble with
light castings. The calculation of sulphur in a mixture is
similar to that given above for silicon, but if precautions are
taken to keep the pig iron low in sulphur, this element need
not be considered in mixture calculations. Not only do we
have to contend with sulphur in the iron but also in the fuel.
From o.oi per cent to 0.07 per cent is added to the iron in
the cupola, depending on the sulphur in the fuel. It seems
that only the sulphur which is in the ash of the coke enters
the iron and especially when the heat is run cold. It is there-
fore best to use plenty of fuel to get a good hot iron, and most
of the sulphur will be driven off before it has a chance to com-
bine with the iron.
While the importance of silicon and sulphur has been
specially dealt with, it is their effect on the relations on the
carbon content of the iron that is really aimed at. Whether
a piece of iron is gray and soft, gray and hard, mottled or
white and amenable only to the emery wheel depends to a
large extent upon the proportion of combined carbon present.
Thus in 3.3 per cent total carbon of which 0.2 is combined
and 3.3 per cent is graphitic, the casting is practically a 2O-car-
bon steel, although it is a soft gray-iron casting. If the total
carbon is diminished to 2.80 per cent with the combined
carbon the same, we have a much stronger iron, yet one which
is easily machined. If the combined carbon is increased the
matrix becomes a tool steel with whatever graphitic carbon
is present to weaken the metal. This casting, however, is
THE CUPOLA AND ITS OPERATION 269
now hard to machine. Increase the combined carbon to the
full amount of the total carbon, and we have a white iron
such as is used for rolls, malleable castings, etc., and which
usually require subsequent treatment to make them service-
able. The state of the graphitic and combined carbon in the
casting is the result of several variable conditions. The silicon
content when above 1.75 per cent makes gray to black
fractures in a casting, and when below may make fractures
ranging from light gray to dead white. The second vari-
able is the thickness of the casting which controls the cool-
ing rate after the metal is poured. Lastly, the temperature
of the melt has its effect, a hot pour making a harder iron
than a cool one.
The making of a good mixture is not a guarantee that the
castings will be right, for, after tapping, there are many
opportunities to spoil good work. The metal may be poured
too hot or held too long before pouring. The molds may be
badly vented and the iron may be poured so that it will shot
or so that slag enters the mold. Hence the necessity of cool-
ness and good judgment in applying remedies for manifest
evils lest greater ones result.
The following method for calculating mixtures for the
cupola is given in The Foundry, October, 1907: " It is required
that the analyses of the iron from the cupola be as follows:
Silicon i. 60 per cent, phosphorus 0.70 per cent, sulphur
less than o.io per cent, manganese less than 0.50 per cent.
Previous experience with iron and coke shows, due considera-
tion being given to local melting conditions, that the approxi-
mate loss of silicon in the cupola will be 0.25 per cent and of
manganese o.io per cent, the sulphur increasing at the
same time 0.03 per cent. The iron and the scrap to be
charged, therefore, must have an average analysis as follows:
Silicon 1.85 per cent, phosphorus 0.70 per cent, sulphur less
than 0.07 per cent, manganese 0.60 per cent. A table
similar to that given below is then made, showing various
weights of metal to be charged, the analyses of the different
metals, and the weight of silicon, sulphur, phosphorus, and
2-0
FOUNDRY PRACTICE
manganese contained in a given quantity of each iron. From
the classes of metal available to form the mixture, selections
are made of the proper quantity to give the respective amount
of silicon, sulphur, phosphorus, and manganese necessary to
give the desired average composition. The weight of each
element is found by multiplying the percentage of each ele-
ment in the different classes of material charged by the
weight of that material, and by dividing the total weight of
each element by the total weight of the material charged,
the percentage composition of the mixture is determined.
By making adjustments of the pig iron and scrap, mixtures
of any desired analysis can be made."
TABLE XVII. — MATERIAL TO BE CHARGED AND METHOD OF FIGURING
ANALYSIS PER CENT
WEIGHT OF *
Si
S
p
Mn
Si
S
P
Mn
Steel scrap
400
O.IO
0.07
O.IO
0.60
0.40
0.28
0.40
.40
Machinery scrap
High sulphur Southern
2,000
i, 600
1.70
0.70
O.IO
O. IO
1 .00
1.50
0.60
0.30
34-00
ii .20
2.OO
I. 60
2O.OO
24.OO
i .00
.80
No. IX
i, 600
3.00
0.03
0,80
1.25
48.00
0.48
12.80
2 .OO
No. 3 foundry
High silicon
4,000
800
i. 75
3.SO
0.07
0.025
0.30
0.07
0.60
0.60
70.00
26.00
2.80
O.2O
12.00
0.56
i .80
< .80
Total
Percentage
10,400
191 .60
1.84
7.36
O.O?!
69.76
O.67
68.00
0.65
* Multiply the weight of each kind of material by the percentage of the element in it
and divide total weight of each element by total weight of material. By relative adjustment
of pig iron and scrap, mixtures for any desired analysis can be made.
CHAPTER XXV
THE AIR-FURNACE AND ITS OPERATION
INSTEAD of the cupola, the air-furnace, more properly
known as the reverberatory furnace, is used for melting iron
for foundry practice, especially where malleable castings are
to be made. The air-furnace has a number of advantages
over the cupola and also certain disadvantages. These ad-
vantages may be summed up as follows: It is economical
of fuel, can be cheaply constructed and easily repaired. It
may be started at any time from the cold condition and can
be quickly cooled after use. It requires no expensive auxiliary
machinery, such as blowers, gas producers, etc. Its principal
disadvantage is that it consumes a greater length of time to
melt the same tonnage than the other forms of melting
apparatus and the metal coming out of it at the end of a heat
is liable to be burned. The most serious disadvantage is
that the action of the flame in the furnace is such as to notice-
ably increase the sulphur content of the iron, an amount of
0.3 per cent frequently being added when the coal used is
high in sulphur. Furthermore, metal cannot be long held in
an air-furnace after it is ready for pouring unless the quality
required is not of the first importance. This necessarily limits
the size of the furnace.
The illustrations, Figs. 145-149, show a typical air-furnace.
At the extreme front of the furnace is a fire-box G, containing
grate-bars on which the coal for melting the metal is burned.
Behind this and separated from it by a bridge wall H, is the
bath or hearth A. This is built on a stone foundation over
which are laid two courses of fire-brick, these being covered
with a thick layer of silica sand to form the hearth. At the
rear of the bath is another wall forming, with the end of the
furnace, a down-take leading to a flue which conveys the waste
271
272 FOUNDRY PRACTICE
gases to the stack. The roof of the furnace over the fire-box
is of arch form and slants downward toward the bridge wall
as shown. The roof over the bath is formed of cast-iron bungs
constructed, as shown in Fig. 149, of iron castings with the tie
rods F extending across them, which when the bung is lined
with fire-brick are tightened to hold the fire-brick in place.
These bungs may be lifted off the furnace to permit charging,
which is done by laying the iron on the hearth. Tapping
spouts are provided in the side of the furnace, as are also
charging doors through which material may be placed in
the furnace if desired. The flames, rising from the fire on
the grate-bars, are deflected by the sloping roof so that they
strike and play upon the metal in the hearth, thus melting it
down to a liquid for pouring.
The hearth is composed of silica sand which is sintered
before the furnace is put in operation. Sand is rammed down
on top of the brick to a depth of about two inches. The
bungs are then put in place and the furnace fired until the sand
fuses together. When the first layer has set another layer is
shoveled in and the operation repeated, the process continuing
until the hearth is of the necessary thickness, which ranges
from six to eight inches. The hearth must be so formed that
the iron will run on it toward the tapping spout. If this is
not done a hoe must be used to empty all pools left in the bot-
tom when the furnace is drained. A good mixture of sand
for the hearth is two parts of silica sand, with a silica content
of 95 per cent or more, to one part of ground silica rock.
The shape of the hearth is important, as there may be
a thin feather of metal around the edge of the hearth, which
may become badly burned during the course of operations.
If the bottom is cut away to a certain extent, around the edge
of the bath, the metal may then be given a thickness of two
or three inches at this point, which, in connection with the
slag covering it, will suffice to prevent burning. Three spouts
at different levels are recommended by Dr. Moldenke in
order that the iron at the surface of the bath may be tapped
first and burning thereby avoided.
THE AIR-FURNACE AND ITS OPERATION
273
When preparing the furnace for the day's heat, the bungs
are removed and the furnace thoroughly cleaned out. If the
sand below the hearth has been injured, it is re-formed and
repaired, this being done while the furnace is hot so that the
new sand will bake on the old. The hearth is then made up
FIG. 147 PLAN
FIQ. 146 SIDE ELEVATION
_ Stack
SECTIONAL ELEVATION
FIGS. 145-149. — TYPICAL AIR-FURNACE.
with a mixture of fire-sand and red clay. Red clay should
be used sparingly, as it has a tendency to crack in drying, per-
mitting the iron to flow down underneath the surface and
float the bottom up. In charging the furnace, sprues are
usually placed on the hearth first, being spread evenly over
the bottom. Over them the pig-iron is piled, half the charge
18
274 FOUNDRY PRACTICE
at each end of the furnace. This method of charging permits
the iron to melt gradually, which would not occur were all the
metal to be thrown in promiscuously and the charge would
require perhaps an hour longer to melt it.
Westmoreland County (Pa.) coal is advised for firing an
air-furnace. The best practice gives about four pounds of
iron melted for every pound of fuel burned.
As the melting proceeds, test-plugs are made by pouring
metal into the molds, formed with a plug one inch in diameter.
These plugs are broken and the fracture examined. If there
is a mottled appearance to the fracture or if black specks
appear in it, the graphitic carbon is too high and must be
reduced by holding the metal in the furnace longer. The
mottled appearance indicates that the silicon in the metal
in the furnace is too high or that the temperature of the furnace
is too low. The charge should be ready for pouring about
four hours after charging is complete.
The principal use of the air-furnace is making iron for
malleable castings. For this purpose a sharp, white iron is
required, which, after casting, is annealed in proper annealing
ovens. The molding of malleable castings is carried on in
practically the same manner as for gray-iron castings, with
the exception that the gating is so arranged that the mold will
fill quickly, as white iron does not remain fluid as long as gray
iron. Instead of providing risers over heavy portions of malle-
able castings, as is done in gray-iron work, a chill is often set
against the heavy part. The iron cools quickly against the
chill, and the light and heavy portions of the casting cool at
about the same time. This eliminates strains and gives a
clean sound casting.
The subject of malleable castings is too wide and com-
plicated to be treated in detail in a book of this character.
The reader is referred to "The Production of Malleable
Castings," * by Dr. Richard Moldenke, which is the most
complete work on this subject and goes into every detail of
malleable practice.
^he Penton Publishing Co., Cleveland.
CHAPTER XXVI
THE BRASS FOUNDRY
CONNECTED with many manufacturing establishments are
brass foundries in which are made castings from the non-
ferrous metals, such as bronze, brass, aluminum, etc. The
molding operations are carried on in practically the same man-
ner as for gray iron, finer sand, however, being used. The
metal being poured at a lower temperature than iron does not
destroy the sand as iron does. The larger castings in brass
are molded in dry sand and in loam exactly as is done for iron.
As the shrinkage of the non-ferrous metals and alloys is greater
than that of iron, more attention must be given to provisions
for allowing the shrinkage of the casting in the mold and also
larger shrinkheads 'must be provided than is usual with iron
castings. The pouring temperature of the metal has an
important influence on the character of the finished casting.
Very hot metal will find its way into the pores of the sand and
produce a rough casting. The temperature at pouring should
be so low as to barely permit the metal to flow and yet produce
a smooth casting. This temperature in turn depends largely
on the composition of the alloys.
Instead of melting in a cupola, the metal in the brass
foundry is melted in a crucible or a reverberatory furnace, the
latter using coal, coke, oil, or gas for fuel. The crucibles for
melting brass, or similar non-ferrous compositions, are made of
clay and graphite, the crucible being formed and then baked
to calcine the clay. Before using, the crucibles should be
seasoned by allowing them to stand in a warm dry place for a
considerable period, after which they are gradually heated up
to a temperature of 255° Fahr. in an annealing oven, remaining
in the oven from 45 to 60 hours.
In Fig. 150 is shown one of the older types of coal-fired
275
276 FOUNDRY PRACTICE
crucible furnace. This is set in the brick-pit A , and is carried
on grate-bearers as shown. The coal or coke is placed inside
the fire-brick lining and the crucible E bedded in it. The
furnace is set with its top practically flush with the floor and
it is connected at the upper end with a flue G. In commencing
FIG. 150. — CRUCIBLE BRASS FURNACE.
operations with this furnace, a good bed of coal is placed on
the grate, over which the crucible is set while the coal is being
fired in order that it may heat up gradually. Copper ingots,
or ingots of other metal which it may be desired to melt, are
placed in the crucible, being so arranged that they will not
wedge with each other, and in expanding crack the crucible.
After the copper has melted, the metal requiring the next
lower degree of heat is added, and after this is melted the other
THE BRASS FOUNDRY 277
metals to form the alloy are placed in the crucible. When
the mixture is entirely melted, the crucible is lifted from the
furnace by means of a special pair of tongs which encircle the
crucible and the metal is skimmed with a birch-rod or a
wrought-iron skimmer. For pouring, the crucibles are carried
in a wrought-iron shank and care should be taken that the
FIG. 151. — THE OPEN-FLAME FURNACE.
crucible be completely emptied of metal, otherwise it will
be badly damaged.
In place of the coal-fired crucible furnace just described,
open-flame furnaces illustrated in Fig. 151 are in wide use. Oil
and air are admitted through the trunnions at a pressure of
about 65 pounds per square inch. The flame from the oil
plays directly on the metal in the furnace. Open-flame fur-
naces have the disadvantage of causing large losses of metal
through oxidation unless great care is taken in the control of
the furnaces. A further development of the oil- or gas-fired
furnace is shown in Fig. 152. This furnace is known as the
crucible-tilting furnace, the metal being melted in a crucible
set in the fire-brick chamber forming the furnace proper and
278
FOUNDRY PRACTICE
flames from the oil or gas playing around the furnace as
shown. The metal is thus protected from the oxidizing effect
of the flame, and the melting loss, with proper regulation of
the furnace, is low.
The pouring temperature of alloys used in the brass foundry
being low, the metal should be poured in the molds as promptly
as possible after melting. The castings, on removal from the
sand, are cleaned by pickling.
The brass foundry requires a book in itself for its proper
FIG. 152.— THE CRUCIBLE-TILTING FURNACE.
treatment. No small part of such a book would be given over
to the composition of alloys and the mixtures for making them.
Every brass founder has his own ideas on these mixtures and
their number is legion. The writer has successfully used the
mixtures given below for the purposes mentioned. For a very
complete treatise on this subject see "Practical Alloying,"1
'The Penton Publishing Co., Cleveland.
THE BRASS FOUNDRY 279
by J. F. Buchanan. See also tables in the Appendix, pages
315 to 317.
Alloy for stationary engine work: ingot copper, 9 pounds;
tin, i pound; zinc, I ounce.
Composition for heavy work: ingot copper, 46 pounds;
tin, 7 pounds; spelter, 3 pounds; lead, iH ounces.
A tough yellow metal: copper, 12 pounds; spelter, 4
pounds; lead, ^ pound; tin, ^4 pound.
Another yellow metal : copper, 20 pounds ; zinc, 8 pounds ;
lead, i pound.
Babbitt metal for heavy bearings: copper, 2 pounds;
antimony, 2 pounds; tin, 72 pounds.
Hardening metal for heavy bearings : tin, 2 pounds; used
with i pound of a mixture of the following proportion : copper,
12; antimony, 24; tin, 27.
A hard bronze: copper, 88; tin, 6; zinc, 4; lead, 2; phos-
phor-tin, 2.
Gun-metal: copper, 44; tin, 4; lead, i; phosphor-tin, i.
Gun-metal: copper, 88; tin, 8; zinc, 4; lead, 2.
Phosphor-bronze: copper, 88; tin, 7; zinc, 4; lead, 2;
phosphor-tin, i.
Phosphor-bronze, medium hardened: copper, 100; zinc,
12; tin, 4; lead, i^.
Yellow brass: copper, 4; zinc, i; lead, fa.
CHAPTER XXVII
FOUNDRY EQUIPMENT
Ladles. — A variety of ladles for transferring the molten
iron from the melting furnace to the molds is used in the foun-
dry, ranging in size from the small hand-ladle holding twenty-
five pounds of iron to ladles containing as much as fifty tons
which are used in steel and heavy iron foundries and are
handled by the crane. Smaller ladles are made of cast-iron
with lugs to which handles are fitted, while the larger ones
are constructed of steel plates riveted together and provided
with trunnions by means of which they are suspended from the
crane. The ladles of all sizes are lined with fire-clay of the
same grade as is used to line the cupola to protect the bottom
and sides from the molten iron. The smaller hand-ladles are
of such size that they may be carried by a single molder and are
used for pouring the lighter castings made in bench molds and
also for feeding risers and shrinkheads in castings which
require churning or pumping. The next larger size of ladle
is known as the double-shank ladle and is carried and poured
by two men. Larger ladles than these are used either for
pouring heavy castings or for transporting large amounts of
iron to central points in the foundry whence the iron is con-
veyed in hand or double-shank ladles to the molds. These
ladles are handled by means of tramways or cranes. The
largest-size ladles holding upward of one ton are handled
exclusively by cranes and are usually lined with fire-brick
ever which fire-clay is daubed. Before using, the ladle should
be thoroughly dried and heated either by means of an. oil-
torch or a fire built in it. Any moisture in the lining will
become steam when the molten metal is poured into it, and
start an agitation in the metal which may seriously damage
the lining and permit the molten metal to come in contact with
280
FOUNDRY EQUIPMENT 28 1
the metal of the ladle, thus burning a hole through it and allow-
ing the molten metal to escape and do serious damage. Most
ladles used in the foundry pour over the lip, but for steel
castings an opening is provided in the bottom of the ladle,
closed by a suitable plug which is removed when the mold is
to be poured and the steel is taken from the bottom of the
ladle. Occasionally the lip of the ladle is made higher than the
rest of the rim and a hole is cut through it through which the
iron is poured. The lip thus acts as a skimmer and prevents
slag from flowing with the iron into the mold. When filling
large ladles the iron is covered with charcoal or some refractory
material to exclude the air and thus prevent oxidation.
Flasks. — Flasks for use in the foundry are made either of
iron or wood. Wooden flasks should be made of substantial
material, as they are liable to burning and in a short time if
made too light will be completely burned away at the joint
and run-outs of the mold will be frequent. For very heavy
castings, iron flasks are more generally used and these are
made so far as possible so that the different parts will be
interchangeable with one another. Thus the pin-holes are
bored in the flanges to a template and the pins are located by
the same template. Thus any number of flasks of the same
size can be piled one on the other to form cheeks and copes.
The ends are usually made so that different flasks can be
butted one to another and a long flask thus formed. For
side-floor work, the flasks are usually made to conform to the
shape of the pattern, thus diminishing the amount of sand
rammed in the flask and making it lighter for the molder to
handle. Large iron flasks should be provided with slotted
holes in the sides through which bolts may be passed to hold
bars in place. By this means the bars can be arranged as
desired to suit the necessities of the pattern in hand. Iron
flasks should be made sufficiently heavy to prevent springing
under the pressure of the metal in the mold. It is a mistaken
idea that because a flask is of iron there is no spring to it.
However, it is not necessary to make the sides of the flask of
uniform thickness to resist the tendency to spring; ribs cast
282 FOUNDRY PRACTICE
on the sides will serve the purpose just as well and make a
lighter construction. Trunnions should be made preferably
of steel cast into the sides of the flask rather than of cast-iron
cast in one piece with the flask. The flask should always be
of such size that there is ample sand between it and the pat-
tern, not only to protect the flask from the molten iron, but
to absorb the gases given off in pouring. In many cases when
iron flasks are made, lugs are arranged on each end of the cope
and drag so that they will come in line with each other. Holes
are bored in these lugs and a rod run through them to form
a guide for lifting the cope over high parts of the pattern.
Steel flasks are coming into use, being light and serviceable,
but on account of their lightness they heat rapidly and may
warp out of shape, in which case it is difficult to restore them
to their original form. I-beams are also frequently used to
form the sides of the flask. Flasks for molding-machine work
are frequently of iron, although for small castings the wooden
snap flasks, of which there are a number of varieties on the
market, are in general use. It is advisable to plane the edges
of iron flasks where good work is expected and the pins should
be carefully fitted.
Tumbling Barrels. — Tumbling barrels are made in a
variety of shapes and sizes. The square tumbling barrel, or
rattler, is convenient for a number of varieties of castings and
is often made of cast-iron with cast-iron heads and provided
with cast-iron stays extending from end to end. Rattlers
are often made with the sides in sixteen or more segments,
any one of which may be replaced when worn out or broken.
They are often combined with a sand-blast arrangement
whereby sand is blown under air pressure into the rattler
through one of the trunnions to assist in cleaning the casting.
Often rattlers are made with wooden staves supported by iron
stays on the outside, or the iron rattler may be lined with
wood. Exhaust-pipes should be connected to each rattler
through which a fan may remove the dust incident to their
use. A very popular form of tumbling barrel for small -cast-
ings is the open tilting tumbling barrel, which may be tilted
FOUNDRY EQUIPMENT
283
FIG. 153. — FOUNDRY RIGS.
284 FOUNDRY PRACTICE
to discharge the tumbled castings and elevated to an inclined
position for rattling. A stream of water is directed into this
barrel while in use in order to prevent dust.
Cranes. — Up to comparatively recent times, the jib-crane
operated by a hand-winch was almost exclusively used in iron-
foundries. These were extremely limited in their application
and were useless beyond a circle of which the crane arm formed
the radius. In the more modern foundries they have been
largely displaced by the traveling crane, either hand or
electric, depending on the weight and amount of work done.
The most important feature in an electric crane for foundry
use, aside from its ability to carry the maximum weight of
casting made in the foundry, is its control apparatus. This
must be such as to permit very gradual starting and stopping,
and of operation at extremely low speeds. In drawing large
patterns from the molds by means of the crane, they must be
started gradually and slowly. Too quick a start will break
the mold. Also, in rolling over copes of large sizes, a sudden
start will shake the sand out of the mold and, in lifting, the
operator must be able to stop the crane the moment that the
cope is vertical and before it has swung clear of its support
on the opposite edge. Furthermore, exact control must be
maintained over the crane when pouring castings from a
crane ladle. The molder must be able to tilt the ladle
continuously to maintain a uniform stream of iron into the
mold and to stop instantly when the mold is full. This
requires the co-operation of the crane operator. Instead of
cranes, traveling electric hoists may be used and the same
considerations apply to them as to cranes. It would be out
of place here to discuss the relative features of different cranes
and the reader is referred to the catalogues of manufacturers
for such information.
Foundry Rigs. — The foundry requires a miscellaneous
equipment of small rigging for handling flasks, ladles, etc.,
for setting cores and securing molds for pouring. A variety
of this equipment is illustrated in Figs. 153 and 154. A is
a yoke and B is one of the slings used with it for handling copes
FOUNDRY EQUIPMENT
285
o
\ / /
\ b/i f
V j l 1
END VIEW. OF
REVOLVING GAGGER BOARD
FIG. 154. — FOUNDRY RIGS.
286 FOUNDRY PRACTICE
and drags by means of the crane. The yoke is made of a solid
timber suspended at the center by means of iron straps and an
eye. Occasionally the yoke is made of iron or a section of an
I-beam. Instead of the yoke, the spreader C is used in con-
nection with a double strand chain which is hooked on to the
trunnions of a flask, the spreader being placed above the flask
at the right height with the chain links in the slots of the
spreader. If trunnions are not cast on the flask, loose trun-
nions D may be bolted to it. These may be used with
wooden or iron flasks. The casting E is usually bolted to
the sides of the cope to permit chains to be hooked to it for
hoisting the cope off and to act as rockers on which the flask
may be rolled over after it has been set on the floor. F is a
form of staple which is frequently bolted to the flask for the
purpose of accommodating crane chains, while G is a similar
staple made of steel around which an iron plate is cast. H
is a hook bolted to the sides of a cope on which the crane
chains are fastened when only a straight lift is desired. /
is a loop forged from steel, usually made in sets of four, to
place over each handle of a cope, when it is necessary to lift
it by means of a crane and it is not desired to use any of the
attachments previously noted. These loops are frequently
used to slip over the arbors of cores when the latter project
beyond the mold, and form a very convenient means of
handling such cores. / is a convenient roller for nailing to
the side of a wooden flask to act as a rocker in rolling it over.
K is a convenient S-hook for handling copes, connecting short
chains, setting cores, and removing castings from the molds.
L is a core-hook for setting cores, and may be made in many
styles and sizes. Chains should be made with a link large
enough to take the hook of the chain, set back a certain dis-
tance from the end. The chain can then be doubled back on
itself with the hook in this link and used as a sling. In
handling medium-sized work, one or two chains having
turnbuckles in them will save considerable time in adjusting
for any given lift.
Straight-edges of various lengths with holes bored in them
FOUNDRY EQUIPMENT 287
so that they can be hung up when not in use are serviceable
tools to have in the foundry. A gagger-board is a useful piece
of equipment for molding gaggers. A bed of molding sand is
spread as nearly level as possible and the gaggers arranged
on a board are pressed down into this bed and the board
leveled with a spirit-level. On lifting the board a series of
gagger-molds are left in the sand, which may be filled with
molten iron and the gaggers formed. In Fig. 154 a revolving
gagger-board is shown at M. The drum is molded plain and
slab-cores forming the gagger-molds are set on the faces. As
fast as one side is poured the drum is revolved and the next
side brought to the top and poured. N is an ingot mold with-
out a bottom in which slack iron from the hand-ladles is
poured. It is set in loose sand, placed on the floor, and when
filled with slack iron is picked up and moved to a new loca-
tion. 0 is a larger ingot mold for receiving slack iron and
also the iron from the cupola at the end of the heat. P is a
cross used for hoisting portions of a mold such as the center
of the loam mold described in Chapter XI, and Q is one of
four slings used with this cross. R is a finger for attaching
sweeps to a spindle, and 6" is a straight-edge used by loam
molders, the notch in the center being fitted around the
spindle.
GLOSSARY
AIR-FURNACE — A furnace for melting iron, principally used
in malleable practice; see reverberatory furnace.
ARBOR — A bar or mandrel used as the center on which is
built up a core.
ANNEAL — To soften or render ductile a casting by the applica-
tion of heat in connection with a carbonaceous material
packed around it. The final process in malleable work.
BAKED CORE — A dry-sand core which has been subjected to
heat, usually in an oven, to render it hard and to fix its
shape: the opposite of green core.
BARS — Ribs placed across the cope portion of a flask.
BASIN — The portion of a cupola below the tuyeres in which
the molten iron collects.
BATH — The iron on the hearth of an air-furnace.
BEAD SLICKER — A tool for finishing a hollow place in a mold.
BED CHARGE — The first coke charged into a cupola.
BELLOWS — An ordinary small bellows used for blowing sand
from the joint of a mold, and for blowing it from deep
pockets in the mold.
BENCH — The framework table at which small molds are made.
BENCH WORK — Molds of such small size that they can be
made at the molder's bench.
BINDER — A bar of wood or iron, with slotted ends to receive
bolts, placed across a cope to hold the cope on the drag.
BLACK SAND — Heap sand.
BLAST — The supply of air to a cupola.
BOD — A ball of clay for closing the tap-hole.
BOSH — See swab.
BOTTOM-BOARD — A board placed on the under side of a mold.
BREAK-OUT — A rupture of a mold permitting metal to flow
out at the joint. Also called run-out.
288
GLOSSARY 289
BREAST — The portion of the lining of a cupola immediately
surrounding the tap-hole.
BRICKS, FIRE — Bricks made of fire-clay used for cupola and
air-furnace lining.
BRICKS, LOAM — Bricks formed of a loam mixture, to set in a
mold and to permit the easy crushing of the mold under
the shrinkage of the casting.
BRUSH — A brush used for sweeping sand from the joint of
molds.
BUCKLES — Swellings in the surface of a mold due to the genera-
tion of steam, below the surface, which cannot escape.
BUNG — A section of roof of an air-furnace.
BUTT — The large round end of a rammer.
CALIPERS — A measuring tool for ascertaining the outside
diameter of cylindrical bodies.
CAMEL'S-HAIR BRUSH — A brush for applying blacking to the
surface of molds.
CARRYING PLATES — Iron plates used to support certain por-
tions of loam molds.
CASTING — The product of the foundry obtained by pouring
molten metal into a mold.
CEMENTITE — The constituent of commercial iron consisting
of iron chemically combined with carbon.
CHAPLET — A piece of metal, shaped in various ways, placed in
a mold to support a core.
CHARGE — The iron and fuel placed in a cupola or air-furnace.
CHARGING DOOR — The opening in a cupola or air-furnace
through which fuel and metal are introduced.
CHEEK — The portion of a mold, made in three parts, inter-
mediate between the cope and drag.
CHILL — An iron surface, sometimes water-cooled, of a mold,
used to chill the molten iron rapidly and thus produce a
hard surface on the casting.
CHILLED WORK — Castings made in a chill mold.
CHUCK — Small bars set between the cross bars of a flask.
CHURNING — See pumping.
CLAMPING BAR — A bar used to tighten clamps on a flask.
19
690 GLOSSARY
CLAMPS — Devices for fastening copes and drags together.
CLAYWASH — A wash formed of clay dissolved in water.
COLD SHUT — An imperfection in a casting due to the metal
entering the mold by different sprues, and cooling, fail-
ing to unite on meeting.
COPE — The upper half of a mold.
COPE DOWN — To build projecting bodies of sand on the sur-
face of the cope to form surfaces of the casting which are
below the level of the joint of the drag.
COPE PLATE — An iron plate used to support certain portions
of loam molds.
CORE — A body of sand, either green or dry, placed in a mold
to form a cavity in the casting.
CORE Box — A box in which cores are formed.
CORE PLATE — A flat iron plate on which green cores are placed
for baking.
CORE-PRINT — The cavity in a mold in which the ends of cores
are set. Also the projections on a pattern which form
and locate the prints in the mold.
CORNER TOOL — A tool for slicking the corner of a mold, in-
accessible to the ordinary form of finishing tools.
CRUCIBLE ZONE — The basin of a cupola.
CUPOLA — A shaft furnace for the melting of iron ; the iron
and fuel being charged in alternate layers, and com-
bustion promoted by air blown in at the bottom of
the furnace.
DOUBLE-ENDER — A molding tool consisting of a combined
slicker and spoon-slicker.
DRAFT — The taper given to the sides of a pattern to enable
it to be easily withdrawn from the mold.
DRAG — The lower half of the mold.
DRAWING THE PATTERN — Lifting a pattern from the sand of a
completed mold.
DRAW-NAIL — A pointed rod of iron or steel driven into a
wooden pattern to act as a handle to withdraw it from the
sand in a mold.
DRAWPEG — A draw-screw.
GLOSSARY 291
DRAW-SCREW — A rod screwed into a pattern to act as a handle
for drawing the pattern.
DRAW-SPIKE — See draw-nail.
DRYER — A metal form, of the same shape as a core, in which
the latter is placed while being baked.
DRY SAND — Sand which has been baked in an oven after
having been formed into a mold.
DRY-SAND MOLD — A mold which has been baked in an oven
to fix its shape permanently, and to give it a hard
surface.
EARS — The lugs on the cope part of a flask into which the pins
on the drag fit.
EYE-BOLT — A bolt with a ring welded at one end.
FALSE CHEEK — A body of sand in a mold, occupying the same
position and performing the same functions as a cheek,
but contained within the cope and drag, although separate
from it.
FEEDING-HEAD — See shrinkhead.
FERRITE — The constituent of commercial iron consisting of
pure iron. See cementite.
FIRE-BRICK — See bricks, fire.
FLANGE TOOL — A tool for furnishing the edges of flanges in a
mold.
FLASK — The frame-work of wood or iron in which the sand is
packed while being molded around a pattern.
FLAT-BACK — A pattern with a flat surface at the joint of the
mold. Thus a flat-back pattern lies wholly within the
drag and the joint of the cope is a plane surface.
FLAT GATE — A wide gate with a narrow opening into the
mold, used for pouring thin flat castings. See Fig. 129.
FLOOR MOLDING — See floor work.
FLOOR WORK — Molds large enough to require molding on the
floor of the foundry.
FLOW-OFF — A channel cut from a riser to permit metal to
flow away from it when it has risen in the riser to a certain
predetermined height.
FLUX — A fusible material, containing lime, such as limestone,
2Q2 GLOSSARY
charged in the melting furnace to combine chemically with
and carry off impurities from the molten metal.
FOUNDRY — A shop where castings are made.
FROZEN IRON — Iron which has solidified.
GAGGERS — Rods of wrought- or cast-iron, with one end bent
at a right angle, used to support hanging bodies of sand
in a mold.
GATE — The hole in the cope through which metal is poured
into the mold.
GATE-STICK — A stick set in the cope while it is being rammed
to form the passage into the mold through which the
molten metal is poured.
GATING PATTERNS — Arranging patterns on a backbone so that
sprues will be formed by the backbone and its connection
to the pattern when the mold is made.
GREEN CORE — A core which has not been baked.
GREEN SAND — Ordinary molding sand which has not been
baked or otherwise been subjected to heat treatment, ex-
cept by coming in contact with molten metal in the mold.
GREEN-SAND CORE — A core made of green sand.
GREEN-SAND MATCH — A false cope in which the patterns are
placed while the drag is being made. Its object is to avoid
the making of a difficult joint on each mold where there
are a number of castings to be made from one pattern.
GRID — See skeleton.
HAND SQUEEZER — A molding machine in which the sand is
compressed to the proper density by pressure applied by
hand to the outer surface of the mold.
HAY-ROPE — A rope made of twisted hay, used to form the
basis of cores made on arbors.
HEAP SAND — Green sand from the foundry floor.
HEARTH — That portion of an air-furnace on which the iron is
melted.
HEAT — The melting period of a cupola or air-furnace.
HORN GATE — A semicircular gate to convey iron over or
under certain parts of a casting, so that it will enter the
mold at or near the center. Also used as a skim gate.
GLOSSARY 293
HUB TOOL — A tool for finishing the mold of pulley hubs.
JARRING MACHINE — A molding machine in which the sand is
packed by the sand, pattern, and flask being raised and
dropped upon a table, the sand itself forming the ramming
medium.
JOINT — The portion of the mold where the cope and drag come
together — the upper surface of the drag and the lower
surface of the cope.
JOLT-RAMMER — See jarring machine.
LIFTER — A molder's tool with a flat end at right angles to the
stem, used to lift loose sand from deep pockets in the mold.
LOAM — A mixture of molding sand and clay used for making
loam molds. See Chapter XL
LOAM BRICKS — See bricks, loam.
LOAM MOLD — A mold built up of brick-work, iron plates, etc.,
covered with loam which is afterward baked on.
MACHINE MOLDING — The operation of making molds on a
molding machine.
MALLEABLE CASTING — A hard brittle casting of white iron,
which is rendered tough and malleable by annealing under
certain conditions.
MELTING ZONE — The portion of the cupola above the tuyere
zone in which the iron is fused.
MOLD — The formed cavity in sand or other material into
which molten iron is poured to obtain a casting of any
desired shape. The term is usually applied to the body
of sand surrounding the cavity.
MOLD-BOARD — The board on which the patterns are laid when
making the drag of a mold.
MOLDING MACHINE — A machine, operated either by hand or
power, for making molds.
MOLDING SAND — Sand suitable for forming into molds. See
Chapter XXII.
NOWEL — See drag.
PARAFFINE-BOARD — A board impregnated with paraffine on
which patterns are mounted for use on the molding
machine.
294 GLOSSARY
PARTING — The plane on which a pattern is split.
PARTING SAND — A fine, sharp, dry sand dusted on the joint
of a mold to prevent the cope and drag adhering to each
other.
PATTERN — The object of wood, metal, or other material whose
shape it is desired to reproduce in metal. The sand of
the mold is formed around the pattern, which is later
withdrawn, leaving a cavity of its exact size and shape to
be filled with molten metal.
PEEN — The flat-pointed end of a rammer. Also, the operation
of ramming with the peen end of a rammer, as peening the
sand.
PEG GATE — A round gate leading from a pouring basin in
the cope to a basin in the drag, whence sprues lead to
the mold. See Fig. 129.
PINS — The projections on the drag of a flask which guide and
hold it in position with relation to the cope.
PIPE TOOL — A tool for finishing the surface of pipe molds.
POURING BASIN — A basin formed in the cope into which the
iron is poured.
POWER SQUEEZER — A molding machine in which the sand is
compressed to the proper density by pressure, applied
by compressed air to the outer surface of the mold.
PUMPING — The action of feeding iron to a casting from a
shrinkhead by forcing it in with a rod moved up and
down in the shrinkhead.
RAMMER — The tool used by the molder for packing sand in a
flask around a pattern. They are made of wood in the
smaller sizes, known as hand rammers, and of iron in the
larger sizes.
RAMMING — The action of packing sand around a pattern in a
flask to form a mold.
RAPPING — The action of jarring a pattern in the sand to free
it so that it may be drawn from the mold.
RAPPING IRON — An iron bar used to strike the draw-nail in
order to jar the pattern preparatory to drawing.
REVERBERATORY FURNACE — A furnace for the melting of iron,
GLOSSARY 295
the iron and fuel being separated. The fuel is burned in
a fire-box, separated from the iron on a hearth by a bridge
wall. A sloping roof deflects the gases of combustion
down on the iron and thus melts it. Largely used in
malleable work.
RIDDLE — A sieve for sifting sand on a pattern.
RISER — A gate formed over a high portion of a mold to act as
an indicator when the mold is filled with metal, and also
to act as a feeder to supply iron to the casting as it shrinks
in passing from the liquid to the solid state.
ROLL-OVER MACHINE — A molding machine in which the mold
is rolled over before the pattern is drawn.
RUNNER — A deep channel formed in the top of a cope, connect-
ing with gates, into which the molten metal is poured.
RUNNER Box — A set-off box in which a runner is formed.
RUN-OUT — See break-out.
SCABS — Imperfections in a casting due to portions of the sur-
face of a mold breaking away.
SET GATE — A gate pattern used to form a gate or sprue, set
against the pattern.
SET-OFF Box — A small box, open at the top and bottom,
fastened to the top of a cope to contain portions of a
mold projecting above the cope.
SHRINKHEAD — A large riser containing a sufficient body of
metal to act as a feeder as the metal of the casting con-
tracts in solidifying.
SHOT — Globules of metal formed in the body of a casting, and
harder than the remainder of it.
SKELETON — A metal framework on which a flat core is built.
SKIM CORES — Cores set in skim gates to act as skimmers.
SKIM GATE — A sprue so arranged as to skim any impurities
from the surface of the molten iron as it flows into the
mold, and restrain them from entering the mold.
SKIN-DRIED MOLD — A green-sand mold whose surface has been
baked for a depth of an inch or more.
SLAG — The earthy impurities fused in the melting furnace, to-
gether with the fused flux charged with the fuel and metal.
296 GLOSSARY
SLAG-HOLE — The opening in a cupola through which slag is
withdrawn.
SLICKER — An elongated, flat, thin piece of steel used for
smoothing the surfaces of molds.
SLIP — A wash applied to the surface of loam molds.
SLURRY — The mixture used to fill in the joints of cores.
SLURRYING — The process of filling in the joints of cores.
SNAP FLASK — A flask hinged at the corners, and separable at
one corner, so that it may be opened and removed from
around a completed mold.
SOLDIER — A wooden stick or rod, clay washed; used to support
bodies of hanging sand, or large green-sand cores.
SPINDLE — The rod or center on which a sweep is revolved.
SPINDLE SEAT — The socket in which the spindle revolves.
SPLIT PATTERN — A pattern made in two or more parts.
SPLIT-PATTERN SQUEEZER — A squeezer type molding
machine, either hand or power, adapted to molding
split patterns.
SPOON SLICKER — A finishing tool for a mold, the end of which
is made of spoon shape.
SPRING DRAW-NAIL — A tool for drawing patterns, especially
gear patterns, by gripping the inside of the hole in the hub.
SPRUE — The channels leading from the gate to the mold.
Also, the metal which solidifies in these channels after the
casting has cooled.
SPRUE CUTTER — A piece of metal, used to cut channels in the
joint to conduct iron from the pouring gate to the mold.
Also a brass tube used to cut the pouring gates in the
copes of machine-made molds.
STACK — The portion of a cupola extending from the top of the
melting zone to the level of the charging door.
STOOL — The support for a green-sand core on a molding
machine.
STOOLING — The process of supporting green-sand cores in
machine molding while the pattern is being drawn.
STOOL PLATE — The plate on a molding machine on which
stools are mounted.
GLOSSARY 297
STRICKLE — A strike with a form cut in one edge to form a
regular surface on a mold.
STRIKE — A flat bar of iron or wood used for striking or sweep-
ing excess sand from the top of a mold.
STRIPPING PLATE — A plate on a molding machine on which the
mold is made and through which the patterns are drawn
from the mold.
SWAB — A Hmp brush made of teazled hemp rope used for wet-
ting molds around the edges of patterns; swabbing, the
action of applying water to a mold.
SWEEP — A piece of wood or iron revolved about a center to
form the surface of a mold.
SWEEP FINGER — The metal piece by means of which the
sweep is attached to the spindle.
TAP-HOLE — The opening in a melting furnace — cupola or air —
through which molten metal is withdrawn.
TIGHT FLASK — A flask with a rigid framework — the opposite
of snap flask.
TROWEL — A molder's tool used for slicking the surface of a
mold.
TUYERES — The openings in a cupola through which air is
blown.
TUYERE ZONE — The portion of a cupola in the region of the
tuyeres, where combustion takes place.
UPSET — A shallow frame set over a flask in which is formed
a green-sand match.
VENT — A small hole formed in a mold to permit the escape of
gas from it.
VENT-WIRE — A wire used for making vents.
VIBRATOR — A device for rapping patterns by compressed air.
VIBRATOR FRAME — A frame in which patterns are mounted
when they are to be drawn in connection with a vibrator.
WHIRL GATE — A gate or sprue arranged to introduce metal
into a mold tangentially, and to thereby give it a swirling
motion.
WIND-BOX — The chamber surrounding a cupola through which
air is conducted to the tuyeres.
APPENDIX
TABLE XVIII. — CIRCUMFERENCES AND AREAS OF CIRCLES
Diam.
Circum.
Area.
Diam.
Circum.
Area.
Diam.
Circum.
Area.
I
3.1416
•7854
3 A
11.192
9.9678
6 Y±
19.635
30.680
A
3-3379
.8866
11.388
10.321
%
20.028
3I-9I9
Yk
3-5343
.9940
II-585
10.680
|J^
20.420
33-I83
A
3.7306
1.1075
11.781
11.045
Y%
20.813
34-472
M
3.9270
1.2272
t!
11.977
11.416
H
2I.2O6
35-785
A
4-1233
1-3530
y&
12.174
H-793
%
21.598
37-122
%
4.3197
1.4849
if
12.370
12.177
7
21.991
38.485
A
4.5160
1.6230
4
12.566
12.566
22.384
39-871
Yi
4.7124
1.7671
A
12.763
12.962
M
22.776
41.282
A
4.9087
I.9I75
Y%
12-959
13-364
N
23.169
42.718
x^
5-1051
2.0739
A
13-155
13.772
Yi
23.562
44.179
H
5.3014
2.2365
M
13.352
14.186
H
23-955
45-664
A:
54978
2.4053
A
13.548
14.607
H
24-347
47-173
il
5-694I
2.5802
«
13-744
15-033
H
24.740
48.707
J^
5-8905
2.7612
I3.94I
15-466
8
25.133
50.265
if
6.0868
2.9483
Yi
H.I37
15.904
H
25-525
51.849
2
6.2832
3-1416
A
14-334
16.349
H
25.918
53-456
A
6-4795
3-3410
§K'
I4.530
16.800
26.311
55.088
8
6-6759
3-5466
14.726
I7.257
H
26.704
56.745
6.8722
3.7583
«
H.923
17.721
N
27.096
58.426
M
7.0686
3.976I
}*
15.119
18.190
H
27.489
60.132
A
7-2649
4.2000
I5.3I5
18.665
H
27.882
61.862
%
74613
4-4301
if
I5.5I2
19.147
9
28.274
63.617
A
7-6576
4.6664
5
15.708
19-635
28.667
65-397
Yi
7.8540
4.9087
A
I5-904
20.129
M
29.060
67.201
A
8.0503
5-I572
N
16.101
20.629
%
29-452
69.029
%
8.2467
5-4H9
A
16.297
21.135
Yi
29.845
70.882
tt
8.4430
5.6727
M
16.493
21.648
H
30.238
72.760
%
8.6394
5-9396
A
16.690
22.166
%
30.631
74.662
if
8.8357
6.2126
H
16.886
22.691
H
31.023
76.589
K
9.0321
6.4918
A
17.082
23.221
10
31.416
78.540
if
9.2284
6.7771
17.279
23758
M
31.809
80.516
3
9.4248
7.0686
A
17-475
24.301
M
32.201
82.516
A
9.6211
7.3662
17.671
24.850
^i
32-594
84.541
y%
9.8I75
7.6699
17.868
25-406
Yi
32.987
86.590
A
10.014
7.9798
«
18.064
25-967
5/s
33-379
88.664
M
10.210
8.2958
if
18.261
26.535
¥
33-772
90.763
A
10.407
8.6179
K
18-457
27.109
34-I65
92.886
/%
10.603
8.9462
if
18.653
27.688
ii
34-558
95-033
A
10.799
9.2806
6
18.850
28.274
%
34-950
97.205
H
10.996
9.6211
K
19.242
29.465
M
35-343
99.402
298
APPENDIX
TABLE XVIII.— Continued
299
Diam.
Circum.
Area.
Diam.
Circum.
Area.
Diam.
Circum.
Area.
H^
35-736
IOI.62
i?H
54-978
240.53
23 5A
74.220
438.36
H
36.128
103.87
*f
55-371
243.98
H
74-6I3
443-01
5/Q
36.521
106.14
M
55-763
247-45
H
75.006
447.69
%
36.9H
108.43
%
56.156
250.95
24
75-398
452-39
V*
37.306
110.75
18
56.549
254-47
H
75-791
457-n
12
37-699
II3-IO
$
56.941
258.02
M
76.184
461.86
YS
38.092
H5-47
57-334
261.59
8
76.576
466.64
H
38.485
117.86
%
57.727
265.18
i^
76.969
471.44
38.877
I2O.28
y
58.119
268.80
%
77.362
476.26
H
39.270
122.72
5A
58-512
272.45
H
77-754
481.11
5/s
39.663
125.19
X
58.905
276.12
H
78.147
485.98
H
40.055
127.68
H
59.298
279.81
25
78.540
490.87
H
40.448
130.19
19 ,
59.690
283.53
H
78.933
495-79
13 i
40.841
132-73
H
60.083
287.27
H
79-325
500.74
4L233
135.30
H
60.476
291.04
%
79.718
505-71
M
41.626
I37-89
%
60.868
294-83
Yi
8o.ui
510.71
3/8
42.019
140.50
H
61.261
298.65
N
80.503
515-72
N
42.412
I43-I4
H
61.654
302.49
%
80.896
520.77
5/^
42.804
145.80
H
62.046
306.35
%
81.289
525-84
M
43-197
148.49
H
62.439
310.24
26
81.681
530.93
K
43-590
151.20
20
62.832
314.16
%
82.074
536.05
14 i
43.982
153-94
«
63.225
318.10
M
82.467
54I-I9
44-375
156.70
M
63-617
322.06
N
82.860
546.35
%
44.768
159.48
H
64.010
326.05
Yz
83-252
551-55
'AA
45.160
162.30
H
64.403
330.06
K
83-645
556.76
H
45-553
165-13
l|
64-795
334-10
y
84.038
562.00
^
45.946
167.99
«
65.188
338-16
K
84.430
567.27
M
46.338
170.87
K
65-581
342.25
27
84.823
572.56
K
46.731
173.78
21
65-973
346.36
H
85.216
577-87
15
47.124
176.71
N
66.366
350.50
M
85.608
583-21
H
47-517
179.67
M
66.759
354-66
3^
86.001
588.57
%
47.909
182.65
8^
67.152
358.84
Yi
86.394
593.96
%
48.302
185.66
Yi
67-544
363-05
5A
86.786
599-37
X
48.695
188.69
5/s
67.937
367.28
X
87.179
604.81
%
49.087
191-75
H
68.330
371-54
H
87.572
610.27
H
49.480
I94.83
ys
68.722
375-83
28
87-965
6I5-75
%
49-873
197-93
22
69.115
380.13
H
88.357
621.26
16
50-265
201.06
%
69.508
384.46
M
88.750
626.80
H
50-658
204.22
/€
69.900
388.82
89-I43
632.36
Yt
51-051
207.39
N
70.293
393-20
Yi
89.535
637-94
N
51-444
210.60
«
70.686
397.61
%
89.928
643-55
H
51-836
213.82
. M
71.079
402.04
/A:
90.321
649.18
H
52.229
217.08
H
71.471
406.49
H
90.713
654-84
%
52.622
220.35
H
71.864
410.97
29 v
91.106
660.52
%
53-014
223.65
23
72.257
415.48
91.499
666.23
17 1
53.407
226.98
H
72-649
420.00
M
91.892
671.96
53.800
230.33
M
73.042
424-56
%
92.284
677.71
M
54-192
233.71
3^
73-435
429.13
H
92.677
683.49
H
54-585
237-10
^
73.827
433-74
H
93-070
689.30
300
APPENDIX
TABLE XVIII.— Continued
Diam.
Circum.
Area.
Diam.
Circum.
Area.
Diam.
Circum.
Area.
29^
93.462
695.13
35%
112.705
1010.8
42
I3I-947
1385.4
%
93-855
700.98
36
113.097
1017.9 ;
ys
132.340
1393-7
30
94.248
706.86
yS
113.490
1025.0
M
132.732
1402.0
94.640
712.76
a
113.883
1032.1
y%
I33-I25
1410.3
M
95-033
718.69
H
II4-275
1039.2
Yi
133-518
1418.6
%
95.426
724.64
Yi
114.668
1046.3
5A
133.910
1427.0
Yi
95-8I9
730.62
5/s
II5.06I
1053-5
y*
I34-303
H35-4
5/£
96.211
736.62
H
H5-454
1060.7
v*
134.696
1443-8
M
96.604
742.64
%
115.846
1068.0
43
135.088
1452.2
%
96.997
748.69
37
116.239
1075.2
ys
I35-48I
1460.7
31
97-389
754-77
H
116.632
1082.5
&
I35-874
1469.1
H
97.782
760.87
M
117.024
1089.8
y%
136.267
1477.6
M
98.175
766.99
y%
117.417
1097.1
Yi
136.659
1486.2
%
98.567
773-14
K
II7.8IO
1104.5
5/s
137.052
1494.7
Yl
98.960
779-31
5/8
118.202
iiu.8
y
137-445
1503.3
«fl
99-353
785-51
H
118.596
1119.2
ys
137.837
I5II-9
M
99.746
791-73
%
118.988
1126.7
44
138.230
1520.5
%
100.138
797.98
38
II9-38I
1134.1
H
138.623
1529.2
32
100.531
804.25
y8
II9773
1141.6
M
139-015
1537-9
H
100.924
810.54
M
I2O.I66
1149.1
*A
139.408
1546.6
3
101.316
816.86
y*
120.559
1156.6
1A
139.801
1555-3
y%
101.709
823.21
1A
120.951
1164.2
y%
140.194
1564.0
Yi
102.102
829.58
H
121.344
1171.7
%
140.586
1572.8
5/o
102.494
835-97
M
121.737
1 1 79-3
H
140.979
I58I.6
%
102.887
842-39
7/8
122.129
1186.9
45
141.372
1590.4
J^
103.280
848.83
39
122.522
1194.6
ys
141.764
1599-3
33
103.673
855-30
H
122.915
1202.3
i/
142.157
1 60S. 2
H
104.065
861.79
123.308
I2IO.O
%
H2.550
I6I7.O
M
104.458
868.31
y%
123.700
I2I7.7
Yi
142.942
I626.O
104.851
874.85
y*
124.093
12254
W
143-335
1634.9
Yi
105.243
881.41
y*
124.486
1233.2
M
143.728
I643.9
%
105.636
888.00
*A
124.878
I24I.O
H
I44-I2I
1652.9
M
106.029
894.62
%
125.271
1248.8
46
I44-5I3
1661.9
%
106.421
901.26
40
125.664
1256.6 \ H
144.906
1670.9
34
106.814
907.92
ys
126.056
1264.5
M
145-299
1 680.0
107.207
914.61
1A
126.449
1272.4
%
145.691
1689.1
M
IO7.6OO
921.32
126.842
1280.3
Yi. 146.084
1698.2
%
107.992
928.06
/^
127.235
1288.2
y% 146.477
1707.4
H
108.385
934.82
H
127.627
1296.2
M ! 146.869
I7I6.5
5/g
108.778
941.61
M
I28.O2O
1304.2
y%
147.262
I725-7
M
109.170
948.42
%
128.413
1312.2
47 .
I47-655
1734-9
K
109.563
955-25
41
128.805
1320.3
1A
148.048
1744.2
35
109.956
962.11
H
129.198
1328.3
M
148.440
1753-5
110.348
969.00
M
129.591
1336-4
y%
148.833
1762.7
M
II0.74I
975-91
H
129.983
1344-5
Yt.
149.226
I772.I
s
III.I34
III.527
982.84
989.80
II
130.376
130.769
1352.7
1360.8
%
149.618
I50.0II
I78I.4
1790.8
%
III.9I9
996.78
M
I3I.I6I
1369-0
7/s
150.404
iSOO.I
2
II2-3I2
1003.8
K
131-554
1377.2
48
150.796
1809.6
APPENDIX
TABLE XVIII.— Continued
301
Diam.
Circum.
Area.
Diam
Circum.
Area.
Diam.
Circum.
Area.
48 Ys
151.189
1819.0
54 ¥
170.431
23II-5
60^
189.674
2862.9
H
151-582
1828.5
170.824
2322.1
190.066
2874.8
Ys
I5I-975
I837.9
y&
171.217
2332.8
!Hs
190.459
2886.6
152.367
1847.5
Ys
171.609
2343-5
M
190.852
2898.6
Ys
152.760
1857.0
H
172.002
2354-3
Ys
191.244
2910.5
M
153-153
1866.5
K
172.395
2365.0
61
191.637
2922.5
7/s
153-545
1876.1
55
172.788
2375-8
y*
192.030
2934-5
49
I53-938
1885.7
173.180
2386.6
192.423
2946.5
I54-33I
I895-4
M
173-573
2397-5
Ys
192.815
2958.5
M
I54-723
1905.0
%
173.966
2408.3
y<i
193.208
2970.6
/o
I55-II6
1914.7
y^
I74.358
2419.2
%
193.601
2982.7
^
I55-509
1924.4
Ys
I7475I
2430.1
M
193-993
2994.8
Ys
I55-902
1934-2
M
I75-I44
2441.1
Ys
194.386
3006.9
%
156.294
1943-9
H
I75-536
2452.0
62
194.779
30I9.I
Ys
156.687
1953-7
56
175.929
2463.0
^i
I95-I7I
303I-3
50
157.080
1963.5
ys
176.322
2474.0
M
I95-564
3043-5
157-472
1973-3
M
176.715
2485.0
%
195-957
3055-7
M
157.865
1983.2
Ys
177.107
2496.1
y&
196.350
3068.0
^
158.258
I993-I
1A
177.500
2507.2
Ys
196.742
3080.3
^
158.650
2003.0
Ys
177.893
2518.3
M
197-135
3092.6
H
159.043
2012.9
M
178.285
25294
H
197.528
3104.9
M
159-436
2022.8
7A
178.678
2540.6
63
197.920
3117.2
%
159.829
160.221
2032.8
2042.8
57 i
179.071
179.463
2551.8
2563.0
198.313
198.706
3129.6
3142.0
51 H
160.614
2052.8
/€
179.856
2574-2
iHj
199.098
3I54-5
161.007
2062.9
Ys
180.249
25854
/^
I9949I
3166.9
iHi
161.399
2073.0
y*
180.642
2596.7
5 /
199.884
3I79-4
Yt
161.792
2083.1
Ys
181.034
2608.0
M
200.277
3I9I-9
%
162.185
2093.2
M
181.427
2619.4
Ys
200.669
3204.4
%
162.577
2103.3
Vs
181.820
2630.7
64
2OI.O62
32I7-0
7A
162.970
2II3-5
58
182.212
2642.1
y*
201.455
3229.6
52 i
163.363
2123.7
K i 182.605
2653.5
M
201.847
3242.2
163.756
2133-9
y±
182.998
2664.9
%
202.240
3254.8
M
164.148
2144.2
Ys
183.390
2676.4
Y&
202.633
3267.5
%
164.541
2154-5
183-783
2687.8
Ys
203.025
3280.1
H
164.934
2164.8
%
184.176
2699.3
203.418
3292.8
%
165.326
2I75.I
M
184.569
2710.9
JA
203.811
3305-6
/4
I657I9
2185.4
1/s
184.961
2722.4
65
204.204
3318.3
K
I66.II2
2195.8
59
I85.354
2734.0
H
204.596
333I-I
53
166.504
22O6.2
185747
2745-6
M
204.989
3343-9
166.897
2216.6
M
186.139
2757-2
205.382
3356-7
M
167.290
2227.O
%
186.532
2768.8
i/£
205.774
H
167.683
2237-5
Yi
186.925
2780.5
Ys
206.167
3382.4
i^
168.075
2248.0
%
187.317
2792.2
M
206.560
3395-3
H
168.468
2258.5
M
187.710
2803.9
Ys
206.952
3408.2
M
168.861
2269.1
H
188.103
2815.7
66
207.345
3421.2
K
169.253
2279.6
60
188.496
2827.4
^8
207.738
3434-2
54
169.646
229O.2
1A
188.888
2839.2
M
208.131
3447-2
170.039
2300.8
M
189.281
2851.0
Ys
208.523
3460.2
j
302
APPENDIX
TABLE XVIII.— Continued
Diam.
Circum.
Area.
Diam.
Circum.
Area.
Diam.
Circum.
Area.
66 Y2
208.916
3473-2
72^
228.158
4H2.5
78 *A
247.400
4870.7
y%
209.309
3486.3
H
228.551
4156.8
%
247-793
4886.2
u
209.701
3499-4
n
228.944
4I7I.I
79
248.186
4901.7
7A
210.094
3512-5
73 ,,
229.336
4185.4
H
248.579
4917.2
67
210.487
3525-7
K
229.729
4199.7
%
248.971
4932.7
210.879
3538-8
M
230.122
4214.1
H
249.364
4948.3
/4
211.272
3552-0
%
230.5H
4228.5
X
249-757
4963.9
%
211.665
3565.2
Yi
230.907
4242.9
%
250.149
4979-5
Yi
212.058
3578-5
H
231.300
42574
H
250.542
4995-2
%
212.450
3591-7
*A
231.692
4271.8
7A
250.935
5010.9
%
212.843
3605.0
H
232.085
4286.3
80
251.327
5026.5
7A
213.236
3618.3
74
232.478
4300.8
ys
251.720
5042.3
68
213.628
3631-7
ys
232.871
43I5-4
Y±
252.113
5058.0
ys
214.021
3645-0
M
233.263
4329-9
%
252.506
5073-8
M
214.414
3658-4
% 233.656
4344-5
Yi
252.898
5089.6
%
214.806
3671-8
g
234-049
4359-2
«
253-29I
5105-4
%
215.199
3685-3
y*
234.441
4373-8
M
253-684
5121.2
5A
2I5-592
3698.7
H
234-834
4388.5
%
254.076
5I37.I
H
215.984
3712.2
7A
235-227
4403.1
81
254.469
5153.0
7/8
216.377
3725-7
75
235-619
44I7-9
H
254.862
5168.9
69
216.770
3739-3
236.012
4432-6
M
255-254
5184.9
y* 217.163
3752.8
M
236.405
4447-4
%
255-647
5200.8
M 1 217.555
3766.4
%
236.798
4462.2
/4
256.040
5216.8
y*
217.948
3780.0
Yi
237.190
4477-0
5A
256.433
5232-8
1A
218.341
3793-7
ys
237-583
4491.8
H
256.825
5248.9
y*
218.733
3807.3
H
237-976
4506.7
7A
257.218
5264.9
ZA
219.126
3821.0
7/s
238.368
4521.5
82
257.611
5281.0
H
219.519
3834.7
76
238.761
4536.5
1A
258.003
5297.1
70
219.911
3848.5
X
239-I54
4551-4
H
258.396
5313-3
ys
220.304
3862.2
M
239.546
4566.4
3A
258.789
5329.4
¥
220.697
3876.0
H
239-939
458i.3
H
259.181
5345-6
22I.O9O
3889.8
Yi
240.332
4596.3
«
259-574
536i.8
Yi
221.482
3903.6
5/s
240.725
4611.4
M
259-967
5378.1
5A
221.875
39I7-5
241.117
4626.4
JA
260.359
5394-3
¥
222.268
3931-4
JA
241.510
4641.5
83
260.752
5410.6
222.66O
3945-3
77
241.903
4656.6
ys
261.145
5426.9
7-i
223.053
3959-2
ys
242-295
4671.8
H
261.538
5443-3
ys
223.446
3973-1
1A
242.688
4686.9
SA
261.930
5459-6
M
223.838
3987-I
%
243.081
4702.1
H
262.323
5476.0
%
224.231
4001.1
%
243-473
47I7-3
5A
262.716
5492.4
%
224.624
4015-2
y%
243.866
4732.5
3A
263.108
5508.8
ys
225.017
4029.2
%
244.259
4747-8
7A
263.501
5525-3
H
225.409
4043-3
y*
244.652
4763-I
84
263.894
5541-8
7/s
225.802
4057-4
78
245.044
4778.4
X
264.286
5558.3
72
226.195
407I-5
ys
245-437
4793-7
¥
264.679
5574-8
H
226.587
4085.7
*A
245.830
4809.0
265.072
5591-4
M
226.980
4099.8
3A
246.222
4824.4
%
265.465
5607.9
iMi
227.373
4114.0
Yi.
246.615
4839.8
H
265.857
5624-5
K2
227.765
4128.2
ys
247.008
4855.2
M
266.250
5641.2
APPENDIX
TABLE XVIII.— Continued
303
Diam.
Circum.
Area.
Diam.
Circum.
Area.
Diam.
Circum.
Area.
84 H
266.643
5657.8
90
282.743
6361.7
95 H
298.844
7106.9
85
267.035
5674.5
H
283.136
6379-4
M
299.237
7125.6
Hi
267.428
5691.2
X
283.529
6397.I
%
299.629
7H4.3
M
267.821
5707-9
«
283.921
6414.9
Yi
3OO.O22
7163.0
3A
268.213
5724-7
«
284.314
6432.6
H
300.415
7181.8
1A
268.606
5741-5
5/o
284.707
6450.4
H
300.807
72OO.6
%
268.999
5758.3
%
285.100
6468.2
ys
3OI.2OO
7219.4
g
269.392
5775-1
%
285.492
6486.0
96
301.593
7238.2
%
269.784
5791-9
91
285.885
6503.9
H
301.986
7257.I
86
270.177
5808.8
H
286.278
6521.8
M
302.378
7276.0
H
270.570
5825.7
¥
286.670
6539-7
%
302.771
7294.9
M
270.962
5842.6
287.063
6557-6
1A
303.164
73I3.8
3^
27I-355
5859-6
H
287.456
6575-5
y*
303.556
7332.8
y
271.748
5876.5
5/s
287.848
6593-5
H
303-949
7351-8
N
272.140
5893.5
% \ 288.241
6611.5
ys
304-342
7370.8
%
272.533
5910.6
Ji
288.634
6629.6
97
304-734
7389.8
^1
272.926
5927-6
92
289.027
6647.6
ys
305.127
7408.9
s?
273.319
5944-7
H
289.419
6665.7
M
305.520
7428.0
H
273.7II
5961.8
H
289.812
6683.8
305.913
7447-1
M
274.104
5978.9
%
290.205
6701.9
H
306.305
7466.2
%
274-497
5996.0
Yi
290.597
6720.1
%
306.698
7485.3
H
274.889
6013.2
Y%
290.990
6738.2
M
307.091
7504.5
^8
275.282
6030.4
M
291.383
6756.4
%
307.483
7523-7
M
275.675
6047.6
jl
291.775
6774-7
98
307.876
7543-0
%
276.067
6064.9
93 292.168
6792.9
H
308.269
7562.2
88
276.460
6082.1
292.561
68II.2
308.661
7581.5
H
276.853
6099.4
M
292.954
6829.5
3/g
309.054
7600.8
M
277.246
6116.7
%
293.346
6847.8
Yi
309.447
7620.1
%
277.638
6134-1
Yi
293-739
6866.1
H
309.840
7639-5
i/£
278.031
6151.4
Y%
294.132
6884.5
N
310.232
7658.9
N
278.424
6168.8
M
294.524
6902.9
8
310.625
7678.3
M
278.816
6186.2
jl
294.917
6921.3
99 v
3II.OI8
7697.7
K
279.209
6203.7
94 j/
295.310
6939-8
3II.4IO
7717.1
89
279.602
622 i . r
295.702
6958.2
M
311.803
7736.6
H
279.994
6238.6
M
296.095
6976.7
3^
312.196
7756.1
M
280.387
6256.1
^
296.488
6995-3
Yi
312.588
7775-6
S
280.780
6273-7
/^
296.881
7013.8
5/8
312.981
7795-2
«
281.173
6291.2
5^
297.273
7032.4
M
3I3.374
7814.8
^8
281.565
6308.8
3^
297.666
7051.0
%
313-767
7834-4
M
281.958
6326.4
J^
298.059
7069.6
100
3H-I59
7854.0
H
282.351
6344.1
95
298.451
7088.2
304
APPENDIX
TABLE XIX.— SPHERES
(Some errors of i in the last figure only.)
Diam.
Surface.
Volume.
Diam.
Surface.
Volume.
Diam.
Surface.
Volume.
%
.00307
.OOOO2
2 %
17.721
7.0144
6 3A
127.68
135-66
.OI227
.00013
18.666
7-5829
l/£
132.73
143-79
-fo
.02761
.00043
%
I9.635
8.1813
137.89
152.25
%
.04909
.OOIO2
1%
20.629
8.8103
P
H3-H
161.03
&
.07670
.OO2OO
S/g
21.648
9.4708
%
148.49
170.14
T%
.11045
•00345
«
[22.691
10.164
7
153-94
179-59
~*h
•15033
.00548
H
23.758
10.889
J^j
159-49
189.39
M
•19635
.00818
U
24.850
11.649
M
165.13
199-53
&
•24851
.01165
7A
[25.967
12.443
%
170.87
210.03
i&
.30680
.01598
if
27.109
13.272
^2
176.71
220.89
M
•37123
.02127
3
28.274
I4-I37
%
182.66
232.13
/%
•44179
.02761
A
29-465
15.039
M
188.69
243-73
H
.51848
•035II
ys
30.680
15-979
jl
194.83
25572
A
.60132
•04385
A
31.919
16-957
8
201.06
268.08
M
.69028
•05393
M
33.183
17-974
H
207.39
280.85
^
.78540
•06545
34-472
19.031
M
213.82
294.01
A
•99403
.09319
iNI
35-784
20.129
H
220.36
307.58
A,
1.2272
.12783
A
37.122
21.268
y2
226.98
321.56
H
1.4849
.17014
H
38.484
22.449
233.7I
335-95
A:
1.7671
.22089
A
39.872
23-674
M
240.53
350.77
i*
2.0739
.28084
N
41.283
24.942
1/9,
247-45
366.02
8
• 2.4053
•35077
H
42.719
26.254
9
254-47
381.70
«
2.7611
•43143
H
44-179
27.611
261.59
397.83
I
3.1416
.52360
H
45-664
29.016
M
268.81
414.41
A
3.5466
.62804
%
47-173
30.466
iHj
270.12
431-44
H
3.9761
•74551
if
48.708
31.965
Vz
283.53
448.92
A
4.4301
.87681
4
50.265
33-510
5/s
291.04
466.87
M
4.9088
1.0227
H
53-456
36.751
H
289.65
485-31
1%
54II9
1.1839
M
56-745
40.195
%
306.36
504.21
g
5-9396
1.3611
60.133
43.847
10
314.16
523.60
6.4919
-5553
Yi
63.617
47.713
Ji
322.06
543-48
i/£
7.0686
.7671
X
67.201
51.801
^
330.06
563-86
A
7.6699
•9974
H
70.883
56.116
*/s
338,16
584.74
%
8-2957
2.2468
H
74.663
60.663
1A
346.36
606.13
tt
8.9461
2.5161
5
78.540
65.450
5/s
354-66
628.04
A
9.6211
2.8062
82.516
70.482
H
363-05
650.46
II
10.321
3-II77
M
86.591
75-767
%
371-54
67342
ji
11.044
3-45H
^1
90.763
81.308
ii
380.13
696.91
i$
H-793
3.8083
^2
95-033
87.113
H
388.83
720.95
2
12.566
4.1888
%
99.401
93-I89
g
397.61
745-51
A
13-364
4-5939
%
103.87
99-541
406.49
770.64
8
14.186
5-0243
%
108.44
106.18
Yi
415.48
796.33
A
15-033
5.4809
6
113.10
113.10
%
424.50
822.58
M
15.904
5-9641
H
117.87
120.31
%
433-73
849.40
A
16.800
6-4751
u
122.72
127-83
*
443-01
876.79
APPENDIX
TABLE XIX.— Continued
305
Diam.
Surface.
Volume.
Diam.
Surface.
Volume.
Diam.
Surface.
Volume.
12
452.39
904.78
24 M
1847.5
7466.7
38 K
4656.7
>988o
H
471.44
962.52
*i
1885.8
7700.1
39
4778.4
31059
%
490.87
1022.7
M
1924.4
7938.3
H
4901.7
32270
H
510.71
1085.3
25
1963.5
8181.3
40
5026.5
33510
13 1
530.93
II50.3
M
2OO2.9
8429.2
^
5I53.I
34783
551-55
I2I8.0
^
2042.8
8682.0
41
528I.I
36087
Yi
572.55
1288.3
%
2083.0
8939-9
1A
5410.7
37423
ZA
593-95
1361.2
26
2123.7
92O2.8
42
5541-9
38792
14
615.75
1436.8
H
2164.7
9470.8
H
5674-5
40194
\/
637-95
I5I5.I
22O6.2
9744.0
43
5808.8
41630
%
660.52
1596.3
%
2248.0
IOO22
1A
5944-7
43099
%
683.49
1680.3
27
2290.2
10306
44
6082.1
44602
«5
706.85
1767.2
X
2332.8
10595
H
6221.2
46141
730-63
1857.0
H
2375-8
10889
45
6361.7
47713
/^
754-77
1949.8
M
2419.2
IllSg
1A
6503-9
49321
M
779.32
2045.7
28
2463.0
II494
46
6647.6
50965
16
804.25
2144.7
M
2507.2
II805
1A
6792.9
52645
Ji
829.57
2246.8
y*
2551-8
I2I2I
47
6939-9
54362
H
855-29
2352.1
H
2596.7
12443
^
7088.3
56115
M
881.42
2460.6
29
2642.1
12770
48
7238.3
57906
17
907.93
25724
M
2687.8
I3I03
H
7389-9
59734
M
934-83
2687.6
H
2734.0
13442
49
7543-1
61601
962.12
2806.2
M
2780.5
13787
X
7696.7
63506
M
989.80
2928.2
30
2827.4
I4I37
50
7854.0
65450
18
1017.9
3053.6
M
2874.8
14494
H
8011.8
67433
M
1046.4
3182.6
1A
2922.5
14856
51
8171.2
69456
Yi
1075.2
33I5.3
H
2970.6
15224
1A
8332.3
71519
%
1104.5
3451-5
31
3019.1
15599
52
8494.8
73622
19
1134.1
3591-4
K
3068.0
15979
H
8658.9
75767
M
1164.2
3735-0
|l
3II7-3
16366
53
8824.8
77952
H
1194.6
3882.5
M
3166.9
16758
H
8992.0
80178
M
1225.4
4033-7
32
3217.0
I7I57
54
9160.8
82448
20
1256.7
4188.8
M
3267.4
17563
K
9331-2
84760
M
1288.3
4347-8
H
3318.3
17974
55
9503-2
87114
Yz
1320.3
4510.9
M
3369-6
18392
H
9676.8
89511
%
1352.7
4677-9
33
3421.2
I88I7
56
9852.0
91953
21
1385-5
4849.1
M
3473-3
19248
N
10029
94438
M
1418.6
5024.3
H
3525-7
19685
57
10207
96967
H
1452.2
5203.7
ZA
3578-5
2OI29
H
10387
99541
M
1486.2
53874
34
3631-7
20580
58
10568
102161
22
1520.5
5575-3
M
3685-3
21037
^
10751
104826
K
1555-3
5767.6
H
3739-3
2I50I
59
10936
107536
J4
1590-4
5964-1
35
3848-5
22449
H
1 1 122
110294
M
1626.0
6165.2
1A
3959-2
23425
60
II3IO
113098
23
1661.9
6370.6
36
407I-5
24429
«
II499
H5949
K
1698.2
6580.6
M
4185-5
25461
6l
II690
118847
^
1735-0
6795-2
37
4300.9
26522
H
II882
121794
M
1772.1
7014-3
H
4417.9
27612
62
12076
124789
24
1809.6
7238.2
38
4536.5
28731
&
12272
127832
306
APPENDIX
TABLE XIX.— Continued
Diam.
Surface.
Volume.
Diam.
Surface.
Volume.
Diam.
Surface.
Volume.
63
12469
130925
751A
17908
225341
88
24328
356819
«
12668
134067
76
18146
229848
H
24606
362935
64
12868
137259
K
18386
234414
89
24885
369122
^
13070
140501
77
18626
239041
H
25165
375378
65
13273
H3794
N
18869
243728
90
25447
381704
^
13478
H7I38
78
I9II4
248475
ji
25730
388102
66
13685
150533
H
19360
253284
91
26016
394570
H
13893
153980
79
19607
258155
H
26302
40II09
67
14103
157480
H
19856
263088
92
26590
407721
y*
I43H
161032
80
2OIO6
268083
H
26880
414405
68
14527
164637
H
20358
273141
93
27172
42Il6l
^
14741
168295
81
2O6I2
278263
H
27464
427991
69,x
14957
172007
H
20867
283447
94
27759
434894
H
I5I75
175774
82
2II24
288696
H
28055
441871
70
15394
179595
H
21382
294010
95
28353
448920
H
I56I5
I8347I
83
21642
299388
N
28652
456047
7i
15837
187402
H
21904
304831
96
28953
463248
H
16061
191389
84
22167
310340
H
29255
470524
72
16286
195433
H
22432
3I59I5
97
29559
477874
H
16513
199532
85
22698
321556
H
29865
485302
73
16742
203689
«
22966
327264
98
30172
492808
H
16972
207903
86
23235
333039
H
30481
500388
74i,
17204
212175
H
23506
338882
99
30791
508047
N
17437
216505
87
23779
344792
K
3H03
515785
75
17672
220894
H
24053
350771
100
31416
523598
1
APPENDIX
307
TABLE XX. — WEIGHT AND SPECIFIC GRAVITY OF METALS
(Kent's "Mechanical Engineers' Pocket-Book," eighth edition)
Specific Gravity,
Range According to
Several Authorities
Specific
Gravity.
Approximate
Mean Value
Used in
Calculation
of Weight
Weight
cSSc
Foot,
Ibs.
Weight
per
Cubic
Inch,
Ibs.
Aluminum
2.56 to 2.71
2.67
166.5
o 0963
Antimony
6 66 to 6 86
6 76
4.21 6
Bismuth
974 to Q QO
9 82
612 4
O 154.4.
Brass: Copper + Zincl
80 20
70 30 >
60 40
50 50 J
( Cop., 95 to 80 )
Bronze ] ~
( Tin, 5 to 20 )
Cadmium
7.8 to 8.6
8.52 to 8.96
86 to 8 7
f8.6o
J 8.40
I 8.36
[ 8.20
8.853
8 65
536.3
523.8
521.3
511.4
552.
C-5Q
0.3103
0.3031
0.3017
0.2959
0.3195
Calcium
i 58
i 58
og s
o 0570
Chromium
Cobalt
Gold, pure
Copper
5-0
8.5 to 8.6
19.245 to 19.361
8 69 to 8 92
5-0
8-55
19.258
8 851
311.8
533-1
1200.9
552
0.1804
0.3085
0.6949
Iridium
Iron, Cast
Iron, Wrought
Lead
22.38 to 23.
6.85 to 7.48
7- 4 to 7.9
1 1 07 to 1 1 44
22.38
7.218
7.70
1 1 38
1396.
450.
480.
7OQ 7
o . 8076
o . 2604
0.2779
Manganese
7 to 8
8
4.QO
o 2887
Magnesium
r 32°
Mercury -s 60°
1 . 69 to i . 75
13.60 to 13.62
I -i eg
i-75
13.62
I"? eg
109.
849.3
846 8
0.0641
0.4915
Ul2°
Nickel
13-37 to 13.38
8 279 to 8 93
13-38
8 8
834-4
548 7
0.4828
O 1175
Platinum
20 -33 to 22 07
21 5
1347 o
o 7758
Potassium
Silver . . .
0.865
10 474 to 10 511
0.865
IO SOS
53-9
655 i
0.0312
O 17QI
Sodium
Steel
0.97
7.69* to 7 932f
0.97
7 8S4
60.5
489 6
0.0350
o 28^4
Tin
7 2QI to 7 4OQ
4.58 i
Titanium .
5-5
5a
•3-2Q 5
O IQI^
Tungsten ....
17 to 17 6
17 ^
1078 7
o 624^
Zinc
6.86 to 7.20
7.00
436.5
0.2526
* Hard and burned.
less
308
APPENDIX
TABLE XXI. — MELTING-POINTS OF VARIOUS SUBSTANCES
(Kent's " Mechanical Engineers' Pocket-Book," eighth edition)
The following figures are given by Clark (on the authority of Pouillet,
Claudel, and Wilson), except those marked *, which are given by Prof.
Roberts-Austen, and those marked f, which are given by Dr. J. A. Harker.
These latter are probably the most reliable figures.
Sulphurous acid — 148° F.
Carbonic acid — 108
Mercury ~ 39, — 38f
Bromine -f- 9-5
Turpentine 14
Hyponitric acid 16
Ice 32
Nitro-glycerine 45
Tallow 92
Phosphorus 112
Acetic acid 113
Stearine 109 to 120
Spermaceti 120
Margaric acid 131 to 140
Potassium 136 to 144
Wax 142 to 154
Stearic acid 158
Sodium 194 to 208
Iodine 225
Sulphur 239
Alloy, iXtin, t iead. . .334, 367!
Tin 446,449t
Cadmium 442° F.
Bismuth 504 to 507
Lead 618*, 62of
Zinc 779*, 786f
Antimony 1150, 1169 f
Aluminum H57*, 1214!
Magnesium 1200
NaCl, common salt I472t
Calcium Full red heat.
Bronze 1692 '
Silver 1733*. I75if
Potassium sulphate. . .1859*, 1958*
Gold 1913*! I947t
Copper 1929*. I943t
Nickel 26oof
Cast-iron, white 1922, 2075!
" " gray 2012 to 2786, 2228*
Steel 2372 to 2532*
" hard 2570*; mild, 2687
Wrought-iron . .2732 to 2912, 2737*
Palladium 2732*
Platinum 3227*, 3iiof
APPENDIX
309
TABLE XXII.— STRENGTH OF ROPES.
(A. S. Newell & Co., Birkenhead. Klein's Translation of Weisbach,
vol. iii, part I, sec. 2)
HEMP
IRON
STEEL
Tensile
Strength,
Gross Tons
Girth,
Inches
Weight
per
Fathom,
Pounds
Girth,
Inches
Weight
per
Fathom,
Pounds
Girth,
Inches
Weight
per
Fathom,
Pounds
*A
2
I
I
2
1^
13^
I
I
3
3%
4
!^8
2
4
*/€
2^
34
ij^
5
41A
5
1%
3
6
2
3]^
i%
2
7
5l/2
7
2^
4
\y±
2/^
8
2M
4!^
9
6
9
2<Hi
5
i%
3
10
2Mi
5^
ii
&A
10
2;H?
6
2
3/^
12
2M
6J^
2^
4
13
7
12
2%
7
2J2
4/^
H
3
7/^
15
7^
14
3H
8
2^
5
16
3/4
8^2
17
8
16
33xg
9
2^2
5/^
18
3K
10
2%
6
20
8*^
18
35^
ii
2%
6J^
22
3M
12
24
9^
22
3Ji
13
3x4
8
26
10
26
4
14
28
ii
3°
4/4
15
3^|
9
30
4^
16
32
4J^
18
3/^
10
36
12
34
4^
20
3M •
12
40
3io
APPENDIX
TABLE XXIII. — PITCH, BREAKING, PROOF, AND WORKING STRAINS OF
CHAINS
(Bradlee & Co., Philadelphia)
,0
D. B. G. SPECIAL CRANE
CRANE
a
£
.s
1
1
|
ij
a
5
5
£
3
V S
.0
1
£
S
4-T
fa
So
L
ft
u
"S
•S
g
V
I
is-o5
1
1
1
1
S
1
Jl
6
1
jj
J35
M
ft
%
if
1,932
3,864
I.2S8
1,680
3,360
I,I2O
A
ft
i
iM
2,898
5,796
1,932
2,52O
5,040
1, 680
X
ft
ij-i
lA
4,186
8,372
2,790
3,640
7,280
2,420
TS
iA
2
i^
5,796
11,592
3,864
5,040
10,080
3,360
H
ift
2^i
iH
7,728
15,456
5,152
6,720
13,440
4,487
A
ift
3rV
2
9,660
19,320
6,440
8,400
16,800
5,600
X
ift
4rV
2^
11,914
23,828
7,942; 10,360
20,720
6,900
ft
itt
itt
2A
14,490
17,388
28,980
34,776
9,660! 12,600
11,592 15,120
25,200 8,400
30,240 10,087
ii
21*8
6yV
2%
20,286
40,572
13,524
17,640
35,280 11,760
x
2A
8%
2$
22,484
44,968
14,989
20,440
40,880
13,620
«
aA
9
3&
25,872
51,744
17,248
23,520
47,040
15,680
i
2^2
io>£
33/8
29,568
59,136
19,712
26,880
53,760
17,927
iA
2^8
12
sA
33,264
66,538
22,176
30,240
60,480
20,160
iJi
2M
13^8
3T$
37,576
75,152
25,050
34,160
68,320 22,770
iA
3A
I3T7jr
4
41,888
83,776 27,925
38,080
76,160 25,380
3^
16
46,200 92,400
30,800
42,000 84,000 28,003
lA
3 A
IQK
IA
50,512 101,024
55,748 111,496
33,674
37,165
45,920 91,840 30,617
50,680 101,360 33,780
i A
3 16
i9rV
4^
60,368
120,736
40,245
54,880
109,760
36,583
iJ6
3%
23
sH
66,528
133-056
44,352
60,480
120,960
40,327
i A
4
25
5rV
70,762
141,524
47,174
65,520
131,140
43,187
i%
4%
3i
5K
82,320
164,640
54,880
2
5%
40
6%
107,520
215,040
71,680
2M
6%
52%
7%
136,080
272,160
90,720
2>i
7
64^
8^
168,000
336,000
112,000
2%
7%
73
9H
193,088
386,176
128,725
3
7H
86
9K
217,728
435,456
145,152
The distance from center of one link to center of next is equal to the inside length of link,
but in practice 3»B in. is allowed for weld. This is approximate, and, where exactness is re-
quired, chain should be made so.
FOR CHAIN SHEAVES. — The diameter, if possible, should be not less than thirty times the
diameter of chain used.
EXAMPLE. — For i-inch chain use 3o-inch sheaves.
APPENDIX
TABLE XXIV. — ANALYSES OF FIRE-CLAYS
(Kent's "Mechanical Engineers' Pocket-Book," eighth edition)
|
<5
_r
<LJ
q
o
.
3
1
3
Brand
H
in
IS
h
?
u
4>O
3
^
£ &>
Loss
H
i
1"*
oBB
a
|
B
I*
1
1
I
Mt. Savage1
50.46,35.90
12.744 -50
0.13
O.O2
TK
ice
1.65
Mt. Savage2
I . 15
ciS 8n in 08
rn en
T2
o
in
I 92
Mt. Savages
I. 53 44- 40J33- 56 14.575; -08
Tr.
O. II
0.247
1-47
Mt. Savage*
156.15 33.30
9-68
.59JO. I? O. 12
0.88
Strasburg, O
0.45 55.87
41-39
.60)0.4010. 30 o . 29
O.20
2.79
Cumberland, Md
i . 15
56.80
30.08 7.69
.67
. . 2 . 1O
3.97
Woodbridge, N. J
67.84
21.83 5-98
-57
0.28 0.242.24
4-33
Carter Co., Ky
68.01
24 . 09 3 . 03
.01
3.01
4.02
Clearfield Co., Pa
48.35
36.37 10.56
.00
0.07
O. 12
2.
54
4-73
Clearfield6 and
44.8O 1O.OO TA.7O
.30
O.2Oil.OO
Cambria Cos., Pa.6. .
5I.SO
44.85; i.Od
• 33
0.23 i. 15
Clinton Co., Pa
Clarion Co., Pa
Farrandsville, Pa
[.'46
1.02
63.1823.70 6.8?
44.61 38.oiji3.63
45.26 37.85 13. 3O
.20
.25
• 03
0.17 0.47
0.080.41
0.08 0.02
2.52
\'%
4*55
3-47
3-59
SOa'o'.ip
0.20
St. Louis Co., Mo
67.47
I9-33-IO. 4S
.56
0.41 O.O7
I.C
7
5- 14
Stourbridge Eng
73-82
15-88
6.45
• 95
Tr.
Tr.
O.9O
3-85
1 Mass. Inst. of Technology, 1871. 2 Report on Clays of New Jersey. Prof. G. H. Cook,
1877. 3 Second Geological Survey of Penna., 1878. « Dr. Otto Wuth (2 samples), 1885.
6 Flint clay from Clearfield and Cambria counties, Pa., average of hundreds of analyses by
Harbison-Walker Refractories Co., Pittsburg, Pa. • Same material calcined. All other
analyses from catalogue of Stowe-Fuller Co., 1907.
312
APPENDIX
TABLE XXV.— SIZES OF FIRE-BRICK
9-inch straight 9 X 41A X 2% inches.
Soap 9 X 2*4 Y.2%
Checker 9X3 X3
No. i Split 9 X4X XiX
No. 2 Split 9 X 4^2 X 2
Jamb. . . .
No. i key.
wide.
No. 2 key.
9 X 2% thick X 4K to 4 inches.
112 bricks to circle 12 feet inside diam.
9 X 2K thick X 4K to 3M inches
wide. 65 bricks to circle 6 ft. inside diam.
No. 3 key.
wide.
No. 4 key .
wide.
9 X 2K thick X 4K to 3 inches
41 bricks to circle 3 ft. inside diam.
9 X 2K thick X 4K to 2% inches
26 bricks to circle iK ft. inside diam.
No. i wedge (or bullhead) 9 X 4K wide, 2 X 2^ to 2 in.
thick, tapering lengthwise. 102 bricks to circle 5 ft. inside
diam.
No. 2 wedge 9 X 41A X 2K to iK in. thick.
63 bricks to circle 2l/2 ft. inside diam.
No. i arch 9 X 4K X 2^ to 2 inches thick,
tapering breadthwise. 72 bricks to circle 4 ft. inside diam.
No. 2 arch 9 X 41A X 2% to \%.
42 bricks to circle 2 ft. inside diam.
No. i skew 9 to 7 X 4K to 2K-
Bevel on one end.
No. 2 skew 9 X 2^ X 4K to 2^.
Equal bevel on both edges.
No. 3 skew 9 X 2^ X 4K to iX-
Taper on one edge.
24-inch circle 8K to sH X 4^ X 2K-
Edges curved, 9 bricks line a 24-inch circle.
36-inch circle 8J< to 6K X 4X X 2.54.
13 bricks line a 36-inch circle.
48-inch circle 8J< to ?J< X 4K X 2^.
17 bricks line a 48-inch circle.
i3X-inch straight I3K X 2X X 6.
i3K-inch key No. i 13^ X 2K X 6 to 5 inch.
90 bricks turn a 12-ft. circle.
i3X-inch key No. 2 13% X 2^ X 6 to 4^ inch.
52 bricks turn a 6-ft. circle.
Bridge wall, No. i
Bridge wall, No. 2
Mill tile
Stoke-hole tiles
18-inch block
Flat back
Flat back arch
22-inch radius, 56 bricks to circle.
Locomotive tile 32 X 10 X 3-
34 X 10 X 3-
34 X 8 X 3-
Tiles, slabs, and blocks, various si
30 in. wide, 2 to 6 in. thick.
13 X b% X 6.
13 X 6K X 3-
18, 20, or 24 X 6 X 3-
18, 20, or 24 X 9 X 4.
18 X 9 X 6.
9 X 6 X 2K.
9 X 6 X 3K to 2#.
36 X 8X3-
40 X 10 X 3-
12 to 30 in. long, 8 to
Cupola brick, 4 and 6 in. high, 4 and 6 in. radial width, to line shells 23 to 66 in. diameter.
A 9-inch straight brick weighs 7 Ib. and contains 100 cubic inches. (= 120 Ib. per cubic
foot. Specific gravity 1.93.)
One cubic foot of wall requires 17 9-inch bricks, one cubic yard requires 460. Where
keys, wedges, and other "shapes" are used, add 10 per cent in estimatingj the number
required.
One ton of fire-clay should be sufficient to lay 3,000 ordinary bricks. To secure the best
results, fire-bricks should be laid in the same clay from which they are manufactured. It
should be used as a thin paste, and not as mortar. The thinner the joint the better the fur-
nace wall. In ordering bricks, the service for which they are required should be stated.
APPENDIX
313
TABLE XXVI. — NUMBER OF FIRE-BRICK REQUIRED FOR VARIOUS
CIRCLES
Diam.
of
Circle
KEY BRICKS
ARCH BRICKS
WEDGE BRICKS
*
1
I
o
2
6
S3
1
o
£
0
z
1
1
I
1
JS
1
5.
ft. in.
\
I 6
25
25
1
2 O
17
I -I
3O
42
42
2 6
1 /
*o
25
ow
•14
31
18
49
60
60
3 o
^0
38
OT-
38
21
36
57
48
20
68
3 6
32
IO
42
10
54
64
36
40
76
4 o
25
21
46
72
72
24
59
83
4 6
19
32
51
72
8
80
12
79
91
5 o
13
42
55
72
15
87
98
98
5 6
6
53
59
72
23
95
98
8
1 06
6 o
63
63
72
30
102
98
15
113
6 6
58
9
67
72
38
110
98
23
121
7 o
52
19
7i
72
45
117
98
30
128
7 6
....
47
29
76
72
53
125
98
38
136
8 o
42
38
80
....
72
60
132
98
46
144
8 6
37
47
84
72
68
140
98
53
151
9 °
31
57
88
72
75
147
98
61
159
9 6
....
26
66
92
72
83
155
98
68
1 66
10 o
21
76
97
72
90
162
98
76
174
10 6
16
85
101
72
98
170
98
83
181
II O
II
94
105
72
105
177
98
91
189
ii 6
5
104
109
72
113
185
98
98
196
12 O
113
113
72
121
193
98
1 06
204
12 6
117
117
For larger circles than 12 feet use 113 No. I Key and as many g-inch
brick as may be needed in addition.
314
APPENDIX
TABLE XXVII.— WEIGHT OF CASTINGS DETERMINED FROM WEIGHT
OF PATTERN
(Rose's " Pattern-makers' Assistant ")
WILL WEIGH WHEN CAST IN
A Pattern Weighing One
Pound, Made of—
Cast-
iron.
Zinc.
Copper.
Yellow
Brass.
Gun-
metal.
Ibs.
Ibs.
Ibs.
Ibs.
Ibs.
Mahogany — Nassau . .
Honduras
10.7
12.9
10.4
12.7
12.8
15-3
12.2
I4.6
12.5
15-
Spanish. .
8-5
8.2
10. I
9-7
99
Pine, red
12.5
12. I
14.9
14.2
14.6
' white
16.7
16.1
19.8
19.0
19 5
' yellow
14.1
13-6
16.7
16.0
16.5
TABLE XXVIII. — DIMENSIONS OF FOUNDRY LADLES
The following table gives the dimensions, inside the lining, of ladles from
25 Ibs. to 1 6 tons capacity. All the ladles are supposed to have straight
sides. (Am. Mack.)
Capacity
Diam.
Depth
Capacity
Diam.
Depth
Capacity
Diam.
Depth
in.
in.
in.
in.
in.
in.
1 6 tons
54
56
3 tons
31
32
300 lb.
11%
IlH
14 "
52
53
2 "
27
28
250 "
10%
II
12 "
49
50
ij^j "
24/^3
25
2OO "
IO
ioj^
10 "
46
48
i ton
22 22
150 "
9
91A
8 "
43
44
X "
2O 2O
100 "
8
8%
6 "
39
40
y* "
17
17
75 "
7
71A
4 "
34
35
1A "
131A
13^2
50 "
(>1A
&A
APPENDIX
315
TABLE XXIX. — COMPOSITION OF ALLOYS IN EVERY-DAY USE IN
BRASS FOUNDRIES
(American Machinist)
Cop-
per
Zinc
Tin
Lead
Admiralty metal
Bell metal
Ibs.
87
16
Ibs.
5
Ibs.
8
4
Ibs.
For parts of engines on board
naval vessels.
Bells for ships and factories.
For plumbers, ship and house
brass work.
For bearing bushes for shafting.
For pumps and other hydraulic
purposes.
Castings subjected to steam
pressure.
For heavy bearings.
Metal from which bolts and
nuts are forged, valve spin-
dles, etc.
For valves, pumps, and general
work.
For cog and worm wheels,
bushes, axle bearings, slide
valves, etc.
Flanges for copper pipes.
Solder for the above flanges.
Brass (yellow). . .
Bush metal
Gun-metal
Steam metal . . .
Hard gun-metal .
Muntz metal
Phosphor bronze.
Brazing metal. . .
14 solder...
16
64
32
20
16
60
92
90
16
50
8
8
40
3
50
4
3
iH
2^
H
4
i
8pho
10 "
s. tin
316
APPENDIX
TABLE XXX.— USEFUL ALLOYS OF COPPER, TIN, AND ZINC
(Selected from numerous sources)
Copper.
Tin.
Zinc.
U. Navy Dept. journal boxes ) _
and guide-gibs ) ~
I 6.
1 82.8
58.22
62
88
|64
187-7
92-5
9i
87.75
85
83
5 13
I 76.5
82
83
20
87
88
84
80
81
97
89.5
89
89
86
85M
80
79
74
64
I
13-8
2-30
I
10
8
II. 0
5
7
9-75
5
2
2
ii. 8
16
15
I
4-4
10
H
18
17
2
2.1
8
2^
I2&
18
18
9%
3
K parts.
3.4 percent.
3948 "
37
2
I parts.
i . 3 per cent.
2-5 "
2
2-5 '
IO
15 " '
2 parts.
11.7 percent.
2 slightly malleable.
1.50 0.50 lead,
i i
4-3 4-3
2
2
2 o antimony.
Tobin bronze
Naval brass
Composition, U. S. Navy
Brass bearings (J. Rose)
Gun-metal
ii ii
U U
Tough brass for engines
Bronze for rod-boxes (Lafond)
" pieces subject to shock. .
Red brass . parts
Bronze for pump casings (Lafond) .
" eccentric straps '
" shrill whistles
" low-toned whistles
Art bronze, dull red fracture.
20 "
5.6 2. 8 lead.
i*
2
2
2>£ yz lead.
93^ 7 lead.
29^ 3^ lead.
Gold bronze .
Bearing metal
English brass of A.D. 1504
APPENDIX
317
TABLE XXXI. — COMPOSITION OF VARIOUS GRADES OF ROLLED
BRASS, ETC.
(Kent's " Mechanical Engineers' Pocket-Book," eighth edition)
Trade Name
Copper
Zinc
Tin
Lead
Nickel
6l S
-18 5
60
4-O
66%
T.T.I/.
Low brass
80
2O
60
4O
\V>
Drill rod
60
6634
40
W1A
\V<>
1^4 to 2
6iY*
20\4
18
The above table was furnished by the superintendent of a mill in Connecticut in 1894.
He says: While each mill has its own proportions for various mixtures, depending upon the
purposes for which the product is intended, the figures given are about the average standard.
Thus, between cartridge brass with 33% per cent zinc and common high brass with 38^
per cent zinc, there are any number of different mixtures known generally as "high brass," or
specifically as "spinning brass," "drawing brass," etc., wherein the amount of zinc is
dependent upon the amount of scrap used in the mixture, the degree of working to which
the metal is to be subjected, etc.
TABLE XXXII.— SHRINKAGE OF CASTINGS
(Kent's " Mechanical Engineers' Pocket-Book," eighth edition)
The allowance necessary for shrinkage varies for different kinds of metal,
and the different conditions under which they are cast. For castings where
the thickness runs about one inch, cast under ordinary conditions, the fol-
lowing allowance can be made :
For cast-iron, ^ inch per foot.
" brass, tV " " "
" steel, 14 "
" mal. iron, J/£ " " "
For zinc, ^ inch per foot.
" tin, rV " " "
" aluminum, rs "
" britannia, -53 " " "
Thicker castings, under the same conditions, will shrink less, and thinner
ones more, than this standard. The quality of the material and the man-
ner of molding and cooling will also make a difference.
Mr. Keep (Trans. A. S. M. E., vol. xvi) gives the following "approxi-
mate key for regulating foundry mixtures" so as to produce a shrinkage
of % in. per ft. in castings of different sections:
Size of casting % i 2 3 4 in. sq.
Silicon required, per cent. ... 3.25 2.75 2.25 1.75 1.25 percent
Shrinkage of a >£-in. test-bar 0.125 0.135 °-I45 o^SS 0-165 in. per ft.
318
APPENDIX
TABLE XXXIII.— SIZES OF PIPES FOR TUMBLING BARRELS, INCHES
DIAMETER
(Data Sheet of The Foundry, Feb., 1910)
Diameter
Length of Barrel, Inches
of
Mill,
Inches
36
48
60
72
84
24
4
4
5
6
6
30
4
4
5
6
6
36
5
5
6
6
7
42
6
6
6
7
8
48
6
6
7
8
8
TABLE XXXIV.— DIAMETER OF EXHAUST FAN INLETS FOR TUMBLING
BARRELS
(Data Sheet of The Foundry, Feb., 1910)
NUMBER OF MILLS
Diameter
of Pipe
to Mill,
Inlet Diameter, Inches
Inches
i
2
3
4
5
6
7
8
9
IO
4
4*A
f>y2
&A
8*A
sy2
10)4
10)4
12
12
12
5
51A
VA
VA
10*4 \ 12
12
H
14
16
16
6
VA
VA
10)4
12
14
14
16
18
18
20
7
VA
10)4
12
14
16
18
18
20
22
24
8
sy2 \ 12
H
16 18
20
22
24
24
27
1
I
APPENDIX
319
TABLE XXXV. — STEEL PRESSURE BLOWERS FOR CUPOLAS (AVERAGE
APPLICATION)
(American Blower Co.)
1
£
*
a a
Q""
1
£,
f*
•3d
il
££
u
Dia. Outlet,
pipes, in.
3
Oz.
2
3
"Sd
|*
In.
3.46
5-19
6.92
8.65
10.38
12. 12
13-83
I5.56
H.P.
constant
at 1000
cu. ft.
1.242
1.86
2.48
3-10
3-73
4-35
4-95
3915
708
3.51
5.58
U%
1%
3.80
5%
0.18
R.P.M.
C.F.
H.P.
1960
361
0.45
2400
434
0.81
2770
500
1.24
3095
560
1-74
3390
610
2.28
3666
665
2.89
4150
752
4.20
17
i%
4-45
6%
0.2485
R.P.M.
C.F.
H.P.
1675
498
0.62
2050
600
I. 12
2362
691
1.72
2645
774
2.40
2895
843
3.15
3130 3340
9i6| 978
3-99 4-84
3540
1038
5-79
19%
1%
|
*
2%
5- II
7%
0.327
R.P.M.
C.F.
H.P.
I460
655
0.82
1785
789
1-47
2060
2300
2520
2730! 2910
3085
1365
7.62
2.26
3.16
4.15
5-25
6.36
'__
24y2
27
5.76
8%
0.4176
R.P.M.
C.F.
H.P.
1292
838
1.04
1582
1006
1.87
1825
1162
2.88
2040
1300
4-03
2235
1415
5.28
2420
1540
6.70
2585
1643
8.14
2740
1746
9-74
6.41
9%
0.519
R.P.M.
C.F.
H.P.
Il62
1040
1.30
1422
1250
2.33
1640
1442
3-58
1835
1612
5.00
2OIO
1760
6.57
2175
1915
8-34
2320
2040
IO. IO
2460
2166
12. IO
7.06
10%
0.63
R.P.M.
C.F.
H.P.
1055
1262
1-57
1290
1520
2.83
1490
1750
4-34
1665
1960
6.08
1825
?$
1975
2375
2105
2475
2233
2630
14.12
32
3%
8.39
i2y2
0.852
R.P.M.
C.F.
H.P.
889
1705
2.12
1087
2055
3-83
231o
5-86
1405
2650
8.23
1535
2890
10.78
1660
3140
13.66
1775
3350
16.60
1880
3555
19.83
37
3%
9.70
14
1.069
R.P.M.
C.F.
H.P.
769
2140
2.66
940
2575
4-79
1085
2970
7.36
121
332
IO.
1328
3620
13-5
I446J 1533
3940' 4200
17. 15 20.00
1625
4460
24.90
42
4%
10.98
16
1.396
R.P.M.
C.F.
H.P.
679
2800
3-48
830
3370
6.27
958
3880
9-63
107
434
13.46
1172
4730
17.6s
1270
5150
22.40
1355
5500
27.25
1435
5825
32.50
47
4%
12.30
I7V2
1.67
R.P.M.
C.F.
H.P.
606
3350
4-17
742
4025
7-5
855
4640
II. 5
956 1048
5200 5660
l6. 12 21 . 12
1 133
6160
26.80
I2IO
657O
32.55
1280
6970
38.90
52
5%
13-6
I9V4
2. 02
R.P.M.
C.F.
H.P.
548
4050
5-03
670
4870
9.06
774
5610
13.9
865
6290
19-5
947
6850
25-55
1025
7450
32.40
1093
7950
39-33
1160
8440
47-10
57
5%
14.92
21
2.405
R.P.M.
C.F.
H.P.
500 611
4820 5800
6.00 10.78
70S
6700
16.62
789 863
7490 8l60
23.2Sj30.45
934
8870
38.60
996
4§485
1056
10040
56. 10
320
APPENDIX
TABLE XXXVI. — STEEL PRESSURE BLOWERS FOR CUPOLAS (AVERAGE
APPLICATION)
(Continued)
1
"8
<r
i,
|s
•3d
0
p
Us
Is
.2 'a
Q
Area of Outlet,
sq. ft.
Oz.
IO 1 II
12
13
14
IS
16
In.
17.28
19.02
20.75
22.5
24.22
25-95
27.66
H.P.
constant
at 1000
cu. ft.
6.20
6.82
7-44
8.07
8.69
9-30
9.92
17
i%
4-45
6%
0.2485
R.P.M.
C.F.
H.P.
3740
1093
6.78
3920
"£
4090
1196
8.9
I9V2
i%
S.n
7%
0.327
R.P.M.
C.F.
H.P.
3255
1440
8.93
3415
1510
10.3
3570
1575
11.72
3710
1642
13.26
3955
1700
14-75
3985
1762
16.4
4120
1820
18.05
22
2%
5-76
8%
0.4176
R.P.M.
C.F.
H.P.
2890
1840
ii .40
3030
930
i .16
3163
2OI2
14.96
3290
2095
16.9
3420
2175
18.9
3535
2250
20.9
3650
2325
23.1
24V2
2%
6.41
9%
0.519
R.P.M.
C.F.
H.P.
2595
2280
14.13
720
395
i -33
2845
25OO
18.6
2960
2605
21.05
3075
2700
23-45
3180
2800
26.05
3280
2885
28.66
27
2%
7.06
10%
0.63
R.P.M.
C.F.
H.P.
2355
2770
17.18
470
910
19.85
2580
3033
22.6
2685
3165
25-55
2790
3280
28.50
2885
3395
31-55
2980
3500
34-7
32
3%
8.39
i2y2
0.8C2
R.P.M.
C.F.
H.P.
1983
3750
23.25
2080
3930
26.80
2170
41X0
30.6
2260
4276
34-5
2345
4430
38.5
2430
4590
42.7
2510
4730
47-
37
42
3%
4%
9.70
14
1.069
R.P.M.
C.F.
H.P.
1715
4700
29.15
1800
4930
33-66
1880
JI50
.33
1955
536o
43.25
2030
5560
48.30
2100
5760
53-55
2170
5940
59-
10.98
16
1.396
R.P.M.
C.F.
H.P.
1515
6150
38.15
1590
6450
44.00
1660
6730
50.15
1728
7010
56.60
1792
7270
63.2
1855
7525
70.
1916
7760
77-
47
52
4%
12.30
I7V2
1.67
R.P.M.
C.F.
H.P.
1352
7350
45.60
1418
7715
52.66
1480
8055
60.0
1540
8390
67.66
1600
8700
75-6
1655
9010
83-9
1710
9300
92.25
5%
13.6
I9V4
2. O2
R.P.M.
C.F.
H.P.
1222
8900
55-20
1282
9330
63.6
1340
9750
72.5
1393
10140
82.0
1447
10520
91-5
1498
10890
IOI.2
1546
II220
III 33
57
5%
14.92
21
2.405
R.P.M.
C.F.
H.P.
1113
10580
65.5
1168
IIIOO
75.70
I22O
II60O
86.33
1270
12080
97-5
1318
12520
109.0
1363
I296O
120.5
1410
13380
132.75
APPENDIX
321
TABLE XXXVII. — CAPACITY OF STURTEVANT HIGH- PRESSURE BLOWERS
Number of
Blower
C%Pef&e,USb.eet ReVStneS Per
Inside Diam.
of Inlet
and Outlet,
Inches
Approximate
Weight,
Pounds *
000
i to 5
200 to 1000
»H
40
00
5 to 25
375 to 800
iH
80
O
25 to 45
370 to 800
2^
140
I
45 to 130
240 to 600
3
330
2
130 to 225
300 to 500
4
550
3
225 to 325
380 to 525
4
760
4
325 to 560
350 to 565
6
1, 080
5
560 to 1 ,030
300 to 475
8
1,670
6
1,030 to vi,540
290 to 415
10
2,500
7
i, 540 to 2,300
280 to 410
10
3,200
8
2,300 to 3,300
265 to 375
12
4,700
9
3,300 to 4,700
250 to 350
16
6,100
10
4,700 to 6,006
260 to 330
16
8,000
ii
6,000 to 8,500
220 to 310
20
12,100
12
8,500 to 11,300
190 to 250
24
18,700
13
1 1, 300 to 15,500
190 to 260
30
22,700
Of blower for J^ Ib. pressure.
322
APPENDIX
TABLE XXXVIII.— SPEED, CAPACITIES, AND HORSE-POWER OF
SIROCCO FANS
(American Blower Co.)
The figures given represent dynamic pressures in oz. per sq. in. For static pressure,
deduct 28.8 per cent; for velocity pressure, deduct 71.2 per cent.
E8
.2-
C£
£
£
&.
I
Oz.
1%
Oz.
a
a
2
Oz.
21/2
Oz.
<L
in.
6
9
12
15
18
21
Cu. ft.
R.P.M.
B.H.P.
155
1. 145
.0185
22O
I,6l5
.052
270
1,980
.095
3io
2,290
• 147
350
2,560
.205
2«
.270
410
3,025
•34
440
3,230
.42
490
3,616
-58
540
3,960
.76
Cu. ft.
R.P.M.
B.H.P.
350
762
.042
500
I,O76
.118
880
808
.208
1,380
645
.326
610
1,320
.216
i, 080
990
.381
700
1,524
.333
790
1,700
.463
860
1,866
.610
930
2,020
-77
1,000
2,152
.95
I, IIO
2,408
1.32
1,220
2,640
1-73
Cu. ft.
R.P.M.
B.H.P.
625
572
.074
1.250
1. 145
.588
1,400
1,280
.82
1,530
1,400
1. 08
2,400
1,120
1.69
1,650
1,512
1.36
1,770
1,615
1.66
2,760
1,290
2.61
1,970
1, 808
2^1
3,090
1.444
3-65
2,170
1,980
3,390
1,580
4.8
Cu. ft.
R.P.M.
B.H.P.
975
456
.US
1,690
790
.600
1,950
912
.923
2,180
1,020
1.29
2,590
I,2io
2.14
Cu. ft.
R.P.M.
B.H.P.
Cu. ft.
R.P.M.
B.H.P.
Cu. ft.
R.P.M.
B.H.P.
1,410
38i
.167
1,925
326
.227
1,990
538
_.470
2,710
462
.640
~3i540
404
.832
2,440
660
.862
3.310
565
1.17
4.340
495
1.53
2,820
762
^.-33
3,850
652
1.81
5,000
572
2.35
3,i6o
850
1.85
3.450
933
2.43
3,720
1,010
3.07
3.980
1,076
3-75
4-450
1,204
5-25
4,880
1,320
6.9
4,290
730
_2_lS3
5,6oo
640
3-28
4,700
800
_3_-33
6,120
700
4_-32
7,780
622
5.48
5,070
864
4.18
6,620
756
5.44
8,400
672
6.90
5,420
924
—Si!.1
7,080
807
6.64
6,060
1,032
7-15
6,620
1,130
8.680
990
12.2
24
2,500
286
.296
7,900
904
9-3
27
30
36
42
Cu. ft.
R.P.M.
B.H.P.
3.175
- 254
_-J73
3,910
228
_.46o
5.650
190
.665
4-490
359
1.05
5.500
440
1-94
6,770
395
2.40
9.750
330
3-44
13,300
283
4-69
6,350
508
2.98
7,100
568
4.16
8,980
.?S
10,050
804
II. 8
11,000
" 880
15-5
Cu. ft.
R.P.M.
B.H.P.
Cu. ft.
R.P.M.
B.H.P.
Cu. ft.
R.P.M.
B.H.P.
5.520
322
_ll30
7,950
269
1.8?
10,850
231
2.55
7,820
456
_3^68
11,300
38l
5-30
8,750
510
5- IS
9,600
560
6. 75
10,350
604
8.53
11,050
645
10.4
12 ,350
?22
14-5
13-550
790
19-500
660
. 2?.S
26,600
566
37-5
12,640
425
_L-4o
17,170
365
IO. I
13,800
466
9-72
18,800
400
13.3
14,900
504
_I2_.25
20,300
432
16.7
15,900
538
-*L°
21,700
462
20.4
17,800
602
20.9
24,250
516
28.5
7.700
163
.903
15,400
326
7.24
48
54
Cu. ft.
R.P.M.
B.H.P.
10,000
,31
14.150
202
3-32
.,17,350
248
6.10
20,000
286
_9_i40
25,400
254
II. 9
22,400
320
13.1
24,500
350
17.2
26,500
378
21.75
28,300
2fi
3I,6OO
452
37-1
34,700
$1
Cu. ft.
R.P.M.
B.H.P.
12,700
127
1.49
17,950
179
4.20
22,000
22O
7.75
28,400
284
16.6
31,100
311
21.9
33,600
336
27.6
35,900
359
33-7
40,200
402
47.1
44,000
440
62.
60
66
Cu. ft.
R.P.M.
B.H.P.
-CuTfT
R.P.M.
B.H.P.
15,650
114
1.84
22,100
161
5.20
26,800
147
6.30
27,100
198
9.58
31.300
228
14-7
35,000
255
20.6
42,3"oo
232
24-9
38,400
280
27.0
46,400
254
32.7
41,400
302
34.1
50,100
275
41.2
44,200
322
41.6
53,600
294
50.4
49,400
36i
58.2
54,200
396
76.5
18,950
104
2.23
32,850
1 80
11. 6
37,900
208
17-8
60,000
328
70.4
65,700
360
92.6
72
78
Cu. ft.
R.P.M.
B.H.P.
Cu. ft.
R.P.M.
B.H.P.
22,6OO
2^
Tf!
30,800
8 1
3.61
31,800
134
7.48
37,350
124
8.77
39.000
165
13.7
45,800
153
16.1
45,200
190
21.2
52,800
I?6
24.8
50,600
212
29.6
55,200
233
_3L»
64,700
215
45.6
59,600
252
49.0
63,600
269
59-8
71,200
301
83.6
78,000
330
no.
91,600
305
129.
59,100
197
34-7
"70,000
233
57.5
74,700
248
70.2
83,500
278
98.
84
90
Cu. ft.
R.P.M.
B.H.P.
43,400
US
IO.2
53.200
142
18.7
6l,6OO
163
28.9
68,700
182
40.4
75,200
200
53-0
81,200
216
66.8
86,800
^
97,100
258
114.
106,400
283
150.
Cu. ft.
R.P.M.
B.H.P.
35,250
76
4.14
49,800
107
ii. 7
61,000
132
21.5
70,500
152
33-1
78,800
170
46.2
86,400
1 86
60.7
93,300
2OI
76.7
99,600
214
93-6
111,200
241
131-
122,000
264
172.
APPENDIX
323
TABLE XXXIX.— CAPACITY OF ROTARY BLOWERS FOR CUPOLAS
Cu. Ft.
per
Rev.
Revs.
per
Min.
Tons
Hour
Suitable
for Cupola
In. Diam.*
Cu. Ft.
RPeCv.
Revs.
&
Tons
Hourr
Suitable
for Cupola
In. Diam.*
1-5
j 200
I 400
I
2
>- l8t020
45
(135
ji65
12
15
> 54 to 66
3-3
175
1335
I
2
j- 24 to 27
( 200
( 130
18
15
)
6
(185
(275
2
3
!• 28 to 32
57
155
( 185
18
21
V 60 to 72
10
j 200
( 250
4
5
j- 32 to 38
65
( HO
« 160
18
21
[ 66 to 84
!I50
4
(185
24
!
13
190
5
V 32 to 40
125
21
175
VA
)
84
]>45
24
> 72 to 90
( 150
5
)
( 160
27
J
17
•j 2°5
VA
[•36 to 45
SI2O
24
)
(250
sy2
)
IOO
135
27
)- 84 to 96
1 66
8
1 60
30
1
24
200
10
f 42 to 54
(US
27
) Two
240
12
)
118
•j 130
30
V cupolas
ISO
10
( 140
33
) 60 to 66
33
1 80
12
48 to 60
210
H
* Inside diam. The capacity in tons per hour is based on 30,000 cu. ft. of air per ton of
iron melted.
324
APPENDIX
TABLE XL.— DIAMETERS OF BLAST PIPES
(B. F. Sturtevant Co.)
g
c
1
1 =
I
ft
ii
u
LENGTH OF PIPE IN FEET
• 20
40
60
80
IOO I2O 140
DIAMETER OF PIPE WITH DROP OF
£
A
5
£
£
£'
£
£
£
£
£
A
9
£
£
£
23
500
6
7
6
7
6
8
7
9
8
8
9
8
3
4
5
6
1
9
10
II
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
30
39
42
45
48
54
60
60
66
66
66
72
72
72
78
i
84
90
90
90
90
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
5.500
6,000
6,500
7,000
7,500
8,000
8,500
9,000
9,500
10,000
10,500
11,000
11,500
12,000
12,500
13.000
13,500
14,000
14.500
15. ooo
10
ii
8
9
12
ii
13
IS
16
17
18
12
13
14
IS
IS
14
IS
17
|2
12
14
IS
II
11
18
18
13
14
15
16
17
IS
17
18
19
20
14
IS
16
17
18
17
18
20
21
12
14
IS
16
18
18
13
13
IS
IS
IS
II
12
12
13
13
IS
11
13
13
IS
18
IS
19
17
20
18
21
23
20
23
20
20
11
18
18
18
18
20
2O
21
21
21
22
22
22
23
23
23
24
14
14
11
16
16
17
11
18
18
19
19
19
19
20
20
20
21
19
20
17
18
21
22
18
19
23
23
19
20
23
24
21
3
22
26
23
23
24
24
25
26
26
26
27
11
22
18
23
20
24
22
26
22
26
23
27
22
23
23
24
24
25
11
26
26
27
27
27
2O
2O
21
21
21
24
25
26
27
22
22
23
23
24
26
27
27
28
28
23
23
23
24
25
28
28
29
29
30
23
24
25
26
26
28
29
30
30
30
25
25
26
27
27
29
30
30
31
31
22
22
23
23
23
24
28
28
24
24
29
29
26
26
31
31
27
27
32
32
28
28
33
33
34
34
34
35
28
28
28
29
30
30
29
29
29
1
26
30
31
31
27
27
27
32
32
32
28
28
28
33
33
34
29
29
30
INDEX
ADMIRALTY metal, composition of,
3i5
Air-furnace, 271, 288
construction, 271
fuel for, 274
operation, 271
Alloys, composition of, 279, 315
copper-tin-zinc-, table of, 316
Aluminum in iron, 237
Analyses of castings, 241
Annealing, 228
Arbor, 132, 288
BARS, 288
Basin, 288
pouring, 294
Bath, 288
Bead-slicker, 288
Bearing metal, 316
Bed charge, 250, 288
Bedding patterns in foundry floor,
48
Bellows, 211, 288
Bench, 288
work, I, 288
Binders, 56, 288
core, 139
Black sand, 288
Blacking, charcoal, 232
coke, 232
Lehigh, 232
Blast, 288
pipes, diameters of, 324
Blowers, cupola, capacities of, 319,
321,322
rotary, for cupola, capacities of,
323
Bod, 255, 288
Bosh, 211, 288
Boshing, 5
Bottom-board, 288
Box, set-off, 295
Brackets on columns, molding, 70
Brass, composition of, 315, 317
founding, 275
red, composition of, 316
Brazing metal, composition of,
315
solder, 315
Break-out, 288
Breast of cupola, 250, 289
Bricks, fire, 289
loam, 124, 289
Bronze, composition of, 316
Brush, 289
Buckle, 131, 289
Bung, 289
Bush metal, composition of, 315
Butt, 289
CALIPERS, 216, 289
Camber, 68
Camel's-hair brush, 289
Carbon, combined, 234
graphitic, 235
in iron. 234
temper, 235
Carrying plate, 118, 289
Car-wheel, molding, 84
Car-wheels, drop test, 88
thermal test, 88
Casting, 289
malleable, 293
shrinkage of, 317
325
326
INDEX
Castings, analyses of iron for, 241
burning on, 204
cleaning, 181
determination of weight of
from weight of pattern, 314
mending broken, 204
straightening crooked, 180
treatment of, while cooling, 176
Cementite, 234, 289
Center of loam mold, 124
Chains, strength of, 310
Chaplet, 156, 289
in cylindrical mold, 159
in quarter-turn pipe mold, 162
use of, 62
use of in column molds, 72
Charge, 289
bed, 288
Charging a cupola, 252
door, 289
Cheek, 289
, false, 291
of loam mold, 123
ring, 1 20.
use of, 20
Chill, 84, 289
Chilled work, 289
Chuck, 289
Churning, 175, 289
Cinders, use of in pit molding, 50
Circles, area and circumference of,
298
Clamp, 210, 290
use of, 33
Clamping bar, 212, 289
Clay for bod, 255
wash, 290
worm, 63
Cleaning castings, 181
Cold shut, 107, 290
Columns, cores for, 73
fluted, pattern for, 74
gating, 72
molding, 65
Columns, round, molding, 69
shrinkage allowance, 74
Coke, ratio of, to iron in cupola
charges, 263
Cooling of castings, 176
Cope, 3, 290
ascertaining proper bearing for,
62, 68, 107
down, 15, 18, 290
plate, 1 19, 290
Copper in iron, 237
Copper-tin zinc alloys, 316
Core, 290
baked, 288
barrel, 149
barrel, venting of, 150
binders, 139
blacking for, 154
box, 138, 290
cake, 148
cover, 148
dry-sand, 138
for columns, 73
for steel castings, 137
green, 292
green, making, 10
green, nailing, 10
grids in, 144
hook, 286
loam, sweeping, 132
locating, 17
machines, 146
ovens, 147
pasting, 63
plate, 142, 290
print, 290
rodding, 144
sand for, 138, 153
setting, 156
Cores, skeleton in, 144
skim, 168
tooth, 130
venting, 63, 142
wax tapers as vents in, 145
327
Core-driers, 103, 145, 291
Corner tool, 212, 290
Crane, 284
floor work, light, 43
Cross, 124
Crucible furnace, 275
tilting furnace, 277
zone, 259, 290
Cupola, 290
blast pressure for, 260
building breast in, 250
calculating mixtures for, 265,
269
charging, 248
construction of, 246
fuel for, 248
igniting, 249
lining, repairs of, 257
operation of, 245
practice, comparative, table of,
262
ratio of iron to fuel, 263
relation of capacity to blast
pressure, 263
slagging, 254
Cylinder, molding in loam, 116
DISK crank, cooling of, 177
Double-ender, 213, 290
Draft, 290
Drag, 3
plate, 118
Draw-bench frame molding in
flask, 56
frame molding in floor, 49
Draw-nail, 290
spring, 216, 296
Draw-peg, 165, 290
Draw-screw, 212, 291
Draw-spike, 212, 291
Dropping bottom of cupola, 256
Dry sand, 291
sand cores, 138
sand mold, 100, 291
Dry sand molds, finishing, 102
sand molds, mixtures for, 100
sand molds, repairing breaks in,
102
Driers, core, 145, 291
EARS, 291
Engine bed, molding, in skin-dried
mold, 91
cylinder, molding, in dry sand,
101
Equipment, foundry, 280
Eye-bolt, 291
FACING, gas-house carbon, 232
material, 228
Rhode Island, 231
False-cheek, 291
use of, 21
Fans, capacities of, 319, 321, 322
Feeding head, 174, 291
Ferrite, 234, 291
Ferro-manganese, 236
Fire-brick, 289
number required for various
circles, 313
sizes of, 312
Fire-clay, analyses of, 311
Fire-sand, 233
Fitting up snap flask, 4
Flange tool, 213, 291
Flask, 281, 291
barred, 31
sectional, 109
snap, 296
tight, 297
Flat back, 291
back pattern, 31
gate, 291
Floor mold, closing, 36
mold, pouring, 36
molding, 30
work, i, 30, 297
Flow-off, 56, 291
328
INDEX
Flux, 291
Fly-wheel, molding, in loam, 128
segment, molding, 82
Former for sheet-metal work, mold-
ing, without pattern, 82
Foundry, 292
equipment, 280
ladles, dimensions of, 314
Frozen iron, 292
Fuel for air-furnace, 274
Furnace, crucible, 275
crucible tilting, 277
open-flame oil, 277
reverberatory, 294
GAGGER, 33, 211,292
board, 287
use of, 45
Gap-press frame, molding, in floor,
58
Gate, 1 68, 292
flat, 171, 291
horn, 169, 292
peg, 1 68, 294
skim, 1 68, 294
set, 1 68
whirl, 172, 297
Gate-cutter, 216
Gate- pin, 213
Gates, location of in barred flask, 33
Gate-stick, 292
Gating, 292
columns, 72
Gear molding, 25
split, molding, 28
Gears, bevel, molding on floor, 39
Graphite, Ceylon, 230
Green-sand match, 17, 292
Grid, 103, 129, 144, 292
use of, 92
Gun metal, composition of, 315, 316
HAND rammer, use of, 4
squeezer, 185
Hand wheel, molding, 17
Hay rope, 132, 292
Head, feeding, 291
shrink, 295
Heap sand, 292
Hearth, 292
cupola, 259
Heat, 292
Horn gate, 27, 292
Hub tool, 213, 293
Hydrofluoric acid, 182
INGOT mold, 287
Iron, cast, shrinkage of, 244
composition of, 234
for castings, analyses of, 241
for columns, 74
for frictional wear, 244
frozen, 292
hard, for heavy work, 243
pig. See Pig Iron
rammer, use of, 32
soft, composition of, 243
JARRING MACHINE, 194, 293
shockless, 195
Joint, 293
making, 4
Jolt rammer, 194, 293
KING, experiments of, on molding
sand, 218
LADLES, foundry, 280
foundry, dimensions of, 314
Lathe-bed legs, molding, 30
Lead, Austrian, 231
German, 231
Mexican, 231
Lifter, 212, 293
Liquid glass, use of, 38
Loam, 293
mixture, 120, 132
mold, 293
INDEX
329
Loam mold, breaking open, 126
molding, 116
MACHINE molding, 293
Malleable casting, 293
Manganese in iron, 236
Match board, 163
green-sand, 292
plate, 165
plates, aluminum, 188
Melting points, Table of, 308
rapidity of, 260
ratio, 252
zone, 250, 259, 293
Mending broken castings, 204
Metals, weight and specific gravity
of, 307
Mixtures, calculation of, for the
cupola, 265, 269
Molasses water, 101
Mold, 293
dry-sand, IOO, 291
face of, strengthened by rods,
92
finishing, 5
floor, closing, 36
floor, pouring, 36
loam, 293
skin-dried, 90, 295
types of, I
renting, II
weighting of, for pouring, 8
Mold-board, 293
Molding car-wheels, 84
columns, 65
cover plate with sweep, 76
cylinder in loam, 116
double groove sheave in three-
part flask, 22
draw-bench frame in flask, 56
draw-bench frame in floor, 49
engine bed in skin-dried mold,
9i
engine cylinder in dry sand, 101
Molding fly-wheel in loam, 128
fly-wheel segment in green
sand, 82
former for sheet- metal work
without pattern, 82
gap-press frame in floor, 58
gears, 25
gears on the floor, 39
hand wheel, 17
in three-part flask, 20
in two-part flask with false
cheek, 21
irregularly shaped patterns, 15
lathe-bed legs, 30
loam, 116
machine, 184, 293
machine, when to use, 202
printing-press cylinders in dry
sand, 108
pulleys, 37
rectangular block in snap flask,
3
round column, 69
sand, 217, 293
sand, analyses of, 220-222
sand for steel castings, 135
sand, tests of, 225
sand, treatment of, 226
solid shot, 23
split gears, 28
tank cover plate with sweep,
80
tools,' 210
type cylinder in dry sand, 112
wire-cloth loom frame, 43
with sweep, 75
Muntz metal, 315
NOWEL, 293
OXY-ACETYLENE welding, 208
PARAFFINE board, 189, 293
Parting, 294
330
INDEX
Parting sand, 294
Pattern, 294
determining weight of castings
from, 314
drawing, 5, 290
drawing with the crane, 47
flat back, 31
gating of, 292
mounting, in vibrator frame,
189
plate, mounting of split pat-
terns on, 192
sectional, 109
split, 296
Peen, 294
Peg-gate, 294
Permeability of sand, 218
Phosphor-bronze, composition of,
315
Phosphorus in iron, 236
Pickling, 182
Pig iron, analyses of, 238
foundry, specifications for, 239
grading of, 237
Pins, 294
Pipe tool, 213, 294
Pit molding, 48
preparation of for molding, 50
Plate, carrying, 289
cooling of, 178
cope, 290
stool, 296
stripping, 297
Plumbago, 230
Print, core, 290
Printing-press cylinders, cooling of,
179
cylinder?, molding, in dry sand,
108
Porosity of sand, 217
Pouring-basin, 294 '
Pouring-box, 73
Pulleys, cooling of, 178
molding, 37
Pumping, 175, 294
Putty worm, no
RAMMER, 210, 294
iron, use of, 32
Rapping, 294
iron, 212, 216, 294
Rattling, 181
Riddle, 210, 295
Riser, 174, 295
for steel castings, 136
location of in barred flask, 33
Rods, use of, to strengthen face of
mold, 92
Roll-over machine, 197, 295
Roller, 286
Ropes, strength of, 309
Run-out, 295
Runner, 56, 295
box, 56
S-HOOK, 286
Sand, black, 288
green, 292
heap, 292
mixtures for dry-sand molds,
100
molding, 217, 293
parting, 294
Scab, 131, 295
Scaffolding, 256
Scrap, use of in cupola, 266, 269
Seacoal, 228
Seating, 121
Sectional flask, 109
pattern, 109
Set-off box, 34, 295
Sheave, double-groove, molding in
three-part flask, 22
molding, 20
Shockless jarring machine, 195
Shot, 295
molding solid, 23
Shovel, 210
INDEX
331
Shrinkage, 174
allowance for columns, 74
of cast-iron, 244
table of, 317
Shrinkhead, 295
Silicon in iron, 235
loss of in melting, 261
Skeleton, 103, 129, 144, 295
for loam mold, 127
use of, 92
Skim core, 295
gate, 295
Skin-dried mold, 90, 295
Slab core, use of, 59
Slag, 295
hole, 256, 296
Slagging cupolas, 254
Slicker, 212, 296
bead, 288
Sling, 284
Slip, 121, 296
Slurry, 143, 296
Snap-flask, 296
fitting up of, 4
molding, 3
Soapstone, 232
Soldier, 211, 296
use of, 13
Specific gravity of metals, 307
Spheres, area and volume of, 304
Spiegeleisen, 236
Spindle, 117, 296
seat, 75, 117, 296
Split pattern, 296
pattern molding machine, 190
pattern, molding of, 8
pattern with web center, mold-
ing of, 12
Spokes, wrought-iron, casting in hub
and rim of wheel, 38
Spoon-slicker, 213, 296
Spreader, 286
Spring draw- nail, 216, 296
Sprue, 296
Sprue cutter, 216, 296
cutter, use of, 7
Squeezer, hand, 292
power, 185, 294
split pattern, 296
Stack, 259, 296
Staples, 286
Starch, use of, 231
Steam metal, 315
Steel castings, 134
castings, cores for, 137
castings, facing for, 135
castings, fire-clay for, 135
castings, molding sand for, 135
castings, risers for, 136
Stock cores, 145
Stool, 192, 296
plate, 192, 296
Stooling of patterns, 192
Straight edge, 287
Strickle, 152, 297
Strike, 210, 297
Stripping plate, 190, 297
Sulphur, absorption of by iron, 260
in iron, 235
Swab, 211, 297
use of, 5
Sweep, 297
finger, 76, 287, 297
molding, 75
molding in flask, 80
use of in column molding, 68
Sweeping loam mold, 120
TALC, 232
Tank cover plate, molding, with
sweep, 80
Tap hole, 297
Tapers, wax, in cores, 145
Thermit welding, 207
Time-study of hand molding, 200
of machine molding, 201
Tin-zinc-copper alloys, 316
Titanium in iron, 237
332
INDEX
Tobin bronze, composition of, 316
Transfer plate, 192
Trowel, 211, 297
Trunnions, loose, 286
Tumbling- barrel, 181, 282
sizes of pipe for, 318
exhaust fan inlets for, 318
Tuyere, 297
zone, 259, 297
Type cylinder, molding, in dry sand,
UPSET, 297
use of, 15
VANADIUM in iron, 237
Vent, 297
wire, 211, 297
Vibrator, 185, 297
frame, 185, 297
Vibrator frame, mounting - pat-
terns in, 189
WATER pail, 210
Weight of metals, 307
Welding, oxy-acetylene, 208
thermit, 207
Whirl gate, 24, 297
Wind box, 297
Wire-cloth loom frame, molding, 43
Wire, vent, 297
Worm, clay, 63
putty, no
YOKE, 284
ZINC -tin-copper alloys, 316
Zone, crucible, 259, 290
melting, 250, 259, 293
tuyere, 259, 297
STATE NORMAL SCHOOL
IM ANGHLES, CALIFORNIA,
UNIVERSITY OF CALIFORNIA LIBRARY
Los Angeles
This book is DUE on the last date stamped below.
SEP8
LO.URO
APR 1 1 1975
Form L9— Series 444
UC SOUTHERN REGIONAL LIBRARY FACILITY
A 000506131 2
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