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SHEET-METAL WOEK

A MANUAL OF PRACTICAL SELF-INSTRUCTION IN THE ART OP

PATTERN DRAFTING AND CONSTRUCTION WORK

IN LIGHT- AND HEAVY-GAUGE METAL,

INCLUDING SKYLIGHTS, ROOFING,

CORNICE WORK, ETC.

WILUAM NEUBECKER

ILLUSTRATED

Ug,l,ze.:,y Google

,1.0, Google

240619

DEC 17 1923

•'A^'1 INTRODUCTION

THE importance of sheet-metttl work in modem manufactur-
ing developments is vastly greater than those not actually in
touch with the work would imagine. Its use in building sky-
lights, roofs, and cornices are visible and obvious applications
of the industry, but there are countless operations in pressed
metal manufacturing where the principles discussed herein find
their most important appUcation, and it is to help those who are
actually working in this field that this volume has been printed.
The sheet-metal draftsman has a very different problem in many
respects from that of the mechanical draftsman. The mechanical
draftsman has to deal, in the main, with square or circular
shapes, and he has perfectly definite plans or elevations to fashion
from the specifications given. His surfaces also are flat, spherical,
or cylindrical and will be sh^ied by the various machines found
in a wdl-equipped machine shop.

Q The aheet^metal draftsman, on the other hand, must have a
deeper understanding of geometrical principles, of the areas of sur-
facea, and many other matters not considered by the mechanical
draftsman. He must be able, in addition to the simple drawing of
the object, to make accurate developments of complex surfaces
and do this so accurately that the sheet-metal form, made from
his drawing, can be put tt^ether without waste and without
distortion of the shape intended.

^ The author of this book has had years of practical eKperience
in sheet^metal work of all classes as well as abundant oppor-
tunity to apply his experience in teaching the subject. All the
studies worked out are typical and the details are so clearly pre-
sented as to make the volume valuable for the beginner as well
as for the most experienced metal worker.

Dijii,.,. AiOOgle

,1.0, Google

CONTENTS

PAGB

Tools &od methods of obtaining patterns 3

Material of construction 3

Shop tools 4

Intersections and developments 5 ^^

Parallel-line development 5

Development by triangulation 15

Approximate developments 22

Workshop problems 26

Sink drainer 26

Conical boss ; 28

Hip bath 30

Bathtub 32

Funnel 36

Strainer ptul 36

Emerson ventilator 42

Elbows 44

Ship ventilator 57

Wrights of cast and wrought iron 62

Copper 62

Lead 62

Brass 62

Zinc 62

Wrights of sheet copper and zinc 63, 64

Standard gauge for sheet iron and steel OS

Weight of flat roUed iron 66-71

Weights of square and round iron bars 72, 73

Weights of angle and tee iron 74

Problems for Ught-gauge metal 75

Oblique piping 75

Rain-water cutrtjff '. 77

Transition piece in rectangular pipe 80

Curved rectangular chute 82

Hopper register box 85

Transition piece in circular pipe , 86

Pipe offset connection 88

Three-way branch 90

Two-branch fork 94

Tapering flange 97

Cylinder intersecting furnace top 100

Coppersmith's problems 105

Sphere 106

Circular tank 107

Curved elbows 113

CONTENTS

PAOX

Workshop problems (continued)

Brewing ketUe 115

Problems for heavy metal 116

Boiler sheila and stacks 117

Moulded cap for stack 117

Three-pieced elbow 122

Pipe interesections 124

GuBset sheet on locomotive 126

Scroll sign ; 128

Skylights 133

Skylight bars 133

Reinforcing strips 133

Core-plate 134

Cap 134

Weight of glass 135

Tools .^ 136

Shapes of bars and cu^'. 136, 137

Raising sash ,^'. 139

Condensation gutyfrs 140

Single-pitch and 4ouble-pit«h skylights 141, 142

Ventilation. ..._." 141

Hip monitor skylight 142

Photographer's skylight 142

Flat extension skylight 142

Hipped skylight without monitor 143

Skylight of long span 143

Gearings 144

Development of patterns for hipped skylight 144

Rules for obtaining length of ventilator 166

Ridge 156

Hip 157

Jack 167

Roofing 168

Metal roofs 168

Tin 168

Copper 158

Galvanized iron 158

Building paper 168

Tables of quantities 160

We^htfl 161

Gauges 161

Metal ; 162

Slstee 162

Hip coverings 162

Roofer's tool 163

Roof mensuration 163

CONTENTS

FAOB

Roofing (continued)

F1at«eam roofing 167

Guttere 168

Flaahings , 169

Sheet l«id 1 170

Soldering 172

Coverii^ a conical tower 174

Standii^-eeiun roofing 177

Corrugated iron rooBng and siding 182

Meaaurements 184

Deflection under loads 184

Distances of supports J84

Laying corrugated roofing and uding 185-IflO

Cornice woA 193

Members of a cornice or entablature 193

Cornice 194

Dentil and modillion courses 194

Bed and crown mould 194

Modillion band and mould 194

Dentil band and mould 194

Panel mould 195

Stop blocks 195

Raking mouldingS' - . - ^ ^ ^ ^ . . . , ^ ^ ^ ^ ^ . ^ , . . . ^ ^ ^ . . . . - ^ , . . . 196

Miter 196

Drawii^ and trscii^ 197

Methods of obtaining patterns 200

Shapes of mouldings ; 202

Problems in miter cutting 204

Sis-pointed star 236

Eyebrow dormer 243

Development oi blanks for curved mouldings 249

Shop tools 250

Apptwdmate blanks 250

Hand and machine hammering 258

lodex 263

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SHEET/METAL WORK.

PAKT L

The Bheet-metal worker of today who wishes to succeed must
know far more than was necessary years ago. There are many
good, practical sheet-metal workers in the trade who are handi-
capped because they are unable to lay out the patterns that arise
in their daily work. Notwithstanding the introdnction of labor-
saviikg machinery, the demand for good workmen has increased.
While most sheet-metal workers acquire practical knowledge in the
shop, they lack the technical education necessary to enable them to
become proficient as pattern cutters and draftsmen. In this
course, special attention is given to the fnndameutal principles
that underlie the art and science of pattern drafting.

Practical vorkshop problems will be presented, such as arise
in everyday practice, thus giving the student the practical
experience ibat usually comes only after long association with the
trade.

CONSTRUCTION.

In oonBtmcting the various articles made from sheet metal,
various gauges or thicknesses of metal are used. For eill gauges
from No. 20 to No. 30 inclusive, we assume in the development
of the pattern, that we are dealing with no thickneES, and we make
no allowance for bending or rolling in the machine. But where
the metal is of heavier gauge than No. 20, allowance must be made \
for shrinkage of the metal in the bending find roUing operations, \
which will be explained in connection with development in heavy
sheet-metal work. Certain instructions for wiring, seaming, and
transferring patterns are not given here as they more properly belong
to tinsmitbing work. It is sometimes the case that the capacity of a
vessel or article must be determined, when the rules given in
Mensuration should be followed. When figuring on sheet-metal
work, the specifications sometimes call for various metals, such aa
galvanized sheet iron or steel, planished iron, heavy boiler j>l!4U,^

i 3HBET-METAL WORK

band iion, square or ronnd lods for bracing, etc., zino, copper, oi
braas; and the weight of the metal mnst often be calculated together
with that of stifFening rods, braces, etc. On this account it is
necessary to have tables which can be consnlted for the Tarions
we^hts.

TABLES.
There is a wide difference between ganges in nse, which is
veij annoying to those who use sheet metal rolled by different
firms according to the Tarions ganges adopted. It would be well
to do away with gauge nmnbers, and use the micrometer caliper
ihown in Fig. 1, which determines the thickness of the metal by the
decimal or fractional parts of an inch ,

Pig.1.

This is the most satisfactory method for the averse mechanic
who works sheet metal manufactured by firms usu^ different
gai^s. The tables on pages 61 to 74 can be consulted when
occasion arises.

SHOP TOOLS.

In allowing edges for seaming and wiring, we must bear In
mind that when a seam is to be grooved by hand or machine the
allowance to be made to the pattern should conform to the rolls in
the machine or the hand tools in use. The edges of the pattern
are nsnally bent on the sheet-iron folder, or brake, while the seam
can be seamed or grooved with the hand groover or giant grooving
machine. Where round pipe work is done in lengths up to 3 feet,
the slip roll former is used, while sqnare or rectangular pipes are
bent up on the brake in 8-foot lensths. Where pipM, elbowi.

SHEET-METAL WORK 6

store bodies, famace shells, metal dmiDB, etc., are made, the sheets
aie out square on the large Bquaring shears, rolled, grooved, and
stiffened, by beadli^ both ends in the beading machine, using
ogee roUs. There is also a special machine for seaming the cross
seams in fuma«e pipes, also a set of machines for the manufacture
of elbows used in sheet-metal work. As before mentioned, if these
machines are at hand, it will be well to make slight modifications
in the patterns so that both the machines and patterns may work
to advanti^.

PATTERNS OBTAINED BY VARIOUS METHODS.

In this course will be explained the four methods osed in
developing patterns for sheet-metal work, namely, parallel line,
radial line, triai^ulation, and approximate developments. Further-
more, practical problems illustrating these methods will be carefully
worked out in every detail.

INTERSECTIONS AND DEVELOPMENTS.

The following problems on parallel line developments have
been selected because they have a particular bearing on pipe work
arising in the sheet-metal trade. All of the problems that wUl
follow should be carefully studied, drawn on cheap paper, and
proven by cardboard models. These models will at once show any
error in the patterns which might otherwise be overlooked. As
only the Examination Plates are to be sent to the School, the
student should draw all the other plates given in this course.

The first problem to be drawn is shown in Fig. 2, being the
intersection between a cylinder and octagonal prism. In drawing
these problems for practice, make the cylinder and oct^pnal prism
both 2 inches in diameter. The height of the cylinder from B to
E should be 4J inches; and the length of the prism from G to H,
3 inches. Let A represent the plan of the cylinder, shown in
elevation by B C D E ; and F, the section of the prism, shown in
plan by G H IJ. Nmnber the comers of the section F as shown,
from 1 to 4 on both sides; and from these points draw horizontal
lines intersecting the plan of the cylinder at 2'3' and 1'4' on both
sides as shown. Establish a convenient intermediate point of
intersection between the comers of the prism, as a and a in A, from.

SHEET-METAL WORK

which draw horizontal lines intereecting the section F at a ' , a ' , o ' ,
and a' . Take a tracii^ of the section F with its variotifl inter-
sections, and place it in its proper position as shown by F', in the

Fig. 2.

center of the cylinder B C D E, allowing the section to make a
quarter turn, and bringing the points i' h' at the top and bottom
on a vertical line, while in the section F, V V are on a horizontal

SHEET>METAL WOBE 1

line. From the varions intereeotionB in F^, draw horizontal lines
intersecting vertical lines drawn from similaTly nnmbered inter>
sections in the plan A, as shown in elevation. A line drawn
through these points will represent the joint between the cylinder
and priem.

For the development for the prism, extend the line H I in plan
as N K, upon which place the stretchont of all the points contained
in the section F, as shown by similar figures and letters on N K.
Through these points, at r^ht angles to N K, draw lines which
Intersect with lines drawn from similarly nnmbered points and
letters in plan, at right angles to J I. Trace a line through points
thnsobtained,andKLMNwillbe the desired pattern. To obtain
the development for the opening in the cylinder, extend the line
D E in elevation as S O, upon which place the stretchout of all the
points contained in the half-circle A, as shown by similar uiuubers
and letters on S O. At right angles to S O and throngh these
points, draw lines intersecting horizontal lines drawn from inter,
sections having similar nnmhers emd letters in elevation, thns
obtaining the intersections shown by T U V W, which will be the
shape of the opening to he cut into one-half of the cylinder.

In Fig. 3 is shown the intersection between a hexagonal and
qnadrangnlar prism, the hexagonal prism being placed in elevation
at an angle of 45° to the base line. When drawing this problem
for practice, make the height of the quadrangular prism ^ inches,
and each of its sides 2 inches. Place the hexagonal prism at an
angle of 45° to the base line, placing it in the center of the
quadrangolar prism in elevation as shown; and inscribe the hex-
agonal section in a circle whose diameter is 2^ inches. Let A
represent the plan of the quadrangular prism placed diagonally as
shown, above which draw the elevation BODE, In its proper
position and proper angle, draw the outline of the hexagonal prism
as shown hy 1' 1' 4' 4^; and on 1' 4' draw the half section as
shown by F, numbering the comers 1' 2' 3' and 4'. From the
comer 1 ' in the plan A, draw the center line 1 ' 4. Take a tracing
of the half section F, and place it as shown by F', placing the
points 1' 4' in F on the center line In F* as shown. From the
comers 1, 2, 3, and 4, draw lines parallel to the colter line, intersect-
ing the twosidesofAC&l' audi' a)at2' 3' andl' 4', asshown. From

JSHEET-MB?rAL WOKK

thetBe Intaneotions drafr vertical lines, which intersect by linev
drawn parallel to 4' 4* from comers having Bimilar nnmbere lu H
thus obtaining the points of intersection 1* 2* 3* and 4*, Dropplntj
vertical lines kom the intersections on the plane 1* 4' in elevation,
and intersecting similarl; numbered lines In nlan, will give the
faorizoatal secticm of 1' 4', as shown by 1° 2° 8' and 4".

Fib. 3.

For the development of the hexagonal prism, extend the line
4' 1' as shown by H J, npon which place the stretchout of twice
the number of spaces contained in the half section F, as shown by
similar figmes on the stretobont line H J. Fromthese points, at
right anf^es to H J, draw lines as shown, which intersect by lines
drawn at right angles to the line of the prism from intersections
l^ to 4*, thus obtainiiur tHta. points of intersection 1* to 4', Lines

.An

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SHEET-METAL WORE ii

traced &om point to point as shown hy J K IJ H, -will be tb»
leqmred development. The shape of the opening to be cut into the
qnadrangolar priBm, is obtained by extending the line D E in
elevation as N O, upon which place the stretchout of one-half
the section A, with the varions points of interseotion, as shown by
similiir figures on O N. At right eingles to O N erect lines from
these points, which intersect by lines drawn from similarly
nnmbered intersections in elevation at right angles to the qnad-
rangolar prism, thns obtaining the points of intersection 1'" to 4'"
on both sides. Then N O P R will be the half development.

Fig. 4 shows the intersection between two cylinders of equal
diameters at right angles. Make the height of the vertical cylinder
8 inches, that of the horizontal cylinder t^ inches, and the diameters
of both 2 inches. Let A represent the plan of the vertical cylinder,
and B its elevation. Draw the plan of the horizontal cylinder C,
shown in elevation by D placed in the center of the vertical
<qrlinder. Draw the half section E in plan and divide it into
equal parts, as shown from 1 to 3 to 1. In a similar maimer draw
the half section E' in elevation, which also divide into the same
nmnber of spaces as E, reversing the nnmbera as sho^te.

The followii^ suggestions are given to avoid confusion in
numbering the points or comers of irregular or round sections in
plan and elevation. If the hEilf section E were bent on the line 1-1
and turned upward toward the reader, and we should view this
section from the front, the point 3 would be at the top, or, if bent
downward, would be at the bottom; therefore tbe points 3 and 3 in
elevation are placed at top and bottom. Now if the section E^ in
elevation were bent on the line 8-3 either toward or away from the
reader, the point 1 when looking down would show on both sides as
shown in plan, which proves both operations. Ko matter whether
the form is simple, as here shown, or complicated as that which
will follow, the student should use his imaginative power. Study
the problem well ; close your eyes and imagine you see the finished
article before you, or, failing in this, make a rough model in the
shop or a cardboard model at home, which will be of service. Now
from the intersections in E, draw horizontal lines intersecting the
circle A at 1', 2' and 3' on both sides. From these points erect
perpendicular lines and intersect them with horizontal lines drawn

SHEET-METAL WORK

_,oogk

SHEET-METAL WOKK 11

from aimilsrly numbered intersections in E*. Lines traced through
these points 3' 2' 1' and 1' 2' 3' will be straight because both
branches are of equal diameters.

For the development of the cylinder D in elevation, extend
the line 3-3 as shown by F G, upon which place the stretchont of
twice the number of spaces contained in E', as shown by similar
numbers 3° to 1° to 3° to 1° to 3° on the stretchout line F G.
From these points, at right angles to G F, draw lines, and
intersect them by lines drawn parallel to the cylinder B from similar
numbers in the joint line. Trace a line through these points in
the development, when F G H I will be the desired shape.

For the openii^ to be cnt into the cylinder B to receive the
cylinder D, extend the base of the cylinder B as shown by 1' 1^,
upon which place the stretchont of the half circle A in plan, as
shown by similar figures on the stretchout line 1^ 1*. From these
points erect perpendiculars, which intersect by lines drawn from
similarly numbered intersections in elevation at right angles to the
line of the cylinder B. Trace a line through the intersections
thus obtained; J K L M will be the shape of the opening.

Fig. 5 shows the intersection of two cylinders of unequal
diameters at an an^ of 45°. Make the diameters of the lai^ and
small cylinders 2 inches and 1^ inches respectively; the height of
the large cylinder 3 inches; and the length of the small cylinder
measured from its shortest side in elevation, 1 inch, placed at an
angle of 45° in the center of the cylinder B. A represents the
plan of the large cylinder struck from the center a and shown in
elevation by B. Draw the outline of the small cylinder C at its
proper angle, and place the half section D in its position as
shown; divide it into a number of equal spaces, as shown from
points 1 to 5. Through the center a in plan, draw the horizontal
line a 5 ; and with & as a center describe a du^^cate of the half
section D with the various points of intersection, as shown by 1>,
placing the points 1 and 5 on the horizontal line a 5. From the
intersections in D* draw horizontal lines intersecting the large
circle A at 3' to 3' as shown, from which i»ints erect perpendicnlar
lines; intersect them by lines drawn parallel to the lines of the
smaller pipe from similarly numbered intersections in D. A lin»

BHEBT-KETAL WOBS

traced tluongh the points thus o'ntamed will reproBont the Inters
section or miter joint between the two pipes.

^ese same principles are applicable no matter what diametem
the pipes have, or at vhat angle they are joined, or whether th*

pipe is placed as shown in plan or at one sida c^ the center line.

For the developmeut of the small cylinder extend the line 6-1

In elevation as shown by F E, upon which place tha stretchpnt

SHEET-METAL WORK

of tbe circle D' in plan, dr twice the amoout of D in elevation,
as Bhown by similar figures on tbe stretchont line F E. At r^lit
angles to F E and throTigh these small Egnres, draw lines vhich
intersect with lines drawn at right angles to the lines of the
small cylinder from similarly numbered intersections in the
miter line in elevation. Trace a line through the points thus
obtained; E F G will be the development for the cylinder C.

To obtain the opening in the laige
(^linder extend the lines of the large
cylinder in elevation as shown at the base
by H J, upon which place the stretchoat
of the intersections contained in the circle
A, being careful to transfer each space
separately (as they are unequal) to the
stretchont line H J. Through these points
and at right aisles to H J erect lines which
intersect with horizontal lines drawn from
similar points in the miter line in elevation
A line traced through the points thus
obtained, as shown by K L M N, will be
the desired development.

Fig. 6 shows the intersection between
a quadrangular prism and sphere, the center
of the prism to come directly over the center
of the sphere. Make the diameter of
the sphere 2^ inches, the sides of the
prism li inches, and the height from /
to c' 2| inches. Draw the elevation of the
sphere A which is struck from the center ^^- &

a, from which erect the perpendicular a i. With any point, as o,
as a center and using the same radius as that used for A, describe the
plan B. Through o draw the two diagonals at an angle of 45°, and
draw tbe plan of the prism according to tbe measurements given.
Nowdraw the elevation of the prismyc' and^ c, the sides of the
prism intersecting tbe sphere at o and c ' . From either of these points
draw a horizontal line intersecting the center line ahatd. Then
using a as a center and a d as tbe radius, describe tbe arc e e'
intersecting the sides of tbe prism extended at e and e' \fe e' f

SHEEI^METAL WOBK

win be tlie derdopment for one of the sides of the prism. Id
praotice the fbnr sides are joined in one.

Fig. 7 shows the interaeotion of a qnadiangnlar prism and
•phere when the center of the prism is placed to one side of the
center of the sphere. Make the diameter of the sphere the same
as in the preceding figure; through x in the plan draw the 45°
diagonal, and make the distance from ai to A ) inch, the sidra of
the prism 1 inch, and the height from E to <} in elevation 1| inches.
Having drawn the elevation and plan of
the sphere, construct the plan of the prism
as shown by A B O D. Parallel to the
center line x y project the prism in eleva-
tion intersecting the sphere at a and c.
Now since the center of the sphere is on
one of the diagonals of the prism in jJan,
either two of the sides meeting at one end
of that diagonal, as B C and C T>, will be
alike, and both will be different from the
other two sides A B and A D, meeting at
the opposite end of the diagonal. There*
fore the line F a in elevaticm will be used
la obtaining the development of D O in
^iaa, while the line B e will be osed in
obtaining the development for the two
sides D A and A B in plan.

Kow from a draw a horizontal line
intersecting the center line a> y at }/
and using ^ as a center and y & as the
radios, describe the aro G H intersecting
the sides of the prism extended to G
and H. Then B F G H is the development for each side of the
prism shown in plui by D O and OB. In a similiir manner, from
the intersection c in elevati(m draw a horizontal line iuterseotii^
the center line xy aid. Then iising y as center and yd as radios,
describe an arc intersecting the sides of the prism at e andy^ &
Fy e will show the development for either side of the inism shown
in plan by D A and A B. By c(nmecting the points G and / it
will be found that the line is a true horizontal line, which proves

Fig. 7.

ELBOW PATTERNS*

In all «lbow work the difflcultr lies in obtaining the correct rim of tlie
miter line. B7 the use of a prot/actor thia is overcome and thus the necessity
of drawing a complete quadrant is avoided. Following the rule given in the
illustration the rise can be easQjr found, when the throat and diameter of the
pipe is known.

In the upper table are shown various pieced elbows, having different
degrees when finished, and the various miter lines. There are six miter pat-
terns shown, the first for a 6-pieoed elbow having 90° when completed; the
second for a 4-pieced 90° elbow; the third for a 3-pieced 90° elbow; the fourth
for a 2-pieced 70° elbow; the fifth for a 2-pieced 90° elbow, and the sixth for
a 2-pieced 106* elbow.

No matter what size of throat the elbow may have, or what diameter
or mimber of pieces, always follow the rule given in the illustration and obtain
the miter line ; then place the half profile in its proper position and place the
full girth of the pipe on the line shown in the piattem by similar numbers.
By revetBing the cut opposite the line 1-7-1 the pattern for the middle pieces
is obtained, after which one cut con be placed into the other as shown on
Page 48.

• The lUuftratian retcmd to wUl b« louad oa the twcic o( thU pas*.

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SHEET-METAL "WORK 15

the two developments. Should the plan of the prism be so placed
on the sphere that all sides wonld be difFerent, then two elevaticms
would be necessary bo that the mtersections of all the sides ooald
be shown.

Devslopmeats by Triansrulatloa. In developing sheet-metal
work of irr^iular forms, patterns are required which cannot be
developed by either the parallel or radial-line methods. These
irre^liilar shapes are so formed that eilthongh straight lines can be
drawn npon them the lines would not mn parallel to one another,
nor wonld they all incline to a common center. In the methods
previously described, the lines in parallel developments run parallel
to one another, while in radisl-line developments all the lines meet
at a common center. Hence in the developnent of any irregular
article, it becomes necessary to drop all previous methods, and
simi^y proceed to measure up the surface of the irr^olar form,
part by part, and then add one to another until the entire surface
is developed. To accomplish this, we have merely to make use of
one of the sinfplest of all geometrical problems, namely, to construct
a triangle having given the three sides. This problem is solved
very early in Mechanical Drawing. To cany out this method
it is necessary only to divide the surface of the plan or elevation
of any irregolar article into a number of equal parts. Use the
distances in plan as the bases of the triangles, and the distances in
elevation as the altitudes or heights of the triangles, or vice versa;
and then find the hypothennse by connecting the two given lengths.

To illustrate this simple principle Fig. 8 has been prepared.
Let A B C D represent the plan of a plane surface, shown in
elevation by A^ B^. We know that the true length of the plane
is equal to A' B^ and the true width is eqnal to A D or B C in plan.
We also know that the vertical height from the bottom of the plane
A' to the top B' is eqnal to B' } as shown. But suppose we want
to obtain the true length of the diagonal line B D in plan on the
developed plane. To obtain this it will be necessary only to take
the length of B D, place it from i to D*, and draw a line as shown
from B' to D', which is the length desired.

While this may look very simple, it is all that there is to
triangulation, and if the student thoroughly understands the simple
principle and studies the problems which will follow, be will have

BHBBT-MBTAL WORK

DO trouble in applying this principle in oomplioated vork. To
make it still clearer we will prove the length of the line B* D^.
Take the distanoe of A* B', place it in plan aa shown hy A B*, and
complete the rectangle A B* (? D. Draw the di^;onal B* D, being
the length sought, which will be fonnd to equal B* B* in elevation.
When drawing this problem in practice, make the plan 4 by 6 inches
and the vertical height in elevation 5 inches.

In obtaining developments by triangolation. the student should

ne all of his oonceptive powers as previously explained. Before

making any drawing, he must

see the article before him in his

mind's eye, so to speak, before

he can pat it down on paper.

Therefore we want to impress

upon the student the necessity of

drawing all the problems that will

follow in this part and in the FraC'

tical Workshop Problems. It

should be understood that tri-

angulation is not given as an

PLAN '^ alternative method, but is used

Fig. 8. when no other method can be

employed, and without it no true pattern could be obtained for

these irregular shapes; hence the necessity of close stu^.

In Fig. 9 is shown an irregular solic' whose base and top are
triangles crossing each other, and in which the principle just
explained will be put tc practical test Inscribe the triangles
shown in plan in a circle whose radius is'equal to a 1, or li^ inches,
and make the height of the article in elevation 2 inches. The
dotted triangles 1 2 3 in plan represent the section of the article on
the line 2-3 in elevation: and the solid triangle 1^ 2^ 3' in plan, the
■eoticm on the line S' 3' in elevation. Now connect the two sections
in plan by drawing lines from 1 to 2^ and to 3^ from 2 to 2^ and to
V, and from 3 to 1^ and to 3*. In a similar manner connect the
points in elevation as shown. It now becomes necessary to obtain
a triangle giving the true length of the lines connecting the
comeiB of the triangle in plan, and as all of these lines are eqpBl
oaly one triangle is neoeaBary. Therefore take the distance from

SHEET-METAL WORK

rm^iasv.

1 to 2* in plan and place It on the line, 3-2 extended in elevation,
as shown from 2 to 1°, and draw a line from 1° to 2^, which Is ths
desired length.

For the pattern, proceed as is shown in Fig. 10. Take the
distance of any one of the sides in the triangle, as 1-2 in Fig. 9,
and place it on the horizontal line
1-2 in Fig. 10. Then using 1 and

2 as centers, with 1° 2' in elevation
in Fig. 9 a» radius, descrihe the
arcs in Fig. 10 intersecting each
other in 2^ Then 1 2 2^ will be
the pattern lor one of the sides
shown in plan in Fig. 9 b; 1 2 2'.
Proceed in this manner in F^. 10
as shown hy the amaU arcs; or a
tracing ma; be taken of the one
side 1 2 2', and traced as shown
miitil six sides are obtained, which
will be the foil pattern and which
is numbered to correspond to the
numbers in plan. ' Fig. 9.

In Figs. 11, 12, and 13 are shown the methods used in develop-
ing a scalene oone. The method of obtaining the development c^
any scalene cone, even though its base is a perfect circle, is g vemed
by the same principle aa employed in the last problem on trianga-

I&tion It is well to remember that any section of a scalene cone
drawn parallel to its base will have the same shape (differing ot
oonrse in size) as the base. This is equally tme of articles whose

SHEET-METAIi WORK

bases are in the shape of a sqiiare, rectangle, hexagon, octagtHi, or
any other polygon. What has jnst been explained ■will be proTen
in oonneoticm with Fig. 11, in vhich ABO repieseuts a side
elevation of a scalene cone, whose plan is shown by 1 4^ 7 4 C.
Draw any hoiizontal line, as A D, on which set off the distanoee

A B equal to 3 inches and B D equal to 2| inches, and the
vertical height D O equal to 4J inches. Draw lines from B eind
A to C, which completes the elevation. In its proper position
below the line A B, draw the plan of A B as 1 4 7 4' struck from
the center O. Throi^h draw the horizontal line C C^, and

SHEET-METAL WORK

inteniect it by a Tertical line drawn from the apex O in eleTation,
thnB obtaining the apex C? in plan. Draw lines from 4 and 4' to <7,
which completes the plan.

As both halves of the scalene cone are symmetrical, it is
necessary only to divide the half plan 14 7 into a nmnber of eqnal
spaces as shown by the small fignrea 1 to 7, and from points
thos obtained draw radial lines to the apex C^. Then these linee
in plan will reioesent the bases of triangles which will be con.
stmcted, wh(»e altitudes are all eqnal to D O in elevation. There-
fore in Fig. 12 draw any horizontal line, as A S, and from any
point, as O, erect the perpen-
dicnlar line O C equal in
height to D in Pig. 11.
Kow from C in plan take the
varions lengths of the lines 1
to 7 and place them on the
line A B in Fig. 12, meaanr-
ii^ La every instance from
the point C, thns obtaining
the intersections 1 to 7, from
which lines are drawn to the
apeiC?. Then these lines win
represent the tme lengths of
similarly numbered lines in
plan in Fig. 11.

For the pattern proceed as is shown in Pig. 13. With C as
center and radii equal to C? 7, 6, 6, 4, etc., in Fig. 12, describe the
arcs 7-7, 6-6, 5-5, 4-4, etc., in Fig. 13 as shown. Now aasnming
that the seam is to come on the short side of the cone, as C B in
Fig. 11, set the dividers equal to one of the equal spaces in
the t^an; and starting on the arc 7-7 in Fig. 13, step from arc 7 to
arc 6, to arcs 5, 4, 3, 2, and 1, and then continue to arcs 2, 3, etc.,
up to 7. Trace a line through these intersectiona as shown by
7-1-7, and draw lines from 7 and 7 to O, which completes the
pattern.

Now to prove that any section of an oblique or scalene cone
ont parallel to its base, has a similar shape to its base (differing in
■ize), draw any line as a } in Pig. 11 parallel to A B. From O in

Pig.l3L

SHEET METAL WORK

pUn ereot a vertioal line interseoting tbe base line A B at (?, from
which drav a line to the apex O, cntting the line a I &t e. Then
the distances e a and e h will be equal; and using as a center and
elaa radins, describe the circle a fh t, which is the tme section
on a i. Then ah "BA
will be the frastam ot
a scalene cone. Extend
the line a i parallel to
A T>, cutting the diagram
of triangles in F^. 12
from atoi. Then with
radii eqnal to the di8<
tances from C- to the
TariouB intersections on
the line a i, and using
O in Pig. 13 as center,
intersect similarly num-
bered radial lines drawn

_X'^^ ^ from 7 to 1 to 7 to the

apex O. A line [traced
as shown from 7' to 1'
to 7' will be the desired
cnt, and 7-7-7'-7' will
be the pattern for the
4 fmstum. The practical
nse of this method is
shown in diagram V in
Fig. 11; a' is the fms.
tnm of the obliqne cone,
on the ends of which are
connected ronnd pipes
Pig. 14. " y andc'.

It is shown in Fig. 14 how in an irr^pilar sdid whose base is
square and top is round, both top and bottom on horizontal planes
are developed. The comers in plan FBG-, OCH, HDEand
E A F abonid be considered as sections of scalene oones. Proceed
by drawing the plan A B C D 3) inches square, which represents the

SHEET-METAL WORK

pinn of the base of the article; and the oirole E F G H 2} inches
in diameter, which shows the plan of the top of the article; the
vertical height to be 3 inches, shown from atoh. As the circle is in
the center of the square, making the four comers symmetrical, it is
necessary only to divide the one-qoarter circle into a nmnber ot
equal parts as shown by the small figures 1, 2, 2, 8, from which draw
lines to the apex B. Complete the elevation as shown by IJ K L.
Now using B as center, and radii equal to B 1 and B 2 in plan,
describe arcs intersecting A B at 1' and 2' as shown. From these
points erect perpendiculars intersectii^ the top of the article I J

HALF PATTERN

jU g.

in elevation at 1' and 2', from which draw lines to K. Then K. 1*
and K 2' will be the true lei^hs of the lines shown in plan by
B 1 and B 2 respectively on the finished article.

For the half pattern proceed as follows: In Fig. 15 draw any
horizontal line, as A B, equal in length to A B in plan in Fig. 14.
Now with K 1' as radius and A and B in Fig. 15 as centers, describe
arcs intersecting each other at 1 From 1 drop a vertical line
intersecting A B at E. Then 1 K should equal J E in elevation
in Fig. 14, which represents the true length through 17 in plan.

Si SHKKT-METAL WORK

Kowwitli radii equal to Kl' and E 2' in elevation, and vitli Bin
Fig. 15 as center, describe the arcs 1-1' and S-2'. Now set the
dividers equal to one of the spaces in G- F in i^an in Fig. 14; and
starting at 1 i^ Fig. 16, step off arcs havii^ similar nnmbers as
shown by 1, 2, 2', 1'. Kow using 1 B as radins, and 1' as center,
describe the arc B C, and intersect it by an arc etmck from B as
center and with B A as radius, as shown at 0. Take a tracing of 1
B 1' and place it as shown by 1' 1'. Now connect the varions
intersections by drawing lines from 1 toA toBtoOto
1' tol' to 1, which completes the half pattern. The trianga>
tar pieces 1 A B or 1' B O will represent the flat sides of the
article shown in plan hy lABorSBO respectively in Fig. 14;
and the conepattems 1-1' Band I'-l'O in Fig. 15, the sections of
the scalene cones 1-3-B and H-G-O respectively in plan in Fig. 14,
This same rule is applicable whether the top opening of the article
is placed exactly in the center of the base or at one side or comer.
Varions problems of this nature will arise in Practical Workshop
ProhlemB ; and if the principles of this last problem are thoroughly
nnderstood, these will be easily mastered.

Approximate Developments. In developing the blanks or
patterns for sheet-metal work which requires that the metal be
hammered or raised by hemd, or passed between male and female
dies in foot or power presses, circular rolls, or hammering machines,
the blanks or patterns are developed by the approximate method,
because no accurate pattern can be obtained. In all raised or
pressed work in sheet metal, more depends npon the skill that the
workman has with the hammer, than on the patterns, which are but
approximate at their best. While this is true, it is equally true
that if the workman imderstands the scientific rule for obtaining
these approximate patterns a vast amount of time and labor can be
saved in bringing the metal to its proper profile. If the tme rule
for averagii^ the varions shapes and profiles in circnlarwork is not
understood, the resolt is that the blank has either too little or too
great a flare and will not form to its proper profile and curve.
Before proceeding to describe the approximate development
methods attention is called to the governing principle nnderlyii^
all such operations. We have previously shown how the patterns
are developed for simple flaring ware; in other w^nds, how to

SHEET-METAL WORK 23

derelop the fmstnm of a oone. The patterns for cnrred or any
other form of circular or hammered work are produced upon the
aame principle. The first illustration of that principle is shown in
Fig. 16, in which A B D represents a sphere 3 inches in diametw
composed of six horizontal sections, stmck from ths center a.

t'm. iC

Divide the quarter circle A into as many ports as there are
flections required in the half sphere (in this case three), and draw
horizontal lines through the ball aa shown. The various radii for
the patterns are then obtained by drawing lines through Oh, ho,
. andoA. Thus 0( extended meets the center line ED at «, which,

e,v\

i;lc

8t SHEET-METAL WOBE

is the fiKiter for Btritung the blank for number 8, using ths radii
t i and « C. In Bimilar manner drav a line from & to c, extending
it nntil it meets E D at (2. Then d e and d 1> will be the radii tor
Uank omnber 2, while A cr is the radios for blank 1 shown at S.
The lengths of the pattern pieces are determined in the same
manner as would be the case with an ordinary flaring pan in
producing the patterns for tin ware, and will be explained

thoroughly fn the Practical Workshop Problems whiob irfll

shortly follow.

In Fig. 17 is BbowD another elevation of a sphere composed of
twelve vertical sections as shown la plan view. While the method
Qsed for obtaining the pattern is by means of parallel lines, and
woidd be strictly aoonrate if the sections in plan remained straight
M from 4 to 4, the pattern becomes approximate as soon as we start
to raise it by means of machine or hammer to conform to the profile
6 inelevation,becaTise the distance aloi^ the carve afrom 4' to4'

SHEET-METAL WORK

in plan is greater than a Btraight dietauce from 4 to 4. The pattern
by this method is obtained as f oUowb : Let B represent the elevation
of the Bphere, and A the plan of the same, 'which is divided into as
many sides as the sphere is to have vertical sections, in this case
12, being careful that the two opposite sides 4-4 and 4' 4' in plan
mn parallel to the center line as shown. Make the diameter of the
aphere4-4' 3 inches.
Divide the haJf ele-
vation into an eqnal
nmnber of spaces as
shown from 1 to 4 to
1, and from these
points drop lines at
right angles to 4-4'
intersecting the mi-
ter lines 1-4 in plan
as shown. Now draw
nuy horizontal Une,
as 1 '-1 ', npon which
place the stretchont
of 1-4-1 in elevation
as shown by l'-4'-
I' on the line I'-l'-
iuO. Through these
points draw lines at
right angles to 1'-
1', which inteTsect
by lines drawn from
similarly nmnbered
intersections on the
Fig. 18. miter lines 1-4 in

plan, at right angles to 4-4. A Une traced throtigh points thne
obtained ae shown by will be the desirtd pattexn.

In Fig. 18 is shown the principle used in obtaining the radii
with which to develop the blank for a curved or circnlar moold
when it is to be hammered by hand. In this connection, only the
principle employed will be shown, leaving the full development and
also ihe development for patterns which axe to be raised 1^ hand

SHEET-METAL WOBK

and hammered by machine, to he explained in |nobIems which vill
follow in Practical Workshop Problems. Draw this problem donbla
the size shown. First draw the elevation A B O D, and throogh
the elevation draw the center line F Q. Then osii^ G as a center,
draw the circles A' B^ and C^ D^ representing respectively the
horizontal projections of A B and O D in elevation. Now draw a
line from A to B in elevation, connecting the comers of the cove
as shown. Bisect A E and obtain the point H, from which at right
angles to A E draw a line intersecting the cove at J. Through J
parallel to A E draw a line intersecting the center line F G at M.
Take the stretchont from J to A and from J to E and place it on
the line J M as shown respectively from J to L and from J to C
Then will M L and M K be the radii with which to strike the
pattern or blank for the cove. From J drop a vertical line intersect^
ing the line D' Q in plan at K. Then with G as center strike the
quarter circle K O. How nsiug M as center and H J as radios,
strike the arc J P. Then on this arc, starting from J, lay off 4 times
the stretchout of N O in plan for the full pattern. It shoold be
understood that when stretching the cove A F, the point J remains
stationary and the metal from J to L and from J to E is hammered
respectively toward J A and J F. For this reason is the stretchout
obtained from the point J.

PRACTICAL WORKSHOP PROBLEMS.

In presenting the 32 problems which follow on sheet-metal
work, practical problems have been selected such as would arise in
every-day shop practice.

In this connection we wish to im-
press upon the student the necessity of
working out each and every one of the
32 problems. Models should be made
from stiff cardboard, or, if agreeable to
the proprietor of the shop, the patterns
can be developed at home, then cut out
of scrap metal in the shop during
lunch hour, and proven in this way. Fig. 19.

Our first problem is shown in Fig. 19, and is known as a sink
drainer. It is often the case that the trap xmder the kitchen sink

SHEET-METAL WORK

1b ohc&ed or Uooked, owing to a coUeotiioii of refnse matter. To
avoid this a elnk drainer ia tised, and is fastened in position throngh
the vire loops a, h and e. The refuse matter is ponred into the
drainer, from which it is easi^ remoTed after the flnid has passed
through the perforations. These drainers may be made of tin or of
Uack or galvanized iron, bnt where a good job is wanted 16-omice
copper should be used. To obtain l^e pattern for any sized drainer,
_JE proceed as follows: First draw the
plan of the drainer A B C in Fig. 20,
making A B and B each two inches
and forming a right angle. Then
using B as center and A B as radins,
draw the aro A O. In its proper poei-
tiou above the plan constmct the side
elevation, making S D 2 inches high,
and draw the line F D. Then will
^ F E D be the side elevation. Divide
the aro A O into eqnal spaces as shown
b; the small figures 1 to 5. For the
pattern nse F D as radius, and with
^ D in F^. 21 as center strike the aro
1 5. From 1 draw a line to D and
step off on 1-5 the same nmnber of
spaces as contained in A in plan la
Fig. 20, as shown by similar figures
in F^. 21. Draw a line from 5 to D.
Then will 1-5-D be the pattern for
the front of the strainer, in which per-
Q forations should be punched as shown.
Fig. 2a To join the sides of this pattern,

use 1 and 5 as centers, and with either F E or A B in Fig. 20 as
radius, describe the arcs E and E^ in Fig. 21. Now Tising D as
center and D E in Fig. 20 as radius, intersect the arcs E and E^ as
shown in Fig. 21. Draw lines from 1 to E' to D to E to 6, which
completes the pattern, to which edges must be allowed for wirii^
at the top and seaming at the back.

When joining a fancet or stop cock to a sheet-metal tank it is

SB SHEET-METAL WOKK

is indicated by A in Fig. 22. In this problem the cone method is
em|doyedt tuiing principles eimilar to those nsed in dereloping a
B of a coud intersected by any line. Therefore in Fig. 23 let

A B xepresent the part plan of the tank, O portion of the fancet
extending back to the tank line, and F G H I the conical "boss"
to fit aronnd & faucet. When
drawii^ this problem make the
radins of the tank D A equal
to Bjt inches, and from D draw
the vertical line T> E. Make
the distance from G- to H equal
to 2£ inches, the diameter of the
faucet F I 1^ inches and the
vertical height K O 1^ inches-
Draw a line from G to H inter-
secting the center line D E at K.
Then using K as center describe
the half section G J H as
shown. Divide J H into eqnal
paita shown from 1 to 4, from *

which drop vertical lines intersecting the line G H as shown,
from which draw radial lines to the apex E cntting the plan line

Dun. ,Ait-f(>riC

SHEET-METAL WORK

of the tank A B as Bhown. From these intersections draw boii*
zoutal lines intersecting the side of the cone H I atl, 2',3',8iid4'.
JHov Qse E as center, tmd with radios equal to E 1 describe the

Fig. 23.

arc I'-l' as ebown. Draw a line from 1" to E, and starting trom
1" set off on 1°-1* four times the ntunber of spaces contained in

so 8HEGT-HBTAL WORE

J H in plan, as shown by Dimilar nmnbers on V 1'. Draw a line
from 1' to E, and with E I as raditis describe the arc N L inter'
secting the radial lines 1° B and 1' E at K and L respectively.
From the varioas nombers on the arc 1° 1' draw radial lines to
the apex E; and osing E as center and with radii eqnal to B 4',
E 3', and E 2', draw arcs intersecting similarly numbered radial
lines SB shown. Trace a line through points thus obtained; then
will N 1° 1 1' L be the pattern for the "boss."

In Fig. 24 is shown what is known as a hip bath. In drawing

out the problem for practice the student shonld remember that it is

similar to the preceding one, the only difference being in the outline

of the cone. Make the top of the cone I B in Fig. 25 equal to 3^

inches, the bottom C D 1| inches, the vertic^ height from K to 5'

2} inches, the diameter of the foot E F 2^ inches, and the vertical

height 5'-5' J-inch. Through the center of the cone draw the

center line K L, and at pleasure

draw the outline of the bath as

shown by A J B. It is imma^

terial of what outline this may be,

the principles that follow being

applicable to any case. Thus, in

the side elevation, extend the

lines B O and A D until they

intersect the center line at L. In

Fig. 21. similar manner extend the sides

erf the foot piece E D and F O until they intersect the center
line at E. Now with 5' as center and with radius equal to 5' D
or 5' C, describe the half section C H D, which divide into equal
spaces as shown by the small figures 1 to 9. From the points of
division erect vertical lines meeting the base line of the bath D O
at points 1, 2', 3', etc., to 9. From the apes L and through these
points draw radial lines intersecting the outline B J A, from which
horizontal lines are drawn intersecting the side of the bath B
as shown from 1 to 9. For the pattern for the body use L as center,
and with L as radius draw the arc F L*. Now starting at any
point, as 1, set off on F L^ twice the stretchout of D H C as shown
by similar numbers on the arc F L^. From the apex L and through
the small figures draw radial lines, which intersect by arcs

SHEET-METAL WORK 31

Btmck from L as center with radii eqnal to similarly numbered
intersections on B C Trace a line throngli points thns obtained,
and Ij^ M N P P will be tbe pattern for the body of the bath,
to which laps should be added at the bottom and sides for seamu^.

F1g;3&

The pattern for the foot is obtained by -osing as radii B D and
B E, and striking the pattern using W- as center, the half pattern
being shown by E^ T E^ D^ Tfi, and the distance ly D^ being eqns'i
to the fitretchont of the half section t> H C in side elevation

88 SHEET-METAL WOKK

It ia nsQsI to put a bead along the edges of the top of a bath as
shown at a and i in Fig. 24. For this purpose tubing is sometimes
used, made of brass, zinc, or copper and bent to the required shape;
or zino tubes may be rolled and soldered by hand, filled -with
heated white sand or hot rosin, and bent as needed. The tube or
bead can be soldered to the body as shown in (A) in F^. 25. Here
a represents the bead, in which a slot is cut as c, and which is then
slipped over the edge of the bath and soldered. Another method
is shown in (B), in which the bath body i is fianged over the bead
a and soldered clean and smooth at c, being then scraped and
sanilpapered to make a smooth joint. A wired edge is shown at e
in Fig. 24, for which laps must be allowed as shown in Fig. 25 on
the half pattern for foot.

In Fig. 26 is shown the perspective view of a bath tub; these
tubs are nsually made from IX tin or No. 24 galvanized iron. The
bottom and side seams are locked and thoroughly soldered, while
the top edge is wired with handles
riveted in position as shown
at A. The method used in de-
veloping these patterns will be
the cone method and triangnla-
Fig. 26l tion. In drawing this problem

for practice (Fig, 27), first draw the center line W 8 in plan ; and using
a as center with a radina equal to IJ inches draw the semicircle
C-12 D. Now make the distance a to & 4 inches; and tming J as
center with a radius of 1| inches draw the semicircle E-7-H.
Draw lines from E to D and from C to H. D E 7 H O 12 D wUl
be the plan of the bottom of the bath. In this case we assume
that the flare between the top and bottom of the narrow end of the
bath should be equal; therefore using a as center and with a radius
equal to 1§ inches draw the semicircle A W B. At the upper end
of the bath the flare will be unequal; therefore from & measure a
distance on line W 8 of 1 inch and obtain c, which use as center,
and with a radius equal to 2 inches describe the arc F 8 G. Draw
lines from P to A and from B to G; and A F 8 G B W A will be
the plan of the top of the bath. Now project the side elevation
from the plan as shown by the dotted lines, making the slant
heightfromItoR2^ inches and from JtoK3^incheB;draw a line

SHEET-METAL WORK

fromEtoR, and J KRI will be the Bide elevation of tlie bath tnb.
In conBtracting the bath in practice, seams aie located at H Q, E E,

N\\\\\.\i'li

^\ '-■ \ \ \ \ \ '' I I

PATTERN \ \ \ \ \ \ \ V 1 '
FOR A-&OD ^^ \ ■> \ \ ^ » V I I
IN PLAN N. ^. ''. \ \ \ », l', I

\\\\\\\n 1

A t>: and O B in plui, thtu making tba tTib in tonr pieoN

84 SHEET-METAL WOBK

The Icnrer end of the bath irill be developed by the cone
method as in the last two problems. From the csenter a drop a line
indefinitely as shown. Extend the side R I of the Bide elevation
until it meets the center line ad at d. Now divide the quarter
circle 12-9 in plan into equal spaces as shown by the small figure
9, 10, 11, and 12, from which drop vertical lines (not shown)
intersecting the bottom of the bath tub in elevation from 9' to 12'.
Then throi^h these points from d draw lines intersecting the top
line of the bath R E as shown, from which draw horizontal lines
intersecting the side I-R extended ss I X at points 9' to 12'.
Then using d ss center and dl ae radios, describe the arc I M,
upon which place the stretchont of D 12 O in plan, as shown
by similarly numbered points on L M. Throng these points from
d draw radial lines, which intersect by arcs drawn from similarly
numbered intersections on I R extended, using d as center. Trace
a line as shown, and L M N P will be the pattern for the lower
end of the tnb A B D in plan. Laps should be allcwed for
wiring and seaming.

Am the patterns for the upper end and sides will be developed
by triangulation, diagrams of triangles must first be obtained, for
which proceed as follows: Divide both of the quarter circles H 7
and G 8 in plan into the same number of spaces as shown respec-
tively from 1 to 7 and from 2 to 8. Connect these numbers by
dotted lines as shown from 1 to 2, 2 to 3, 3 to 4, etc From the
various points 2, 4, 6, and 8 representing the top of the bath, drop
lines meeting the base line J J" in elevation at 2^, 4*, 6*, and 8*,
and cutting the top line of the bath at 2', 4', 6', and 8'. Then
will the dotted lines in plan represent the bases of the triangles,
which will be constructed, whose altitudes are equal to the various
heights in elevation. Tate the various distances 1 to 2, 2 to 3,
3 to 4, 4 to 5, etc., in plan up to 8, and place them on the vertical
linel'-8' in (B) as shown from 1' to 2', 2' to 3', 3' to4', 4' to 5',
etc., up to 8'. For example, to obtain the true length of the line
6-7 in plan, remembering that the points havii^ even numbers
represent the top line of the bath and those having mieven
numbers the base Hue, draw at right angles to l'-8' in (B), from
6', a line equal in height to 6»-6' in elevation, and draw a line
from 6* to 7' in (B), which is the length desired. For the true

SHEET-METAL WORK 86

length of 6-S in plan it is necessary only to take this distance
place it from 6' to 5' in (E) and draw a line from 6'^ to 5'. In this
way each altitude answers for two triangles. In plan draw a line
from 1 to 0. Then will two more triangles he necessary, one on the
line 1-0, and the other on B G or 0-2. From 2' in elevation draw
a horizontal line, as 2' e, intersecting the vertic^ line dropped
from at €. Now take the distances 1 and 2, and place them
in (A) as shown by the horizontal lines O'-l' and 0^2^ respectively.
At right angles to both lines at either end draw the vertical lines
O'-O'" and OM)' eqnal in height respectively to C? 0' and e 0'
in elevation. Draw in (A) lines from 2* to O' and from 1' to 0'",
which are the desired lengths. Before proceeding with the pattern,
a true section must be obtained on 2'-8' in side elevation. Take
the various distances 2' to 8' and place them on the line 2'-8' in
Fig. 28. At right angles to 2'-8'
Eind throt^h the small figures draw
lines as shown. Now measuring in
each and every instance from the
center line in plan in Fig. 27, take the
various distances to points 2, 4, and ^
6 and place them on similarly num- Fig. 28.

bered lines in Fig. 28, measuring in each case on either side of the
line 2'-8', thus obtaining the intersections 2-4-6. A line traced
throt^h these points will be the true section on 2'-8' in elevation
in Fig. 27.

For the pattern for the upper end of the tub proceed as follows:
Take the distance of 7'-8' in (B) and place it on the vertical line
7-8 in Fig. 29. Then using 8 as center and with a radius equal
to 8'-6 in Fig. 28, describe the arc 6 in Fig. 29, which intersect by
an arc struck from 7 as center and with 7'-6' in (B) in Fig. 27
as radius. Then using 7-5 in plan as radius, and 7 in Fig, 29 as
center, describe the arc 5, which intersect by an arc struck from 6
as center and with 6^-5' in (B) in Fig. 27 as radius. Proceed in
this manner, using alternately as radii first the divisions in Fig. 28,
then the length of the slant lines in (B) in Fig. 27, the divisions
on 7 E in plan, then again the slant Hues in B, until the line 1-3
in Fig, 29 is obtained. Trace a line through points thus obtained,
as shown by 3-8-7-1. Trace this opposite the line 8-7, as 8h9jrft^'

SHEET-METAL WOBK

by 2' 1'. Then will 2-8-2'-l'-7-l ba tita desired pittent, to
which tape most be allowed.

For the pattern for the side of the bath draw any tine 9-1 in
9^. 80 eqnal to 0-1 In plan In Fig. 27. Kow with a radioB equal

Fig. 88.

to 9-P In the pattern X and with 9 in Fig. 80 oa a oenter, describe
the arc 0, which intersect by an arc atrack from 1 as center and
with I'-O"' in (A) in Fig. 27 as radios. Now taking a radios eqoa)
to 0^-2* in (A) with in Fig. 30 as center, describe the arc 2, which
intersect by an ato
etmck from 1 aa center,
and with 1-2 in Fig. 29
tis radios. Draw Iloee
from corner to comer in
Fig. 30, which gives
the desired [rattem, to
which lape are added
Fig. 3a for Beaming and wiring.

In Fig. 31 is shown a perspBctive view of a fiiunel strainer
pait These pails are nsoally made from IX bright tin, and tlte
same principles as are osed in the development of the pattern are
applicable to similar forms, soch as bnckets, coat bods, chotes, eta
This problem presents an interesting stndy in triangnlation, the
principles of which have 1>een explained in previous problems
^iBt draw the oenter line O I in Fig. 32, at right angles to whiob

SHEET-METAL WORK 37

draw H E and H F each eqxisil to 1^ inclies. Make the vertical
height H O 3^ inches and D 2 inches. Now make the Tertical
heights measuring from O G, to A, and to P leepectively 2^
inches, and 1^ inches. Make the horizontal distance from C to G-
2| inches, the diameter &om G to A 1§ inches, and from A to B
|-inch, and draw a line from B to C, Connect poLDts by lines;
then will ABCDEFGbe the side elevation of the pail. In its
proper position below F E, with J as center, draw the plan K L M N.
Also in its proper position draw the section onAGasOPBS.
Now draw the rear elevation making Q^ U and G* V each equal to
H E, and 1' T and I'-l' each eqnal to D. Project a line from
B in side, intersecting the center line in rear at4'. Then through
the three points 1' 4' T draw the cnrve at pleasnre, which in this
case is strnck from the center a, W Y X Z represents the opening
on G A in side obtained as shown by the dotted lines but having
nobearingonthepattems. Pails
of this kind are nsnally made
from two pieces, with seams at
the sides, as in Fig. 31, The
pattern then for the back shown
by O D B H in side elevation in
Fig. 32 will be obtained by the
cone method, stmck from the
center I, the stretchout on E^ E^
in the pattern being obtained
&om the half plan. The pattern
for O D E H is shown with lap Fig- 31.

and wire allowances by D^ D* E* E^ and needs no further explanation.
The front part of the pail shown byABOHFGwillbe
developed by triangnlation, bnt before this can be done a tnie
section mnst be obtained on B C, and a set of sections developed
as follows: Divide one-h^ of 1' 4' T in rear elevation into eqnal
parts as shown from 1' to 4', from which draw horizontal lines
intersecting the line B O as shown. From these intersections
lines are drawn at right angles to B C eqnal in length to similarly
nxunbered lines in rear as 3'-3', 2'~2', and I'-l'. Trace a line
as shown, so that O 1'" 2"' 3'" 4'" will be the true half section
onBO. Toavoidaocmfosionof linestakeatiaoingof ABOHFG

SHEET-METAL WOEK

and place it as shown by similar letters in Fig. 33. Now take
tracings of the half sections in Fig. 32, as H E D O, C 1'" B,
P O S, and the quarter plan K J M, and place them in Fig. 33 on
similar lines on which they represent sections as shown respectively
by H 9' 8' C, C 8 B, A 3 O, and F 9 H. Divide the half section

A 3 G into 6 equal parts as shown by the small figm^s 1 "to 6.
As this half section is divided into 6 parts, then must each of the
sections B 8 O and F 9 H be divided into 3 parts as shown respeo^
tively from 6 to 8 and 9 to 11. As C 8' and H 9' are equal
^respectively to C 8 and H 9 they are numbered the same as shown.

SHEET-METAL WORK 39

Now at right angles to G A, B O, O H, and H P, and from the
Tarioiis intersections contained in the eections G 3 A, B 8 O,
08' 9' H, and H 9 P, draw lines intersecting the base lines of the
sections G A, B 0, H, and H P at points shown from 1' to 11',
Now draw dotted lines from B to 5' to 6' to 4' to 7' to E to O,
and then from H to E to 10' to 2', ete until all the points are

Pig.3a

oonnected as shown. These dotted lines represent the bases of the
sections whose altitodes are eqnal to similar nnmbers in the Tarions
sections.

In order that the student may thoroi^hly miderstand this
method of triaugnlation as well as similar methods that wiU fpU<n[<t i ,

SHEET-METAL WOKK

tn other problems, the model in Fig. 34 hsa been prepared, which
showB a perspective of Pig, 33 -with the eections bent np In theii
proper positions. This view is taken on the amnr line in Fig- 33.
the letters and figures in both views being similar. For the true
sections on the dotted lines in E A B in Fig. 83. taks the lengths
of the dotted lines C E, E 7'. 7' 4', etc^ and place them on the
horizontal line in Fig. 35 as shown by similar letters and figures.
From these small Sgures, at right angles to the horizontal line,
exetA the vertical heights C S, K 3. 7' 7, etc., eqnal to similai

TerUoal heights in the sections In Fig. 83. Connect these points
In Fig. 86 by dotted lines as shown, which are the desired tme
distances.

In E^. 86 are shown the tme sections on dotted lines In
G E H F in Fig. 33, which are obtained in precisely the same
manner, the only difference being that one section is placed inside
of another in Fig. 36. For the pattern proceed as is shown in
Fig. 37. Draw any vertical line as Q F eqnal to G F in Fig. 33.
With radins eqnal to G- 1 and with G in Fig. 37 as center describe
the arc 1, which intersect by an arc struck from F as center and

SHEET-METAL WORK

wHIiaTadinBeqtialtoFlin^.86. Now vitb F U tn EHg. 83 as
ladltis and F in Fig. 87 as center, deeoribe the aro 11, whiob it
inteneoted by an arc strack from 1 ai center and wiUi 1-11 Id
]!1g. 86 BB radins. Proceed in this manner tmtil the line 8-d
in Vig. 87 has been obtained. Then nsing 8'-9' in Fig. 88 U
ladins and 9 in Fig. 87 as oenter, describe the aro 6, which il
intenected by an aro struck from 8 as center and vith 8-8 in Sig

ing.n

% as radius. Now nse alternately as tadil, first the divisIcmB In
B 8 O la Fig. 83, then the length of the alant lines in Fig. 86,
the dlTiaionB In E 8 A in Fig. 83, and ^ain the distances in
Fig. 85, nntQ the line B A in Fig. 87 has been obtained, which is
obtained from B A in Fig. 83. Trace a line throngh points Urns
obtained In Fig. 87 as shown by ABSgFGA. Trace this
half pattern oppoalte the line GF. Then will BAO A'B'8*

€^

Fic.sa

POTI

9* F98be the pattern for the front half of the paiL If tat
any reason the pattern is desired in one piece, then trace one*
half of D> D* E> E* in Fig. 83 on either aide of the pattern In
Fig. 87 as shown by the dotted linea 8' D' £' 9* and E D 8.
Allow edges for wiring and seaming.

Fig 88 shows the method tar obtaining the pattern tor an
Emerson Tentilator shown in Fig. 39. . ooulc

SHEET-METAL WOBE

While the regnlar EmerBon Tentilator haa a flat diBO for a
hood it is improved by placing a cone and deflector on the top
as shown. To make iixe patterns, proceed as shown in Fig. 38.
Fiist draw the center line a h, on either side of which lay off

SHEET-METAL WORK

1^ inches, making the pipe A, 3 inobee in diameter. The mle
nsnally employed ie to make the diameter of the lower flare and
upper hood tvice the diameter of the pipe. Therefore make the
diameter oi 8 d 6 inohes. From s and
d, draw a line at an angle of 45° to inter-
sect the line of the pipe at t and i; this
completes B. Measure 2 inches above
the line t i and make u m the same
diameter as s d. Draw the bevel of the
deflector so that the apex will be \ inch
above the line t i and make the apex
of the hood the same distance above um
as the lower apex is below it. Then draw
lin^ as shown which complete C and D, ^8- 39.

Now with <; as a center and radii eqnal io c e and c d draw the
quarter circles ef and d h respectively, which represent the one-

HALF PATTERN
rOR
HOOD AND OEFLECTOn

Fig. 38.

Fig.«L

quarter pattern for the horizontal ring closing the bottom of the
lower flare. For the pattern for the hood, nse ? as a center and
Im as a, radios. Now draw the arc m m'. Take the stretohont

M SHEEIVUB'/AI. WOBE

of the quarter drde 1 to ti oa dh^ and plooe twioe this amonut
oa in in' as shown from 1-6-1. Draw a line from 1 to 2. Then
m' 6 m 2, Till be the half pattern for the hood. Ab the defleotn
haa the same berel as the hood, the hood pattern wiU also answer
for the deflector.

When Beaming the hood and deflector together as shown at
n, the hood o is donUe-seaioed to the deflector at r, which allows
the water to pasB over; for this reason allow a doable edge* on
the iwttem for the hood as showOi while on the deflector bnt a
single edge is required. Edges should also be allowed on a <2 kf.

For the pattern for the lower flare, extoid the line d i nntil it
intersects the center line at^. Then with radii eqnal to^ itmdj d
and with J in Fig. 40 as center describe the arcs i i' anddd'.
On one aide as (2 draw a line toj. Then set o£F on thearo d d'

«■-

ng.u.

Fte.tt.

wrloe the uiunber of spaces contained tn (f A in Fig. 88 as shown
in Fig. 40. Draw a line from d' to i and allow edges for seaming,
^len dd' i' i wUl be the halt pattern for the lower flare.

The braces or enpports E and F, Fig. 38, are nsnally made of
galvanized band [iron bolted or riveted to hood and pipe. The
hood D most be water tight, or the water will leak into the deflector,
from which it will dnp from the apex inside the building.

Elbows. There is no other article in the sheet-metal worker^
line,of which there are more made in practice than elbows. On this
aooomit rules will be g^ven tat constrocting the rise of the miter
line in elbows of any size or diameter, also for elbows whose
sections are either oval, square or ronnd, including tapering elbows
Before taking up the method of obtaining the patterns, the rule
irill bs giyen for obtaining the rise of the miter li^,^^^f«^»iM

SHEET-METAL WORE

or nnmber of pieces. No matter how many pieces an elbow has,
they join together and form an angle of 90°. Thus when we speak
of a two-pieced, three-pieced, four, five or six-pieced elbow, we
nnderstand that the right-angled elbow is made np of that number
of pieces. Thxis in Fig. 4X is shown a two-pieced elbow placed in
the qnadrant O B, which equals 90" and makes O A B a right
angle. From A draw the miter line A a at an angle of 45° to the
base line A B. Then parallel to A B and A O and tan^ut to the
quadrant at C and B draw lines to intersect the miter line, as
shown. Knowing the diameter of the pipe as D or E B draw
lines parallel to the arms of the pipe, as shown. Then C B E D
will be a two-pieced elbow, whose miter line is on angle of 45°.

In a similar manner draw the quadrant B C, Fig. 42, in which
it is desired to draw a three-pieced elbow. Kow follow this simple

Fig. 43.

Fig.«.

role, which is applicable for any number of pieces: Let the top
piece of the elbow represent 1, also the lower piece 1, and for every
piece between the top and bottom add 2. Thus in a three-pieced
elbow:

Top piece equals 1

Bottom piece equals 1

One piece between 2

Total equals 4
Kow divide the quadrant of 90" l^ 4 which leavee 22i^*. A»
one piece equals 23i^°, draw the lower miter line A a at that
angle to the base line A B. Then as the middle piece represents
two by the above rule and equals 45°, add 45 to 22( and draw the
second miter line A £, at an angle of 67i^° to the base line A B.
Kow tangent to the quadrant at C and B draw the vertioftl and,

SHEET-METAL WORK

horizontal lines shown, imtU they intereect the miter lines, from

which intersections draw the middle line, which will be tangent to

the qnadrant at F. CD and B E show the diameters of the pipe,

which are drawn parallel to the lines of the elbow shown.

Fig. 43 shows a foor-pieced elbow, to which the same mle is

applied. Thas the top and bottom piece equals 2 and the two

middle pieces eqnal 4; total 6. Now divide the quadrant of 90° by

90
6. — a ^ 15. Then the first miter line A a will eqnal 15°, the

second A J 45°, the third A c 75°, and the vertical line A O 90°.

The last example is shown in Fig. 44, which shows a five,
pieced elbow, in which the top and bottom pieces eqnal 2, the 3
90

middle pieces 6 ; total 8. Divide 90 by 8.

: Hi. Then the

first miter line will equal lli°, the second 33|°, the third B6i°,and
the fonrth 78|°. By
nsing this method an
elbow haTUig any nnm-
bar of pieces may be
laid out. When draw-
ing these miter lines it
is well to nse the pro-
tractor shown in Fig. 45,
which illustrates how to
lay out a three-pieced
elbow. From the center
point A of ' the protrac-
tor draw lines through
Fig.45. 22i°,and67J°. Nowset

off A a, and the diameter of the pipe a h. Draw vertical lines
from a and h to the miter line at c and(2. Lay off similar distances
from A to a' to 5' and draw horizontal lines intersecting the 67i^°
miter line at c' and d' . Then draw the lines d d' and c c' ix>
complete the elbow. In practice, however, it is not necessary to
draw out the entire view of the elbow; all that is required is the
first miter line, as will be explained in the following problems.

A a b

,AiOOglC

SHEET-METAL WORK 47

EXERCISES FOR PRACTICE.

1. Make the diameter of the pipe 1} inches and the diatancee
from A to E li^ inch^ in Figs. 41 to 44 inclnsive.

To obtain the pattern for any elbow, using bnt the first miter

Fie. 46.

line, proceed as follows: In Fig. 46 let A and B represent respect*
ively a two- and three-pieced elbow for which patterns are desired.
First draw a section of the elbow as shown at A in Fig. 47 which

Pig. 47.

is a circle 3 inches in diameteri divide the lower half into eqnal
spaces and number th« points of division 1 to 7. Now follow the
rale previously given ; The top and bottmn piece equals 2;tl)en

48 SHEET-METAL WOBE

for a twD-pieoed elbow divide 90 by 2. In its proper position below
the section A draw BODE making E D 45°. From the Tarions
points of intersection in A drop vertical lines intersecting E D a£

a£wnoN/^

}

1 3<

4°

\, 1/

i ti

, / \

Fll.<S.

■hown. In line with B O drav E L upon vhlch place twice flie
number of spaces contained in tlie section A as shown by simiiar
Bgaree on K L; from tliese points drop ^rpendicnlars to intersect

.Ai

oogi

SREiET-MEFrAL WOSK 49

with lines drawn from similar Interseotions on E D, parallel to K L.
Trace a line throngh points shown; then K L O K M will be
the pattern. To this laps niTiat be allowed for seaming.

Now to obtain the pattern for a three-pieced elbow, follow the
rnla Top and bottom pieces eqoal 2, one middle piece eqnala 2;

90
total 4. -J = 22J, Therefore in line with the section A below

the two-pieced elbow draw F G J H, making H J at ein an^e of
22^° to the line H B. Proceed as above using the same stretchout
lines; then U P R S T will be the desired pattern. It should be
onderstood that when the protractor is used for obtainii^ the angle
as shown in Fig. 45, the heights a o and 1> d measured from the
horizontal line form the basis for obtaining the heights of the
middle pieces, inasmuch as they represent one-half the distance;
for that reason the middle pieces connt 2 when tising the mle.
Therefore, the distances F H and 0- J (Fig. 47), repreemit one-half
of the center piece anA. U T S B P one-half the pattern for the
center piece of a three-pieced elbow.

Fig. 48 shows how the patterns are laid into one another, to
pTOTent waste of metal when cntting. In this esunple we have a
three-pieced elbow whose section is 2 X 2 inches. It is to be laid
oat in a quadrant whose radins is 6 inches. Use the same
principles for square section as for ronnd; nnmber the comers of
tiie section 1 to 4. In line with S t draw D E upon which place
the Btretehont of the sqnare section as shown by similar numbers
on D E; from which draw horizontal lines which intersect lines
drawn parallel to D E from the intersections 1' 2' andS' 4' in A
in elevation, thus obtaining similar {>oints in the pattern. Then
A* will be the pattern for A in elevation. For the pattern for B
simply take the distance from 2' tojF and place it on the line 4 4'
extended in the pattern on either side as shown by 4' 4' on both
sides. Now reverse the cnt 4' 2' 4' and obtain 4' 2' 4*. By
measnrement it will be fonnd that 4' 4' is twice the length of 2' 2
as explained in connection with Figs. 45 and 47. Make the distance
from 1' to a' the same as ^ to a in O and draw the vertical line
}'}' intersecting the lin^ 44' extended on both sides. Then A*, B',
and O^ will be the patterns in one piece minos the edges Ipb

60 SHEET-METAL WORK

seaming which mnst be allowed between these cuts; this would of
course make the lengths b' 4', 4' 4' and 4' 4 as much longer as
the laps wonld necessitate.

This method of catting elbows in one piece, from one sqnare
ia applicable to either roond, oval or sqnare sections.

In Figs. 49 and 50 are shown three-pieced elbows snch as are

Pig. 49.

Pig. 50.

used in fnmace-pipe work and are usnally made from bright tin.
Note the difference in the position of the sections of the two
elbows. In Fig. 49 a & is in a yertical position, while in Fig. 50 it
is in a horizontal position. In obtaining the patterns the same
rule is employed as in pre-
Tions problems, care being
taken when developing the
patterns for Fig. 49 that
the section be placed as in
Fig. 51 at A; and when
developing the patterns for
Fig. 50, that the section be
placed as shown at A in
Fig. 52/

Pig- 51. Fig. bS shows a taper-

ing two-pieced elbow, romid in section. The method here shown
is short and while not strictly aoomrate, gives good results.
It has been shown in previous problems on Intersections and
Developments that an oblique section throngli the opposite

^lEET-METAL WORK 61

■idra of a cone is a true ellipse. Bearing this ia mind it is
evident that if the fmsttun of the cone H I O N, Fig. 54, were
a Bolid and cnt oUiquely by the plane J K and the seTend parts
placed sido hy Bide, both woold present true ellipses of exactly the
same size, and if the two parts were placed together again turning
the npper piece half-way arotmd aa shown by J W M K, the edges

of the two pieces from J to K ffonld exactly coincide. Taking
advantage of this fact, it is necessary only to ascertain the angle of
the line J K, to produce the required angle, between the two pieces
of the elbow, both of which have an equal flare. The angle of the
miter line, or the line which cuts the cone in two parts, most be
foond accurately so that when joined together an elbow will
be formed having the desired
angle on the line of its axis.
Therefore draw any vertical
line as A B. With C as a center
describe the plan of the desired
diameter as shown by E D F B.
At right aisles to A B draw the
bottom line of the elbow H I
equal to E.F, or in this case, 3
inches. Measuring from the line Pigr- 53.

H I on the line A B the height of the fmstmn is 6 inches.
Through X' draw the upper diameter O N, IJ inches. Extend the
contour lines of the fmstnm tintil they intersect the center line
at L. Divide the half plan E D F into a number of eqnal parts
as shown; from these points urect lines intersecting the base line
H I from which draw lines to the apex L. As the elbow is to he
in two pieces, and the axis at right angles, draw the angle ^)^|3k

U SHEET-METAIi WORE

bisect it at IT and diaw tlie Hue B Y. No matter vliat Uie ang^e of
the elboT, use this method. Now establish the point J at some
oonTenient point on the cone, and from J, parallel to B T, drav the
miter line J K intersecting the radial lines drawn throngh the oone;
from these points and at right angles to the center line A B draw
liiua intersecting the side of the cone J H from 1 to 7. If it ia

Fig. 54.
1 to faiow how the side of the tapering elbow wotiM look,
take a tracing of N O K J, reverse it and place it as shown by
JWMK.

For the pattern proceed as followv: With L as a ooiter and
L fi M a xadini deeoribe the arc 1 1. Starting fnnn 1 set t^ on

SHEET-METAL WORK

this arc twice the stretchout of 1 4 7 in plan, as shovn bysitnilar
fignreB on 1 l,froni which draw radial lines to the apex L. Again
using L as center with radii equal to L K, L 1, L 2 to L 7, draw arcs
as shown intersecting radial lines having similar numbers. Through
these intersections draw the line J' L'. Then O' N' J' E' L'
or A will be the pattern for the upper arm (A) in elevation, and
P' K' T' X Y or B the pattern for the lower arm (B) in elevation.

Fig, 55.

The pattern should be developed full size in practice and then
pricked from the paper on to the sheet metal, drawing the two
patterns as far apart as to admit allowing an edge to A at a; also
an edge at & to B for seaming.

When a pattern is to contain more than two pieces the method
of ocmstmcting the miter lines in the elevation of the cone is

H SHEET-METAIj wobe

slightly different as shown in Fig. 55. AsBome the bottom to be
3 inches in diameter and the top IJ inches. liSt the yertical height
be 4 inches. In this problem, as in the pieceding, the Tarious
pieces necessary to form the elbow are cot from one cone whose
dimensions most be determined from the dimensions of the required
elbow. The first step is to determine the miter lines, which can
be done the same aa if regrdar pieced elbows were being developed.
As the elbow is to consist of fonr pieces in 90°, follow the mle
given in connection with elbow drafting. The top and bottom

90
piece equal 2; the two middle pieces equal i; total 6. — s *= 15

Lay :>tF A B C D according to the dimensions given, and draw the
half plan below D C; divide it into eqoal parts aa shown. From
the points of division erect perpendiculars intersecting D C, from
which draw lines meeting the center line E 4 at F,

Fig. 66. Pig. 57.

We assnme that the amount of rise and projection of the elbow
are not specified, excepting that the lines of axis will be at right
angles. Knowing the angle of the miter line, it becomes a matter
td judgment upon the part of the pattern draftsman, what length
shall be given to each of the pieces composing the elbow. Therefor,
establish the points G, I and K, making D G, G I, I K and K A
4, 1|, I and 1 inch respectively. From G, I and K draw the hori.
zontal lines G 1', 1 1° and K 1». To each of these lines draw the
lines G H, IJ and K L respectively at an angle of 15° intersecting
the radial lines in the cone as shown. From these intersections
draw horizontal lines cutting the side of the cone. Then nsing F
as a center, obtain the varioos patterns O, P, B and S in the
manner already explained.

SHEET-METAIi WOKK

In Fig. 66 is Bhown a side view of tlie elbow, resulting from
preceding operations; while it can be drawn from dimensionB
obtained in Fig. 55, it wonld be impossible to draw it without first
having these dimensions.

In Fig. 57 is shown a perspective view of a tapering sqnare
elbow of square section in two pieces. This elbow may have any
given taper. This problem will be developed by triangnlation and
parallel lines; it is an interesting stndy in projections as well as
in developments. First draw the elevation of the elbow in Fig. 58
making 1-6 eqnal to SJ inches, the vertical height 1-2, 4J inches,
and 6-5, 24 inches; the projection between 1 and 2 shonld be
I inch and between 5 and 6, g inch. Make the horizontal distance

DEVEU>PEMENTS
Fig. 68.
from 5 to 4, 2 inches, and the rise at 4 from the horizontal line
\ inch, and the vertical distance from 4 to 3, IJ inches. Then draw
a line from 3 to 2 to complete the elevation.

In its proper position below the line 1-6, draw the plan on
that Une, bb shown by 1' 1' 6' 6'. Through this line draw the
center line A B. Aa the elbow should have a true taper from 1 to 3
and from 4 to 6, we may develop the patterns for the top and
bottom pieces first and then from these constract the plan. There-
fore, take the distances from 1 to 2 to 3 and from 4 to 5 to 6 in
elevation and place them on the line A B in plan as shown respec-
tively from 1" to 2° to 3° and from 4° to 5° to 6°; through these
points draw vertical lines as shown. While the full developmoits

56 SHEET-METAL WORE

E and D are shown we shall deal with but one-half in the explana-
tion which follows. As the elbow U to have the same taper on
either side, take the half distance of the bottom of the elbow 1-6
and place it as shown fFom l°-6° to l'-6', and the half width of
the top of the elbow 3-4 and place it as shown from 3° to 3' and 4"
to 4'. Then draw lines from 3* to 1' intersectii^ the bend 2° at
2', and a line from 4' to 6' intersecting the bend 5" at 5'. Trace
these points on the o^^KJsite side of the line A B. Then 1' 3' ah
will be the pattern for the tc^ of the elbow and 6' 4' c 5 the
pattern for the bottom. From these varions points of intersection
draw horizontal lines to the plan, and intersect them by lines
drawn from similarly numbered points in the elevation at right
angles to A B in plan. Draw lines through the points thus
RATTrRN FOR obtained in plan as shown by 1', 2 ',3', 4',

^a 5'and6' whiohwiUrepresentthehalEplan
1^-' I view. For the completed plan, trace these
.-^.^ lines OE^)osite the line A B as shown. It
will be noticed that the line 3-4 in eleva-

-««>' » tion is perpendicnlar as shown by 3' 4'

in plan while the points 2 ' and 5 ' project

from it, showing that the piece 2-3-4-5

Fig. 69. in elevation mnst be slightly twisted

along the line 5-3 when forming the elbow. Similarly slight

, bends will be required along the lines 1-5 and 5-2.

It will now be necessary to obtain the tme lengths or a
diagram of triangles on the lines 1-5, 5-2 and 5-3. Connect similar
nombers in plan as shown from 1' to 5', 5' to 2' and 5' to 3', the
last two lines being already shown. From similar points in eleva-
tion draw horizontal lines as shown by 2-A, 3^, 5-e and ft-t?.
Take the distances from 1' to 5', 5' to 2' and 5' to 3' in plan and
place them on one of the lines having a similar nnmber in eleva-
tion, as shown respectively by 1* 5", 5^= 2^ and 5" 3^. From the
points marked 5^ draw vertical lines intersecting the horizontal
line drawn from 6 at 5"^, & and 5' respectively. Now draw the true
lengths 1* 5', 2" 5'', and 3" 5". For the pattern draw any line as
1-6 in Fig. 59 equal to 1-6 in Fig. 58. Now with 6' 5' in D as a
radius and 6 in Fig. 59 as a center, describe the arc 5 which is
intersected by an arc struck from 1 as a center and the tme length

SHEET-HETAL WOBK ff7

l> 5* in Fig. 58 as radiiiB. Them tusing the tme length S'- ^ as
radina and 5 ia Fig. Sd as center, describe the aro 2, irhich is
intersected by an arc stmck from 1 as center and 1' 2' in E in
Fig. 58 as radins. Using the tme length 5^ 3' as radios and 5 in
Fig. 59 as center, describe the arc 3, and intersect it b; an arc
stmck from 2 aa center and 2' 3' in E in Fig. 58 as a radius. Now
with 6' 4' in D as a radius and 5 in Fig. 59 as a center, describe
tbt aro 4, and intersect it by an aro stmck from 3 as center and
3-4 in the elevation in Fig. 58 as a radius. Draw lines from point
to point in Fig. 59 to complete the pattern. Laps should be
allowed on all patterns, for seaming. Slight bends will take place
as shown on the pattern, also as is shown by a 4 and o in Fig. 57
If the joint is to be on the line 2-5 in elevation in Fig. 68, the
necessary pieces can be joined feather.

In Fig, 60 is shown a perspective view of a five-piece tapering
elbow, having a round base and an elliptical top This form is
generally knowu as a ship ventilator.
The principles shown in this problem
are applicable to any form or shape no
matter what the respective profiles may
be at the base or top. The first step is
to draw a correct side view of the elbow
as shown in Fig. 61. The outline A
6 O D E F can be drawn at pleasure,
but for practice, dimensions eire given
First draw the vertical line A F
equal to 4^ inches. On the same
Pig. 6tt line extend measure down 1\ inches to

/and draw the horizontal line H B. Fromyset off a distance of
IJ inches at G, and using G as a center and Q- F as a radius
dwcribe the arc F B intersecting H B at E, from which draw the
vertical line E D equal to 1 inch. Draw D O equal to 1| inches,
then draw O B. From B lay off 5| inches, and using this point (H)
as a center and H B as a radius describe the aro B A, The portion
shown B E D C is a straight piece of pipe whose section is shown
oy I J K L. Now divide the two fires B A and E F into the same
number of parts that the elbow is to have pieces (in this case four)
and draw the lines of joint or miter lines as shown by TJ Y, etc.

S8 SHEET-METAL ^OBE

Bisect each one of the joint lines and obtain the points ahed a&d «.
Then A E C D E F will be the aide view.

The patterns will be developed by triangnlation, bnt before
this cEin be done, tme Bections most be obtained on all of the lines
in side elevation. The tme sections on the lines B E and C D are
shown by I J K L. The length of the sections are shown l^ the
joint lines, bnt the width mnst be obtained from a front ontline of
the elbow, which is constructed as follows: In its proper relation
to the side elevation, diaw the center line M B upon which draw

FRONT OUTUNE

Pig. 61.

the ellipse M N O P (by methods already given in Mechanical
Drawing) which represents the section on A F in side. Take half
the diameter I K in section and place it on either side of the center
line M R as R T or E S. Then draw the outline O S and T N in
a convenient location. While this line is drawn at will, it should
be itndeTBtood that when once drawn, it becomes a fixed line. Now
from the various intersections ah c d and e in the side elevation,
draw lines through and intersecting the front outline as shown on

SHBBT-METAL WORK

one side by O, h', e', d' and e', Thsa. these distanoes vill repre-
sent the widths of the sections shown by similar letters in side.
For example, the method will be shown for obtaining the true
section on U V, and the pattern for piece 1 in side
elevation. To avoid a confusion of lines take a
tracing of A F V U and place it as shown by 1,
13, 12,0 in Fig. 62. On 1-13 place the half proffle
M N P of Fig. 61. Bisect 0-12 in Fig. 62 and
obtain the point 6; at a right angle to 0-12 from 6
draw the line 6 6' equal to i' &' in front outline in
Fig. 61. Then through the three points O, 6' and
12 in Fig. 62, draw the semi-ellipee, which will
represent the half section on U V. The other

Fig.62.

seotions on the joint lines in side elevation are
obtained in the same manner.

If the sections were required for piece 2 in
side it would be necessary to use only O 6' 12 in
Fig. 62 and place it on U Y in Fig. 61, and on a
perpendicular line erected from c, place the width
e' c' shown in front and through the three points
obtained again draw the semi-elliptical profile or
section. Now divide the two half sections (Fig. 62)
into equal parts as shown by the small figures, from
which at right angles to 1-13 and 0-12 draw lines
intetBecting these base lines from 1-13. CJonneot opposite points
aglto2to3to4to6, etc., to 12. Then these lines will represent

60 SHEET-METAL WORK

the basea of sections whose altittides are eqnal to the heights in
the half section. For these heights proceed as follows:

Take the various lengths from 1 to 2, 2 to 3, 3 to 4, 4 to 6, etc.,
to 11 to 12 and place them on the horizontal line in Fig. 63 as
shown by similar figures; from these points erect vertical lines
equal in height to similar figures, in the half section in Fig. 62 as
shown by similar figures in Fig. 63. For example: Take the dis-
tance from 7 to 8 in Fig. 62 and place it as shown from 7 to 8 in
Fig. 63 and erect vertical lines 7-7', and 8-8' equal to 7-7' and
8-8' in Fig. 62. Draw a line from 7' to 8' in Fig. 63 which ia the
tme length on 7-8 in Fig. 62. For the pattern take the distance of
l-O and place it as shown by 1-0 in Fig. 64, Now nsing O as a
center and O 2' in Fig. 62 as a radins, describe the arc 2 in Fig. 64

Fig. 64.

and intersect it by an arc stmck fTC»n 1 as a center with 1-2' in
Fig. 63 as a radius. Nov with 1-3' in Fig. 62 as a radins and 1 in
Fig. 64 as a center, describe the arc 3, and intersect it by an arc
stmck from 2 as center and 2'-3' In Fig. 63 as a radins. Proceed
thns, nsing alternately as radii, first the divisions in 0-6'-12 in
Fig. 62, then the proper line in Fig. 63, the divisionB in l-7'-13 in
Fig. 62 and again the proper line in F^|;. 63, nntH the line 12-13
in Fig. 64 is obtained, which equals 12-13 in Fig. 62. In this
manner all of the sections are obtained, to which laps must be
allowed for wiring and seaming.

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BHEET-METAL WORK

TABLES.

f tie (ollowing tables will be found convenient tor the Sheet-Metal Worker:

TABLB9 PAOX.

WeightoICaat Iron, Wrought Iron, Copper, Lead, Brosa and Zinc 62

Sheet Copper 63

Sheet Zinc 61

Standard Gauge for Sheet Iron and Steel 66

Weights of Flat Foiled Iron 68-71

Square and Bound Iron Bats 72-73

Angles and Teee 7«

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SHEET COPPER.

OfQcial table adopted by the Aesociation of Copper Uanufacturera of
the United States. BoUed copper has Bpeciflo gravity of 8.93. One cnbio
foot weighs 558.125 poonde. One square foot, one inch thick, weighs 4ASI
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11.72

12.19

12.66

10.42

10.94

iU6

11.08

12.60

13.08

ISM.

14.06

26.00

11.46

12.03

ie.60

13.18

13.76

14.32

14.90

16.47

s7.eo

i!.eo

13.13

18.76

14.38

16.00

16.68

16.88

30.00

18Ji4

14iS

14.90

16.67

J?g

1^98

17.60

13.28

32.50

14.53

16.31

16.04

16.77

13.88

18.96

10.69

36.00

16.63

18,41

17.19

17.97

19.53

20.81

21.09

8730

16.S7

17.60

19.17

20.88

21.67

28.60

40.00

'ir

17:71

18.69

19.48

20.36

21i6

22.14

23.62

28.91

istsa

18.76

19.69

20.63

21 A8

23.44

24.38

26.31

45.00

19.79

20.78

81.77

28.76

24.74

25.73

26.72

47JiO

S0.8S

21.88

2i.9S

23.96

ESiop

26.04

27.08

28.13

60.00

lA-

S1.88

22.97

24.06

85.16

26.86

27.34

28.44

29.53

52.50

sa.ti2

24.06

25.81

26.35

87.50

88.66

29.79

30.94

65.00

23.96

86.16

26.85

27.65

28.76

29.96

31.15

88.34

67.60

25.00

26JS6

27.60

88.75

80.00

31.26

82.60

33.76

60.00

20.04

27.84

28.66

29.95

aija

82.66

33,86

86.16

82.60

27.08

28.44

29.79

81.16

88J0

38.86

sejEi

86.66

65.tlD

88.18

29.63

30.04

32.34

38.7S

S6.16

St.66

87.97

67iO

89.17

30.63

88.08

33M

86.W

36.46

W.9B

89.33

7DJiO

S0.£1

81.78

88.23 84.74

36.86

37.76

89J7

40.7S

72.60

88.81

84.38 35.94

87.60

86.06

40.63

42.10

7eJio

H»

ssjes

83.01

36.62 87.14

38.76

'40.86

41.88

43.56

77JI0

33.33

Z5M

86.67

88.33

40.00

41.67

43.33

46.00

80.00

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SHEET-METAL WOBK

WDOHTS OP PLAT ROLLED IRON PER LINEAR FOOT.

(Continned)

SSi

7«"

7^"

7H"

8Ji"

BH"

Iff'

6JS

Ul
MS
LBS

iM
lU

4.e>

1£&

1.61
Ul

4.81
US

1.W

1.7!
144

lis

188

1.77
161

6.S1
7.03

1«
106

117
7Je9

SM
7M
llOO

lOJM

7JK
8.0B
M£7

iioe

IIM
l&U

ISS
10.00
11.B7
IISI

169
10.B1

1176

1140
14.17

111
10,M
1176
14J8

17«
20.00

1118
1408
IIH
17J»

lltS
1110
IIU
1111

14JK

lias

17.18
1171

lUS
1116

16.00

iiei'
im

MOO

1147
17.19
1191
»I.6S

16.94
17.71
1148
Zi3A

1141
1128
2106
21.83

HfiO
S.0O

27Jia

SIOS

20.42
n.88

1194
81.16

tiu

£117

HUl

ni8

S144

sun

BlOO
S167

24.0C
SS.78

2166

2170
81ES
27J4
29.17

VM
40.00

W.71
»J7

S168
87.19
E&70
USl

tSM

e&ii

sr.tt

tan

84J8

8110
8148

80.09

84.01
BUS

4160

60«l

».I8
K.08

n.7S
8SJtS

S4.74
»J!G

S&81
KM

1191

sua

8<J»
17.81
80£l
41£6

27.19
8196

4178
4160

S&88
4176

BlfiO

S7je

S7.7S

HOC

4168
4119
417S

4DJI
41.98
416)
46A

41.07
41IS
46.00
4107

4SJ>7
44.00
4141

4111

4127

4101
47.81
49.68

46JI7
17.10
4fti8
61M

70.00

4&SB

41.76
45J«

4167

46«

41B1
4188
4144

61W

41SS
4144
60.06
«.«7

4&BS
60.00

4184
61.66
61IS
61»

6118

G186

TiM

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SHEET-METAL WORK

WGiaHTS OP FLAT ROLLED IRON PBR LINBAR FOOT

(Continued)

SB:

BH"

«-.

10"

lOi"

lOJ"

03"

1^
8.76
6.S3
7JS0

1.98

6.78
7.71

l.SS
8.96
6.94
7.92

2.08
4.06
6.09

ai8

2.08
4.17
BJ!6
8Jn

2.14
457
6J1

8.54

2.19
4.88
6.66

8.76

2je4
4.48
6.72
a96

6.00
10.00

9.18
l\X6
18.1S
16.00

9.51
11.68
13.49

16.42

9.90

11£S
13.86
16.83

laiB
12.19
14Ji8
16^

10.42
12.50
14.68
16.67

10.68
1851
14.95

17.08

10.94
18.18

16.31
17.60

llJgO
18.44
16.68

17.92

12JS0
16.00
17.60
80.00

1B.88

18.76
S0.63
SS.50

17J4
19.E7

21.20
23.13

17.81
19.79
21.77
28.76

I8J88
20.81
B2.34
E4.38

18.75
20.83
22.92
26.00

I9i2
81.36
23.49
25.62

19.69
21.88
24.06
26:26

20.16
22.40
24.64
26£8

as.60

85.00
27.60
30.DO

S4.S8
S6.26
£8.18
80.00

26.tS
26.93
28.91
80.83

26.73
27.71
29.69
31.57

28.41
28.44
80.47
82^0

27.08
29.17
31.26
33.33

27.76

29.90
32.03
34.17

28.44

30.63
38.81
86.00

29.11
31.36
33.69
35.83

32J»

35.00
37.60

40.00

lit
1>

81.88
83.75
36.68
87£0

32.76
84.69
86,61
38.64

33.66
85.63

37.60
39.68

34.63
36M
88.69
40.63

35.42
37.60
89.58
41.67

36.30
33.44
40.67
42.71

37.19
89.88
41.66
48.76

3S.07
40.31
42.66
44.79

42.60
46.00

47i0
60.00

89.38

lliS
48.18
46.00

40.47

42.40
14.33

46i6

4i.G6
43.54
4S.62

47.60

42.66

44.60
46.72
48.7B

48.76

46.83
47.92
50.00

44.84

46.88
49.11

45.94
48.13
60.3f
52i0

47.03

49i7
61.61
63.76

62.50

66.00
67.60
60.00

46.88
48.7B
60.63
fi2£0

4&18
60.10
62,03
53.96

49.43
51.46
53.44
56.42

60.78
62.81
54.84
66.88

62.08
64.17
66.26
68.83

63.39
65.68
67.68
66.79

urn

66.88
59.06
61.26

66.99
68JB3
60.47

62J0
65.00
67JiO
70.00

54J8
6tSB

sais

60.M

67.81
69.74
61.87

61J5
68^

62.97
66.W

60.4S

64.G8
66.67

61.93
64.06
66.20
68.83

63^
66.63
t7M
70J»

64.96
67.19
69.43
71.67

TSiO

75.00
77.60
80^

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SHEET-UETAL WOBK

WBKltlTS OP FLAT ROLLED IRON PER LINEAR POOT.

(Cmiclndod)

11" llj" llj" llj" 12" 121" 12*^' 12i"

izecy Google

SHEET-METAL WORK

SQUARE AND ROUND IRON BARS.

lUctMN

OaldtlMC.

Vd|U>t

Imit

.Si

i>.i.i»tat

•LSJT

xaa
•osa

.117

.041
.092

jooaa

.0166
.0362

J3031
.0123

.0276

.1963
.3937
.6880

.aos

.326
.4S9
.638

.164
.266
.368
JSOl

.0626

.0977
.1406
.1914

.0^1
.0767
.1104
.1503

.7864
.9817
1.1781
1.3744

.839

1.065
1.803

1.676

.664
.828
1.028
1.237

.3600

.3164
.8906
.4727

.1963
.2485

.3068
.3712

1.5708
1.7671
1.9636
2.1598

1.876
2.201
2.662
2.930

1.473
1.728
2.004
3.301

.5625
.6602
.7666
.8789

.4418
.6186
.6013
.6803

2.3662
3.6626
2.7489
3.9462

3.383

3.763
4.219
4.701

2.618
2.966
3.313
3.692

1.0000
1.1389
1.3666
1.4102

.7854
.8866
.9940
1.1075

3.1416
3.3379
3.6343
8.7306

6.208
6.742
6.302
6.888

4.091
4.610
4.960
6.410

1.5625
1.7237
1.8906
3.0664

1.2273
1.3630
1.4849
1.6330

3.9270
4.1233
4.3197
4.5160

7.500
8.138
8.802
9.492

6.880
6.392
6.913
7.465

2.2600
2.4414
2.6406
3.8477

1.7671
1.9176
2.0739
2.2366

4.7124
4.9087
6.1051
5.3014

10.21
10.96
11.72
13.61

8.018
8.601
9.204
8.828

3.0625
3.2863
3.6166
3.7639

2.4053
2.5803
2.7613
2.8483

6.4978
6.6941
6.8905
6.0868

18.33
14.18
16.06
16.96

10.47
11.14
11.82
12.63

4.0000
4.3639
4.6166
4.7863

3.1416
3.8410

3.6466
3.7583

6.2833
6.4796
6.8759
6.8722

16.88
17.88
18.80
19.80

13.26

14.00
14.77
15.56

5.0625
5.3477
8.6406
5.9414

3.9761
4.20P0
4.4301
4.6664

7.0688
7.2649
7.461S
7.6676

2a83

21.89
22.97
24Jta

16.36
17.19
18.04
18.91

6.3600

6.5664
6.8006
7.2327

4.9087

5.1672
6.4119
6.6727

7.8640
8.0508

8.4430

,AiOOglc

bheet-hetal wobk

50oARB AND ROUND IRON BARS.

(Concluded)

WUUKUI

TtiEUot

.§£

lima

aot«

26.21
26.37

27.66
28.76

19.80
20.71
21.64
23JS9

7.5625
7.9102
8.2656
8.6289

6.9396

6.2126
6.4918
8.7771

8.6394
8.8357
0.0321
0.2284

80.00
31.26
32.56
33.87

23.66
34.66
26.57
26.60

9.0000

9.3789
9.7666
10.160

7.0686
7.3662
7.6699
7.8798

9.4248
9.6211
9.8170
10.014

1 ■

36.21
36.58
37.87
39.39

27.65
28.73
20.83
30.94

10.663
10.973
11.391
11.816

8.2968
8.6179
8.9462
9.3806

10.210
10.407
10.603
10.799

40.83
42.30
43.80
4B.33

32.07
33.23
34.40

35.eo

12.260
12.691
13.141
18JS98

9.6211
9.9678
10.321
10.680

10.990
11.193
11.388
11.586

46.88
48.46
60.06
61.68

36.82
88.06
39.31
4a69

14.063
14.635
16.016

II.04fi
11.416
11.793

12.177

11.781
11.977
12.174
,12.370

4
1

63.33
56.01
66.73
68.46

41.89
43.21
44.65
45.91

16.000
18.604
17.016
17.636

12.666
12.963
13.364
13.772

12.566
12.763
12.959
13.166

60.21

6i.es

63.80
65.64

47.29
48.69
BO.ll
61.65

18.063
18.598
19.141
10.691

14.186
14.607
15.033
16.466

13.352
13.648
13.744
13.941

87.60
69.39
71.80
73.24

63.01
54.60
66.00

57.62

20.250

20.816
21.391
21.973

I6.80i
16.349
16.800
17.257

14.137
14.334
14.630
14.728

■ :

75.21
77.20
79.22
81.26

69.07
60.63
62.22
63.82

22.663

23.160
23.760
24.370

17.721
iai90
1&665
19.147

14.923
16.119
15.316
16.513

83.33

66.45

S5.O0O

19.635

15.708

,1.0, Google

BHDET-UETAL WOBE

ANGLE IRON.
Wdtht Per Utww Pool.

• ta *H 2i I

• •• «A 1«K

1 «« «« I2«

»K»S«xft »

9 |8 xH 7

«i'2X»A B

•M«S««« »«

a «a .)i SMiA

iXilXiA 2X

iH'iKxft a

l««lM«ft IM

1 xl «« 1

K« «•« It

x%..

TEE IRON.
Wdcht Per Linear Root.

....SO LbB.

..SO

..KH

..U

SHxSKxK 12K

» x3 iH 'X

!«x2Xx)< S

tKxSi.A 6

ajixaxiW « 1

a xa in an

m'lX^a a

iKxWx« am

i«xi«xM aw

1 xl xK I

«x KxH X

,1.0, Google

COTiSTmjCTION DRAwma
sKowiria
5Hr.ET MKTAL DRUn AMD VEMTILATOU IN
VENTlLATIOri WORK

Se.ctio'na.l view sViowin^ vcntUs-Tion

pipes connccfcd to drum in sdXic

6.130 stea-m coils in drum To

crea-la suction.

kGocwIc

SHEET METAL WORK.

PART II.

PROBtenS FOR LIGHT QAUQE flETAL.

It JB often thecase that the sbeet
1 metal ■worker receives plane for

vent, heat, or blower pipes to be
constructed, in which the true
lengths and angles are not shown
but must be obtained from the
plans or measnrementa at the
' bnilding.

Figs. 66 and 66 show the prin*
ciples employed for obtaining the
tme angles and lengths in obliqne
piping, itbeing immaterial whether
the piping is round, square, or oval
in section. The only safe way in
obtaining these angles is to use the
center line as a basis and after this
line has been obtained, bnild the
pipe around it, so to apeak. la Fig.
65 let A B C represent the eleva-
tion of the elbow shown in plan by
D E. Through the center of the
pipes draw the center line ah cd
which intersect the center lines of
the pipe in plan at e andy. In ele-
vation the rise of the middle piece
B on the center line is eqaal to A c
and projects to the right a distance
eqii^ ioh h, shown in plan \>ye/;
this same pipe projects forward in
While the miter lines in elevatip^ii^

Pig. 65.
D a distance equal Uyea.

SHEET METAL WOBK

and k I hare been drawn straight, they wonid in reality show cnrred
lines; those lines have not been projected as there is no necessity
for doing so.

With the various heights and projections in plan and eleva-
tion the trne length and trae angles are obtained as shown in Fig.

Fig. 66. /

66, in which draw the horizontal line e ^eqnal to e^in plan in
Fig. 65. Take the height from h to o and place it from _/ to c in
Fig. 66 on a vertical line erected from y. Draw a line from e to
c which is the trne length on the center line of the pipe shown by
£ in elevation in Fig. 66. From the points c and e in Fig. 66
draw perpendicular lines, making Y e X and X e Z = the trne angles
shown by « & X and Xg d respectively in Fig. 66. On either
side of the center line in Fig. 66 lay o£F the h^f diameter of ths
pipe as shown, and in its proper positioo draw the profile W.

SHEET METAL WOBK 77

Divide tbis into eqaal spaces and obtaio the pattern A B D E C
ID tlie usual mauner. As both angles are similar the miter cut
C E D cau be used for all of the patterns. In drawing thie prob-
lem for practice make the diameter of the pipe 2 inches, the height
from A to e 3J inches in Fig. 65, the projection S to A 3^ inches,
and tbe projection in plan e to a 5^ inches.

Our next problem is that of a rain-water cut-off, a perspective
view of which is shown in Fig. 67. While the miter cuts in this prob-
lem are similar to elbow work the intersection between the two
beveled arms, and the cut-off or slide on the inside require atteo.
tioD. Make the diameter of the
three openings each 2 inches; A
to B (Fig. 68) IJ inches. From
E at an angle of 45° draw B C 3J
inches and C D 2 inches. From
G draw the vertical miter line
G h. Make the distance from B
to T ^ inch. Place the line d e
of the cut-off ^ inch above the
line T U as indicated at a and
the line eoto the right of h G, ae
indicated by t, a distance of ^g

inch. FamJlel to G H draw c d ='ig, 87.

giving slight play room between

G H, intersecting etZ and e eatf^andcrespectively. Fromeat right
angles tod c, draw a line as shown, intersecting A G at /", which is
the pivot on which the cut-off c d e will turn either right or left.
The angles of the pipes on opposite sides are constructed in similar
manner; ABCDEFGHIJKLM will be the elevation, N,
the section on A M and O P B S the section on I J. B T U L
shows how far the upper tube projects into the body under which
the scoop e d c turns right and left to throw the rain water into
either elbow as desired. The pattern for the upper piece A T XI M
is a straight piece of metal whoae circumference is equal to N.

For the pattern for (A), divide the half section O P R into
equal spaces as shown, from which erect lines intersecting the miter
line H £ as shown, and from which, parallel to K L and E. \j, draw
lines intersecting the joint lines G A L as shown. As none of th*

SHEET METAL WOKK

lines ]U8t drawn interaect the corner h, it will be neceaeary to ob-
tain this point on the half section O P R from which the stretch-
out of the pattern is taken. Therefore from h, parallel to LK
draw h h' intersecting H X at h', from which, parallel to K J, drop
a line interaecting the profile O P R S at h". At right angles to
L K draw stretchout of O P R S as shown by similar numbers on
T" IT', through which at right anglea to T' U' draw lines which are
interaected by lines drawn at right angles to L K from similar in-

tersections on G A L and II K. A line traced through points thus
obtained as shown by X Y Z V W will be the pattern for (A).
From y in the elevation at right anglea to L K project a line inter-
aecting the miter cut X T Z at _/' andy. Aty andy" holes are
to be punched in which the pivot foi the acoop e'd e in elevation
will turn.

While the pattern for (B) can be obtained as that for (A) waa
obtained, a short method is to take the distance K to J and place

SHEET METAL WOEK 79

it as shown from W to J' and V to J' on the lines of the pattern
X W and Z V respectively extended. W V J' J' will be the pat-
tern for B.

To avoid a confnsion of lines in the development of the scoop
or cnt-off cd e, this has been shown in Fig. 69 in which <leo'\%9,
reproduction of rf e c in Fig. 68. A true section of the scoop must
now be drawn on a; e in Fig. 69 so that its dimenaiona will allow
it to turn easily ioBide of the joint line G A in elevation in Fig.
68, Therefore draw any horizontal line as 4 5 in Fig. 69, at right
angles to which fromydraw a vertical line intersecting 4 5 aty.
Now take a distance fS inch less
than one-half the diameter of O K ry---'i."_V}.;rxr:i.
in Fig. 68, and place it in Fig. 69 |\^_-^i-_i--f\

on either side of the line 4 5 on the ^ X^^^s^^Z^-^W* *

vertical line just drawn as shown ^-[-} ^'v ^i-.j *''^

from / to 2 and / to 2". Extend i gjj, "^

d c till it intersects 4 5 at 4. Draw a j/^i a
line from 4 to 2'; by bisecting this «R--fe^-9
line we obtain the line a h intersect- to?*vj
ing 4 5 at *■ Then with * as center '^ a i?- ao
and * 2' as radius, describe the arc 2' 2.

From 2 and 3' draw horizontal lines equal to f e as shown by 2 1
and 2' 1'. Then will 1 4 1' be the true section on x e. Divide
the half section into equal spaces as shown from 1 to 4, from which
erect lines intersecting c e and e d. Extend a; e as mj, upon which
place the stretchout of 1 4 1' as shown by similar numbers on xj,
through which draw vertical lines. These lines intersect with hori-
zontal lines drawn from similar intersections on d e c. Through
points thus obtained draw the line 1 n 1' m. which is the desired
pattern. As the pivot hole /"falls directly on line 2, then f"'f"
will be the position of the holes in the pattern. Laps must be
allowed to all patterns.

In putting up rectangular hot air pipe it is often the case
that the pipe will be placed in the partition of one story, then has
to fall forward and twist one quarter way around to enter the par-
tition of the upper story which runs at right angles to the lower
one. A perspective view showing this condition is shown in Fig.
70, where the upper opening turns one quarter on the lower one

SHEET METAL WORE

and leaning to the right as mach as is shown in Fig. 71 in plan.
This problem is known as a transition piece in a rectangnlar pipe.
Fall size measurements are given In Fig. 71 which should be
drawn one-half eize. The height of the transition piece is 1 foot
8 inches, the size of the openings, each 4 X 10 inches tnrned as
shown, two inches to the left and two inches above tlie lower section
as shown. From the plan constmct the front and side elevations as
shown by the dotted lines. A B D and E F G H will then be
the front and side elevations of the transition piece respectively

FHONT ELEVATION

SIDE ELEVATION

Fig. 70.

Fig. 71.

eqnal to 20 inches or 10 inches for practice. Number each side
of the plan (a), (J), (c), and [d). Through the front and side
elevations draw the vertical and horizontal lines S T and U V
respectively at pleasure. These lines are only used as bases for
measurements in determining the patterns. For the pattern for
the side marked (a) in plan take the length of B C and place it
on the vertical line B C in Fig. 72. Through the points B and
C draw the horizontal lines E F and H G, making B F and B E,
and C G and H equal respectively to the distances measured from
the line U V in Fig. 71 to points F, E, G, H. Draw lines from
E to H and F to G in Fig. 72, which is the pattern for (a).

SSEET METAL WOKE

For the pattern for (b) in Fig. 71 take the distance of A D,
and place it as shown by A D in Fig. 72; through A and D draw
E F and H G, making A F and A E, and D G and D H equal

Pig. 78.

respectively to the distances measared from the line [J Y in side
elevation in Fig. 71 to poiDts F, E, G, H. Draw lines from E
to H and F to G in Fig. 72, which will be the pattern for (b). In
similar manner obtain the patterns for (c) and (d) in plan in Fig. 71.
The lenf^s of E H and F G are placed as shown by similar letters

Pig. 73.

Fig. 74.

in Fig, 72, while the projections to A, B, C, D are obtained
from A, B, C, D in front elevation in Fig. 71, measuring in
each instance from S T.

If desired the top and lower flange shown in the perspective
in Fig. 70 can be added to the patterns in Fig. 72. Laps are
allowed to the patterns to allow for double seaming at corners, if,
however, the pattern shonld be required in one piece, it woald only /

SHEET METAL WORK

be necesaary to join the varione pieces in their proper positioos as
shown hy a d be in Fig. 73, which would bring the seam on the
line J N in plan in Fig. 71.
In Fig. 74i8shown a per-
spective view of a curved
rectangular chute the con-
struction of which arises in
pipingandblowerwork. The
problem as here presented
shows the sides a and a in
vertical planes having the
same height, while the bot-
tom b has more width than
the top c. The top opening
is to rise above the bottom
opening a given distance
equal to C. First draw the
plan and elevation as shown
inFig. 75,makeABeqnal to
3 inches, B8 2^ inches; with
a radiiiB equal to ^ inch, with
a as center draw the quarter
circle 8 2. From 2 draw the
vertical line 2 equal to 1|
inches and draw C D equal to
1^ inches. Make D 1 equal
to C 2 and using a as center
and ffl 1 as radius draw the
arc 1 h. From A draw a
line tangent to X J aa A 7.
A B C D will be the plan of
the chute. In line with A B
draw the section S T U V.
In line with D draw the
-^ o -ti section EFI H as shown.

Place the desired rise of the
*^' chute as shown by F * in ele-

• ration and from i draw a horizontal line as i K, which intersect by

SHEET METAL WORK SS

a line drawn from A B in plan as shown. Make K J equal to F £
and draw the lines F K, K I, and E J, J H. F E J K is the elava-
tion of the outside curve, B. I K J the inside curve, F I K the
bottom, and £ H J the top.

Having the plan and elevation in position we will first draw
the pattern for the two vertical sides. For the pattern for the side
of the chute shown by B C in plan proceed as follows: Divide
the inner cnrve 2 to S into egnal parts as shown by 2-4-6 and 8,
from which points drop lines Intersecting the inside of the chnte in
plan HJKIas shown. Atrightanglesto JK draw LM, upon which
place the stretchout of B C in plan as shown by similar letters and
numbers on L M, through which draw vertical lines which inter-
sect lines drawn parallel to L M from H J, Through points thus
obtained draw the line R 2^ 4^ QV S^N. The same method can

Fig. 76.
be employed for the cnrve P O, bnt as the height H I and J K are
equal, having a common profile B C, take the height of H I or J K
and place it on vertical lines as K F and N O and trace the curve
B K as shown by P O. .N O P K is the pattern for C B in plan ;
To obtain the pattern for the ontside curve divide the curve 1-7
into equal parts as shown, from which drop vertical lines inter-
secting similar points in E J X F, in elevation at right angles to
E F draw W X, upon which place the stretchout of D A in plan as
shown. From the divisiona on W X drop vertical lines, which
intersect by lines drawn from similar numbered intersections on
E J. Trace a line through these points as shown by c/'and draw
d e sa explained in connection with the inside pattern, o d ef\%
the pattern for the outside of the chute shown in plan by D A.

As both the top and bottom of the chute have the same bevel,
the pattern for one will answer for the other. Connect opposite
points in plan as shown from C to 1 to 2 to 3 up to 8, then to A.
Id similar manner connect similar points on the bottom in eleva<
tioD as shown from 1 to 2 up to K. The lines in plan represent

M SHEET METAL WORE

the baBSB of the aectioDB whose altitudes are etjiial to tb» varioas
heights iQ elevatioD, measured from i K. Take the Tarions lengths
from 2 to 3 to 4 to 5 to 6 to 7 to 8 to A ID plan and place them as shown
by similar nambera on the horizontal line a S (Fig. 76); throngh
a b draw vertical lines, equal in height to similar numbers in ele-
vation, in Fig. 75, measared from the line i E. For example take
the distance 4 5 in plan and place it as shown by 4 5 in Fig. 76.
Erect perpendiculars 4 4' and 5 5' equal to 4" 4 and 5" 5 in eleva- '
tion in Fig. 75. Draw a line from 4' to 5' in Fig. 76, which ia the
true length of 4 5 in plan in Fig. 75. Proceed in similar manner
for the balance of the sections. Take a tracing of 1 2 C D in plan
and place it as shown by 1, 2, C, D in Fig. 77. Now using 1 as

Pig. 77. Fig. 7a

center and 1^ 3^ in (a;), in Fig. 75, as radius, describe the arc at
3, in Fig. 77, which is intersected by an arc, struck from 2 as
center, and 2' 3', in Fig, 76, as radius. Now with radius eqnal to
2^ 4V in (Y) in Fig. 75 and 2 in Fig. 77 as center, describe the
arc at 4 which is intersected by an arc, struck from 3 as center and
3' 4', Fig. 76, as radius. Proceed in this manner, using alternately
as radius, first the divisions in the pattern (2), Fig. 75, then the
slant lines in Fig. 76, the divisions in the pattern (Y), Fig. 75,
then again the lines in Fig. 76 until the line 7 8, Fig. 77, haa been
obtained. Then nslng? as center, with a lino equal to 7^ in (X),
Fig. 75, as radius, describe the arc A, Fig, 77, which is inter-
sected by an arc struck from 8 as center and 8' A, Fig. 76,
as radius. Then with radius, equal to 8^ N in (Y), Fig- 75, and
8, Fig. 77, as center, describe the arc B, which is intersected
by an arc, struck from A as center and A B in plan in Fig. 75
as radius. Trace lines through points thus obtained in Fig, 77,

SHEET METAL WOBE

and A B C P will be the desired pattern. Laps must be allowed
on all patterns for doable seaming the corners.

In Fig. 78 ia shown a perspective view of a hopper register
box nsnally naade from bright tin or galvanized iron in hot air
piping. In drawing this problem, the student should first draw
the half plan, making the semi-
circle 3| inches diameter, and
placing it directly in the center
of the rectangular top, which
is 8| inches wide and Scinches
long. Draw the elevation from
the plan as shown by A B C D
E F G H, making the vertical
height V W, 2J inches, and the
flanges at die top and bottom
each ^ inch. I K L M in plan
is the horizontal section on A B
in elevation and OPE the sec-
tion on £ F.

The pattern will be devel-
oped by triangolation, and the

first step is to develop a set of triangles. Divide the quarter circle

O S. into equal spaces, as shown by the numbers 1 to 7 in plan, from

which draw lines to the apex M. These lines represent the bases

of triangle whose vertical height is equal to V W in elevation.

Therefore, in Fig. 80, draw any horizontal line as T U, upon which

place the various lengths H 1, M 3, K 3, etc.)

Fig. 79) as shown by similar numbers on

T U. From T U erect the line T S equal to

the vertical height V W (Fig. 79). Then

draw the hypotenuses 81, 8 3, S 3, etc., in

Fig. 80, which represent the true lengths of

Pig. 80. similar numbered lines in plan in Fig. 79.

For the half pattern with seams on I O and

P K in plan, take a tracing of D Y W in elevation and place it

as shown by D y 7 in Fig. 81. Now using D as center, and with

radii equal to the various slant lines in Fig. 80 from S 1 to 8 7

strike small arcs as shown from 1 to 7 in Fig. 81. Set tiie dividers

86 SHEET METAL WORE

equal to the spaces contaioed in O B, in Fig. 79, and starting from
point 7, in Fig. 81, step from one arc to another until 1 is obtained.
Then UBing 1 as center and E D (Fig. 79) as radins describe
tbe arc T>' in Fig. 81. "With D ae center and M I in plan in Fig.

Fig. 81.
79 ftS radius, draw another arc intersecting the one previously
drawn at D'. Draw a line froml to D' to D in Fig. 81, 7 1 D' D V
is tbe quarter pattern, and the left-hand side of the Hgure may be
made by tracing the quarter pattern reversed as shown by V D"
1' 7. Take the distance of the flange D A in elevation in Fig. 79
and place it at right angles to the line D' D, D C, D" ae shown
respectively by A" A', A A*^ and A^ A^, which completes the half
pattern with laps allowed as shown

The pattern for the collar E F G H in
elevation in Fig. 79 is simply a straight
strip o^ metal, equal to the circumference
of O P R in plan.

It is often the case that two unequal

pipes are to be connected by means of a

transition piece as shown by A in Fig. 82,

Pj g2 the ends of the pipes being cut at right

angles to each other. As the centers of

both pipes are in one line when viewed in plan, making both

halves of the transition piece equal, the problem then consists of

developing a transition piece, from a round base to a round top

placed vertically. Therefore in Fig. 83 draw 1 5 equal to 24 inches,

and at an angle of 45° draw 5 6 1| inches. At right angles to 1 5

draw 6 10 4 inches long and draw a line from 10 to 1. On 1 5 draw

the semicircle 1 3' 5, and on 6 10 draw the semicircle 6 8' 10.

SHEET METAL WORK

Divide both oi these into equal spaees ae shown, from which draw
lines perpendicntar to their respective base lines. Connect opposite
points as shown by the dotted lines, and construct a diagram of

^'-'-^

11 I I* 2 3 45 7 a 9K>

Fig. 83. Fig. 81.

sections as shown in Fig. 84 whose bases and heights are eqaal to
similar mimbered bases and heights in Fig. 83. For example, take
the distance 4 8 and place it as shown by 4 8 in Fig. 84, from which
points erect the yortical lines 4 4' and 8.8' equal to 4 4' and 8 8' in
Fig. 83. Draw a line from 4' to 8', Fig. 84, which is the true

iTig.

Fig. SO.

length on similar line in Fig. 83, For the pattern take the dis-
tance of 1 10 and place it as shown by 1 10 in Fig. 85. Using 1
as center, and 1 2', Fig. 83, as radins, describe the arc 2 in Fig. 86,'
intersect it by an arf struck from 10 as center and 10 3', Fig. 84,
as radius. Then using 10 9' in Fig. 83 as radius, and 10, Fig. 85, as

SHEET METAL WOHK

center, deBcribe the arc 9, and iDtersect it by an arc struck from 2
as center, and 2' 9', Fig. 84, ae radius. Proceed in this manner
neiDg alternately as radii, first the divisions in the half profile
1 3' 5, Fig. 83, then the length of the propei- bypotennae in Fig
84, then the divisions in 6 8' 10 in Fig. 83; then again the hypot-
ennBe in Fig. 84 nntil the line 5 6 in Fig. 85 has been obtained,
whieh is equal to 5 6 in Fig. 83. Laps should be allowed for
riveting and seaming as shown.

Fig. 87.

In Fig. 86 is shown a perspective of an offset connecting
a round pipe with an oblong pipe, having rounded corners.

The first step ie to properly draw the elevation and plan as
shown in Fig. S7. Draw the horizontal line A B equal to one
inch, B 5' one inch, and from 5' at an angle of 45° draw 5' 6' equal
to 2J inches and 6' IJ inches. Make the diameter C D 2| inches
and D i" 0' IJ inches. Hake A. 1' J inch and draw a line from 1' to

SHEET METAL WORK 89

10' which completes the elevation. Directly above the line A B
draw the Bection of the oblong pipe, making the sides 1 1 and 5 6
equal to 1^ iDches, to which describe the semicircles on each end
as shown. Id similar manner draw the section on D C, which is
chowD by 6 8 10 8. A duplicate of the oblong pipe is also shown
in plan by E F, showing that the centers of the pipe come in one
line, making both halres symmetrical.

The patterns for the pipes will first be obtained. Divide the
semicircular ends of the oblong eection into equal .parts, in this
case four, also each of the aemicircles of the round pipe in similar
nnmberof pans as shown respectively from 1 to 6 and 6 to 10. Draw
vertical lines from these intersections cutting the miter line of the
oblong pipe at 1* 2' 3' 4' 5' and the miter line of the round pipe at
6' T 8' 9' and 10'. In line with A B draw

B M, upon which place the stretchout of BL-™ ^ "

the oblong pipe as shown by similar num-
bers; from B M drop vertical lines inter-
secting the lines drawn parallel to B M.
from similarly numbered points on 1' 5'. Fig. 88.

Trace a line through points thns obtained,

and P N O will be the pattern for the oblong pipe. Now take the
stretchout of the round pipe, and place it on C H; erect vertical lines
as shown intersecting the lines drawn parallel to O H from similar
intersections on 6' 10'. I J H O is the pattern for the round pipe.

The transition piece 1' 5' 6' 10' will be developed by triangu-
lation, and it is nsual to obtain true sections on the lines 1' 6' and
6' 10'; however, in this case it can be omitted because we have the
true lengths of the various divisions on the lines 1' 6' and 6' 10' in
the miter cuts in P and L respectively.

The next step is to obtain a diagram of sections giving the
tme lengths, for which proceed as follows: Connect opposite points
in elevation as shown from 1' to 9' to 2' to 8' to 3' etc., as shown.
For example draw center lines through the oblong and round sec-
tions as shown by a J and c d respectively, and take the length of
1' 10' in elevation and place it as shown from 1 to 10 in Fig. 88.
From 1 draw the vertical line 1 1' equal to the height of 1 in the
oblong section in Fig, 87 above the center line a h. As point 10
in plan has no height, it falls on the center line e d in plan, tbim

90 SHEET METAL WORE

draw a line from 1' to 10 in Fig. S8. Now take the distance from
1' to 9' in elevation, Fig. 87, and place it as shown from 1 to 9 in
Fig. 8S. Erect the lines 1 1' and 9 9' eqnal to pointe 1 and 9 in
the oblong and round sectioDS in Fig. 87, measured respectively
from the lines a h and c d. Draw a line from 1' to 9' in Fig. 87,
Proceed in this manner until all of the sections are obtained. For
the pattern proceed as shown in Fig. 89, in which draw any verti-
cal line as « 10 equal to 1' IC in elevation in Fig. 87. Now, with
one-half of 1 1 in pattern P as e 1 as radius, and e in Fig. 89 as
center, describe the arc 1 which ia intersected by an arc struck
from 10 as center and 10 1', in Fig. 88 as radine. With radius
eqnal to 10" 9" in pattern L in Fig. 87, and 10 in Fig. 89 as center
describe the arc 9, which is intersected by an arc struck from 1 ae
center and 1' 9', in Fig. 88 ae radius. Now, using as radius 1" 2"
in pattern P in Fig. 87 and 1 in Fig. 89 as center, describe flie
arc 2 which is intersected by an arc struck from 9 as center and
9' 2' in Fig. 88 as radins.

Proceed in this manner, using alternately as radii, first the
divisions in the pattern cnt I J, Fig. 87, then the length of the
slant lines in Fig. 88, the divisions in the cnt O N in Fig. 87, then
again the slant lines in Fig. 88 until the line 5 6 in pattern, Fig.
89, has been obtained. Then using 5 as center and 1 « in P, Fig.
87, ae radins, describe the are e' in Fig. 89, and intersect it by an
arc struck from 6 as center and 6' 5' in elevation in Fig. 87 ae
radins. Draw lines through the various intersections in Fig. 89;
10 £ e' 6 is the half pattern. By tracing it opposite the line e 10,
as shown by e V 5' e" 6' 10, the whole pattern, e' e «" 6' 10 6,
ia fonnd. Laps should be allowed on all patterns for seaming or
riveting both in Figs. 87 and 89.

In Fig. 90 is shown a perspective view of a three-way branch
round to round, the inlet A being a true circle, and the outleta B, C,
and D also being true circles, the centers of which are in the same
vertical plane, thns making both sides of the branch symmetrical.

First draw the elevation and the varions sections as shown in
Fig. 91. Draw the center line a h. From 5 draw the center Ime
of the branch C at an angle of 58° as shown by i d. Make the
center lines a h and b d each 3i^ inches long. Make the half
diameter of the branch B at the outlet J inch, and the full diam-

SHEET HETAL WORE 91

eter of the branch C at the oDtlet 1^ inches placed on either aide
of and at right angles to the center lines. Draw a line from e \x>f,
and with i and h as centers and radii eqnal to | inch draw arcs
intersecting each other at e. Draw lines from i to o to h. In
similar manner obtain A and the opposite half of B. A B C is
the elevation of the three branches whose sections on ontlet lines
are shown respectiTOly by G F and E and whosd section on the
inlet line is shown by D.

The next step is to obtain a trne section on the miter line or
line of joint b c. Knowing the height h o and the width at the

Pig. 89. Fig. 90.

bottom, which is eqnal to the diameter of D, the shape can be
drawn at pleasure as shown in Fig. 92, i oi6 drawn equal to & o,
Fig. 91, while h d and h a are equal to the half diameter D in Fig.
91. Now through a c dia Fig. 92 draw the profile at pleasure as
shown, which represents the true section on c S in Fig. 91.

As the side branches A and C are alike, only one pattern will
be required, also a separate pattern, for the center branch both of
which will be developed by triangnlation. To obtain the measure-
ments for the sections for the center branch B, proceed as shown
in Fig. 93 where 1 4 5 8 is a reproduction of one-half the branch
B in Fig. 91. As the four quarters of this center branch are alike
»oly one quarter pattern will be developed; then, if desired, th«
quarter patterns can be joined together, forming one pattern. Now

SHEET METAL WOBK

take a tracing ot c h a, Fig. 92, aod place it on the line 5 8 as
shown in Fig. 93. Similarly take a tracing of the quarter profile
F in Fig. 91 and place it on the line 4 1 in Fig. 93. Divide the
two profiles 1' 4 and 5 8' each into the same number of spaces as
shown respectively by points 1' 2' 3' 4 and 5 6' T 8', from which
points at right angles to their respective base lines 1 4 and
5 8 draw lines intersecting the base lines at 1 2 3 4 and 5 6 7 8.
Now draw solid linea from 3 to 6 and 2 to 7 and dotted lines from
3 to 5, 2 to 6, and 1 to 7. These solid and dotted lines represent

Fig. 91; Fig. 92. Pig. 93.

the bases of the sections whose altitudes are equal to the various
heights of the profiles in Fig. 93. The slant lines in Fig. 94 rep-
resent the true distances on similar lines in Fig. 93, as those in
Fig. 95 represent the true distances on dotted lines in Fig. 93.

For the pattern take the length of 1' 8',Fig. 94, and place it
as shown by 1 8 in Fig. 96, and using 8 as center and 8' 7' in
Fig. 93 as radius draw the arc 7, which intersect by an are struck
from 1 as center and 1' 7' in Fig. 95 as radios. Then using 1' 2'
in Fig. 93 as radius draw the arc 2, which intersect by an arc
struck from 7 as center and 7' 2' in Fig. 94 as radius. Proceed
iu this manner until the line 4 5 in Fig. 96 has been obta}ned

SHEET METAL WORK

which eqnale 4 5 in Fig. 93. Trace a line through points thns
obtained in Fig. 93, then will 14 5 8 1 give the quarter patteni.
. If the patterD is desired in one piece trace as shown by
similar figures, to which laps mast be allowed for riveting.

As the two branches A and C in Fig. 91 are alike, one pat-
tern will answer for the two. Therefore let 1 7 8 11 14 in Fig.
97 be a reproduction of the branch C in Fig, 91. Now take a trae-
ing otah cia Fig. 92 and place it as shown by 11' 11 8 in Fig.
97; also take a tracing of the half section E and the quarter sec-
tion D in Fig. 91 and place them as shown respectively by 1 4' 7 and

Pig. «.

Pig. 96.

Fig. 95.

11 11' 14 in Fig. 97. Now divide the two lower profiles 8 11 and
11' 14 each into 3 equal parts, and the upper profile 7 4' 1 into 6
eqnal parts as shown by the small figures 8 to 11', 11' to 14 and 1
to 7. From these points, at right angles to the various base lines,
draw lines, intersecting the base lines as shown by similar num-
bers. Draw solid and dotted lines as shown, and construct the
sections on solid lines as shown in Fig. 98 and the sections on
dotted lines as shown in Fig. 99 in precisely the same manner as
described in connection with Figs. 94 and 95.

In Fig. 100 is shown the pattern shape (to which laps must
be allowed for riveting) obtained as was the development of Fig.
96. First draw the vertical line 1 14, Fig. 100, eqnal to 1 14 in
Fig. 97. Then use alternately as radii, first the divisions in 1 4' 7 in
Fig. 97, the proper slant line in Figs. 98 and 99 and the divieions
in 11' 14 nntil the line 4 11, Fig. 100, is obtained. Starting from

SHEET METAL WORE

the point H aae as radii in their regular order the distttDces marked
off between 11' and 8, Fig. 97, then the proper slant lines in Figs.
98 and 99, the distances shown in the semicircle, 1 4' 7, Fig. 97,
until the line 7 8, Fig. 100, is drawn equal to 7 8, in Fig. 97. Then

rf.

Fig. in.

Pig. 98.

t:iB. 99.

1 7 8 11 14, Fig. 100, will be the half pattern. If the pattern is
desired in one piece trace 1 7' 8' 11' 14 opposite the line 1 14
as shown.

In Fig. 101 is shown a perspective view of a two-branch fork
oval to round, commonly used as breeching for two boilers. As

Fig. 100.

Fig. im.

both halves of the fork are symmetrical the pattern for one will
answer for the other.

While the side elevation shown in Fig. 102 is drawn com-
plete, it is only necessary In practice, to draw one half as follows,
and then, if desired, th^ other half elevation can be traced opposite

SHEET METAL WOBK

to the center line E J. First draw J B, 1^ ineheB, equal to the
half diameter of the outlet, aod the vertical center height J Y, 2^
inches. Establish the height of the Joint J E one inch, and the
desired projection Y D on the base line 1^ inches. Draw the
length of the inlet D 2| inches, and draw a line from C to B
and D to E. Draw a similar fignre opposite the line J E, and
A B G D E F G shows the side elevation of the fork. In their
proper position below A B draw the sections M and K whose
semicircular ends are stmck from ab o and d with radii eqnal to
J inch. Now draw an end elevation in which the trne section on

J E is obtained. Draw the center line^e and extend the lines
A B and G C in elevation as A P and G S. Take the half diam-
eter L J and place it on either side of ^yas showo bj OF. In a
similar manner take the half diameter of the section 'N s.b d t and
place it on' either side of e/ ae shown by E S. Then O P S R
shows the end elevation. Draw E T intersecting e^ at T. Now
draw the cnrve O T P, which in this case is strnck from the center
U, being obtained by bisecting the line O T. It shoold be ander-
Btood that the carve O T P, which represents the true section on
J E, can be made any desired shape, but when once drawn, repre-
sente a fixed line.

90 SHEET METAL WORK

The pattern will be developed by triangalation, for which
diagrams of Bections moBt be obtaiaed from which to obtain meas-
urements. These sections are obtained as follows: In Fig. 103
1 4 5 12 13 is a reprodnction of J B C D E, Fig. 102. Reprodnce
the quarter profile H L I, the half profile O T, and the half profile
mnoaa shown by 1' 1 4, 1" 13 1 and 12 9' 8' 5 in Fig. 103.
Divide the ronnd ends in a each into 3 parts and the profiles b and
c also each into 3 spaces, as shown by the figares. Drop liaee
from these figures at right angles to the base lines from 1 to 15 ae
shown and draw solid and dotted lines in the usual manner. While
in some of the previous problems only dotted Hoes were drawn, we

£36X1 III0967B

Fig. 105.

have drawn both solid and dotted lines in this ease, in order to
avoid a confusion of sections. A diagram of sections on solid lines
in Fig. 103 is shown in Fig. 104, the figures in both correspond-
ing; while Fig. 105 shows the true sections on dottod lines. The
method of obtaining these sections has been described in connection
with other problems.

For the pattern draw any vertical line as 4 5, Fig. 106, equal
to 4 5 in Fig. 103. Then with 5 6', Fig. 103, as radius and 5 in
Fig. 103 as center draw the arc 6, intersecting it by an arc struck
from 4 as center and 4 6', Fig. 105, as radius. Then using 4 3',
Fig. 108, as radius, and 4 in Fig. 106 as center, describe the arc 3,
intereectiDg it by an arc struck from 6 as center and 6' 3' in Fig.
104 as radius. Proceed in this manner, using alternately as radii,
first the divisions in a in Fig. 103, then the slant lines in Fig.
106; the divisiona in c in Fig. 103, then the slant lines in Fig.

SHEET METAL WORK

104, tiDtil the line 1 8, Fig. 106, is obtained. Now using 8 as
center and 8' 9', Fig. 103, as radius draw the arc 9 in Fig. 106,
interBecting it by an arc strnck from 1 as center and 1" 9', Fig.
104, as radius. Then starting at 1 in Fig. 106 use alternately as
radii, iirst the divisions in b in Fig, 103, then the slant lines in
Fig. 105, the divisions in a in Fig. 103, then the length of the
slant lines in Fig. 104 until the line 12 13 is obtained in Fig. 106,
which equals 12 13 in Fig. 103. Trace a line through points thus
obtained in Fig. 106, then will 4 1 13 12 9 8 5 be the half pattern. '
If the pattern is desired in one piece, trace this half opposite the
line 4 5 as shown by 1' 13' 12' 9' 8', allowing laps for riveting.
In Fig. 107 is shown a perspective view of a tapering flange
■ around a cylinder passing through an inclined roof, the flange

Fig. 107.

being rectangular on the roof line. The problem will be 'developed
by triangulation, a plan and elevation first being required as shown
in Fig. 108.

First draw the angle of the roof A B at an angle of 45°,
through which draw a center line C D. From the roof line A B
OD the center line set aS.ab equal to 4 inches and through h draw
the horizontal line £ F, making B F and B E each one inch.
Through d on the center line draw the horizontal line G H, making
d H and d G each two inches. From H and G erect perpendiculars
intersecting the roof line at K and L. Then draw lines from £ to
K 8 d F to L, completing the elevation. Construct the square in
plan naking the four sides equal to G H. Bisect 11 I and draw
the c< nter line c e intersecting the vertical center at d'. Then with
radiu. equal to S F or J £ in elevation and d' in plap as cent«r.

98 SHEET METAL WORK,

draw the circle 14 7 4' representing the horizontal section on E F
ia elevation, while G H IJ ia the horizontal section on K L id
elevation. As the circle in plan lain the center of the aqnare
making the two halves symmetrical it is only Decessarytodividethe
semicircle into equal spaces as shown from 1 to 7 and draw lines

Pig. 108.

from 1, 2, 3 and 4 to G, and 4, 5, 6 and 7 to H. Then will the
lines in 1 G 4 and 4 H 7 represent the bases of triangles which
will be constructed, whose altitudes are shown respectively by the
vertical heights in K £ and L F in elevation. Therefore draw hori-
zontal lines through E F, K, and L as shown by F O, K N, and L M.
From any point as R and T on F O, draw the perpendicnlara R S
and T U respectively, meeting the horizontal lines drawn from L
and K. Now take the various lengths in plan as 01, Q'^, Q3. and

SHEET METAL WOHK 99

G4 and place them on the line F O as shown by Tl, T2, T3 and T4,
from which points draw lines to U which will represent the trne
lengths on similar lines in plan. In similar manner take the dis-
tances in plan from H to 4, to 5, to 6, to 7, and place them on the
line F O, from R to 4, to 6, to 6, to 7, from which points draw lines
to S which represent the trne lengths on similar lines in plan.

For the pattern take the distance F L in elevation and place
it on the vertical line 7' L in Fig, 109. At right angles to 7' L
draw L S eqnal to i? H or <? I in plan, Fig. 108. Draw the dotted

Fig. loe.

line from 7' to S in Fig. 109, which should be equal to S 7 in W
in Fig. 108. Now with radii eqnal to S 4, and S J- and S, Fig.
109, as center, draw the arcs indicated by similar numbers. The
dividers should equal the spaces in the semicircle in plan in Fig.
108, and starting at 7' in Fig. 109, step from are to arc of corre-
sponding numbers as shown by 6', 6', 4'. Draw a dotted line
from 4' to 8. Then using S as center and L K in elevation, Fig.
108, as radius, describe the arc U in Fig. 109, intersecting it by an
arc struck from 4' as center and U 4, Fig. 108, as radius. Kow
using V ^, and U | in X as radii, and U, Fig. 109, as center,
describe arcs having similar numbers. Again set the dividers
equal to the spaces in plan in Fig. 108, and starting from 4' in
I^. 109 step to corresponding numbered arcs as shown by S', 2", 1'.

100 SHEET METAL WORK

Draw a dotted line from 4' to U to 1'. With K E in elev&tioo,
Fig. 108, ae radiua, and 1' in Fig. 109 as center, describe the
arc e intersecting it by an arc struck from U as center and G 6 in
plan in Fig. 108 as radias. Draw a line connecting B, U, e, and 1*.
7' 4' 1' e U S L 7' ehowe the half pattern, which can be traced
opposite the line 7' L to complete the fall pattern as shown by
7- 4" 1" <■' L" S' L.

One of the difficalt problems often encountered by the sheet
metal worker is that of a cylinder joining a cone furnace top at
any angle. The following problem shows the principle to be
applied, no matter what size the farnace top haB, or what size pipe
is used, or at what angle the pipe is placed in plan or elevation, the
principles being applicable under any conditions.

Fig. 110 shows a view of a cyl-
inder intersecting a conical far-
nace top, the top being placed to
one side of the center of the top.
. ■ A B C D represents a portion of
the conical top, intersected by the
cylinder F F G H, the side of the
cylinder H I to intersect at a
given point on the conical top as
at H. This problem presents an
interesting study in projections,
_ intersectionB, and development, to

which close attention ^ould be
given.
In Fig. Ill first draw the center line A X. Then draw the
half elevation A B C D, making A B 1| inches, C D 3J inches
and the vertical height A D 2J inches. Draw the line from B to
C. Directly below C D draw the one-quarter plan using Z as
center, as shown by Z C D' and in line with A B of the elevation
draw the quarter plan of the top as Z B' A'. Let a in the eleva-
tion represent the desired distance that the side of the cylinder is
to meet the cone above the base line as H in Fig. 110. From a,
parallel to D in Fig. Ill, draw a h. Then from a drop a ver-
tical line intersecting the lino Z C in plan at a'. Then usingZ as
center and Z a' as radius, describe the quarter circle a' h'. Z a' b'

SHEET METAL WORE

in piftn represODts the true section on the horizontal plane a i ia
elevation. Now locate the point where the side o£ the cylinder ae
H in Fig. 110 shall meet the arc a' h' in plan, Fig. Ill, ae shown

S^p^

,1.0, Google

102 SHEET METAL WORK

At S". Throngh 3" draw tlie horizontal line iDtersecting the center
liae at K.', the outer arc at W and extend it indefinitely to 3.
From 3 erect the perpendicniar equal to the diameter of the cylin-
der, or 1| inches, hisect it and obtain the center c. Using o as
center with c 7 as radius, describe the profile of the cylinder as
shown, and divide it into eqoal parts from 1 to 8. From these
points draw lines parallel to 3 E', intersecting the outer arc D' C
at N' O' P' E' and the center line Z X at I', G', E', A'. With Z
as center and the various intersections from K' to A' as radii,
describe the arcs K' L', I' J', G' H', E' F', and A' B'. From the
intersection B', F', H', J', L' erect vertical lines into the elevation
intersecting the side of the cone B as shown by similar letters
B F R J L. From these points draw horizontal lines through the
elevation as shown respectively by A B, E F, G H, I J, and K L.
These lines represent a series of horizontal planes, shown in plan
by similar letters. For example, the arc E' F' in plan represents
the trne section on the line E F in elevation, while the arc G' H'
is the true section on the line G H in elevation, etc.

The next step is to construct sections of the cone as it would
appear, if cut by the lines fthown in plan by K' M', I' N', G' 0',E'
F', and A' B'. To obtain the section of the cone in elevation on
the line A' K' in plan, proceed as follows: At right angles to the
line A' E' and from the intersections on the various arcs, draw lines
upward (not shown) intersecting similar planes in elevation cor-
responding to the arcs in plan. A line traced through intersections
thus obtained in elevation as shown from A to E, will be the true
section on the line A' B' in plan. For example, the line £' iS} of
the cylinder intersects the arcs at K' 3" and M' respectively. From
these intersections, erect vertical lines intersecting K L, i a, and X>
in elevation at K, 3', and M respectively. Trace a curve through
these points, then will K 3' M be the section of the cone if cut on
the line^' M' in plan. In similar manned obtain the other sections.
Thus the section line E F, G O, and I N in elevation, represent
respectively the sections if cut on the lines E*^ P', G' O', and I' N'
in plan. Now from the given point 8" in plan erect a line which
mnst meet the intersection of the plane h a and section K M in
elevation at 8'. From 8' at its desired angle, in this case 45°, draw
the line 3' 7. At any point as d at right angles to 3' 7 draw the

SHEET METAL \fOSK lOS

line 1 5 throngh d, making d 6 and d 1 each equal to half the
diameter of the cjlinder shown in plan. With (2 5 as radiua and tt
as center draw the profile of the cylinder in elevation, and divide it
into the same number of parts as ahown in C in plan, being careful
to allow the circle d in elevation to make a quarter turn, bringing
the number 1 to the top as shown.

The next operation is to obtain the mit«r line or line of joint
between the cylinder and cone in elevation. By referring to the
plan it will be seen that the point 7 in the profile c lies in the plane
of the section A' K'. Then a line from the point 7 in the profile
d in elevation, drawn parallel to the lines of the cylinder, must cut
the Bection A R which corresponds to the plane A' E' in plan as
shown by 7' in elevation. The points 6 and 8 in the profile c in
plan, are in the plane at the section E' P', then must the corre-
sponding points 6 and 8 in the profile d in elevation, intersect the
section E P as shown by 6' and 8'. As the points 1 5, 2 4, and 3
in the profile c in plan, are in the planes of the sections G' O', I' W,
and K' M' respectively, the corresponding points 1 5, 2 i, and 8 in
the profile d in elevation must intersect the sections G O, I N, and
K K respectively at points 1' 5', 2' 4', and 3' as shown. Trace a
line through these points, which will show the line of intersection
between the cone and cylinder.

For the pattern for the cylinder, proceed as follows: At right
angles to the line of the cylinder in elevation, draw the line T U
upon which place the stretchout of the profile d as shown by sim-
ilar figures on T U, In this ease the seam of the pipe has been
placed at 1 in d. Should the seam be desired at 3, 5 or 7, lay
off the stretchout on T U starting with any of the given numbers.
At right angles to U T from the small fignres 1 to 1 draw lines
which intersect with lines drawn from similar numbered intersec-
tions in the miter line in elevation at right angles to 1' 1, result-
ing in the intersections 1 to 5° to 1° in the pattern. Trace a line
through points thus obtained, then will U V "W T be the develop-
ment for the cylinder to which laps must be allowed fflir riveting
to the cone aa shown in Fig. 110 and seaming the joint T W in
pattern in Fig. 111.

While the pattern for the cone is obtained the same as in
ordinary flaring ware, the method will be described for obtaining

SHEET METAL WORK

the pattern for thfl opeQing to be cut into the coop. Before this
can be done a plan view of the intersection between the pipe and
cone moat first be obtained ae follows: From the varions in-
tersections 1' to 8' in elevation drop vertical lines intersecting
lines drawn from similar nnmbers in the profile c in plan, thus
obtaining the intersections 1" to 8" through which a line is traced
which is the desired plan view.

For the pattern for
the opening in the
cone, the oatline of
the half elevation and
one -quarter plan with
the various points of
intersections both in
plan and elevation in
Fig. 112 is a repro-
duction of similar
partsin Fig. Ill, and
has been transferred
to avoid aconfnsion of
lines which would
otherwise occnr in ob-
taining the pattern.
Parallel toDOin Fig.
112 from the Tarious
intersections 1' to 8'
draw lines intersect-
ing the side of the
cone B from 1 to 8.
Through the varioas
intersections 1" to 8"
in plan from the apex
Z draw lines intersecting the outer curve from 1" to 8° as shown.
Extend the line C B in elevation until it meets the center line D A
extended at E. Tlien using £ as center, with E C and E B as radii
draw the arcs C F and B It respectively. At any point as 2^ on
the arc C F lay off the stretchout of the various points on D* C in
plan from 3* t * 6" ae shown by similar figures on F as shown

SHEET METAL, WORK 106

from 2^ to 6^. From these points draw radial linee to the apex
E, and intersect them by arcs struck from E as center whose radii
are equal to the various intersections on B C having similar nambers.
Thus arc 4 intersects radial line 4^ at 4^; arcs 3, 5, and 2 intersect
radial lines 3^, 5^, and 2^ at 3^, 5^, and 2^, and so on. Trace a
line through points thns obtained as shown from l' to 8^ which is
the desired shape. If a flange is desired to connect with the cylin-
der, a lap mast be allowed along the inside of the pattern.

COPPERSniTH'S PROBLEMS.

In the five problems which will follow, particular attention if
given to problems arising in the coppersmith's trade. While all
the previous problems given in the course can be used by the ftop-
persmith in the development of the patterns where similar shapes
are desired, the copper worker, as a rule, deals mostly with ham*
mered surfaces, for which flaring patterns are required. The prin-
ciples which will follow, for obtaining the blanks or patterns for
the varioQs pieces to be hammered, are applicable to any size oi
shape of raised work. The copper worker's largest work occurs in
the form of brewing kettles, which are made in various shapes, to
Bait the designs of the different architects who design the work.
Id hammering large brewing kettles of heavy copper plate, the
pieces are developed, hammered, and fitted iu the shop, then set
together in the building, rope and tackle being used to handle the
various sections for hammering, as well as in construction at the
building. While much depends upon the skill the workman has
with the hammer, still more depends upon the technical knowledge
in laying out the patterns.

In all work of this kind the patterns are but approximate, but
no matter what size or shape the work has, the principles contained
in the following problems are applicable to all conditions.

In Fig, 113 is shown a perspective of a sphere which is to be
constructed of horizontal sections as shown in Fig. 114, in whicJi
for practice draW the center line A B, on which, using a as center.
and with radius eqnal to 2^ inches, describe the elevation of the
sphere BODE. Divide the quarter circle D into as many
spaces as the hemi-sphere is to have sections, as shown by C F Q D,
From these points draw horizontal lines through the elevation, as

108 SHEET METAL WORK

shown by C E, F H, and G I, Now through the extreme points
as E H, H I, and I D draw lines interaectiog the center line B A
at J, K, and D respectively. For the pattern for the first section
Z, take D I as radins, and nsing D' in Z' as center, describe the
circle shown. For the pattern for the second section T, use K 1
and K H as ladii, and with K' as center draw the arcs I' V and H^

Fig. 113.

Fig. IH.

H*. From any point aa H' draw a line to the center K'. It now
becomes necessary to draw a section, from which the trne length
of the patterns can be obtained. Therefore with i F as radius,
describe the quarter circle F L, which divide into equal spaces, as
shown by the figures 1 to 5. Let the dividers be equal to one of those
spaces and starting at H' on the ouier arc in Y' step oft four times
the amount contained in the quarter section F L^ as shown from 1

SHEET METAL WOEK lOT

to 5 to 1 to 5 to 1 in Y'. From 1 or H' draw a line to K'. Then
will H' I' I' H' be the pattern for the section Y in elevation.

For the pattern for the third section, use J as center, and with
radii equal to J H and J E draw the arcs H H' and E E'. Now
Bet the dividers eqnal to one of the equal spaces in F L and starting
from H set ojf four times the amount of L F as shown from 1 to 5
to 1 to 5 to 1 on the inner curve H H'. From the apex J through
H' draw a line intersecting the onter curve at E'. E E' H' H
shows the pattern for the center section. It will be noticed in the
pattern X' we space off on the inner curve, while on the pattern
Y' we space off on the outer curve. These two curves must contain
the same amount of material as
they join together when the ball is
raised. To all of the patterns laps
must be allowed for brazing or
soldering. The patterns shown
are in one piece; in practice where
the sphere is large they are made
in a number of sections. Fig. 115.

In Fig. 115 is shown the per-
spective view of a circular tank whose outline is in the form of
an ogee. The portion for which the patterns will be described is
indicated by A A, made in four sections, and riveted as shown
hj ah e d.

Fig. 116 shows how the pattern is developed when the center
of the ogee is flaring fts shown from 3 to 4 in elevation. First
draw the elevation A B C D, making the diameter of A B equal
to 7 inches, the diameter of D 4 inches, and the vertical height
of the ogee 1| inches. Through the center of the elevation draw
the center lineyA, and with any point upon it as i, draw the half
plan through A B and C D in elevation as shown respectively by
E F and H G. Now divide the curved parts of the ogee into
equal spaces as shown from 1 to 3 and 4 to 6. Draw a line through
the flaring portion until it meets the center line^A a.tj. j will,
therefore, be the center with which to strike the pattern. Take
the stretchout of the curve from 3 to 1 and 4 to 6 and place it on
the flaring line from 3 to 1' and 4 to 6' as shown by the figures.
Then will 1' 6' he the stretchout for the ogee. It should bs under.

SHEET JUETAL WORE

6tood that no hammering is done to that part shown from 3 to 4.
The portion shown from S to 1' is stretched to meet the required
profile 8 2 1, while the lower part 4 to 6' is raised to conform with
the lower curve 4 5 6. Therefore, knowing that the points 3 and 4
are fixed points, then from either of these, in this case point ^

Fig. llli.

drop a vertical line intersecting the center line E F in plan at a.
Then with i as center and ia&s radius, describe the quarter circle a e,
and space it into equal parts as shown by a, b, c, d, e, which represent
the measuring line iu plan on the point A in elevation. Using ^'
as center, and J 6', J 4, J 3 and j' 1' as radii, draw the arcs 1"-!'",
3". 3'", 4"-4"' and 6"-6"' as ehown. From 1" draw a radial line to /'
intersecting all the arcs as shown. Now starting at 4" step o£E on

SHEET METAL WOEK

the arc 4"-4"' twice the Btretchout of the quarter circle ae as shown
by similar letters a to e to a' in pattern. From J draw a line
through a' intersecting all of the area as shown. l".l"'-6"'-6"
shows the half pattern for the ogee.

While in the previoas
problem the greater part of
the ogee was flared, occasion
may arise where the ogee is
I composed of two quarter cir-
I cles struck from centers as
1°^ shown in Tig. 117. First
\ draw the center line A B,
] then draw the half diameter
I of the top C C eqaal to 3J
I inches and the half diameter
I £ D 1| inches. Make the
I vertical height of the ogee IJ
I inches, throTigh the center of
I which draw the horizontal line
[ a h. From C and D draw ver-
tical lines intersecting the
horizontal line ah,&ta and h
respectively. Then nsing a
and h as centers with radii
eqnal respectively to a C and
b D draw the quarter circles
shown completing the ogee.
In the quarter plan below
which is struck from the cen-
ter F, G J and H I are sec-
tions respectively on D E and
C C in elevation. The meth .
odaof obtaining the patterns in
this case are slightly different
■ than those employed in the previous problems. The upper curve
shown from to <? will have to he stretched, while the lower curve
shown from c to D will have to he raised. Therefore in the stretch-
out of the pattern of the upper part from 1' to 3 and 8 to 5' the

Fig. H7.

no SHEET METAL WOBK

edges must be stretched so aa to obtain more material to allow the
metal to increase in diameter and conform to the desired shape
shown from 1 to 3 and 3 to 6. In the lo'ver carve the opposite
method must be employed. While in the npper curve the edges
had to he stretohed to increase the diameters, in the lower cnrve
the edges mnst be drawn in by means of raising, to decrease the
diameter, because the diameters to the points 5" and 9' are greater
than to points c and d.

To obtain the pattern for the upper curve C o which must be
stretehed, draw a Una from C to c; bisect it and obtain d, from
which erect the perpendicular d 3 intersecting the curve at 3.
Through 3 draw a line parallel to C c intersecting the center line
A B at m. Now divide the curve e into equal spaces as shown
from 1 to 5 and starting from the point 3 set off on the line just
drawn on either side of 3 the stretehout shown from 3 to 1' and 3
to 5'. 1' B' shows the amount of material required to form the
carve O c. In this case 3 represents the stationary point of the
blank on which the pattern will be measured. Therefore from 3
drop a vertical line intersecting the line F H at XO. Then using
F as center and F 10 as radius, describe the arc 10 16, and divide
it into equal Bpaces aa shown from 10 to 16. Now with radii equal
to m 5',m S and m 1', Fig. 117, and with m in Fig. 118 as cen-
ter, describe the arcs 5 5', 3 3' and 1 1'. Draw the radial line m 1
intersecting the two inner arcs at 3 and 5. As the arc 3 3' repre-
sents the stationary point 3 in elevation in Fig. 117, then set the
dividers equal to the spaces 10 16 in plan and step off similar
spaces in Fig. 118 on the arc 8 8', starting at 3 as shown by simi-
lar numbers 16 to 10. Through 10 draw a line to the apex m,
intersecting the inner curve at 6' and the outer curve at 1'.
1 1' 5' 6 18 the quarter pattern for the upper curve or half of the
ogee, to which lape must be allowed for riveting and brazing.

For the pattern for the lower curve in elevation in Fig. 1X7
draw a line from e to D; bisect it at e and from e erect a perpen-
dicular intersecting the curve at 7. From 7 draw a horizontal line
intersecting the center line at^. Now the rule to be followed in
" raising " is as follows : Divide the distance from e to 7 into as
many parts, aa the half diameter F 7 is equal te inches. In this
case 7^equals 2^ inches; (any fraction up to the -j^ inch is not

Dull,..., .AiOOglC

SHEET METAL WOEK 111

taken into consideratioD, btit over ^ inch one Ib added). Therefore
for 2^ inches nse 2. Then divide the distance from 4 to 7 into
two parts as shown at i and throngh i parallel to c D draw a line
as shown intersecting the center line at X. Mow divide the curve
to D into eqaal spaces as shown by the fignres 5 to 9. Let off
on either side of i the stretchont from 5 to 9 as shown from 5" to

Fig. 118.

9'. From i drop a vertical line intersecting F H. in plan at 23.
Then nsing F as center draw the arc 23 17 as shown, which rep-
resents the measaring line in plan on i in the stretchout.

The stndent may naturally ash, why is i taken as the measuring
line in plan, when it is not a stationary point, for when "raising" i
will be bulged outward with the raising hammer until it meets
the point 7. In bulging the metal outward, the surface at i
stretches as much as the difference between the diameter at t and

112

SHEET METAL WOBK

7. In other words, if the meaaaring point were taken on 7 it
woald be found that after the monld was *' raised " the diameter
would be too great. But by OBing the rale of dividing e 7 into as
many parts as there are inches iny" 7 the diameter will be accurate
while this rule is but approximate. In this case e 7 has only bet-n
divided into two equal parts, leaving but one point in which a line
would be drawn througu parallel to c J>. Let ua suppose that the
semi-diameter t\f is •qnal to eleven inchee. Then the space from
« to 7 would be divided into just so
many parts, and through the firtt part
tjearest the cove ih.e\\Tievou\6. be drawn
parallel to o D and used as we have

/ I I J used i. Now with radii eqoal to n 9',

( y r __j-.. ■"> i, and n 5" and n in Fig. 118 as center,

t-Zr t — ^ describe the arcs 5" 5'" * »' and 9 9'.

From any point as 5" draw a line to n
intersecting all the arcs shown. Now
take the stretchout from 17 to 33 in
plan. Fig. 117, and starting from 17 in
Fig. 118 mark off equivalent distances
on the arc * i' as shown. Draw a line
through 23 to the apex n, intersecting
the inner and outer arcs at 9' and 5'".
Then will 9 5" 5'" 9' be the greater pat-
tern for the lower part of the ogee.

Another case may arise where the
center of the ogee is vertical as shown from e to ti in Fig. 119 in
A B. In this case the same principles are applied as in Fig. 117;
the pattern for c d in Fig. 119 being a straight strip as high as
c d and in length equal to the quarter circumference o' c" in plan
in Fig. 117 which is the section on e in elevation. These rules
are applicable to any form of mould as shown in Fig. 119, by
^ifi ^> andy. The bead i in J would be made in two pieces with
a seam at i as shown by the dotted line, using the same method
as explained in connection with o D in elevation in Fig. 117.

The coppersmith has often occasion to lay out the patterns
for carved elbows. While the sheet metal worker lays them out

Fig. 119.

SHEET METAL WORK

113

in pieces, tlie coppersmith's work mast form a curve aa shown id
Fig. 120 which represents a curved elbow of 45",

In Fig. 121 is shown how an elbow is laid out having 90%
similar principles being required for any degree of elbow. First
draw the side elevatioQ of the elbow aa ubown by A B C D, mak-

Fig. 121. Fig. 120.

iDg the radius E B equal to 4J inches and the diameter B 2
inches. Bisect C B at K. Then with E as center and E K as
radius draw the arc K J representing the seam at the sides. Draw
the front view in its proper position as F G H, through which
draw the center line F I representing the seam at back and front,
thus makiug the elbow in four pieces. Directly below B draw

lU SHEET METAL WOEK

the aectioti of the elbow ae shown hy a b c d struck from M as
center. Through M draw tiie diameters S d and a c. The inner
curve of the elbow ad o in plan will be stretched, while the outer
curve ah c ia plan will be raised. Through il draw the diagonal
3 6 intersecting the circle at 3 and /" respectively. Now draw
a d/ through jr' parallel to a c^ draw a line intersecting the center

Fig. 122.

line A E extended at O. On either side of _/" place the stretchout
" of 6 a and Q d &s shown hy/a' tati/d'. Then with radii equal
to O d' and O a' and with O on the line A B, Fig. 122, as center
describe the arcs d d and a a. Make the length oi d d equal to
the inner curve D C in Fig. 131. From a and d in Fig. 122
draw lines to the apex O extending them to meet the outer curve
at a and a. Then will a d d ahe the half pattern for the inner
portion of the elbow for two sides. The radius for the pattern for
the outer curve is shown in Fig. 131 by N o', N h', placing the

SHEET METAL WORE 116

stretchout of the carve on either aide of the point e. bhc c,in Fig.
122 shows the pattern for the outer cnrve, the length 5 i being
obtained from A B in elevation in Fig. 121.

In work of this kind the patterns are made a little longer, to
allow for trimming after tht elbow is brazed together. Laps mnat
be allowed on all patterns for brazing.

Fig. 123 showB a perspective view of a brewing kettle, made
in horizontal sections and riveted. The same principles which
were employed for obtaining the patterns for a sjjiere in Fig. 114
are applicable to this problem. Thus in Fig. 124, let A B C rep-
resent a full section of a brewing kettle as required according to
architect's design. Through the middle of the section draw the
center line D E. Now divide the
half section B to C into as many parts
as the kettle is to have pieces as
shown by c, d, e,J'. From these
small letters draw horizontal lines
through the section, as shown by

A, d d^, e', and_/y' and in its
proper position below the section,
draw the plan views on each of these

horizontal lines in elevation, excep- pig_ 123.

ting (f (2, aa shown respectively by

1 F G H, e" e'" and/"'/"", all struck from the center a. Now
through the points d draw a line which if extended would meet
the center line. Then this intersection would be the center with
which to draw the arcs c c' and d tZ"; the Saoge c h would be
added to the pattern as shown by h'. The stretchout for this pat-
tern 1' would be obtained from the curved line' F G H I in plan
and stepped off on the outer arc c <f. In similar manner through
d e, ef, andy draw the lines intersecting the center line D E
at K, L, and C. Then using the points as center, describe the
patterns 2', and 3', and the full circle 4'.

The stretchout tor the patterns 2' and 3' is obtained from the
circle e" e'" in plan and placed on the inner curve of the pattern 2',
and on the outer curve of the pattern 3'. If desired the stretchout
could be taken from f"f"' in plan, and placed on the inner curve
of 3' which would make the pattern similar as before.

SHEET METAL WOEK

Id large kettles of this kind, the leogth of the pattern is guided
bj the size of the sheets id stock, and if it was desired that each ring
was to be made in 8 parts then the respective circle in plan from
which the stretchoat is taken wonld be divided into 8 parts, and
one of these parts transferred to the patterns, to which laps must
be allowed for seaming and riveting.

FULL SECrriON f---^

Fig. 124.
PROBLEMS FOR WORKERS IN HEAVY METAL.

While all of the problems given in this course are applicable to
developments in heavy metal as well as in that of lighter gauge, the
following problems relate to those forms made from boiler plate.

When using metal of heavier gauge than number 20, for pipes,
elbows, or any other work, it is necessary to have the exact inside
diameter. It is CQBtomary in all shops working the heavier metal,

SHEET METAL WORK 117

to add a, certain amount to the stretchout to make up for the loss
incurred in bending, in order that the inaide'diameter of the article
(pipe, stack, or boiler Bbell) may be kept to a uniform and desired
size. This amount varies according to different practice of work-
men, some of whom allow 7 times the thickness of the metal used,
while others add but 3 times the thickneaa. Theoretically the
amonnt is 3.1416 times the thickness of the metal.

For example, suppose a boiler shell or stack is to be made 48
inches in diameter out of ^-inch thick metal. If this shell is to
measure 48 inches on the inside, add the thickness of the metal,
which is ^ inch, making 48^ inches. Xultiply this by 3.1416
and the result will be the width of the sheet. If, on the other
hand, the outside diameter is to measure 48 inches, subtract the
thickness of the metal, which would give 47^ inches and multi-
ply that by 3.1416 which would give the proper width of the sheet.
It is well to remember that no matter what the thickness of the
plate may be, if it is not added, the diameter of the finished article
will not be large enough; for where no account is taken of the
thickness of the metal, the diameter will measure from the center
of the thickness of the sheet. "While this rule is theoretically cor-
rect there is always a certain amount of material lost during the
forming operations. It is, therefore, considered the best practice to
use Boven times the thickness of the metal in question. The cir-
cumference for a stack 48 inches in diameter inside using ^ inch
metal would be, on this principle, 3.1416 X 48 + (7 X J) to which
laps would have to be allowed for riveting. Where the stack has
both diameters equal a butt joint is usually employed with a collar
as shown at either a or } in Fig. 125, but where one end of the stack
is to fit into the other, a tapering pattern must be obtained which
will be described as we proceed.

In putting up large boiler stacks it is usual to finish at the
top with a moulded cap, and while the method of obtaining the pat-
terns is similar to parallel line developments, the method of devel-
oping such a pattern will be given showing how the holes are
punched for a butt joint.

In Fig. 126 a view of the moulded cap on a stack is shown.
On a large size stack the cap is often divided into as many as 33
pieces. If the stack is to be made in horizontal sections the rules

118 SHEET METAL WORK

given in the problems on coppersmithing apply. While in obtain-
ing the patterns for a cap in vertical sections, the plan is usually
divided into 16 to 32 sides, according to the size of the stack; we
have shown in Fig. 127 a quarter plan so spaced as to give 8 sides to
the full circle. This has been done to make each step distinct, the
same principles being applied no matter how many sides the plan has.

First draw the center line A B and with any point as C with
radius eqnal to 4j^ inches draw the quadrant D £. Now tangent to
D and E, draw the line D F and E G, and at an angle of 45°, tan-
gent to the curve at Y, draw (i F intersecting the previous lines
drawn at G and F. C D F G E shows the plan view of the extreme
outline of the cap. Directly above the plan draw a half section of
the cap, the curve 5 S being struck from b as center and with a radius
equal to d S or 1^ inches. Then us-
ing the same radius with a as center
describe the quarter circle 6 2. Xake
2 1 equal to § inch, and 8 9 one inch.
From the comers F and G in plan
draw the miter lines F C, C G.
Divide the profile of the cap into
eqnal spaces as shown by the figures
1 to 9, from which drop vertical
lines, intersecting the miter line F C
as shown. On C D extended as C H
place the stretchoat of the profile of
_ ^ the cap as shown by similar numbers.

At right angles to D H draw lines
as shown, and intersect them by lines drawn parallel to D H from
the intersections on C F. Trace aline through points thus obtained
as shown by J I and trace this outline on the apposite side of the

SHEET METAL WORK 119

line D H as shown by J' I'. Then will J I I' J' be the complete
pattern for one side.

When riyeting these pieces together an angle is asnslly placed
on the inside and the miters batt sharp, filing the corners to make
a neat fit. This being the case the holes are panched in the pat-
tern before bending as shown by X X X etc. Assuming that the

Fig. 127.

stack on which the cap is to fit is 48 inches in diameter, obtain
the circnmference as previously explained and divide by 8 (be-
canse the plan is composed of 8 pieces) placing one-half of the dis-
tance on either side of the center line D H in pattern. Assuming
that -jlj of the circumference is equal to 9 e, trace from e the en-
tire miter cut, as partly shown by « * to the line I' I. If the ^
cireomference were equal to 9 (2, the ont would then be traced as
shown in part \>j d h until it met the line I V. This, of course,

UO SHEET METAL WORK

wonld be done on the half pattern 9 J 1 1 before tracing it opposite
the center line D H. Should the plan be divided into 32 parts,
divide the oircamference of the stack by 32 and place ^ of the cir-
cnmference on 9 J in pattern, measuring from the center line D H,
and after obtaining the proper cut, trace opposite the line D H.

In constmcting a stack where each joint tapers and fits inside
of the other, as shown in Fig. 128, a short rnle is employed for
obtaining the taper joints without having recourse to the center.
In the illnstration a h represents the first joint, the second C slip-

^* © #*■

ping over it with a lap eqaal to^, the joint being riveted t<^ther
at e and d. When drawing the first taper joint a b, care must be
taken to have the diameter atyon the outside, equal to the inside
diameter at the bottom at k. This allows the second joint to slip
over a certain distance so that when the boles are punched in the
sheets before rolling, the holes will fit over one another after the
pipe is rolled.

In Fig 139 ah d is 9. taper joint drawn on the line of its
inside diameter, as explained in Fig. 128/*, and e in Fig 129 rep-
resents respectively the half sections on a J and d c. By the short
rule the radial lines of the cone are produced without having

SHEET METAL WORK 121

recoaree to the apex, which, if ohtained in the fnll-eize drawings,
would be BO far away as to render its nse impracticable. A method
Bimilar to the following is used for obtaining the arcs for the pattern
in all cases where the taper is so slight as to render the use of a
common apex impracticable.

Let© bod, Fig. ISO, be a reproduction oia b o din Fig. 129.
On either side of. a d and } e, in Fig. 130, place duplicateB of
ahodna shown by i' o' and a' d'. This can be done most accurately
by nsing the diagonals d b and c a as radii, and with d and a as
centers deecribe the arcs b b' and a a' respectively, and intersect

Fig. 130;

them by arcs struck from a and h as centers, with radii equal
respectively tea i and daasshown. Id precisely the same manner
obtain the intersection o' and d' at the bottom. Now through the
intersections h'aha' and <£ cdc' draw the curve as shown by bend-
ing the straight-edge or any straight strip of wood placed on edge
and brought against the varioue intersections, extending the curves
at the ends and top and bottom indeGnitely. Since the circumfer-
ence of the circle is more than three times the diameter, and as we
only have three times the diameter as shown from c' to ' <2' and
b' to a', then multiply .1416 times the bottom and top diameter d c
and a b respectively, and place one-half of the amount on either side
of the bottom and top curves as shown by e, e', and h, h', Now take
one-half of seven times the thickness of the metal in use and place

122 SHEET METAL WOKE

it on either side on the hottom and top carves as shown "bj/,/" and
i, i', and draw a line from i toy and *' toy. To this lap must be
allowed for riveting. The desired pattern is shown by i ^ f f.

Fig. 131 shows a three-pieced elbow made from heavy metal,
the two end pieces fitting into the center pieces, to which laps are
allowed for riveting. The principIsB which shall be explained to
cut these patterns and malie the necessary allowance for any thick-
ness of metal is applicable to any elbow.

In Fig. 132 draw as previously described the elbow ABC,
below Q H draw the section of the inside diameter as D which is
struck from a, and divide into equal spaces as shown by the figures
1 to 6 on both sides. Throngh these figures draw vertical lines
intersecting the miter line 5 c, and from
these intersections parallel to c t2 draw
lines intersecting the line d e »a shown.
Before obtaining the stretchout for
these elbows, a preliminary drawing
must be constructed, in which an allow-
ance is made for the thickness of the
material that is to be used. This draw-
ing makes practical use of a principle
~ ,„. well known to draughtsmen from its

application to the proportional division
of lines and is clearly shown at (K). In allowing for the thick-
ness of the metal in use, it is evident that we cannot allow it at one
end, but must distribute it uniformly throughout the pattern. In
(R) draw any horizontal line as £ F, upon which place the stretch-
ont of the inside diameter of the pipe D, as shown by similar
figures on E F. From 1° on E F lay off the distance 1° m, equal
to 7 times the thickness of the metal in use as before explained.
Then using E as center and £ m as radius, draw the arc m, 1' inter-
secting the vertical line drawn from 1°, and from the various
intersections from 1 to 1° on E F erect perpendiculars intersecting
the slant line 1 1' at 2' 3' 4', etc., ea shown. The slant line 1 1.
with the various intersections is now the correct stretchout for the
elbow made of such heavy material called for by the specifications.
On O H extended, as B. I, place the stretchout of the slant line
1 1' ai shown from 1 to 1' on H I. At right angles to H I and

SHEET METAL WORK

123

from the varioaa intersections, erect lines, which are intersected
by lines drawn parallel to H I from similar nnmbered intersec-
tions on the miter line i c. Trace the curve L M. L M I HshowB
the pattern for the two end pieces of the elbow.

As the middle section A. in Fig. 131 is to overlap the two end
pieces, it is unneceBsary to allow for any additional thickness on

Fig. 132.

acconnt of this lap when suitable flanging machines are available;
bat since it is desirable, in some instances, to make an allowance
in the pattern for riveting, the method of allowing for this lap
will be explained.

In (R), Fig. 132, lay off on the line E F the distance m n
t>qual to 7 times the thickness of the metal in use, and with radius
LTjnal to E « draw an arc intersecting the line 1° 1' extended at 1".
Draw the slant line from 1" to 1 and extend all the vertical lines
to intersect 1 1" at 2" 3" 4", ete. The slant line 1 1" is the cor-

SHEET METAL WORK

rect stretchoat for the middle section B. At right aDglea Ut d o
draw J K eqn&l to 1 5" 1" in (K), as shown hy Bimilar figures in
J K, through which draw lines at right angles to J K, and inter-
sect them by lines drawn at right angles to <^ <t as shown. Trace
the cnrved lines to produce O F K S, which is the pattern for the
middle section, to which fianges are al-
lowed as shown bj dotted lines.

The perspective of an intersection
between pipes having different diam-
eters in boiler work is shown in Fig.
133. While the method of obtaining
the patterns is similar in principle to
parallel line developments, a slight
change is required in obtaining the
allowance in the stretchoat for the thickness of the metal in use.
Let A B, Fig. 134, represent the part section of a boiler struck
with a radius eqnal to 3|" and let 1 7 7° 1° be the elevation of the
intersecting pipe, whose inside diameter is 4|", as shown by 1 7.

Divide the half section 14 7 into an eqoal number of spaces, as
numbered, from which drop vertical lines intersecting the outside
line of the boiler at 1° to 7° as shown. A true stretchout must now
be obtained in which allowance has been made for the thickness
of the metal in use. Therefore, in Fig. 135, on the horizontal
line A B lay off the stretchout of twice the inside section of

SHEET METAL WOBK 125

the pipe in Fig. 134, sb shown hj Bimilar figares on A B in Fig.
136, adding 1^ a, equal to 7 times the thickness of the metal in
nse. For example, stipposing ^-inch steel was ased; the distance
1^ a would then be equal to 7 X J, or 1 J inches. Now draw the arc
a 1', using 1 as center, which is intersected bj the rertical line drawn
from 1^. From 1' draw a line to 1, and from the various points
on A B erect perpendiculars intersecting 1 1' at 2' 3' 4', etc. 1 1'
shows the true stretchout to be he laid oS on the line 1 7 extended
in Fig. 134 aB 1 1', and from the various intersectionB on 1 1' drop
vertical lines and intersect them by lines drawn parallel toll' from
similar intersections on the curve 1° 7° as shown. Trace a curved
line as shown from to D. 1 C D 1' shows the pattern for the
vertical pipe to which a flange must be allowed for riveting as
shown by the dotted line.

It is now necesBary to obtain the pattern for the shape to be
cut out of the boiler sheet, to admit the mitering of the vertical
pipe. lu some shops the pattern is not developed, only the vertical
pipe is flanged, as shown in Fig^ 138, then set in itB proper posi.
tion on the boiler and line marked along the inside diameter of the
pipe, the pipe is then removed and the opening cut into the boiler
with a chisel. We give, however, the geometrical rule for obtain-
ing the pattern, and either method can be used.

As A B in Fig. 134 represents the ontside diameter of the
boiler, to which 7 times the thickness of the metal used must be
added to the circumference in laying out the sheet, and as the ver-
tical pipe intersects one-quarter of the section as shown "by ah c,
take the stretehont from 1° to 7° and place it from 1° to 7° on
F G in (E), to which add 7° e, eqnal to J of 7 times the thick.
nesB of the plate used. Draw the arc e 7", using 1° as center,
intersecting it by the vertical line drawn from 7°. Erect the usual
vertical lines and draw 7" 1°, which is the desired stretehont. Kow
place this stretchout on the line A B in Fig. 136, erecting vertical
lines as shown. Measuring in each and every instance from the
line 1 7 in Fig. 134, take the various distances to points 2, 3, 4, 5,
and 6 and place them in Fig. 136 on lines having similar numbers,
measuring in each instance from A B on either side, thus obtain-
ing the points 2, 3, 4, 5, ind 6. Tracd the curve 1" 4 7" 4, which
is the desired shape.

SHEET METAL WORK

Fig. 137 shows a perspective of a gasset sheet A on a loco-
motive, the method of obtaining this pattern in heavy metal is
shown in Fig. 138. First draw the end view ABC, the semi-
circle 4 14 being strack from a as center with a radius equal to 2

Fig. 135.

ioches. Make the distance 4 to C and 4 to B both 8| inches and
draw C B. Draw the center line A F, on which line measure np
2^ inches and obtain f>, which use as center with radius equal to a
4, draw the section of the boiler D E F G. In its proper position
draw Oie side view HIJKLMN. HILMNH shows the
side view of the gusset sheet shown in end view by G A E D G.
Divide the semicircle 4 1 4 in end view into equal spaces as
shown, from which draw horizontal lines intersecting H N in side

Fig. 136. Fig. 137.

view from 1' to 4'. From these intersections parallel to H I,
draw lines indefinitely intersecting 1 L from 1" to 4". At right
angles to N L produced draw the line at c d, on which a true
section must he obtained at right angles to the line of the gusset
sheet. Measuring from the line A D in end view, take the vari.
ous distances to points 2, 3, and 4 and place them on correspond-
ing lines measuring from the line od on either side, thus obtaining

SHEET METAL WORK 127

the intersections 1° to 4", a line traced through these points will
be the true section. In (Y) on any line as O P lay ofE the stretch-
out of the true soetion 8S shown from 4°, 1°, 4°. As the gusset
sheet only covera a portion equal to a half circle, add the distance -
4° e equal to ^ of 7 times the thickness of the metal in use and

nsiug 4° at tlie left, as center with 4° e as radius, describe the arc
e 4^, iotersecting it at 4^ by the vortical line drawn from 4°. From
O P erect vertical lines intersecting the line drawn from 4^ to 4°
at 3^, 2^, 1^, etc. 4° 4^^ is the true stretchoutj and shonld be
placed on the line K S drawn at right angles to H I. Through
the numbers on H S and at right angles draw the lines shown
and intersect them bylines drawn from similarly numbered inter-
sections on 11 N and I L at right angles to H L Throuj^h points

128 SHE£T METAL WOBE

dins obtained trace a carved line 4^, 4^, and 4^, 4^. It now be-
comes necessary to add the triangular piece shown by L M N in
Bid© view, to the pattern which can be done as follows : Using L M
in side view as radius and 4^ at either end of the pattern as oen-
•tera, describe the arcs m and n; intersect them by arcs strack from
4^ and 4^ as centers, and If N in side view as radins. Then draw
lines from 4^ to m to 4^ in the pattern on either side. The fall pat-
tern shape for the goeset sheet will then be shown by m. 4^ 4^ m
4^ 4^, to which laps most be allowed for riveting.

Fig. 139 shows a conical piece connecting two boilers with
the flare of A saoh that the radial lines can be nsed in developing
the pattern. In all each eases this method shoold be used in pref-
erence to that given in connection with Fig. ISO. Thus in Fig.
139 the centers of the two boilers are on one line as shown by a 5.
While the pattern is developed the same as in flaring work, the
method of allowing for the metal nsed is shown in Fig. 140.

A B D is the elevation
of the conical piece, the half
inside section being shown
by 1 4 7 which is divided
into eqaal spaces. 1 7 1 in '
Mg. 139. (E) is the foil stretchout of

the inside section A 4 D in
deration, and 1 « is equal to 7 times the thickness of the metal
used. The line 1 1' is then obtained in the usual manner as are
the various intersections 2' 3' 4', etc. Now extend the lines A B
and D in elevation until they meet the center line a b &t a.
Then using a o and a d draw the arcs 1' 7' and 1" 7". From 1'
draw a radial line to a, intersecting the inner arc at 1". Now set
the dividers eqnal to the spaces on 1 1' in (E) and starting from 1'
in the pattern step ofi 6 spaces and draw a line from 7' to a inter-
secting the inner arc at 7". 1' 7' 1" 7" shows the half pattern to
which flanges must be allowed for riveting.

Fig. 141 shows a view of a scroll sign, generally made of '
heavy steel, heavy copper, or heavy brass. So far as the sign is
concerned it is simply a matter of designing, but what shall be
given attention here is the manner of obtaining the pattern and
elevation of the scroll. As these scrolls are usually rolled tip in

■• L:,J.., ...LlOOQiC

SHEET METAL WORK

form of a spiral, the method of drawiog the spiral will first
be shown.

Ketablieh a center point as a' in Fig. 142, and with the desired
radius describe the circle shown, which divide into a polygon of

Pig. 140.

any number of sides, in this case being 6 sides or a hexagon.
The more sides the polygon has, the nearer to a true spiral will
the figure be. Therefore number the corners of the hexagon 1 to

Fig. 141.
5 and draw out each side indefinitely as 1 a, 2 ^, 3 c, 4 (2, 5 e, and
6^. Kow using 3 as center and 2 1 a's radins, describe the arc
1 A; then neiog 8 as center and 3 A as radius, describe the arc

180 SHEET METAL WORK

A B, and proceed id similar raanoer ueiDg as radii 4 B, 5 C, 6 D,
and 1 £, nntil the part of the spiral ahown has been drawn. Then
using the same centers as before continue until the desired spiral is
obtainedithefoUowingcurves running parallel to those first drawn.
The size of the polygon a', determines the size of the spiral.

In Fig. 143 let A B C D represent the elevation of one comer
of the flag sign shown in Fig. 141. In its proper position in Fig.
143 draw a section of the scroll through its center line in elevation
as shown by a 17 to 1, which divide into equal spaces as shown
from 1 to 17. Supposing the scroll is to be made of ^ inch thick

Fig. Ii2.

metal, and as the spiral makes two revolutions then iiiultiplj |
by 14, which would equal 1| inches. Then on E F in Fig 144
place the stretchout of the spiral in Fig. 143, as shown by similar
numbers, to which add 17 E equal to 14 times the thickuesa of
metal in use, and draw the arc E 17' in the usual manner and
. obtain the true stretchout with the various intersections as shown.
Through the elevation of the corner scroll in Fig. 143 draw the
center line E F, upon which place the stretchout of 17' E, Fig,
144, aa shown by similar numbers on EF in Fig. 143. At right
angles to EF, through I'and 17', draw 17° 17° equal to A B and 1' 1"
equal to the desired width of the scroll at that point. Then at
pleasure draw the enrva 1" 17° on either side, using the straight-

SHEET METAL WORK

izecy Google

182 SHEET METAL WORE

edge and bending it aa required. Tlien will 1° 1° 17° 17° be tbe
pattern for tbe scroll using beavj metal.

If it is desired to know how this scroll will look when rolled
up, then at right angles to E F and through the intersections 1' to
17' draw lines intersecting the carves of the pattern 1°-17° on
both sides. From these intersections, shown on one side only,
drop lines intersecting similar nnmbered lines, drawn from the
intereectione in the profile of the scroll in section parallel to A B.
To avoid a coofasion of lines the points 1^, 8^, 5^, 7^, 10^, 12^,
and 17^ have only been intersected. A line traced throngh points
thus obtained as shown from 1^ to 17^ in elevation gives the pro-
jections at the ends of the scroll when rolled np.

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SKYUGHT WORK*

Tlie upper fllUBtration ebows the layout of & flat pitched sksrlight whose
curbmeaaurese'— 0*X7'— ff", the run ot the rafter or length of the glass being
6' O* on a horizontal line. Five bais are required, maVing the glass 16 Incbee
wide A working section through AB and CD b shown below.

It wHI be noticed In the section through AB that the flashing is looked to
the rooflng and flanged around the inside of the angle iron oonstmction; over
this the curb of the skylight rests, bolted through the angle iron as shown, the
bcdt being capped and soldered to avoid leakage.

Tbe same construction is used in the section through CD, with the excep-
tion, that when the flashing cannot be made In one piece, a cross lock Is placed
In the manner indicated, over the fireproof blocks.

* The lUoBtntlon reterred to will be found aa the bftck of tbli page.

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COnSTQUCTICM DRAWITiG SHOWIMG LAYOUT

OF FLAT 3KYLJGHT AMD METHOD OF

FASTEniMG FLAaniMG OK ArtGLE

men con3TRucTiori.

Ci^b me«-aut^e. 6-crx 7-(
Five bo.Y'-s spe>^ce-<3- 1-3"

si^fe

lube.

-"Fife 1
blocl

.Roofirjs,

Boof ^^"«'-

upper end ot curb

Section

Ihroui

jh lov/er-

and of

A,-B

,--

FOR EXPLANATION OF THIS PROBLEM SEE BACK OF PAOB

SHEET METAL WORK

PART UI

SKYLIGHT WORK

Where formerly skylights were constructed from wrou^t iron
or wood, to-day in all the large cities they axe being made of galvanized
sheet iron and copper. Sheet metal skylights, having by their peculiar
tonstrucdon lightness and strength, are superior to iron and wooden
lights; superior to iron lights, inasmuch as there is hardly any expan-
»on or contraction of the metal to cause leaks or breakage of glass; and
superior to wooden lights, because they are fire, water and condensa-
tion' proof, and being less clumsy, admit more light.

The small body of metal used in the construction of the bar and
curb and the provisions which can be made to carry off the inside con-
densation, make sheet metal sl^lights superior to all others constructed
from different material.

CONSTRUCTION

The construction of a sheet metal skylight is a very simple matter,
if the patterns for the various
intersections are properly devel-
oped. For example, the bar
shown in Tig. 145 conasts of a
piece of sheet metal having the
required stretchout and length,
and bent by special machinery,
or on tiie r^ular cornice brake,
into the shape shown, which rep-
resents strength and nudity with
the least amount of wdght. A A
represent the condensation gut-
ias to rec^ve the condensation
horn the inade when the warm air strikes against the cold surface of
J, while B B show the rabbets or glass-rest for the glass.
In Rg. 146* C C is a re-enforcing srtrip, which is used to hold tiw

SHEET METAL WORK

two walb O O together and impart to it great rigidity. Ylh&i s^light

bai9 are required to bridge long spans, an intonal core is made of

^eet metal and placed as shown at A in Fig. 147, v^ch adds to its

wdght-sustaining power. In this figure B B shows the glass laid on
a bed of put^ with the metal cap
C C C, resting snugly agiunst the
glass, fastened in position by the
rivet or bolt D D. Where a very
large span is to be bridged a bar
similar to that shown in Fig. 148 is
used. A heavy core plate A made
of i^ch diick metal is used, riveted
OT bolted to the bar at B and B. In
construction, all the various bars
tarminate at the curb shown at A B
C in Fig. 149, which is fastened to
P^- 1*7- the wooden frame D E.

The condensation gutters C C in the bar 6, carry the water into

the internal gutter in the curb at a, thence to the outside through holes

fffovided for this purpose at F F. In Rg. 150 is shown a sectional

view of tbe construction of a double-pitched

skylight A shows the ridge bar with a core in

the center and cap attached over the glass. B

shows the cross bar or dip whJdi is used in

large skylights where it is impossible to get the

glass in one length, and where the glass must '

be protected and leakage prevented by means

of the cross bar, the gutter of which conducts

the waier into the gutter of the maiu' bar,

thence outside the curb as before expluned.

C is the frame generally made of wood or angle

iron and covered by the metal roofer with flash-
ing as shown at F. D shows the sl^light bar

with core showing the glass and cap in position. E is the metal curb

against whidi the bars terminate, the condensation being let out

through the holes shown.

In constructing pitched skytights having double pitch, or being

hipped, the pitch is usually one-third. In other words it is one-third

SHEET METAL WORK

of the span. If a skj^light were 12 feet wide and one-third pitch were
required, the rise in the center would be one-third of 12, or 4 feet.
When a flat sigrlight is made the
pitch b usually built in the wood
or iron frame and a Bat skylight
laid over it. The glass used in
the construction of metallic ' sky-
lights is usually J-inch rou^ or
ribbed glass; but in some cases
heavier glass is used.

If for any rehson it is deshed
to know the weight of the various
thickness of glass, the following
table will prove valuable.
Welgbt bf Rougb aiass Per
Square Foot.
Tliickness in inches.

i- A- i- }■ J- i- i. 1-

Weight in pounds.

2. 2}. 3J. 5. 7. 8}. 10. 12J.

,1.0, Google

ise

SHEET -METAL WORK

SHOP TOOLS

In tlie smaller sliops the bars are cut with the hand shears and
formed up on the ordinary cornice brake. In the larger shops, the
at'ips required for the bars or curbs are cut on the large squaring
shears, and the ihiters on the ends of these strips are cut on what is
known as a miter cutter. This machine consists of »ght foot presses
on a single table, eatii press having a diff ^ent set of dies for the purpose
of cutting the various miters on the various bars. The bars are then
fenced on what is known as a Drop Press in which the bar can be
formed in two operations to the length of 10 feet.

METHOD EMPLOYED IN OBTAINING THE PATTERNS
The method to be employed in developing the patterns for the
various skylights is by parallel lines. If, however, a dome, conserva-
tory or circular skylight is required, the blanks for the various curbs,
bars, and ventilators are laid out by the rule given in the dis-
cussion of circular mouldings beginning on page 249.

VARIOUS SHAPES OF BARS

In addition to the shapes of bars shown in Figs, 145 to 14S in-
clusive, there is shown in Fig. 151 a pWn bar without any condensation
gutters, the joint being at A. B B represents the glass resting on the
rabbets of the bar, while C shows another form of cap which covers

Fig. 151. Fig. 152. Fig. 153.

the joint between the bar and glass. Kg. 152 gives another form of
bar in which the condensation gutters and bar are formed from one
piece of metal with a locked hidden seam at A. Pig. 153 shows a bar
on which no putty is required when glazing. It will be noticed that
it is bent from one piece of metal with the seam at A, the glass B B
resting on the combination rabbets and gutters C C. D is the cap
which is fastened by means of the cleat E. These cleats are cut about
J-inch wide from soft 14-oz. copper, and riveted to the top of the bar

SHEET METAL WORK

at F; tiien a slot b cut into the cap D as shown from a to & in Fig. 154;
then the cap is pressed firmly onto the gla^ and the cleat E turned
down which holds the cap in position.

When a skylight is constructed in which rtusing sashes are r^
quired, as shown in Fig. 155, half bars are required at the sides A and
B, while the bars on each side of the sash to be
raised are so constructed that a water-tight joint
is obttuned when closed. This is shown in Fig.
156, which is an enlarged section through A B in
.Pig. 155. Thus in Fig. 156, A A represents the
two half bars with condensation guttra-s as shown,
the locked seam taking place at B B. C C repre-
sent the two half bars for the raising sash with the caps D D attach-
ed to same, as shown, so that when the sash C C is closed, the caps

Fig. 154.

Fig. 155.
D D cover the ]omt between the glass E E and the stationary half
bars. F F are the half caps soldered at a a to the bars C C which
protect the joints between the glass H H and the bars C C.

VARIOUS SHAPES OF CURBS
In Figs. 157, 158 and 159
are shown a few shapes of curbs
which are used in connection
with flat s^Ii^ts. A in Fig.
157 shows the curb for the three
sides of a flat skylight, formed in
one piece with a joint at B, while
C shows the cap, fastened as previously described. "A" shows the
height at the lower end of the curb, wh'ch is made as hi^ as the
e'lass is thick and allows the water to <-iin oto'. In Fie. 158, A is

138 SHEET METAL WORK

another form of sl^light formed in one piece and riveted at B;
a shows the hei^t at the lower end. In the previous figures the frame
on which the metal curb rests is of wood, white in Fig. 159 the frame is

Fig. 157.

Fig. 158.

of angle iron shown at A. In this case the curb is slightly changed
as shown at B ; bent in one piece, and riveted at C In Figs. 160, 161,
and 162 are ishown vimous shapes of curbs for pitdied skylights in
addition to tliat shown in Kg, 149. A in Fig. 160 shows a curb formed
in one piece from a to 6 with a ojudensation hole or tube shown at B.

Kg. 160. Kg. 161. Fig. 162.

In Fig. 161 is shown a slightly modified shape A, with an offset to
rest on the curb at B. When a skylight is to be placed over an opaiing
viboae walls are Inick, a gutter is usually placed around the wall, as

SHEET METAL WORK

139

shown in Fig. 162, in which A represents a section of the wall on which
a gutter, B, is hung, formed from one piece of metal, as shown from a
to 6 to c. On top of this flie metal curb C b soldered, whidi is also
formed from one piece with a lock seam at i. To stiffen this curb a
wooden core U slipped inside as shown at D. Ftom the inade con-
densation gutter / a 14-oz. copper tube runs through the ciurb, shown
at d. The condensation from (he gutter e in the bar, drips into the
gutter /, out of the tube d, into the main gutter B, from which it is con-
v^ed to the outside by a leader.

In Fig. 163 is shown an enlarged section of a rtdsing sash, tak^
through C D in Fig. 155. A in Fig. 163 shows the ridge bar, B the
lowCT curb and C D the side sections of the bars explained in connec-
tion with Fig. 156. E F in
Fig. 163 shows the upper
frame of the r^ang sa^, fit-
ting onto the half ridge bar
A. On each rtusing sash, at
the upper end two hinges H
are riveted at E and I, whidi
aUow the sash to ruse or close
by means of a cord, rod, or
gearings. J K shows the
lower frame of the sash fitting
over tile curb B. Holes are
punched at a to allow the
condensation to escape into b,
thence to the outside through
C. Over the hinge H a hood

leakage. Fig. 164 shows a section tiirough A B in Fig. 167 and rep-
resents a hipped s^Iight having one-third pitch. By a sl^light of
one-third pitch is meant a sl^Iight whose altitude or hei^t A B, is equal
to. one-third of the span C D. If the skylight was to have a pitch of
one-fourth or one-fifth, ihea the altitude A B would equal one-fourth
or one-fiftii respectively of the span C D.

The illustration shows the construction of a hipped skylight with
ridge ventilator which will be briefly described. C D is the curb; E E
the inside vrntHfitoj; F F the outside ventilatw finrming a ctq> over the

Fig. 163.
I placed whidi prevents

140

SHEET METAL WORK

glass at a. G shows the hood held in position by two cross braces H.
J represents a section of the common bar on the rabbets of which the
glass K K rests. L shows the condensation gutters on the bar J,

Fig. 164.

which are notched out &s shown at M, thus allowing the drip to enter
the gutter N and discharge through the tube P. The foul air escapes
under the hood G as shown by the arrow.

izecy Google

SHEET METAL WORK 141

VARIOUS STYLES OF SKVLIOHTS

In Fig. 165 is shown what is known as a single-pitch light, and is
placed on a curb made by the carpenter which has the desired pitch.

Pig. 166.
These skylights are chiefly used on steep roofs as shown in the illus-
tration, and made to set on a wooden curbs pitching the same as the

Fig. 167.
roof, the curb first being flashed. Ventilation is obtiuned by raising
one or more lights by means of gearings, as shown in Fig. 155.

itizecy Google

142 SHEET METAL WORK

fig. 166 shows a double-pitch sl^Ught. Ventitatioti is obtained
by pladng louvres at each end as shown at A. Fig. 167 shows a
skyli^t with a ridge ventilator. He corner bar C is called the hip
bar; the small bar D, mitering against the com^ bar, is called the jack
bar, while E b called the common hax. fig. 16S illustrates a hip mon-
itor skylight with glazed opening sashes for ventilation. These sashes
can be opened or closed separately, by means of gearings similar to
those shown in Fig. 177 In Fig. 169 is shown the method of rdsing

Fig. 169.
sashes in conservatories, greenhouses, etc., the same apparatus being
applicable to both metal and wooden sashes. Tig. 170 shows a view
of a photographer's skylight; if de^ed, the vertical sashes can be made
to open.

In fig. 171 is shown a flat extenaon skylight at the rear of a store
or building. The upper side and ends are flashed into the brick work
and made water-tight with wateq>roof cement, while the lower side
rests on the rear wall to whidi it is fs9t$ned. In 90010 ^a^ ^9 r^H'

SHEET METAL WORK 143

gutter is of caat iron, put up by the iron worker, but it is usually made
of No. 22 galvanized iron, or 20-oz. cold-rolled copper. To recave
the bottom of the gutter and skylight, the wall should be covered by a
wooden plate A, Fig. 172, about two inches thick, and another plank
set edgeways flush with the inside of the wall, as shown at 6. The
two planks are not required when a cast iron gutter is used.

Vig. 173 shows a hipped skyli^t without a ridge ventilator, set
on a metal curb in which louvres have been placed. These louvres
may be made stationary or movable. When made movable, they are

Fig. 170.
constructed as shown in Fig. 174, in which A shows a perspectiTe view,
B shows thran closed, and C open. They are operated by the quad-
rants attached to the upright bars a and b, which in turn are pulled up
and down by cords or chains worked from below. When a skylight
has a very long span, as in Fig. 175, it is constructed as shown in Fig.
176, in which A represents a T-beam which can be trussed if necessary.
This construction allows the water to escape from the bottom of the
upper Ught to the outside of the top of the lower skylight, the curb C
of the upper light fitting over the curb B of the lower light ,

144 SHEET METAL WORK

Id "Fig. 177 is shown the method of applying the gearings- A
shows the side view of the metal or wooden sash partly opened, B the

Fig. 171.

end of the mun shaft, and C the binder that fastens the main shaft !o
the upright or rafter. D shows the quadrant wheel attached to main
shaft and E is the worm wheel, geared to the quadrant D, commun-
icating motion to the whole shaft
F is a hinged arm fastened to the
main shaft B and hinged to the
sash. By turning the hand-wheel
the sash can be opened at any
angle.

DEVELOPMENT OF PATTERNS
FOR A HIPPED SKYLIQHT
The following illustrations
and text will explain the princi-
ples involved in developing the
pattera* for the ventilator, curb,
hip bar, commoD bar, jack bar,
and CToss bar oi clip, in a
hipped skylight, lliese prind-
plea are also applicable to any other form of li^t, whether flat,
double-pitdi, sinele-oitch, ete.

SHEET METAL WORK 145

In Fig. I7S is shown a half secUon, a quarter plan, and a
diagonal elevation of a hip bar, including the patterns for the curb,
hip, jack, and common bars. TTie method of making these drawings
will be explained in detail, so that the student who pays close atteutioa

Fig US
will have no difficulty in laying out any patterns no matter what the
pitch of the slqrlight may be, or what angle ita plan may have.

Krst draw any center line as A B, at right angles to which lay oil
C 4', equal to 12 inches. Assuming that the light is to have one-third

Fig. 174.
pitch, then make the dbtance C D equal to 8 inches which is one-third
of 24 inches, and draw die slant line D 4.' At right angles to D 4' place
a section of the common bar as shown by E, through which draw lines
parallel to D 4', intersecting the curb showii from a to / at the bottom
and the inside section of the ventilator from F to G at the top. At

,AiOOglc

146 SHEET METAL WORK

pleasure draw the sectiod of the outade v^it shown from % to I and the
hood shown from miop. X represents the section of the brace resting
<m t ; to uj^old the hood resting on it in the comer o. 'Die condensa-

Iflg. 176.
tion gutters of the common b^ E are cut out at the bottom at 5' 6'
l^ch allows the drip to go Into the gutter d e f ot the curb and pass
out of the opening indicated by the arrow. Number the comers of
each half of the common bar section E as shown, from 1 to 6 on eadi
side, through whicli draw lines
parallel to D 4' until they inter-
sect the curb at the bottom as
shown by sdmilar numbers 1' to
6', and the in£dde ventilator at the
top by similar figures 1"* to 6*.
This completes the one half-sec-
tion of the slgrlight. From tiiis
section &e pattern for the oom-
B mon bar can be obtained without

^■"^- the plan, as follows:

At right angles to D 4' draw the line I J upon whidb place the
stretdiout of the section E as shown by similar figures on IJ. Ilirough
these small figures, and at right angles to IJ, draw lines, and intersect
them by lines drawn at right angles to D 4' from amilarly numbered
intersections 1' to 6' on tlie curb and 1' to 6" on the inside ventilator.
Trace a line throu^ points thus obtained; then A' B' C* D' will be the

SHEET METAL WORK 147

pattern for the common bar in a hipped skylight. TTie some method
would be employed if a pattern were developed tor a flat or a double-
pitch light. From this smue half section the pattern for the curb is
developed by taking the stretchout of the various corners in the curb,
aby i' cde and /, and pladng them on the center line A B as shown
by similar letters and figures. Through these divisions and at right
angles to A B draw lines which intersect with lines drawn at right
angles to C 4' from similar points in the curb section a f. Trace a line
through points thus obtained ; then E* P / a will be the half patton for
the curb shown in the half section. V represents the condensation hole
to be punched into the pattern between each light of glass in the sky-
light. As the p<^on c d turns up on c 4', use r as a center, and with

Hg.l77.
the radius r a strike the semicircle shown. Above this semicircle
punch the hole V.

Before the patterns can be obtained for the hip and jack bars, a
quarter plan view must be constructed which will give the points of
intersections between the hip bar and curb, between the hip bar and
vent, or ridge bar, and between the hip and jack bar. 'Hierefore, from
any point on the center line A B as K, draw K L at right angles to A B.
As the skylight forms a right angle in plan, draw &om K, at an angle
of 45°, the hip or diagonal line K 1°. Take a tracing of the common
bar section E with the various figures on same, and place it on the hip
line K 1° In plan so that the points 1 4 come direcUy on the hip as
shown by E*. llirou^ the various figures draw lines parallel to E 1°

,1.0 D,Google

SHEET METAL WOEK 149

on&Jialf of which are intersected by mlical lines drawn parallel to A
B from similar points of intersection 1' to 6' on the curb, tmd 1" to 6*
on the ventilator in the half section, as shown respectively in plan by
inta'sections 1° to 6" and 1' to C Below the hip line K 1° trace tlie
opposite intersection as shown. It should be understood that the
section E' in plan does not indicate the true profile of the hip bar
(whichmust be obtained later),but is only placed there to give the hori-
zontal distances in plan. In laying out the work in practice to full size,
the upper half intersection of tiie hip bar in plan is all that is required.
It will be noticed that the points of intersections in plan and one half
section have similar numbers, and if the student will carefully follow
each point the method of these projections will become apparent

Having obtained the true points of intersections in plan the next
step is to obtain a diagonal elevation of the hip bar, from wbidt a true
section of the hip bar and pattern are obtained. To do this draw any
line as R M parallel to K 1°. Tbis base line R M has the same eleva-
tion as the base line C 4' has in the half section. From the various
points V to 6° and 1' to 6" in plan, wect lines at right angles to K 1"
crossing the line R M indefinitely. Now measuring in each and every
instance from the line C 4' in the half section take the various distances
to points D 1" 2" 3' 4" 5* and 6" at the top, and to points 1' 2' 3' 4' 5'
and 6' at the bottom, and place them in the diagonal elsvation meas-
uring in ea^ and every instance from the line R M on the «mllarly
numbered lines drawn from the plan, thus locatiiig respectivdy die
points N 1' 2* 3* 4' 6' and 6' at the top, and 1' 2' 3' 4' 5' and 6' at
the bottom. Through the points thus obtained draw the miter lines
1* to 6* and l' to 6* and connect the various points by lines as shown,
which completes the diagonal elevation of the hip bar intersecting the
curb and vent, or ridge. To obtain the true section of the hip bar,
take a tracing of the common bar E or E* and place it in the position
shown by E', b«ng careful to place the points I 4 at right angles to
1' 1' as shown. From the various points in the section E* at right
uigles to 1' V draw lines intasecting similarly numbered lines in the
diagonal elevation as shown from I to 6 on either ^e. Connect these
points as shown; then £' will be the true profile of the hip bar. Note
ihe difference in the two profiles; the normal E* and the modified E*.

Having obtEuned the true profile E* the pattern for the hip bar is
obtained by drawing the stretchout line O P at right angles 1' 1'.

150 SHEET METAL WORK

Pake the siretchout of the profile E* and place it on O P as shown by
smilar figures. Through these small figures and at right angles to
O P draw lines which intersect by lines drawn at rigjit angles to 1' 1'
from ^milarly numba^d points at top and bottom, thus obtaining the
points of intersections shown. A line traced through the points thus
obtained, as shown by IP J* K* L' will be the pattern tor the hip bar.

For the pattern for the jack bar, take a tracing of the section of the
common bar E and place it in the position in plan as shown by E*
bong careful to have the points 1 and 4 at right angles to the line 1' 1°.
It is immaterial how far the section E' is placed from the comer 2° as
the intersection with the hip bar remains the same no matter how far
the section is placed one way or the other. Throu^ the various
corners in the section E* draw lines at right angles to the line 1° 1^ inter-
secting one half of the hip bar on similarly numbered lines as ^own by
the intersections !•- 2'- S"- 4"' 5^ 6^ and !■■ 2^ 3* 4'' 5* and &; also inter-
secting the curb in plan at points I'' to 6^. The intersection betwe^i
the jad£ bar and curb in plan is not necessary in the development of
the pattern as the lower cut in the pattern for the common bar is the
same as the lower cut in the pattern for the jack bar. However, the
intersection is shown in plan to make a complete drawing. At ri^t
angles to the line of the jack bar in plan, and from the various inter-
sectbns with the hip bar, erect lines intersecting similarly numbered
lines in the section as shown. Ilius from the various intersec-
tions shown from 1^ to 6^ in plan, erect vertical lines intersect-
ing the bar in the half section at points shown from 1^ to 6^. In
similar manner from the various points of intersections 3', S', and &
in plan, erect lines intersecting the bar in the half section at points
shown by S' 5' 6*. Connect these points in the half section, as shown,
which represents the line of joint in the section between the hip and jack
bars.

For the pattern for the upper cut of the jack bar, the same stretch-
out can be used as that used for the common bar. Therefore, at right
angles to D 4' and from the various intersections l"" 2^ S"" i"* 5^ and 6^
draw lines intersecting similar numbered lines in the pattern for the
common bar as shown by similar figures. In similar manner from the
various intersections 3^ 5' and 6' in the one half section, draw lines at
rij^t angles to D 4' intersecting similarly numbered lines in the pattan
as shown hy3' 5' and 6*. Trace lines from point to point, then the

SHEET METAL WORK 151

cut shown from N* to P will represent the miter for that part shown in
plan from 2^ to 6^, and the cut shown from P to C in the pattern will
represent the cut for that part ^own in plan from 2'- to &*. The
lower cut of the jack bar remains the same as that shown in the pattern.
The half pattern for the end of the hood is shown in ¥\g. 179, and
u obtfuned as follows: Draw any vertical line as A B, upon which
place the stretchout of the section of the hood mno piu Fig. 178, as
shown by similar letters m » o p on A B in Fig. 179. At right angles
to A B and through the anall letters draw lines, making them equal in
leDgtb, (measuring from the line A B) to points having similar letters
in Fig. 178, also measuring from the center line A B. Connect points
shown in Fig. 179, which is the half pattern for the end of the hood.
For the half pattern for the end of the outside ventil&tor, take the

HALPRWTERN

FOR er^o OF

0UT3JDE VEMT

Fig. 179.

Fig. 180.

■^ HAURorrWJN
TOR EMD OP
INSIDE VENT

Fig. 181.

stretchout of ft i ; & I in Fig. 17S and place it on the vertical hne A B in
¥ig. 180 as shown by dmilar letters, through which draw horizontal
lines making them in length, measuring from A B, equal to «milar
letters in ilg. 178, also measuiing from the center line A B. Connect
the points as shown in Fig. 180 which is the desired half pattern. In
Fig. 181 is shown the half pattern for the end of the in^de ventilator,
the stretdiout of which isobtained from F 1* 2* 3" 4' H G in Kg. 178,
the pattern bdng obtained as ^q^lained in connection with Figs. 179
and 180.

When a skylight is to be constructed on which the bars are of such
lengths that the glass cannot be obtained in one length, and a cross bar
or clip is required as shown by B, in Fig. 150, which miters against the
main bar, the pattern for this intersecting cut is obtained as shown in

SHEET METAL WORK

^. 182. Let A repres^it the section of the main bar, B the elevation
of tfie CToas bar, and C its section. Note how this ooss bar is bent so
that the WBtta follows the direction of the arrow, causing no leaks be-
cause the uppo" glass a is bedded in putt^, while the tower light b is
c^tped bjr the top flange of the bar C (See Ffg. 150). Number all of
the oomcrs of the section C as shown, from 1 to 8, from which points
draw horizontal lines cutting die mun bar A at points 1 to 8 as shown.
Atrij^ angles to the lines in B draw the vertical line DE upon whidi

Fig. 182.

place the stretdiout of the ooss bar C, shown l^ amilar figures,
through whidi draw horizontal lines, intersecting them witii lines
drawn parallel to D E from similar numbered intersections against the
main bar A, &xia obtaining the points of intersections 1' to S' in the
pattern. IWe a line through points of intersections tiuu obtuned
which win be tfie pattern for the end cut of the cross bar.

In fig. 183 is shown a carefully drawn working section of the
Qirret saah shown in Vig. 168 at A. These sa^es are opomted by
Dun... ,AiOo;;lc

SHEET METAL WORK

meana of cords, diuns or gearings from the inside, the pivot on which
they turn b«ng shown by R S in Fig- 183. The method of obtaining
the patterns for these sashes will be omitted, as they are only square and
butt miters which the student will have no trouble in developing, ppo-
viding he understands tlie construc-
tion. This will be made clear by
the foDowing explanation ;

A B represents the upper part of
the turret proper with a drip bait on
same, as shown at B, against which
the sashes close, and a double aeam,
as shown at A, which makes a tight
joint, takes out the twist in boiding,
and avoids any soldering. This up-
per part A B is indicated by C in
I^. 168, over wbidi the gutter B is
placed as shown by X U Y in Fig.
183. C I) represents the lower part
of the turret proper or base, whidi
fits over the wood^i curb W, and is
indicated by D in Fig. 168. E in
Fig. 183 represents the mullion
made from one piece of metal and
double seamed at a. This mullioD
is joined to the top and bottom.
He pattern for the top end of the
mullion would simply show a square
cut, wlule the pattern for the bot-
tom would represent a butt miter
against the slant line i j. Before forming up this mullion die holes
should be punched in the sides to admit the pivot R S. Tliese mullions
are shown in portion in F^. 168 by E E, etc.

F G in Fig. 183 represents the section of the inde of the sash bdow
the pivot T. Noti<» ihai liaa lower half of the Ade of the sash has a
lock attadiment which hooks into the fiange of the mullion E at F.
While the side of the sash is bent in one piece, the upper half, above the
pivot T, has the lodt omitted as shown by J K. Thus when the sash
opens, &e upper half of the sides turn toward &a inside as shown by

Fig. 183.

154 SHEET METAL WORK

the arrow at the top, while the lower halt swings outward as shown by
the arrow at the bottom. When the tower half closes, it locks as shown
at F, which makes a water-tight joint; but to obtain a water-tight joint
for the upper half, a cap is used, parti; shown by L M, into which the
upper half of the side of the sash closes as shown at M. This cap is
fastened to the upper part of the mullion E with a projecting hood /
whidi is placed at the same angle as the sash will have whea it is
op^ed as shown b; e e' and d d' or by the dotted lines.

The side of the sash just explained is shown in Fig. 168 at H.

The pattern for the side of the sash has a square cut at the top, miteting

with H I at the bottom, in Fig. 183, the same as a square miter. H I

represents the section of the bottom of the sash. Note where the metal

is doubled as at b, against which the glass rests in line with the rabbet

on the side of the sash. A beaded edge is shown at H whidi stiffens it.

TTiis lower section is shown in Fig. 168 by G and has square cuts on

both ends. N O in Fig. 183 shows the section of the top of the sash

shown in Ilg. 168 by F. Fhe flange N in Fig. 183 is flush with the out-

A side of the glass, thereby allowing

the glass to slide into the grooves

in the sides of the sash. Aha the

glass is in position the angle P is

tacked at n. A leader is attached

to the gutter Y as shown by B° in

Fig. 168. While the method of

construction shown in Fig. 183 is

' generally employed, eadi shop

has different methods; what we

have aimed to give is the general construction in use, after knowing

which, the student can plan his own construction to suit the conditions

which are apt to arise.

In the following illustrations, Figs. 184 to 187, it will be explained
how to obtain the true lengths of the ventilator, ridge, hip, jack, and
common bars in a hipped skylight, no matter what aze the skylight
may be. Using this rule only one set of patterns are required, as for
example, those developed in connection with Figs. 178, 179, 180, and
181, which in this case has one-third pitch. If, however, a sl^light
was required whose pitch was different than one-third, a new set of
patterns would have to be developed, to which the rule above niaitioi>

SHEET METAL WORK

155

ed would also be applicable for skylights of that particular pitcb.
Using this rule it should be understood Uiat the size of the curb, or
frame, forms the bans for all measurements, and &aX one of the lines
or bendsof the bar should meet the line of the curb as shown )nl%. 178,
^ere the bottom of the bar E in the half section meets the line of the
curb c 4' at 4', and the ridge at the top at 4'. Therefore when laying

IS 11 K> 9

705432 10

Fig. 185.
out the lengths of the bars, th^ would have to be measured on the line
4 of the bar E from 4' to 4" on the patterns, as will be explained as we
proceed.

The first step is to prepare the trianglea from iduch the lengths
of ibe common and jack bars are obtuned, also the lengths of the hip
bars. After the drawings and patterns have been laid out full size
according to the principles explained in Fig. 178, take a tracing of the
triangle in the half section D C 4' and place it as shown by A 12 O, in
Fig. 184. Divide O 12, which
will be 12 inches in full size, into
quarter, half-inches, and inches,
the same as on a 2-foot rule, as
shown by the figures O to 12.
From these divisions erect lines
until they intersect the pitch A O
which completes the triangle for
obtaining the true lengths of jack

— tf-o--
a

\l«'[ 16-

16'

16- ley

•1

\-'

I't

N«

Fig. 186.

and common bars for any size sl^light. In ^milar manner take
tracing of N R 4' in the diagonal elevation in 'F]g. 178 and
place it as shown by B 12 O in Fig. 185. The length 12 O then
becomes the base of the triangle for the hip bar in a skylight whose
base of tiie triangle for the common and jack bars measures 13 inches
Dun... ,AiOo;;lc

SHEET METAL WORK

^ '

7'^

»■ ,«■ ,6- »N

Fig. 187.

as shown in Fig. 184, the hd^ts A 12 in Fig. 1S4 and B 12 in Fig. 185
bang equal. Now divide 12 O in 12 equal spaces i^cb will represent
inches when obtaining the measiu-ements for the hip bax. Divide
eadi of the parts into quarter-inches as shown. From these devisions
erect lines intersecting the hypothenuse or pitch line B O as shown.
To ttcplain how these triangles are used in practice. Figs. 186 imd
187 have been prepared, showing respectively a skylight without and
with a ventilator whose curb
measures 4 ft. x 8 ft. Three
rules are used in connection
with the triimgles in Figs. 184
and 185, the comprehension of
which will make clear all that
follows.

Rule I. To obtfun the
length of the ridge bar in a
sli^light without a ventilator, as in Fig. 186, deduct the short side
of the frame or curb from the long side.

^sample: In Fig. 186, take 8 feet (long side of frame)— 4 feet
(short ^de of frame) - 4 feet (length of ridge bar a &) .

Rule 2. To find the length of the ventilator in a skylight deduct
the short dde of the frame &om the long side and add the width of the
desired ventilator (in this case 4 indies, as shown in Fig. 187).

£xamp2e: In Figure 187 take 8 feet (long side of frame)— 4 feet
(short ^de of frame) — 4 feet. 4 feet + 4 inches (width of inside
ventilator) - 4 feet 4 inches, (length of inmde ventilator a' 6'). To
find the size of the outside ventilator A I and hood m p in fig. 178
^mply add twice the distance a h and a c respectively to the above size,
4 indies, and 4 feet 4 inches, which will give the widths and lengths of
the outside vent and hood.

Rule 3. To find the lengths of either common or hip bar (in any
size s^light) deduct the width of the ventilator, if any, from the length
of the shortest side of h'ame and divide the reminder by two. Apply
the length thxis obtained on the base line of its respective triangle for
common or hip bars and determine the true lengths of the desired bars,
^m the hypo&enuse.

Examj^i As no ventilator is shown in Fig. 186, there will be
nothing to deduct for it, and the opo^tion is as follows : 4 feet (sbort-

SHEET METAL WORK 157

eat side of &ame) ^2-2 feet. We have now the lengdi vnth which
to proceed to the triangle for common and hip bars. Thus the length
of the common bar c d will be equal to twice the amount of A O in Fig.
184, while the length of the hip bar & e in Fig. 186, will be equal to twice
the amount of B O in Fig. 185. Referring to Figs. 186 and 187 the
jack bars i j are spaced 16 inches, Ihwefore, the length of the jack bar
for 12 indies will equal A O in Fig. 184, and 4 inches equal to 4° Q;
both of which are added togetber for the full length.

The lengths of the common and hip bars will be diorter in Kg.
187 because a ventilator has been used, while in Fig. 186 a ridge bar
was employed. To obtain the lengths of the common and hip bars in
Fig, 187useRule3: 48 indies (lengthof short »de)— 4 inches (width
of inside ventilator) - 44 inches; and 44 indies ^2-22 inches or
1 foot 10 inches. Then the length of the common bar c* d' measured
with a rule will be equal to A O in Fig. 184 and 10* O added together,
and the length of the hip bar e' f in Fig. 187 will be equal to B O in Fig.
185 and 10" O added together. Use the same method where fraction-
al parts of an inch occur. In laying out the patterns
according to these measurements use the cuts shown
in Figs. 178, 179, 180, and 181, bdng careful to
measure from the arrowpoints shown on eadi pattern.

It will be noticed in Fig. 178 we always meas-
ure on line 4 in the patterns for the hip, common,
and jack bars. This is done because die line 4 in
the profiles E and E* come directly on the slant line
of the triangles which were traced to Figs. 184 and
185 and from which the true lengths were obtained.
Where a curb might be used, as shown in Fig. 188,
which would bring the bottom line of the bar 1}
inches toward the inside of the frame b, all around, then instead of
using the size of 4 x 8 feet as the basis of measurements deduct 3
inches on each side, making the basis of measu/ementa 3 ft. 9 inches
X 7 ft. 9 inches, and proceed as explained above.

izecy Google

1S8 SBEET METAL WORK

ROOFING

A gcxxl metai covering on a roof is as important as a good foun-
datioD. Ilere are various materials used for this purpose such as te/ne
plate or what is commonly called roofing tin. Tlie rigid body, or the
base of roofing tin, consists of ihin sheets of ste^ (black plates) that
are coated •mOi an alloy of tin and lead. Where a first-class job is
deared soft and cold rolled coppo should be used. The soft copper
is gener^y used for cap flashing and allows itself to be dressed down
well after &e base flashing is in position. The cold-rolled or hard cop-
per is used for the roof coverings. In some cases galvanized sheet iron
or steel is employed. No matter whether tin, galvanized iron, or
copper is employed ihe method of construction is the same, and will
be explained as we proceed.

Anoflier form of roofing is known as corrugated iron roofing,
whifji consists of black or galvanized sheets, corrugated so as to secure
straigth and stifhess. Roofs having less than one-^iird pitch should
be covered by what is known as flat-seam roofing, and should be cover-
ed (when tin or copper is used) with sheets 10 x 14 inches in »ze ratho*
than widi sheets 14 x 20 inches, because the larger number of seams
stiff^is the surface and prevents the rattling of Uie tin in stormy
weaflier. Steep roofs should be covered by what is known as standing-
seam roofing made from 14' x 20* tin or from 20" x 28". Before any
metal is placed on a roof the roofer should see that the sheathing boards
are well seasoned, dry and free from knots and naited close together,
Beforelaying the tin plate a good building paper, free from add, should
be laid on the sheathing,or the tin plate should be painted on the imdeif-
ade before laying. Corrugated iron is used for roofe and sides of
buildings. It is usually laid direcUy upon the purlins in roofs, and
be!d in place by means of clips of hoop iron, whidi endrcle the purlins
and are riveted to the corrugated iron about 12 inches apart. The
me&od of constructing fiat and double-seam roofing, also corrugated
iron coverings, will be explained as we proceed.

TABLES

The foHowing tables will prove useful in figuring the quanti^ of
material required to cover a g^ven number of square feet.

SHEET METAL WORK 159

FLAT-SEAM ROOFING

Table ahowtng quaiitlt]r of 14 x 20-iiich tin required to cover a given

number of square feet with flat Beam tin roofing. A sheet of 14 x 20 inches with

with }-inch edges meesures, when edged or folded, 13 x 19 inches or 247

Bquare inches. In ttie following all fractional parts of a aheet are counted a

full sheet

Ifil

500

780

456

TOO

580

BOO

ISO

810

»70

118

too

820

880

010

180

seo

S»

840

170

«a

184

880

410

140

040

874

B80

OBO

179

880

440

800

450

tet

880

000

5»

480

800

511 .

140

470

517

480

too

SS8

710

540

too

710

sso

s«o

600

G!0

750

■00

444

«eo

671

110

7T0

440

000

578

121

1000 Bquare feet, 683 sheets.
A box of 112 sheets 14 x. 20 inches will cover approximately 192 square feet.

Example. How much 14 x 20 inch tin with i-inch edges is re-
quired to cover a roof 20 feet x 84 feet? Take 20 X 84 - 1,680
square feet.

Referring to the table for Flat Seam Roofing, 1000 square feet require
583 sheets and 680 square feet require 397 sheets, making a total of

It should be understood that this amount is figured on the basis
of 247 square inches in an edged sheet, whidi will be a trifle less when
the sheets are laid on the roof.

Example. What quantity of 20 z 28-inch tin will be required to
lay a standing seam roof, measuring 37 feet long x 45 feet in width?
Take 37 X 45 - 1,665 square feet, or 16 squares and 65 feet. Refer-
ring to the table for Standing Seam Roofing, 16 squares require 4
boxes and 48 sheets, and 65 feet require 20 sheets, making a total of 4
boxes and 68 sheets.

SHEET METAL WORK

STANDINO-SEAH ROOFING

Table eboving the quantity of 20 X 2&-inGh tin In boxes, and iheets

required to lay any glvoi Btanding-seam roof.

„.r^

««.a,.,^

■Q.pnT

BOXM

sanra

•QDAMa

«,x-

™™

Size of sheet before working, 20 X 28 inchea. Exposed on roof 27x17] inches.
Square inches per sheet exposed 479} Inches. Sheets per box 112.

SHEET METAL WOEK

NET WEIGHT PER BOX TIN PLATES
Basis 14 X 20, 112

Trade Mrm

8»-lb.

tE-lb.

tO-lb.

»-lt>.

lOO-lb.

W«lgMp«l)«.lb.

100

Sl»or

Sheet!

10 xu

ui I i»i

STANDARD WEIGHTS AND- GAUGES OP TIN PLATES

WsSsSS.":::

Weight. boi,Ux«>. lb..,..

"jj-

'lOO

■1

HI.

..5

1»

1GB

.MR

lara»A?::::

eao

Its

ICUSN

lOMin

IXMXSO

izMzn

'iSliSlrSS'S'^'^ ::

»£,,.

■MM too

lb.
ISBloIM

lb.

,,l^iOOglC

SHEET METAL WOEK

OTHER FORMS OF METAL ROOFINQ

There is another form of roofing known as metal slates and shin-
gles, pressed in various geometrical designs with water-tight lock attach'
ments ao that no solder is required in
laying the roof. Rg. 189 shows the
general shape of these metal shingles
which are made from tin, galvanized
iron, and copper, the dots a a a a
representing the holes for nailing to
the wood ^eathing. In Fig. 190, A
represents the side lock, showing the
first opaation in laying the metal slate
or shingle on a roof, a representing the
nail. B, in the same figure, shows the
/i yV * metal slate or shingle in posdtion cover-

-^^ ^v. T-*^ ^«*JI J ing the nail b, the valley c of the bottom
Fie- 189' slate allowing the wato-, if any, to

flow aver the next tower slate as in Ai in Fig. 189.

In Hg. 191 is shown the bottom slate A covered by the top slate B,
the ridges a a a keeping the water irom
backing up. Fig. 192 shows the s^le of
roof on whidi diese shingles are employed,
that Is, on ste^ roofs. Note the con-
struction of the ridge roll, A and B in
Fig. 192, which is first ntuled in position
at a a etc., after which the shingles B are
slipped under the lock «. Fig. 193 show;
a roll hip covoing whidi is laid from the
top downward, die bwer ^id of the hip having a projection piece fca*
nailing at a, over v^ch the top end of the next piece is inserted, thus

AHEATHIHC SOARO

SHEATHINfi BMRO

Fig. 190.

Kg. 191.
covering and concealing the ntdls. fig. 194 represents a perspective
view of a valley with metal slates, showing how the slates A are
locked to the fold in the v^iey B. There are many other forms of

SHEET METAL WORK 165

metal 3hiiigies,'but the shapes shown herewith axe known as the
Cortright patents.

TOOLS REQUIRED
Fig. 195 shows the various hand tools required by the metal roof-
er; starting at the left we have the soldering copp», mallet, Bcrsper,

stretch-awl, shears, hammer, and dividers. In addition to these hand
tools a notching machine is required for cutting off the comers of the

Fig. 193.
sheets, and roofing folders are re-
quired for edging the sheets in flat-
seam roofing, and hand double seamer
and roofing tongs for standing-seam
roofing. The roofing double seama
and squeezing tongs can be used for
standing-seam roofing (in place of the
hand double seamer), whidi allow the
operator to stand in an upright position if the roof is not too steep.
ROOF MENSURATION
While some mechanics understand tiioroughly the methods of

SHEET METAL WORK

layiiig the various tdnds of roofing, there are some, however, who do
Qot undo^itaiid how to figure ftom architects' or scale drawings the
amount of material required to cover a ^ven surface in a fiat, irr^ular
shaped, or hipped roof. The modem house with its gables and va-

Fig. 195.
rtous ioTO'sectiiig roofs, forming hips and valleys, render it necessary to
give a short diapter on roof measurement. In Figs. 196 to 198 in-
clusive are shown respectively the plans with full size meaaurementa
lor a flat, irregular ,and intersected hipped roof, showing how the length
of the hips and vall^s are obtained direct from
&e architects' scale drawings.

The illustrations shown herewith are not
drawn to a scale as architects' drawings will be,
but the measurements on the diagrams are as-
sumed, which will clearly show the principles
which must be applied when figuring from scale
drawings. Assuming th&t the plans from which
we are figuring are drawn to a quaxter-indi scale,
then ^en measumnents are taken, every quarter
inch represents one foot. ^ inch — 6 inches, fg
indi — 3 inches, etc. If the drawings were drawn to a half-inch
scale, then ^ inch - 12 inches, ^ inch - 6 inches, ^ inch - 3 inches,
^ incli = 11 inches, etc.

A B C D in Fig. 196 represents a flat roof with a shaft at one side
as shown bj abed. In a roof of this kind we will figure it as if there
was DO air shaft at all. Thus 64 feet X 42 feet - 2,6SS square feet
TlieshaftisI2.5 X 6 feet- 75 square feet; then 2,688 feet - 75 feet -

SHEET METAL WORK

2,613 square feet of roofing, to whidi must be added an allowance for
the fl nailing tuming up agfunst and into the walls at the ^des.

In Fig. 197 is shown a flat roof with a shaft at each side, one shaft
bang insular, forming an irr^ular shaped
roof. The rule for obtwning the area is sim-
ilar to that used for Hg. 196 with the ext^tion
&at the area of the irr^ular shaft x x x x m
Fig. 197 is determined differently to that of the
shaft 6cd6. Thus A B C D - 108 feet X 45
feet - 4,860 square feet. Find die area of 6 c
d e which is 9.25 X 39.5 - 365.375 or 365|
square feet. To find the area of the irregular
shaft, bisect xx and xx and obtain a a,
measure the lengdi of a a which is 48 feet, and
multiply by 9. llius 48 X 9 - 412, and 412

+ 365.375 - 777.375. The entire roof minus

the shafts - 4,860 square feet - 777.375 - "[■ — - a»^ — 4**
4,082.625 square feet of surface in Fig. 197. ^- 197.

In Fig. 198 is shown the plan, front, and ade elevations of an in-
tersected hipped roof. A B C D represents the plan of the main build-

Fig. 198.
ing intersected by the wing E F G H. We will first figure the main
roof aa if there were no wing attadied and then deduct the space takeo

166 SHEET METAL WORK

up by the intersection of the wing. While it may appear cUfiBcult to
aome to figure the quantitiea in a hipped roof, it is vexy ample, if the
rule is understood. As the pitdi of the roof is equal on four aides the
length of the rafter shown ttom O to N in front elevation rqiresents
the true leogUi of the pitdi on each side. The length of the building
at ihe eave is 90 feet and the length of the ridge 4S feet Take
90 -48 -42, and 42-1-2 -21. Now dther add 21 to the length of the
edge or deduct 21 irom the lengdi of &e eay^ i^di ^vea 69 feet as
shown from S to T. The length of the eave at the end is 42 feet and
it runs to an apex at J. Then take 42 feet -f- 2- 21, as shown from T
toU. IfdesiredthehiplinesAI, J Band J C can be bisected, obtun-
ing respectively the pomts S, T, and U, which when measured mil be
of similar Mzes; 69 feet and 21 feet. Aa the length of the rafter O N
is 30 feet, then multiply as folfows : 69 X 30 - 2070. 21 X 30 - 630.
Then 630 + 2,070- 2,700, and multiplying by 2 (for opposite ades)
fl^ves 5,400 square feet or 54 squares of roofing for the main building.
From this amount deduct the intersection E L F in the plan as follows:

The widfli of the wing is 24 feet 6 inches and it intersects flie main
roofasshownat E LF. Bisect E L and L F and obtain points W and
V, which when measured will be 12 feet 3 inches or one half of HG,
24 feet 6 indies. The wing intasects the mtun roof from Y to F* in the
side elevation, a distance of IS feet. Then take 18 X 12.25 - 220.5.
Deduct 220.5 from 5400 - 5,179.5. The wing measures 33 feet 6
inches at the ridge L M, and 21 feet 6 indies at the eave F G, thus
making the distance horn V to X - 27 feet 6 inches. The length of
the rafter of the wing is shown in front elevation by P K, and is 18 teet.
Then 18 X 27.5 - 495, and multiplying by 2 (for opposite ^de), gives
995 sq. ft iadieving. Wethenhave a roofing area of 5,179.5 square
feet in the mun roof and 995 square feet in the wing, maldng a total of
6,174.5 square feet in the plan shown in Fig. 198.

If it is de^ed to know ihe quantity of ridge, hips, and vall^ in
the roof, the following method is used. The ridge can be taken from
the plans by adding 48' + 33'&' - 81' - 6*. For flie true length of
the hip I D in the plan, drop a vertical line from F in the front elevation
until it intersects the eave line 1°. On the eave line extended, place the
distance I D m the plan as shown from 1° to D° and draw a Une from
D° to P which will be flie true length of flie hip I Din the plan. Multi-
ply this length by 4, which will give the amount of ridge capping re-

SHEET METAL WORK 167

quired. Ttds length of hip can also be obtained from the plan hy tak-
ing the vertical hei^t of the roof P I' in the elevation and placing it at
right angles to I D in the plan, as shown, from I to P, and draw a line
from P to D which is the desired length.

For the length of the vall^ L F in the plan, drop a vertical line
from P in the side elevation until it intersects the eave line at V.
Take the distance F Lin the plan and place it as shown from F° to L**,
and draw a line from L" to P, which b the true length of the valley
shown by L F in the plan. Multiply this length by 2, whidi will g^ve
the required number of feet of valley required. 'Diis length of valley
can also be obtained from the plan by taking the vertical hdght of die
roof of the wing, shown by F° P in the side elevation, and placing it at
right angles to F L in tiie plan, from L to P, and draw a line from P
to F which is die desired lengdi similar to P L° in the ade elevation.
FLAT-SEAAl ROOFINQ

The first step necessary in preparing the plates for flat seam
roofing is to notch or cut off the four coruCTS of the plate as shown in
Fig. 199 Tihich shows tiie plate as it is taken from the box, the shaded
corners a a a a representing tiie comers which are
notched on the notching machine or with the shears, i
Care must be taken when cutting off these comers not
to cut off too little otherwise the sheeti will not edge
well, and not to cut off too much, otherwise a hole will
show at the comers when the sheets are laid. To find

tiie correct amount to be cut off proceed as follows: ^' ,

Assuming tiiat a ^inch edge is desired, set the dividers at } indi
and scribe the lines b a and a c on the sheet shown in Pg. 199, and,
where the lines intersect at a, draw the line f^ e at an angle of 45 degrees,
g^ which represents the true amount and true angle to be

cut off on each corner. After all the sheets have been
notched, they are edged as shown in Kg. 200, the long
sides of the sheet being bent ri^t and left, as shown at
a, while the short ^de is bent as shown at b, ni ft king
the notdied cornar appear as at e. In some cases
^' • after the sheets are edged the contract requires that the
sheets be pEunted on the underside before laying. Tliis is usually
done with a small brushy bdng careful that tiie edges of the sheets

SHEET METAL WORK

are not aoiled with punt, whidi would interfere with aoldering. Be-
fore laying the sheets the roof boards are sometimes covered with an
oil or roan-sized paper to prevent the moisture or fumes &om bdow
from rusting the tin on the underside. As before mentioned, the same
method used for laying tin roofing would be applicable for laying
copper roofing, with the exception that the copper sheets would
have to be tinned about 1} inches around the edges of the sheets
after they ore notched, and before they are edged.

In f^. 201 is shown how a tin roof is started and thesheets laid
-nbta a gutter is used at die eaves with a fire wait at the ade. A rq>re-

Fig. 201.

seats a galvanized iron gutter with a portion of it lapping on the roof,
with a lock at C. In hanging the gutter it is flashed against the fire
wall at J; after whic^ the base flashing D D is put in position, flajaHing
out on the roof at E, with a lock at F. VHiere the base flashing E
miters with the flange of the gutter 6 it is joined as shown at b, allowing
the flange E of tiie base flashing as shown by the dotted line a. As the
water disdiarges at G, the sheets are Iwd in the direction of the arrow
H, placing tiie nails at least 6 indies apart, always starting to nul at
the butt e e, etc Care should be taken when nuling that the nul heads
are well covered by the edges, as shown in W, by a. Over the base
flashing D D J the cap flashing L is placed, allowing it to go into the
wall as at O.

SHEET METAL WORK 169

When putting in base Bashings there are two methods employed.
In Fig. 202 is shown a side flashing between the roof and parapet wall.
A shows the flashing turning out on the roof at B, with a lock C, attach-
ed and flashed into the wall four courses of brick above the roof line,
as shown at D, where wall hooks and
paintstdns or roofer's cement are used to
make a tight joint Flashings of thb
kind diould always .be painted on the
undo^de, and paper should be placed
between die brick work and metal, be-
cause the moisture in the wall is apt to
rust the tin. This method of putting in

a ,. . ..■.,. 1 Fig. 202.

nasbmg is not aavisable m new work,

because ^en the building is new, the walls and beams are liable
to settle and when this occurs the flange D tears out of the wall, and the
result is disagreeable leaks that staSn the walls. V/hea a new roof is
to be placed on an old building where the walls and copings are in
place and the brick work and beams have settled, there is not so much
danger of leakage.

The proper method of putting in flashings and one whidi ^lows
for the expanaon and contraction of the metal and the setUement of the
building is shown in F^. 203, in which A shows the cap flashings.

Fig. 203. Fig. 204.

punted frith two coats of paint before using. When the mason has
built his wall up to four courses of brick above the roof line the cap
flashing A is placed in position and the wall and coping finished; the
base flashing B is then slipped under the cap A. In practice die cap
flashing is cut 7 inches, then bent at right angles through the center,
making each ^de a and b 3^ inches. The base flashing B is tlien
slipped under the cap flashing A as shown at C.

170

SHEET METAL WORK

Where the cost b not considered and a good job is de^ed, it is
better to use sheet lead cap flashings in place of tin. They last longer,
do not rust, and can be dressed down well to lay tight onto the base
flashings. Into the lock C the sheets are attached. After the sheets
are hid the seams are flattened down well by means of a heavy mallet,
_ with sli^tly convex faces, after which the roof
is ready for soldering. When a base flashing
is required on a roof which abuts agunst a wall
composed of dap boards or shingles as shown
in I'ig. 204, then, after the last course of tin A
Fig. 205. i)gg been Ifud, the flashing B with the lock a is

locked into the course A imd extends the required distance under the
boards D. The flashing should always be painted and allowed to dry
before it is placed in portion. In the previous figures it was shown
how the sheets axe edged, both »des bang edged right and left. In
Fig. 205 is shown what is known
as a valley sheet, where the short
sides are edged both one way, as
shown at a a, and the long sides
ri^t and left as shown at bb.
Sheets of this kind are used when
the water runs together from two
directions as shown by A in Big.
206. By having the locks a and a turned one way the roof is l(ud in
both directions.

Fig. 207 shows a part plan of a roof and chimney A, around which
the flailing B C D E is to be placed, and explains how the coma? C
and D are double seamed,
whether on a chimney,
bulkhead, or any other ob-
ject on a roof when the
water flows in the direction
of the arrow F. The first
operation is shown at a and
the final operation at b.
"Rius it will be seen that the water flows past the seam and not agunst
it. In laying flat seam roofing especially when copper is used, allow-
ance must be made for the expansion and contraction of the sheets.

Fig. 206.

Kg. 207.

. SHEET METAL WORK 171

Care should be taken not to nail directly through the sheet as is shown
in W, Fig. 201, While this method is generally employed in tin
roofing, on a good job, as well as on copper roofing, cleats as shown at
D in Kg. 208 should be used.

To show how they are used, A and B represent two locked-edged
^eets. The lock on the cleat D is locked into the edge of the sheets
and nailed into the roof boards at a & c and d,ara3 often as required.

"^'i-l

Fig. 208.
Id this manner the entire roof can be fastened with cleats without
having a ntul driven into the sheets, thereby allowing for expansion
and contraction of the metal. The closer these cleats are placed, the
firmer the roof will be and the better the seams will hold. By using
fewer cleats, time may be saved in laying the roof, but double this time
is tost when soldering the seams, for the heat of the soldering copper

Fig. 20g.
will raise the seams, causing a succession of buckles, which retard
soldering and require 10 per cent more solder. When the seams are
nuled or cleated close it lays fiat and smooth and the soldering is done
with ease and less solder.

When a connection is to be made between metal and stone or
terra cotta, the method shown in Fig, 209 is employed. This illus-
tration shows a stone or teira-cotta cornice A. The heavy line abed

172 SHEET METAL WORK

repreaents the gutter lining, widdi ia usually made from 20-os. cold-
rolled copper. If the cornice A is of stone, the stone cutter cuts a
raggle into the top of the cornice A as at B, dove-tail in shi^, after
vhich die lining abedia put in position as shown. Hien, bang care-
ful that there is no water or moisture in the raggle B, molten lead is
poured into the ra^le and after it is cooled it is dressed down well with
Hie rft^iHring diisel and hammer.

By having the dove-tail cut, the lead is secured firmly in position,
holding down the edge of the lining and making a tight joint Should
flie cornice be of terra cotta this raggle is cut into the clay before it is
baked in the ovens. This method of making connection between

r^^^ — #3:0

Pig. 210.
metal and stone is the same no matter vdiether a gutter or upright wall
is to be flashed. When a flashing between a stone wall and roof is to
be made tight, then instead of u»ng molten lead, cake.9 of lead are cast
in molds made for this purpose, about 12 indies long, and these ore
driven into the raggle B as shown in Fig. 209 at X.

The most important step in roofing ts the soldering. The s^le of
soldering copper employed is shown in fig. 210 and weighs at least 8
pounds to the pur. When rosin is used as a flux, it is also employed
in tinning the coppers, but when add is used as a flux for soldering zinc
or galvanized iron, salammoniac is used for tinning the coppers. It
will be noticed that the soldering coppers are forged square at die ends,
and have a groove filed in one side as shown at A. When the copper
b turned upward the groove should be filed
tovrard the lower ^de witMn } indt from
the coma, so that when the groove is placed
upon the seam, as shown in Fig. 211, it acts
fig- 211. as a guide to the copper as the latter is

drawn along the seun. The groove a bdng in the position shown,
the largest heated surface b rests directly on the seam, "soaMng"
it thoroughly with solder. As the heat draws the solder between
die locks, about 6 pounds of i and ^solder are required for 100 square
feet of surface uang 14 x 2(^inch tin. Tba use of add in soldering
seams in a tin roof is to be avoided as acid coming in contact with the

SHEET METAL WORK

173

bare edges and comers, where the sheets aie folded and seamed to-
gether, will cause rusting. No other soldering dux but good dean
rosin should be employed, llie same flux (rodn) should be used
when soldering copper rooflng ^^lose edges have previously been
tinned unth roan.

We will now consider the soldering of upright seams. Ilie solder-
ing copper to be employed for this purpose is shEq>ed as shown in F!g.
212. It is forged to a wedge shape, about 1 indi wide and ^ indi

4^=ZD

Fig. 212.

thi(^ at the end, and is tinned on one mde and the end only; if tinned
otherwise, the solder, instead of remaining on the tinned ade when
soldering, would flow downward; by having the soldering copper tin-
ned on one mde only, the remuning sides are black and do not tend
to draw the solder downward. The soldaing copper bdng tiius pre-
pared, tiie upright seam, ^own in Fig. 213, where the sheet B overlaps
the sheet A 1", is soldered by first tacking the seam to make it lay close,
then thorou^y soaking die seam,
and thai placing ridges of solder
across it to strengthen the same.
In u»ng the soldering copper it
should be held in the position
shown by C. which albws the sol-
der to flow forward and into the
seam, triiile if the copper were held
as shown by D, the solder would
flow badcward and away from the
seam. In "soaking" the seam with
solder the copper should be placed
directly over tiie lapped part, so that the metal gets tlunroughly
heated and draws the solder between the joint. It makes no differ-
ence where this cross joint occurs; the same methods are used.

The roof bdng completed, tiie rosin is scraped off the seams and
the roof deaned and painted with good iron oxide and Unseed oQ paint.
Some roofers omit tiie scraping of roan uid paint directly over it.
tbii is the cause of rusting of seams which sometimes occurs. If the

Fig. 213.

174 SHEET METAL WORK

punt is applied to the rosin, the latter, with time, will crack, and the
rain will soak under the cracked rosin to the tin surface. Even when
the surface of the roof is dry, hy ruung the cracked rosin, moisture
will often be found underneath, which naturally tends to rust the plate
more and more with each storm. If the rosin is removed, the entire
tin surface is protected by paint.

One of the most difficult jobs in flat-seams roofing b that of cover-
ing a conical tower. As the roof in question is round in plan and taper-
ing in elevation, it is necessary to know the
meibod of cutdng the vanous patterns for the
sheets. In Fig. 214 ABC shows die eleva^
tion of a tower to be covered with flat seam
roofing, u^ng 10 X I44ndi tin at the base. As-
suming that the tower through B C is 10 feet 6
inches, or 126 indies, in diameter, the drcum-
ference is obtained by multiplying 126 by
3.1416 vrfiich equals 395.8416, or say 396
inches As 10 X 14^ndt plate is to be used at
the base of the towCT tiie nearest width which
can be onployed, and which will divide the
space into equal spaces, is 13^- indies without
edges, thus dividing the circumference in 30
equd spaces. This width of 13}- inches to-
gether with the length of the rafter A B or B C
in elevation, will be the baas from which all the
patterns for tiie various courses will be Iwd off.
Pig. 214. At any convenient place in the shop or at

the building, stretch a piece of tar felting of
tiie required length, tacking it at the four corners with n^ls to
keep the paper from moving. Upon the center of the felting strike
a chalk line as A B in Fig. 215, making it equal to the length
of the rafter A B or A C in Fig. 214. At right angles to A B in
Fig. 215 at eitiier side, draw the lines 6 D and B C eadi equal to 6|
inches, being one half of the 13}- above referred to. From tiie points
C and D draw lines to the apex A (shown broken). As the width of
the sheet used is 10 indies and as we assimie an edge of f indi for
eadi fflde, tiius leaving 9^ indiea, measure on the vertical Une A B
lengths of 9^ inches in succesaon, until the apex A is reached, leaving

SHEET METAL WORK

175

the last sheet at the top to come as it may. Through the points thus

obtained on A B draw lines parallel to C D intersecting the lines A C

and A D as shown. Then the various shapes marked 12 3 etc. will

be the net patterns for similarly numbered

courses. Take the shears and cut out the

patterns on the felting imd number diem as

required.

For example, take the paper pattern

No. 1, place it on a sheet of tin as shown in

Fig. 216, and allow f-inch edges all around,

and notch the comers ABC and D. Mark

on the tin pattern "No. 1, 29 more", as 30

sheets are required to go around the tower,

and cut 29 more for course No. 1. Treat

all of the paper patterns &om No. 1 to the

apex in ^milar manner. Of course where

the patterns become smalls in aze at the

top, the waste from other patterns can be

used.

In Ilg. 217 is E^own how the sheets

should be edged, always being careful to

have the narrow side towards the top with

the edge toward the outside, the same as in

flat seam roofing. Lay the sheets in the

usual manner, breaking joints as in general

practice. As the seams are not soldered

care must be taken to lock the edges well.

After the entire roof is laid and before closing the seams with the mallet
take a small brush and
paint the locks with thick
white lead, then dose
with the mallet This
will make a water-tight
job. After the roof is

Fig. 215.

Fig. 216. Fig. 217.

completed the finial D in Fig. 214 b put in position.

As the method used for obtaining the patterns for the various
sheets in Fig. 215 is based upon the principle used in obtaining the
envelope of s rieht cone, some student may aay that in accurate pat-

*^ Dun... .AiOO^IC

176 SHEET METAL WORK

terns &e line from C to D and all following lines should be curred,
as if struck with a radius from the ceater A, and not straight aa shown.
To those the writer would say that the curve would be 90 little on a
small pattern, where the radius is so long, that a strai^t line answers
the purpose just as well in all practical work; for it would amount to
considerable labor to turn edges on the curved cut of the ^eet, and
there b certjunly no necessity for it.

When different metab are to be connected together, as for instance
tin roofing to copper flashing, or copper tubes to galvanized iron gut-
ters, or zinc flashings in connection with copper linings, care must be
taken to have the copper sheets thoroughly tinned on both ^deswhereit
joins to the galvanized iron, zinc, or other metal, to avoid any electroly-
^ between the two metals. It is a fact not well known to roofers
that if we take a glass jar and fill it with water and place it in separate-
\y, two clean strips, one of zinc and the other of copper, and connect the
two with a thin copper wire, an electrical action is the result, and if the
connection remains for a long time
(as the action is very faint) the zinc
would be destroyed, because, it may
be ssid, the zinc fumisbes the fuel
for the electrical action, the same
as wood furnishes the fuel for the
fire. Therefore, if the copper was
not tinned, before locking into the
other metal, and the joint became
wet with rain, the coating of the
**■ metal would be destroyed by the

electrical action between the two metals, and the iron would rust
through.

While the roofer is seldom called upon to lay out patterns for any
roofing work occasion may wise that a roof flashing is required around
a pipe passing through a roof of any pitch, as shown in Fig. 218, in
which A represents a smoke or vent pipe passing through the roof B B,
the metal roof fla^ng bdng indicated by C C. If the roof B B were
level the opening to be cut into the flashing C C would ^mply be a
true circle the same diameter as the pipe A. But where die roof
pitches the opening in the flashing becomes an ellipse, whose minor
axis is the same as the diameta of the pipe, and whose major axis is

SHEET METAL WORK

equal to the pitch a b. In Fig. 219 is shown how this opening is ob-
tfuned hj the use of a few naib, a string, and a pencil, whidi tiie roofer
will always have handy.

First draw the line A B representing the slant of the roof, and
then make the pipe of the desired size passing through this line at its
proper angle to the roof
line. Next draw the center
line R S of die pipe, as
shown. Call the point
where this line intersects
die roof line, I, and the
pomts where D £ and C F
intersect A B, G and H re-
spectively. Through I draw
K L at right angles to A B,
making K I and I L each
equal to the half diameter
of the pipe. Having estab-
lished the minor axis K L
and the major axis G H,
the ellipse is made by tak-
ing I H, or half the major
a^s, as a radius, and with
L as a center strike arcs in- ^- 2^*-

tersecting the major axis, at points M and N. Drive a small naK in
each of these two points and attach a string to the nails as ^hown by
the dotted lines K M N, in such a way that when a pencil point is
placed in the string it will reach K. Move the pencil along the
string, keeping it taut all the time until the ellipse K H L G is ob-
t^ned. Note how the position of the string changes when it reaches
a, then b, eta

STANDINQ-SEAM ROOFING

Another form of metal roofing is that known as standing seam,
which is used on steep roofs not less than J pitch, or ^ the width
of the building. It consists of metal sheets whose cross or horizontal
seams are locked as in flat seam roofing, and whose vertical seams are
standing locked seams, as will be described in connection with Figs.

ITS

SHEET METAL WORK

Fig. 220.

220 to 229 inclusive. Assume that 14 x 20-indi sheets are used and
the sheets are edged on the 20-inch sides only, as shown by A in Fig.
220, making the sheet 13 x 20 inches. After the required number of
sheets have been edged, and assuming that the length of the pitched
roof is 30 feet, then as many sheets are
locked together as will be required, and
the seams are closed with the maHet
and soldered. In practice these strips
are pr^ared of the required length in the
^op, punted on the underside, and when
dry are rolled up and sent to the building.
If desired they can be lud out at the build-
ing, which avoids the buckling caused by rolling and transportation
from the shop to the job.

After the necessary strips have been prepared th^ are bent up
with the roofing tongs, or, what is better and quicker, the roofing edger
for standing-seun roofing. This is a machine into which the strips of
tin are fed, being, dis-
charged in the required
bent form shown at A or
B in %. 221, b^t up 1
inch on one ade and If
inches on the other side.
Or the machine wfll, if ^- ^^^■

desired, bend up If indies and Ij inches, giving a J-inch finished
doubled seam in the first case and a l-inch seam in the second.
A^en laying standing-se^n roofing, in no case should any nuls
be driven into the sheets. This applies to tin, copper or galva-
nized iron sheets. A cleat should be used, as shown
in Fig. 222, whidi also shows the full size for laying
the sheets given in Fig. 221. Thus it will be seen in
Fig. 222 that } inch has been added over the measure-
ments in "Fig. 221, thus allowing edges.

These cleats shown in Fig. 222 are made from
scrap metal; they allow for the expansion and con-
traction of the roofing and are used in practice as shown in i^. 223,
which represents the first operation in laying a standing-seam roof,
and in which A represents the gutter with a lock attached at B. T^

Dun... ,AiOo;;lc

ng. 222.

SHEET METAL WORK 179

gutter being Fastened in portion by means of cleats under the
lock B — the same as in Bat seam roofing — the standing seam strips
are laid as follows: Take the strip C and lock it well into the
lock B of the gutter A as shown, and place the deat ^lown in Fig.
222 tightly against the upright bend of the strip C in Fig. 223 as shown
at D, and fasten it to the roof by means of a 1-inch roofing nul a.

Fig. 223.
Press the strip C firmly onto the roof and turn over edge b of the cleat
D. TTiis holds the sheet C in position. Now take the next sheet E,
press it down and agunst the cleat D and turn over the edge d, whicji
holds £ in position. These cleats should be placed about 18 indies

Fig. 224. Fig. 225.

apart and by using them it will be serai that no nails have been driven
through the sheets, the entire roof being held in position by means of
the cleats only.

The second operation is shown in fig. 224. By means of the
hand double seamer and mallet or with the roofing double seamers and
squeemg tongs, the single seam is made as shown at a. The third
and last operation is shown in Fig. 225 where by the use of the same
tools die doubled seam a is obtfuned. In Fig. 226 is shown how tbe
finish b made with a comb ridge at the top. T^e sheets AAA have

180

SHEET METAL WORK

on the one side die single edge aa shown, while the opposite side B has
» double edge turned over as shown at a. Ilien, standing seams bb6
are soldered down to e.

In Fig. 227 is shown how the side of a wall is flashed and coimter

Fig. 226.
flashed. A shows the gutter, B the leader or run water conductor,
and C the lock on the gutter A, fastened to the roof boards hy cleats

Fig. 227.
an shown at D. The back of the gutter b flashed up agiunst the wall
as high as shown by the dotted line E. F represents a standing-eeam
strip locJced into the gutter at H and flashed up again^ the wall as high

SHEET METAL WORK

aa shown by the dotted line J J. As the flashing J J E is not fastened
at any part to the wall the beams or wall can settle without disturbing
the flailing. The counter or cap flashing K K K is now stepped as
shown by the heavy lines, the joints of the Iwick work bang cut out to
allow a one-inch flange ddd etc. to ente'. Hiis is well fastened with
flashing hooks, as indicated by the small dots, and dien made wat^-
dght with roofer's conent. As will be seen the cap flashing overlaps the
base flashing a distance indicated by J J and
covers to L L ; the comer is double seamed at
ab. M shows a sectional view through the
gutter showing bow die tubes and leaders are
joined. The tube N is flanged out as shown
at i t, and soldered to the gutter; the leader
O is thai slipped over die tube N as shown,
and fastened.

In the secdon on Flat-Seam Hoofing it
was expluned how a conical tower. Fig. 214,
^ould be covered. It wifl be shown now
how this tower would be covered with stand-
ing-seam roofing. As the circimaference of
the tower at the base is 396 inches, and
assuming fliat 14 x 20-inch tin plate Ls to
be used at the base of the tower, the nearest
width whidi can be employed and which
will divide the base into equal spaces is 17 ^^
inches, without edges, thus dividing the cir-
cumference into 23 equal parts. Then the
width of 17^ indies and the length of the
rafter A B or AC in elevation will be the |
basis from which to construct the pattern
for the standing seam strip, for whidi pro-
ceed as follows:

Let A B C D in fig. 228rqn-e3ent a 2&-mdi wide strip locked and
soldered to the required lengdi. 'nm>ugh the center of the strip draw
the line E F. Now measure the length of the rafter A B or A C in Rg.
214 and place it on the line E F in Fig. 228 as ^owti from H to F. At
right angles to H F on either side draw F O and F L maMng each
equal to 8H inches, being one half of the 17^ above referred to.

SHEET METAL WORK

CVom points L and O draw lines to the apex H (shown broken). At
right angles to H L and H O draw lines H F equal to Ij inches and
H S equal to IJ indies respectively. In similar manner draw L D and
OC and connect by lines the points PD and SC. TTien will P S C D
be the pattern for the standing seam strip, of which 22 more will be
required. When the strips are all cut out, use the roofing tongs and
bend up the sides, after which th^ are laid on
the tower, fastened with cleats, and double
seamed with the hand seaxaet and mallet in
the usual manner.

If the tower was done m copper or galva-
nized sheet iron or steel, wh^e 8-foot sheets
oould be used, as many sheets would be cross-
locked together as required; then metal could
be saved, and waste avoided, by cutting the
sheets as shown in Fig. 229 in which A B C D
shows the sheets of metal locked together, and
E and F the patton sheets, the only waste be-
ing that shown by the shaded portion. Where
the finial D in Fig. 214 sets over the tower, the
standing seams are turned over flat as much
^" as is required io receive the finial, or small

notches would be cut into the base of the finial, to allow it to slip over
the standing seams. Before closing the seams, they are p^ted with
white lead with a tool brush, then closed up tight, which makes a good
tight job.

CORRUGATED IRON ROOFING AND SIDING
Corrugated iron is used for roofs and sides of buildings. It is
usually laid directly upon the purlins in roofs constructed as shown in
Figs. 230 and 23X, the former being constructed to receive sidings of
corrugated iron, while in the latter figure the side walls of the building
are brick. Special care must be taken that the projecting edges of the
corrugated iron at the eaves and gable ends of the roof are well secured,
otherwise the wind will loosen the sheets and fold them up. The cor-
rugations are made of various sizes such as 5-inch, 2^inch, l^-lnt^
and f-inch, the measurements always being from A to B in Fig. 232,
and the depth being shown by C. The smaller corrugations give a

SHEET METAL WORK 183

more pleasing appearance, but the larger corrugations are stilTer and
will span a greater distance,thereby permitting the purlins to be further
i4>art.

Fig. 230.
The thickness of the metal generally used for roofing and siding
varies from No. 24 to No. 16 gauge. By actual trial made by The

Fig. 231.
Keystone Bridge Company it was found that corrugated iron No. 20,
spanning 6 feet, began to give
permanent deflection at a load of
30 lb. per square foot, and that
it collapsed with a load of 60 lb.
per square foqt. Tlie distance ^'

between centers of purlins should, therefore, not exceed 6 feet, and
preferably be less than this.

Dun... .l^iOO^lC

184

SHEET METAL WORK

TABLES

The following tables will prove of value when desiring any infor-
mation to which they appertain.

MEASUREMENTS OF CORRUGATED SHEETS
Dimensions of Sheets and Coirugationa.

^ 1

Mtnolk.

Hk^^

'^S^:

MlMh.

» iDCh.

tSlncb.

BtMt.

RESULTS OF TEST
of a corrugated sheet No. 20, 2 feet wide, 6 feet long between aupporbi, loaded
imitormlj with fire clay.

Load

per square foot.

lb.

Deflection

at center under load.

Inches.

load removed.

5
10

Brokedown.

Not D ted.

The following table shows the distance apart the supports should
be for different gauges of corrugated sheets:

Nos. 16 and IS 6 to 7 feet apart.

Noa. 20 and 22 4 to 6 feet apart.

No. 24 2 to 4 feet apart.

No. 28 2 feet tipMt,

_,oogk

SHEET METAL WORK

The following table is calculated for sheets 30i inches v,
corrugating.

ijl

Welslit per Manre of 100 sqnaTS teet. when
lBia.naiowlnB a InoheB Up in lengUi and
IM lachea or one corroeatlon In width ot

5f«.

6..«t

7 teet

8 teet

Steet

10 teet

I.M

1.48
I.M

1:11

375

154
IN

850

ISO

lis

848
140

84S

361
185
14B

•s.

.«fi

LAYING CORRUOATED ROOFING

When laying corrugated m)n on wood sheathing use galvanized
iron naHs and lead washers. The advantage in using lead washers is
that they make a tight joint and prevent leaking and rusting at the ntui
hole; the washa being soft it easily shapes itself to any curve. In Fig.
233 is shown how these washers are used; A shows the full size nfdl

Fig. 233.
and washer. When laying, commence at the left hand corner of the
eave and end of the building. Continue laying to the ridge by lapping
the second sheet over the first 4 iDches,the left-hand edge b^g finished
by means of a gable band A, formed as shown in Fig. 234, into which
the corrugated sheet B is well bedded in roofer's cement C. When it
u not de^ed to use this gable band the sheet must l>e well secured at
the edge to keep the wind from Taising the sheets from the roof in ,
stono, as at A in Fig. ^-tf).

SHEET METAL WORI^

Should the gable have a fire wall, then 1^ the sheets A butt against
the wall and flash with corrugated flashing as shown in fig. 235, over
whidi the r^ular ciq) or counter flashing is placed as expUuned in
connectbn with fig. 227. Should
the ridge of the roof A butt
against a wall, as shown at B in
Fig. 230, then an end-wall flash-
ing is used as ia shown in Kg.
236 which must also be c^ped,
bj ^th^ u^ng cap flashing <xt
allowing the corrugated siding
to ovo-Iap this end-wall flashing

Rg. 234. Fig. 235.

as would be the case at B in fig. 230. Now i
second course at the eaves, giving one and one half corrugations iac
ade lap, b^ng careful that the side corrugations center each other
exactly and nul with washers as shown in Fig. 237. Nail atevery
other corrugation at end laps,

and at about every 6 inches at
aide laps, nailing through top
of corrugation as shown in
Fig. 237. Continue laying in

Fig. 236.
tfiis manner until the roof is covered.

The same rule is to be observed in r^ard to laps and flashing if
die corrugated iron were to be fastened to iron purlins, and the method
of fastening to the iron frames would be accomplished as shown in Figs.
238 to 240 inclusive. Assuming that
steel structures are to be covered, as
shown in Figs. 230 and 231, tiien let
A in Fig. 238 be the iron rafter, B
the cross angles on whic^ the sheets D are laid, then by means
of the clip or clamp C, whidi is made from hoop iron and bent around
the angle B, the sheets are riveted in position. In Fig. 239 is shown
(mother form of clamp, which b bent, over the bottom of the angle iron.

Fig. 237.

SHEET METAL WORK

187

f%. 240 shows still another method, where the clamp F is riveted to the
sheet B at E, then turned ajound the angle A at D. . To avoid having
the storm drive in between the corrugated opening at the eaves, cor-
rugated wood filler is used as shown in Fig. 241. llus keeps out the

Fig. 240.

Fig. 238. Fig. 239.

snow and sleet. On iron framing this is made of pressed metaL
Another fonn of corrugated iron roofing is shown in f^. 242. lUs is
put down with cleats in a manner similar to standing-seam roofing.

If there are hips on the roof, the corrugated iron should be care-
fully cut aud the hip covered
with sheet lead. This is best
done by having a wooden cove
or filler placed on the hip,
agdnst whidi the roofing butts.
Sheet lead is then formed over
this wooden core and into the
corrugations, and fastened by
means of wood screws through the lead cap into the wooden core.
The lead being soft, it can be worked into any desired shape.
When a valley occm'S in a hipped roof, form &om plain sheet iron
a valley as shown in Vig. 243, b^ng sure to give it two coats of paint
before laying, and make

inches on eadi ade.
^'^' ^^- Fit it in the valley, and

cut the corrugated iron to fit the required angle. Then lap the
corrugated iron over the valley from 6 to 8 inches.

W^en a chimney is to be flashed, as shown in Pig. 244, use plain
iroD, bending up and Sashing into the chimney joints, and allowing

»u .XMo;;\^-

188 SHEET METAL WORK

Ihe flashing to turn up under the corrugated iron at the top about 12
inches and over the corrugated iron at the bottom about the same
distance. At the side the flashing should have the shape of tfie cor-
rugated iron and receive a lap of about 8 inches, the entire flashing

Fig. 242.
bdng well bedded in roofer's cement. When a water-tight joint is
required around a smoke stack, as ahown in Fig. 245, the corrugated
iron is first cut out as shown, then a flashing built around one half the
upper part of the stack to keep the water from entmng iaade. This
is best done by using heavy
sheet lead and riveting it to
the sheets, using strips of sim-
ilar corrugated iron as a
washer to avoid damaging the
lead. Before riveting, the
flas^ng must be well bedded
in roofer's cement and then
make a beveled angle of
cement to make a good joint.
After thb upright flashing is
in position a collar is set over
the same and fastened to the
stack by means of an iron ring
bolted and made tight as shown. Cement is used to make a water-
tight joint around the stack. This construction gives room for the
stack to sway and allows the beat to escape.

Sonietitnes the end wall flashing shown in Fig. 236 can be used

Fig. 243.

SHEET METAL WORK 189

to good advantage in building the upright flashing in f^. 245. Where
the corrugated iron meets at the ridge, as at D and D in Figs. 230 and

Fig. 244.
231, a wooden core is placed in portion as explained in connection with
the hip ridge, and an angle ridge, pressed by dealers who fumiah the

Fig. 246.
cnrrugeted iron, is placed over the ridge a3 shown in "Fig. 246. When
a ridge roll is required, tlie shape shown in Fig. 247 is emptojed.

190

SHEET METAL WORK

These ridges are fastened direct to the roof sheets b; means of riveting
or bolting.

LAVINQ CORRUQATED SIDINQ
Before putting on any corrugated siding or ctapboarding, us
diown in Fig. 248, a finish is usually made at the eaves by means of a

hanging gutter or a plain cornice, shown in Kg. 249, which is fastened
to the projecting wooden or iron rafters. This method is generally
used on elevators, mills, factories, bams, etc., where corrugated iron,
crimped iron or clapboards are used for either roofing or ^ding. Tina

Fig. 247.
style of cornice covers the eaves and gable projections, so as to make
the building entirely ironclad. When laying the siding commence
at the left hand corner, laying the courses from base to cornice, giving
the sheets a lap of two inches as the ends and one and one half corrugi^

tions at the sides. Nul side laps every 6 inches and end laps at evay
other corrugation, driving tiie naib as shown in Fig. 250.

Where the sheets must be fastened to iron framing use the same
method as explained in connection with Figs. 238, 239 and 240. In
this case, instead of naiUng the sheets, they would be riveted. If siding
is put on the wooden studding care should be taken to space the stud-
ding the same distance apart as the laying width of the iron used. Id

SHEET METAL WORK 191

thia case pieces of studding should be placed between the uprights at
the end of eadi sheet to nail the laps. When covering grain elevatots

Fig. 249.

y to use swinging scaffolds. Commence at the base and
carry up the course to the eave, the lengdi of the scaffold. Commence
at the left hand and give the sheets a lap of one corrugation on the ;»de
and a two-inch lap at the end.
Nail or rivet in every corru-
gation 3 inches from the lower
end of the sheet; this allows
for settling of the building.

When any structure is to
be covered on two or more
sides, comer casings made of
flat iron are employed, of a
shape similar to tliat shown at
B, Fig. 251. It will be seen
that a rabbet is bent on both
sides a and h to admit the ^'

siding. Tias makes a neat finish on the outside and hides the
rou^ edges of the uding. If a window opening is to have
caangs a jamb is used as shown at A, Fig. 251, which has a similar rab-
bet at a to receive the siding, and a square bend at 6 to nail agiunst the
&ame. In Fi^. 252 is shown the cap of a window or opening. It is

102 SHEET MSVKL WORK

bent 90 that a ia nailed to the window or other frame at the bottran,
while b forms a flashing over which the ading will set. ¥\g. 253 diows
the siU of a window, whidi has a rabbet at a, in whicii the ^ding ia

Fig. 262. Fig. 253.

slipped ; then b forms a drip, and any water coming over the sill passes
over the siding without danger of leaks; c is nailed in white lead to the
window frame.

Another use to which corrugated iron is put is to cover sheds and
awnings. Sheets Ifud on wood are nuled ia the usual manner, while
^eets Ifud on angle iron construction are fastened as expluned in the

Fig. 254. j

[Receding secUons. In Fig. 254 is shown an awning over a store \iiad
on angle iron supports. In work of this kind, to make a neat app«par-
ance, the she^ are curved to conform to the iron bracket A.

Dun... ,AiOo;;lc

CORNICE OVER BRICK BAY •

An elevation and plan of a brick bay are shown in the iUuBtration, the
sides of which are 8 inches, 3 fe«t 2 inches and 5 feet 10 Inches wide. Laps
or flanges for soldering are to be allowed on the 3 feet 2 inch pieces and no laps
on the 8 inch and 6 feet 10 inch pieces. The lookouts or iron braces are indi-
cated In the plan b; the heavy dashes making a total of 9 required.

After the detail section is drawn and knowing the an^e of the bay in plan,
tlie angle is placed as shown by AfiC, being careful to place CB on a line 'drawn
vertically from 3-4 in the section. The miter line is then drawn as shown by
BD, the section divided Into equal spaces, and vertical lines dropped to the
miter line BD as shown. At right angles to BC the girth of the section is
drawn as shown by similar figures from 1 to 26, through which points at right
an^ea to 1-26, lines are drawn and intersected by similar numbered lines
drawn from the miter line BD at right aa^es to BC, thus obtaining the upper
miter cut shown. Now using this miter cut in practice, make the distance
from either points 25 or 24 (which represents the line of the wall) equal to
8 Inches, 3 feet 2 Inches and 6 feet 10 inches. The 3 feet 2 inches and 5 feet
10 inches have opposite miter cuts as shown.

As will be seen by the plan, two eight Inch pieces will be required, one
right and one left and two 3 feet 2 inch and one 6 feet 10 inch pieces. Nine
Iron lookouts will be required formed to the shape shown in the detail sectioa
where holes are punched for bolting as there indicated,

•TheilluMntloniotnnd to will be lound on the back of thli piga.

izecy Google

SHEET METAL WORK

PART IV

CORNICE WORK

There is no trade in the building line to-day which has made audi
rapid progress as that of Sheet-Metal Cornice, or Architectural Sheet-
Metal Work. It b not very long since the general scope of this branch
of craftsmanship merely represented a tin-shop business on a large
scale. But as things are to-day, this is changed. From an enlaj^ed
tin-shop business, sheet-metal cornice work, including under that title
every branch of architectural sheet-metal work, has become one of tiie
substantial industries of the country, comparing favorably with almost
any other mechanical branch in the building trades. Nor is this work
confined to the larger cities. In the smaller towns is shown the prcg-
ress of architectural sheet-metal work in the erection of entire btiilding
fronts constructed from sheet metal.

CONSTRUCTION

Sheet-metal cornices have heretofore, in a great measure, been
duplications of the designs commonly employed in wood, which, in
turn, with minor modifications, were imitations of stone.

With the marked advancement of this industry, however, this
need no longer be the case. A sheet-metal cornice is not now inaita^
tive. It possesses a variety and beauty peculiarly its own. No pat-
tern is too complex or too difficult. Designs are satisfactorily executed
in sheet metal which are impossible to produce in any other materiial.
By the free and judicious application of pressed metal ornaments, a
product is obtained that equals carved woric. For boldness of figure,
sharp and clean-cut lines, sheet-metal work takes the lead of all com-

In order that there may be no misunderstanding aa to the various
parts contfuned in what the sheet-metal worker calls a "cornice,"
Fig. 255 has been prepared, which gives the names of all tiie menbers
in the "entablature" — the architectural name for what in the shop is

SHEET METAL WORK

known as the cornice. 'Die term "entablature" is sddom heard
among mechanics, a very general use of the word "cornice" having
supplanted it in the common language of business.

An entablature consists of three principal parts — the eomtce, the
friase, and the arcktirave. A glance at the illustration will serve to
show the relation diat each bears to the others. Among mechanics
the shop term for architrave is foot^nunJdtng; for frieze, panel; and for

" LOCKJ-

znnr:

/ daVE ' /* _MOULD_

OUAHTER ROUND / [If^"^ ^"If A^

Fig. 255.
the subdi^sions of the cornice, dejiiil course, modiUton eoarw, tW-
moidd, and croivti-movid. In the modillion course, are the vwdUtiori'
band and modUlum'^mould; while in the dentil course are the dentU-
band and detUHtnouid. Drips are shown at the bottom of the crown-
and foot>-mould fasdas, and the ceiling under the crown mould is called
the ptanceer. The edge at the top of the cornice is called a lock, and is
used to lock the metal roofing into, when covering the top of the coi-

.Ai

OOg\

SHEET METAL WORK

195

nice. In tiie panel, there are the panel proper, the panel-rtundd, and
the stile. The side and front of the modillion are also shown.

Fig. 256 shows the side and front view of what is known as a
bracket. Lai^ terminal brackets in
cornices, which project beyond the
mouldings, and against which the
mouldings end, are called trusses, a
front and a side view of which are
shown in Kg. 257. A block placed
above a common bracket against
which the moulding ends, is called a
stop block, a front and a ade view of
which are shown in Fig. 258.

Fig. 256.

Rg. 259 is the front eleva-
tion of a cornice, in which are
shown the truss, the bracket, the
modillion, the dentil, and the
panel. It is sometimes the case,
in the construction of a cornice,
that a bracket or modillion is
called for, whose front and sides
are carved as shown in the front
and side views in Fig. 260. In
that case, the brackets are ob-
tained from dealers in pressed
ornaments, who make a specialty
of this kind of work. The same
FRONT SIDE applies to capitals which would

^" ^^^' be required for pilasters or col-

umns, such as those shown in Figs. 261 and 282. The pilaster or
fulumn would be formed
up in sheet metal, and the
capital purchased and sol-
dered in position. In Fig.
263, A shows an inchned
moulding, which, as far as
general position is con-
cerned, would be the

Fig. 258.
as a gable moulding.

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196 SHEET METAL WORK

Raking mouldings are those which are inclined as in a gable or
pediment; but, inasmuch as to miter an inclined moulding (as A) into a
horizontal moulding (as B and C), under certain conditions, necessi-
tates a change of profile, the term "to rake," among sheet-metal work-
ers, has come to mean "to change profiles" for the accomplishment of

Fig. 259-
such a miter. Hence the term "raked moulding" means one whose
profile has been changed to admit of mitering.

The term mifer, in common usage, designates a joint In a mould-
ing at any angle.

Drawings form a very important part in sheet-metal architectural

FRONT ELEVATION SIDE ELEVATION

Fig. 260.
work. An elevaiion. is a geometrical projection of a building or other
object, on a plane perpendicular to the horizon — as, for example,
Figs. 259 and 263. Elevations are ordinarily drawn to a scale of ^ or

SHEET METAL WORK M7

i inch to the foot. A sectional drawing shows a view of a building of
other object as it would appear if cut in two at a g^ven vertical line —
as, for example. Fig. 255. Detail draumga are ordinarily full me, and

Fig. 261. Fig. 262.

are oftei called working dravdngs. Tracings are duplicate drawings,
made by tradng upon transparent cloth or paper placed over the orig-

Flg. 263.

inal drawing. Many other terms might be mtroduced here; but
enough, we believe, have been presented to give the student the leading
general points.

1 SHEET METAL WORK

A few words are necessaiy on the subject of faaUtiing ike eonviee

Sheet-metal cornices are made of sudi a wide range of ^zes, and
are required to be placed in so many different locations, that the
methods of construction, when woodm lookouts are employed and

Rg. 264.
when the cornice is put together at the building in parts, are worthy <rf
the most careful study. The general order of procedure In putting
up, is as follows:

The foot-moulding or architrave a b (Fig. 264) is set upon the
wall finished up to /, the drip a being drawn tight agiunst the waU.
The brickwork is then carried up, and the lookout A placed in position,
the wall being carried up a few courses higher to hold the lookout in
position. A board B is then nailed on top of the lookouts (which
should be placed about three feet apart); and on this the flange of the
foot-mould b is fastened. The frieze or panel 6 o is now placed into
the lock B, irfiich is closed and soldered; when the lookout C and the
t>oard D are placed in their proper positions, as before described.

SHEET METAL WORK

The planceer and bed-mould c d are now lovlted and soldered at
D, and tlie lookout E placed in position, with a board F placed under
the lookouts the entire length of the cornice; onto this board the plim-
ceer is fastened. Having the proper measurements, the framer now
constructs his lookouts or brackets G H I E, fastening to &.e beam at
T, when the crown-mould rf e is fastened to the planceer, through the
flange of the drip at d, and at the top at e. The joints between lengtns
of mouldings, are made by lapping, riveting, or bolting, care being
taken that they are joined so neatly as
to hide all indications of a seam when
finished and viewed from a short
distance.

If brackets or modillions are to
be placed in position, the^ are riveted
or bolted in position; or sometimes the I ~
bade of the cornice is blocked out
with wood, and the brackets screwed
in position dirough their flanges.

While a galvanized-iion cornice
thus constructed on wooden lookouts
will resist fire for a bng time, a strict-
ly fireproof cornice is obtuned only
by the use of metal for supports and
fastenings, to the entire exclusion of
wood. Hiis fireproof method of con-
struction is shown in Fig. 265. In-
stead of patting up in parts on the building, the cornice is con-
structed in one piece in the shop of upon the ground, and hoisted
to the top of the wall in long lengths easily handled. A drip a is used
at the bottom of the foot-mould, and the joints made in the way in-
dicated at b and c, with a lock at d. Band iron supports and braces
aifi used, formed to the general contour of the parts as shown by A B
C, and bolted direct to the cornice, as shown, before hoisting.

When the cornice sets on the wall as at C, anchors are fastened
to the main brace, as at D and E, with an end bent up or down for
fastening. If the cornice sets perfectly plumb, the mason carries up
bis wall, ^lich holds the cornice in a firm position. The top and
back are then framed in the usual manner and covered by the m^ij

Fig. 265.

300 SHEET METAL WORK

loofer. In constnictiiig cornices in this manner, the mouldings are
run duDUf^ adid, bdiind all bradiets and modillions. The bndcets
and modillioos are attached by means of rivedng thn>u{^ outside
flanges.

SHOP TOOLS
One of the most important tools in cornice or ardiitectural sheet*
metiU worldly shop is the brake. On those operated by hand, sheets
are bent up to 8 feet in one continuous length. In the larger shops,
power presses or brakes are used, in which sheets are formed up to 10
feet in length, the press being so constructed that they wiH form ogees,
squares, or acute bends in one operation.

I^arge 8- or 10-feet aquarmg shears abo form an important ad-
dition to the shop, and are operated by foot or power.

When cornices are constructed where the planceer or frieze is veey
wide, it is usual to put crimped metal in, to avoid the waves and buck-
les showing in the flat surface; for this purpose the crimping machine
is used.

In pr^mring the iron braces for use in the construction of fire-
proof cornices, a punching machine and slitting shears are used for
cutting the band iron and punching holes in it to admit the bolts.
While braces are sometimes bent in a vise, a small madiine known as a
brace bender is of great value in the shop. In huge fireproof building
constructions, it is necessary that all doors, window frames, and even
sashes be covered with metal, and made in so neat a manner that,
v^en pfunted and grained, no differences will be apparent to indicate
whether the material is wood or metal, the smallest bends down to i
indi bang obtained. Ihis, of course, cannot be done on the brakes
just mentioned, but b done by means of the draiw-bench, vMch is con-
structed in lengths up to 20 feet and longer, operated by means of an
endless chain, and capable of drawing the sheet metal over any shaped
wood mould as tighUy as if it were cast in one piece. The smaller
tools in the shop are similar to those referred to on page 4 pf
t.}<itt volume.

METHOD EMPLOYED FOR OBTAINING PATTERNS

The principles applied to cylinder developments, as expl^ned
on page 5 and following in the treatment of the Parallel-
Lme method of development, are also applicable for obtaining

SHEET METAL WORK

the patterns for any moulding where all members run parallel; for it
makes no difference what profile is employed, so long as the lines run
parallel to one another, the parallel-line method is used. While
this method b chiefly employed in cornice work, other problems will
arise, in which the "Radial-Line" and the "Triangulatlon" methods
will be of service.

The term generally used in the shop for pattern cutting on cornice
work is miter cutting. To illustrate, suppose two pieces of mouldings
are to be joined together at
angle of 90°, as shown in Fig.
266. The first step necessary
would be to bisect the given
angle and obtun the miter-
line and cut each piece so that
they would miter together. If a
carpenter had to make a joint of this kind, he would place hb moulding
in the miter-box, and cut one piece right and one piece left at an angle
of 45°, and he would be careful to hold the moulding in its proper po-'
sition before sawing; or else he may, instead of having a return miter
as shown, have a face miter as in
a picture frame, shown in Fig.
287. The sheet-meta! cornice-
maker cannot, after his moulding
is formed, place it in the miter-
box to cut the miter, but must
lay it out — or, in other words,
develop it — on a flat surface or
sheet of metal. He must also be

Fig. 267.

careful to place the profile in its proper position with the miter-
line; or else, instead of having a return miter as shown in Fig. 266, he
will have a face miter as shown in Fig. 267. If he lays out his work
correctly, he can then cut two pieces, form one right and the other left,
when a miter will result between the two pieces of moulding and will
look as shown n Fig. 266. If, however, a face miter is desired, as
shown in Fig. 267, which is used when miters are desired for pands
and other purposes, the method of laying them out will be explained as
we proceed. The same principles required for developing Figs. 266
and 267 are used, whether the mouldings are mitered at angles of 90°

202

SHEET METAL WORK

or otherwise. The method of raking the mouldings — or, in other
words, changing thor profile to admit the mitering of some other
moulding at various angles — will also be thoroughly explained as we
proceed.

VARIOUS SHAPES OF MOULDINOS

llie st^le of mouldings arising in the cornice shop are chiefly

Roman, and are obtuned by uang the arcs of a drcle. In some cases,

Greek mouldings are used, the outhnes of which follow the curves

of conic sections; but the majority of shapes are arcs of circles. In

Fig. 268. Fig. 269.

Figs. 26S to 272 inclusive, the student is ^ven a few simple lessons on
Roman mouldings, which should be carefully followed. As all pat-
tern-cutters are required to draw their full-size details in the shop from
small-scale drawings furnished by the architect, it follows that they
must understand how to draw the moulds with skill and ease; others

Fig. 270. Fig. 271.

wise freehand curves are made, which lack proportion and beauty,

In Fig. 268, A shows the mould known as the cyma recta, known
m the shop as the ogee, which is drawn as follows :

Complete a square abed; draw the two diagonals a c and b d,
intersecting each other at e. Through e, draw a horizontal line inter-
secting adatj and bc&th. Then, with / and h as centers, draw re-
spectively the two quarter-circles a e and e e.

SHEET METAL WORK 20S

In Fig. 269, B shows the cyma Teveraa, known in the shop as the
ogee, reversed. Complete a square abed, and draw the two diagonals
&(2and ac intersecting ate; through c, draw a vertical line intersecting
abaXf and cd&th, which points are the respective centers for the arcs
a e and e c.

C in Fig. 270 shows the cavetio, called the cove in the shop, which
is drawn by completing a square abed. Draw
the diagonal 6 d at 45°, which proves the
square; and, using d as a. center, draw the
quartep^arcle a c.

In Pig. 271, D represents the ovolo or
echinus, known in the shop as the quarter- — ™-

rmmd, which is constructed similarly to C in L-i '

Fig. 270, with the exception that b in Fig. 271 pj^ 272.

is used to obtain the curve a c,

E in Fig. 272 is known as the torus, known in the shop as a head-
nundd. A given distance a 6 is bisected, thus obtaining c, \^ch is the
center with which to describe the semicircle a b.

All of these profiles should be drawn by the student to any de-
sired scale for practice. In preparing mouldings from sheet metal.

Fig. 273.
it is sometimes required that enrichments are added in the ogee, cov^
and bead. In that case the mould must be bent to receive these en-
richments, which are usually obtiuned from dealers in stamped or
pressed sheet-metal work. Thus, in Fig. 273, F represents a front
view of a crown mould whose c^ee is enriched, the section of the en-

20t

SHEET METAL WORK

richment being indicated by a & in the section, in which the dotted line
d c shows the body of the sheet-metal moulding bent to receive, the
pressed work. In Kg 274, H represents part of a bed-mould in which

e(^l^«nd-dart enrichments are placed. In this case the body of the
mould is bent as shown by c d in the section, after which the egg-and-
dart is soldered or riveted in position. J in Fig. 275 represents part

Fig. 275.
of a footnnould on which an enriched bead is fastened. The body of
the mould would be formed as indicated by c in the section, and the
bead a b fastened to it. This same general method is employed, no
matter what shape the pressed work has.

PRACTICAL MITER CUTTINQ
Under this heading come the practical shop probl^ns. 'Hie prob-
lems which will follow ^ould be drawn to any desired scale by the
student, developed, and bent from stiff cardboard to prove the accu-
racy of the pattern. If the student cannot use the small brake in the
shop and test his patterns cut from metal, he can use the dull blade of
a table knife, over which the bends can be made, when using cardboard
patterns. This at once proves interesting and instructive not
only from the purely manipulation standpoint but also from the
faet that, in this manner, a check on the accuracy of one's work

SHEET METAL WORK

205

will be obtained. While the problenis selected cannot possibly
cover the whole field, th^ have been chosen with care so as to
illustrate sufBciently the basic principles involved.

The first problem will be to obtain the development of a square
return miter, such as would occur -v^en a moulding had to return
around the corner of a building, as shown in Fig. 276. In ¥ig. 277
are ishown two mrfliods of ob-
tiuning the pattern. The first
method which will be descnbed
is the "long" method, in which
are set forth all the principles
applicable to obtaining pat-
terns for mouldings, no matter ^- ^*-
what angle the plan may hava The second metliod is the "short"

, ELEVATION

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206 SHEET METAL WORK

rule generally employed in the shop, viiidi, however, can be used only
n^en the angle H G F in plan is 90*^, or a rif^t angle.

To obtain the pattern by the first method, proceed as follows:
First, draw the devation of tlie mould as shown by 1,B,A, 11, drawing
the coves by the rule previously given. Divide the curves into equal
spaces; and number these, including the comers of the fillets as shown
by the small figures 1 to 1 1. In its proper position below ttie devation,
draw the soffit plan as shown by C D E F G H. Bisect the angle H G
F by the tine G D, which is drawn at an angle of 45°. From the va-
rious intersections in the elevation, drop tines intersecting the mitei^line
as shown. At right angles to H G, draw the stretchout line 1' 11',
upon which place the stretchout of the mould 1 11 in devation, as
shown by similar figures on the line 1' 11'. At right angles to 1'
11', and from the numbered points thereon, draw lines, which intersect
by lines drawn at right angles to H G from similarly numbered inter-
sections on the miter-line G D. Trace a line through the intersectiofis

Fig. 278.
thus obt»ned, as shown by J G. Then will 1' G J 11' be the deared
pattern. This gives the pattern by using the miter-line in plan.

In developing the pattern by the short method, on the other hand,
the plan is not required. At right angles to 1 B in elevation, draw the
stretchout line 1' 11", upon whidi place the stretchout of the profile
1 11 in elevation, as shown by dmilar figures on 1' 11", at riglit
angles to which draw lines through the numbered points as shown,
which intersect by lines drawn at right angles to 1 B from similarly
numbered intersections in the profile in elevation. Trace a line through
points thus obtained, as shown by G K. Then will G 1* 11" K be
fOmilarto J G 1' 11' obtained from die plan.

SHEET METAL WORK 207

In Fig. 278 is shown a horizontal moulding butting against s
plane surface oblique in elevation. A miter cut of this kind would
be required when the return moulding of a dormer window would butt
against a mansard or other pitched roof. In thb case we assume A
to be the return butting against the pitched roof B. The method of

Fig. 279.

obtaining a pattern of thb kind is shown in Fig. 279. Let A B C D
represent the elevation of the return, A D representing the pitch of the
roof. In its proper position as shown, draw the section 1 11, whici
divide into equal spaces as shown, and from which, parallel to A B,
draw lines intersecting the slant line A D from 1 to 1 1, as shown. At
right angles to AB erect the stretchout line 1' 11', upon which place
the stretchout of the section as shown by similar figures on 1' 11'.
At right angles to 1' 11', and through the numbered points thereon,
draw lines, which intersect by lines drawn at right angles to A B from
similarly numbered intersections on the slant line A D. Through

SHEET METAL WORK

the various intersections thus obtained, draw E F. Then will E F
U' 1' be the desired pattern.

It is sometimes the case that the roof against whidi the moulding
butts, has a curved surface either concave dt convex, as shown by B C
in Fig. 280, which surface is convex. Complete the elevation of the
moulding, as D E; and in its proper portion draw the section 1 9,
which divide into equal spaces as shown by the small figures, from
which draw horizontal lines until they intersect the curved line B C,
which is struck from the center point A. At right angles to the Une
of the moulding erect the line 1' 9', upon which place the stretchout

Fig. 280.
of the section, as shown by the figures on the stretchout line. Throu^
the numbered points, at right angles to 1' 9', draw lines, which
intersect by lines drawn at right an^es to 2 D from similarly numbered
intersections on the curve B C, thus resulting in the intersections 1' to
9" in the pattern, as shown. The arcs 2" 3" and 7" 8' are simply repro-
ductions of the arcs 2 3 and 7 9 on B C. These area can be
traced by any convenient method; or, if the radius A C is not too long
to make it inconvenient to use, the arcs in the pattern may be obtuned
as follows: Using A C as radius, and 7" and 8" as centers, describe
arcs intersecting each other at A'; in similar manner, using 2* and 3'
as centers, and with the same radius, describe arcs intersecting each

SHEET METAL WORK

other at A*. Witb the same radius, and with A' and A' aa centers,
draw the arcs 8" 7" and 3" 2" respectively. Trace a hne through
the other various intersections as shown. Then will 1' 1" 9" 9' be the
desired pattern.

In Fig. 281 is shown an elevation of an oblong or rectangular
panel for which a miter-cut is de^red on the line a b — known as a
"panel" or "face" miter. 'Hie
rule to apply in obtEuning this
pattern is shown in Fig, 282.
A shows the part elevation of
the panel; a b and c d, the
mitCT-lines drawn at angles of
45*. In its proper poation
with the lines of the mould-
ingj draw the proffle B, the
curve or mould of which divide
into equal spaces, as shown
by the figures 1 to 7; and from
the points thus obtMned, par-
allel to 1 6, draw lines into

Fig. 28X. Fig. 282.

secting ttie miter-line a 6 as shown. From these intersections, par-
allel toh d, draw Unes int^secting also c d. At right angles tobd
draw the stretchout line 1' 7', upon which place the stretchout of the
profile B. At right angles to 1' 7', and through the numbered
points of division, draw hnes, which intersect by lines drawn at right
angles to b d from similarly numbered intersections on the miter-
lines a b and c d. Trace lines through the various points of inter-
section in the pattern as shown. Then will C D E F be the required
cut for the ends of the panel.

The same miter^^uts would be employed .for the long ^de acia

SHEET' METAL WORK

Fig. 281, it being necessaiy only to make D E in Fig. 282 that length
when laying out the patttem on the sheet metal.

Where the miter-cut is required for a panel whose angles are other
than right angles, as, for example, a triangular panel as shown in Fig.
283, then proceed as shown in Fig, 284. First draw the elevation of
the triangular panel as shown by A B C, the three sides in the case
bdng equal. Bisect each of the angles A, B, and C, thus obtfuning the
miter-lines Ae,Bb, and C a. In line with the elevation, place in its
proper position the profile
E, whidi divide into equal
spaces as shown; and from
the numbered division
points, parallel to A C, draw
lines cutting the miter-line
Ca. From these intersec-
tions, paralld to C B, draw
lines intersecting the miter-
line b B. At right angles to
C B draw the stretchout line
1' 7', upon which place the

Fig. 284.

stretchout of the profile E. Through the numbered points of divi-
sion and at right angles to 1' 7', draw lines as shown, which intersect
by lines drawn at right angles to C B from intellections of similat
numbers on the miter-lines a C and b B. Through the points thus
obt^ned, trace the pattern F G H I.

It makes no difference what shape or angle the panel may have;
the principles above explained are applicable to any case.

In ornamental cornice work, it often happens that tapering mould-
ed panels are used, apian and elevation of which are shown in I^. 285.

SHEET METAL WORK ■ 211

By referring to the plan, it will be seen that the four parts 6 a, a 6', 6* o*.
and a' h are symmetrical ; therefore, in practice, it is necessaiy only to
draw the on&<|uarter plan, as shown in Fig. 2S6, and omit the eleva-
tion, ^nce the hdght d e (Fig. 285) is known. Thus, in Fig. 286, draw
the quarter-plan of the panel, no matter what is its shape, as shown

Fig. 285.
by a 1 5 6 9. Divide the curves from 1 5 and 6 9 into equar
spaces, indicated respectively by 1, 2, 3, 4, and 5, uid 6, 7, 8, and 9.
From these points, draw lines to the apex a. As the pattern will be de-
veloped \fj triangulatbn, a set of triangles will be required, as shown in

_.SE!iiIElil,iNE.

Fig. 286.
Fig. 2S7, for which proceed as follows: Draw any horizontal line, as
a 1; and from a erect the perpendicular a a' equal to the height the
panel is to have. Now talce the lengths of the various lines in fig. 286
from a to 1, a to 2, a to 3, etc, to a to 9, and place them on the line a 1 in
FV. 287, as shown by «milar numbers, lluai u^ng as radii the various

* * Dun... ,A^OO^IC

212

SHEET METAL WORK

lengths a' 1, a' 2, a' 3, etc., to a' 9, and with any point, a5 a' in Fig.
288 as center, describe the various arcs shown from 1 to 9. From any
point on the arc 1 draw a line to a'. Set the dividers equal to the
spaces contained in the
curve 1 5 in Fig. 286; and,
starting from 1 in Fig. 288
step from one arc to an-
other having similar num-
bers, as shown from 1 to 5.
In similar manner, take the
distance from 5 to 6 and
*■ the spaces in the curve 6 9

in Kg. 286, and place them on corresponding arcs in Rg. 288, step-
ping from one arc to the other, resulting in the points 5 to 9. Trace
a line through the points
thus obtained. Then
win a' 1 5 6 9 o' be the
quarter-pattern, which
can be joined in one-
half OT whole pattern as
desred.

In Fig. 289 is shown
a perspective of a mould- pi^ 288.

ing which miters at an

angle other than a right angle. This occurs when a moulding is
required for over a bay window or other structure whose angles vary.
The rule given in Fig. 290 is applicable
to any angle or profile. First draw a
section or an elevation of the moulding
as shown by A B 14 1. Directly below
the moulding, from its extreme point,
as 2 3, draw a plan of the desired
angle as shown by C 2 D. Bisect this
angle by using 2 as center and, with
any radius, describing an arc meeting
the ffldes of the angle at C and E. With the same or any other radius,
and with C and E as centers, describe arcs intersecting each other in F-
From the comer 2, draw a line through F. Then will 2 H be the

Fig. 289.

SHEET METAL WORK

213

miter-line, or the line bisecting the angle C 2 D. Now divide the
profile 1 14 into equal spaces as shown by the %ure3, and from the
points thus obtained drop vertical Unes intersecting the miter-line 2

Pig. 290.
H in plan from 1 to 14 as shown-
At right angles to C 2, draw flie
line J K, upon which place the
stretchout of the profile in elevation
as shown by similar figures on the
stretchout line, through which drop
Hnes perpendicular to J K, which
intersect with lines drawn parallel
to J K from similarly numbered
^' points of intersection on the miter-

line 2 H. Trace a line as shown by L M, which is the miter-cut

desired.

When two mouldings having different profiles are required to

miter together as shown in Fig. 291, where C miters at right angles.

SHEET METAL WORK

with D, two distiiict operations are necessoiy, whidi are clearly shown
in Figs. 292 and 293. The first operation is ahown in Fig. 292, in
whidi C represents the elevation of an ogee moulding which is to
miter at right angles with a moulding of different profile as shown at D.

H Divide the profile C into equal

Jg" "-^'^'^"'^^la spaces, from which points draw
horizontal hnes intersecting the
moulding D from 1' to W. At
right angles to the line of the
moulding C, draw the hue A B,
upon which place the stretchout
of the profile C as shown by simi'
lar figures on A B. At right
angles to A B, and through the

PATTFHN FOR O
Fig. 292.

points indicated by the figures,
draw lines, which intersect with
lines drawn parallel to A B from
amilarly numbered intersections
in the profile D. Trace a line
through the points thus obtained,
as shown by E H. Then vrill E
F G H be the pattern for C in
elevation.

To obtain the pattern for D,
draw the elevation of D (Fig.

angles with a moulding whose profile is C. Proceed in precisely
the same manner as e9q>lained in connection with Fig. 292. Divide
the profile D in fig. 293 into equal parts, as shown, from
whidi draw horizontal lines cutting the profile C. ^ right angles

F^g. 2B3.
, which is to miter at right

SHEET METAL WORK 216

to the lines of the moulding D, draw the stpet<iiout line A B, upon

which place the stretdiout of the profile D. At right angles to A B,

and through the numbered points of division, draw lines as shown,

whidi intersect by lines drawn paralld to A B from similarly numbered

intersections in the profile C. Through these points of intersection

draw F G. Then will E F G H be the desired pattern for D.

It should be understood that ^en the patterns in Figs. 292 and

293 are formed and joined together, they will form an inside miter, as

is shown in fig. 291.

If, however, an outside

miter were required, it

would be necessaiy only

to use the reverse cuts of

the patterns in Figs. 292

and 293, as showQ by E J

H in Rg. 292 for the

mould C, and F J G in

Fig. 293 for the mould D. „ _

*,,„... Fig. 294.

When joining a

curved moulding with a straight moulding in either plan or eleva-
tion even though the curved or str^bt mouldings each have the
same profile, it is necessary to establish the true miter-hne before
the pattern can be correctly devdoped, an example being given in
Fig. 294, whidi shows an elevation of a curved moulding which
is intersected by the horizont^ mouldings A B. The method of ob-
twning this miter-line, also the pattern for the horizontal pieces, is
clearly shown in Fig. 295. First draw the profile whidi the horizontal
moulding is to have, as 1 10. Let the distance 9 B be established.
Then, with C on the center line as center, and A C as radius, describe
die arc B A. From any point on the line 9 B, as a, erect the vertical
line a b. Through the various divisions in the profile 1 10, draw
horizontal lines intersecting the vertical line a b from 1 to 10 as shown.
From the center C, draw any radial line, asCd, cutting the arc B A at e.
Now take the various divisions on a b, and place them from etodaa
shown by points 1' to 10*. Then, using C as center, with radii deter-
mined by the various points on e d, draw arcs intersecting horizontal
Unes of sinular pupbers dTftVQ through the dividoQs on tt b. Through

SHEET METAL WORK

these points of interaection, draw the miter-line shown. The student
will note that this line is insular.

Having obtained the miter-line, the pattern is obtained for the
horizontal moulding by drawing the stretchout line E F at right angles
to 9 B. On E F lay off the stretchout of the profile 1 10; and
through the numbered points and at right angles to E F, draw hori-
zontal lines, which intersect with lines drawn at right angles to 9 B
from similariy numbered in-
tersections in the miter-line
determined by horizontal Unes
already drawn throu^ the
vertical line o b. Trace a line
through the points thus ob-
tdned, as shown by H I J K,
which is the desired pattern.

Fig. 295. Fig. 296.

In Fig. 29(i is shown a shaded view of a gable moulding intersect-
ing a pilaster, the gable moulding B cutting against the vertical pilaster
A, the joint-line being represented by a 6 c. To obtain this joint-line,
without which the pattern for the gable moulding cannot be developed,
an operation in projection is required. This is explained in Fig. 297,
in \rfiicli BCD sliows the plan of the pilaster shown in elevation by E.
In its proper position in plan, place the profile of the gable moulding,
as shown by A, which divide into equal spaces as shown by the figures
1 to 8, through which draw horizontal lines intersecting tlie plan of the
pilaster B C D as shown by similar figures. For convenience in pro-

SHEET METAL WORK

217

jecting the various points, and to avoid a confu^on of lines, number
the intersections between the lines drawn from the profile A thtough
the wash B 2, "7°", "4°", and "3°". At the desired point H in deva-
tion, draw the lower line of the gable moulding, as H F. Take a
tracing of the profile A
in plan, with all of the
various intersections on
same, and place it in
elevation as shown by
A', pladng the line 1 8 at
right angles to H F.
Tlirough the various in-
tersections 1, 7°, 4°, 3",
2, S, 4, 5, 6, 7, and 8 in
A', and parallel to F H,
draw lines ind^nitdy,
whidi intersect by lines
drawn at right angles to
C B in plan from ^-
ilariy numbered intersec- ,
lions in the pilaster C D
B, thus obtuning the
points of intersection 1^
to 8^ in elevation.

For the pattern, pro-
ceed as follows: At right
angles to H F, draw the
stretdiout line JK, upon
which place the stretch-
out of the profile A or A*,
with all the points of in-
tersection on the wash ^- ^^-
1 2. At right angles to J K, and through the numbered points, draw
lines as shown, which intersect by lines drawn at right angles to H
F from similarly numbered intersections in the joint-Une 1' 8*
Through the points thus obtained, trace the miter-cut M N O. Then
will L M N O P be the pattern for the gable moulding.

In Fig. 298 are shown gable mouldings mitering upon a wash. The

218

SHEET METAL WORK

mouldings A A intersect at any desired angle the wash B. In diis case,
as in the preceding problem, an operation in projection must be gone
through, before the pattern can be obtained. This is clearly shown
in Fig. 299. Draw the section of the
horizontal moulding B* with the wash
a b. From this section project lines,
and draw the part elevation D C.
^- 288. Knowing the bevel the gable is to

have, draw C B, in thU case the top line of the moulding. Draw a
section of the gable mould, as A, which divide into equal parts as
shown from 1 to 8; and through the point of division draw lines
parallel to B C, indefinitdy, as shown. Take a tradng of the profile '
A, and place it in section as shown by A*. Divide A into the same

ELEVATION
Fig. 299.
number of spaces as A; and from the various divisions in A* drop
vertical lines intersecting the wa^ a 6 as shown, from which points
draw horizontal lines intersecting lines drawn parallel to B C
through amilarly numbered points in A, at 1'' to 8°. Trace a line
through these intersections as shown, which represents the miter-line
or line of joint in elevation.

For the pattern, draw any line, as E F, at right angles to B C, upon
whidi place the stretchout of the profile A, as shown by similar figures
on the stretchout line E F. Through the numbered pomts of diviaon
and at right angles to E F, draw lines as shown, which intersea by

SHEET METAL WORK 219

lines drawn at rigHt angles to B C from similarly numbered intersec-
tions on 1° 8° and on the vertical line B D. A line traced through
points thus obtmned, as shown by G H IJ, will be the desired pattern.

In Pig. 300 is shown a front view of a turret on which four gables
are to be placed, as shown by A A; also die roofs
over same, as shown by B B. The probl^n con-
sists in obtiuning tbe developments of the gable
mouldings on a square turret. In developing
this pattern, the half-elevation only is required,
as shown in Fig. 301, in whidi first draw the
center hne E F; then establish the half-width of
the turret, as C D, and draw the rake B C. At
right angles to the line B C, and in its proper
position as shown, draw the profile A, which
divide into equal spaces as shown by the figures
1 to 6, through whidi, parallel to B C, draw hues intersecting the
center line F E as shown; and extend the lines bdow C, indefinitely.
Now take a tradng of the profile A, and place it in position as
shown by A', bang careful to have it spaced in flie same number of
divisions, as shown from 1 to 6, through which, parallel to D C, erect
lines intersecting similarly numbered lines drawn through the profile
A, thus obtaining the intersections 1° to 6°, through which a line is
traced, which represents the line of joint at the lower end between
the two gables.

For the pattern, take a stret<diout of A, and place it on the line
J K drawn at ri^t angles to B C, as shown by the figures 1 to 6 on J K.
At right angles to J K, and through these points of division, draw lines,
whidi intersect by lines drawn from ^milarly numbered intersections
on F B and 1° 6^*. Trace a line through the points thus obtained,
as shown by F° B° C° 6°, which is the desired pattern, of which eight
are required to complete liie turret, four formed right and four lefL

If the roof shown by B in Fig. 300 is desired to be added to the
pattern in Fig. 301, tiien, at right angles to F° 6*, draw the line F° P
equal to F H in the half-devation, and draw a line from P to 6^ in the
pattern.

In Fig. 302 is shown front ^ew of an angular pediment with hori-
zontal returns at bottom A and top B. In this problem, as in others
whii^ will follow, a change of profile is Qecessaiy bdore th« correct

220

SHEET METAL WORK

pattern for the returns can be developed. In other words, a new piCK
file must be developed from the given or nonnal profile before the pat-
terns for the required parts can be devdoped. It should be under-
stood that all given profiles are aiways divided into equal spaces; there-
lore the modified profiles will contain unequal spaces, eadi one ot

Fig. 301.
which must be carried separately onto the stretchout line. Bearing
this in mind, we shall proceed to obtain the modified or changed pro-
files and patterns for the horizontal returns at top and foot of a gable
moulding, as at B and A in Fig. 302, the given profile to be placed in the
gable moulding C. In Fig. 303, let C represent the gable moulding

DUN... ,AiOo;;lc

SHEET METAL WORK 221

placed at its proper angle with the horizontal moulding G H. Assum-
ing that 6^ 6° is the proper angle, place the given profile A at right
angles to the rake, a^ shown; and divide same into equal spaces as
shown from 1 to 10, through which points, parallel to 6' 6° drawUnes
towards the top and bottom of the
raking moulding. Assuming that the
length 6* 6° is correct, take a tracing
of the profile A, and place it in a ver-
tical positicn below at A' and above
at A', being careful to have the points
fi and 6 in the profiles directly m a ver- ^s- 303,

tical position below the points 6* and 6°, as shown. From the va-
rious intersections in the profiles A^ and A^ (which must contmn the
same number of spaces as the given profile A), erect vertical lines
intersecting lines drawn through the profile A, as shown at the lower
end from 1" to 1(F, and at the upper end from 1° to 10°. Trace a line
through the points thus obtained. Then will 1' 1(F be the modified
profile for the lower horizontal return, and 1° 10° the modified profile
for the upper horizontal return.

Note the difference in the shapes and spaces between these two
modified profiles and the given profile A. It will be noticed that a
portion of the gable moulding miters on the horizontal moulding G H
from 6"^ to 10".

For the pattern for the gable moulding, proceed as follows: At
right angles to E F, draw tlie stretchout line J K, upon which place
the stretchout of the given profile A, as shown by the figures 1 to 10 on
J K. Through these figures, at right angles to J K, draw lines as
shown, which intersect with lines drawn at right angles to E F from
similarly numbered intersections in 1" 10° at the top and 1* 6"
IC at the lower end. Trace a line through the intersections thus ob-
tdned. Then will L M N O be the pattern for C.

For the pattern for the horizontal return at the top, draw a side
view as shown at B, making P R the desired projection, and the profile
1 10 on B, with its various intersections, an exact reproduction of
1° 10° in the elevation. Extend the line R T as R S; and, starting
from 10, lay off the stretchout of the profile in B as shown by the figures
1 to 10 on R S, being careful to measure each space separately. At
right angles to R S draw the usual measuring lines, which intersect

222 SHEET METAL WORK

hy lines drawn parallel to S R from similarljr numbered points in the
profile in B. Trace a line through points thus obtained. Then will
U y 10 1 be the pattern for the return B.

In ^milar manner, draw the side view of the lower horizontal
return as shown at D, making the projection W 10 equal to P R

m B. The profile shown from 1 to 10 in D, with all its divisions, is
to be an exact r^roduction of the profile 1" to 10" in elevation. Extend
the line W X as X Y, upon which lay off the stretchout of the profile
1 10 in D, being careful that eadi space is measured separatdy,
as tb^ are all unec|ual. 'fhiouf^h the figures op X Y draw UncQ m

SHEET METAL WORK

shown, whidi intersect by lines drawn parallel to W Y from the various
intersections in the profile in the side D. A line traced through points
thus obtained, as shown by Z V, wiU be the desired cut, and 1 Z
V 10 the pattern for the return D.

In fig. 304 is shown a front view of a segmental pediment widi
upper and lower horizontal returns.
rOiis presents a problem of obttuning
&e pattern for horizontal returns at
top and foot of a s^mental pediment,
shown respectively at A and B, the
^ven profile to be placed in C. The ^- ^^■

principles used in obtaining these patterns are similar to those
in the preceding probl^n, the only difference being that the mould-
ing is curved in elevation. In fig. 305 the true method is clearly
given. First draw the center line B D, through which draw the horizon-

ia — ^— M

Fig. 305.
tal line C C?. From the line C C estabUsh the haght B ; and with the
desired center, as B, draw the arc E C intersecting the line C* C at C. ,
In its proper position on a vertical line F G, paralld to D B, draw the
given profile of the curved moulding as shown by A, which divide into
equal spaces as shown from 1 to 10. Hirough these figures, at right
angles to F G, draw lines intersecting the center line D B as shown.

SHEET METAL WORK

Tien, using B as center, with radii of various lengths corresponding
to the various distances obtained from A, describe arcs as shown, ex-
tending them indefinitely below the foot of the pediment. The point
C or 6* being established, take a tracing of the profile A, with all the
various points of intersection in same, and place it as shown by A^,
being careful to have the point 6 in A^ come directly below the point
G" in elevation in a vertical position, llien, from the various inter-
sections in A' erect vertical lines intersecting sunilarly numbered arcs
drawn from the profile A. Trace a line as shown from 1" to lO*,
which is the modified profile for die foot of the curved moulding.

Establish at pleasure the point 1' at the top, and take a tracing
of the given profile A. pladng it in a vertical position below 1', as
shown by A', From the various
intersections in A' erect verticfJ
lines intersecting similarly num-
bered arcs as before. Through
these intersections, shown from
1' to IC, trace the profile shown,
which is the modified profile for
the top return.

The curved moulding shown
in elevation can be made either
by hand or by machine. The
general method of obtaining the
blank or pattern for the curved
moulding is to average a line through the extreme points of the
profile A, as I J, extending it until it intersects a line drawn at right
angles to D B from the center B, as B H, at K.

We will not go into any further demonstration about this curved
work, as tlie matter will be taken up at its proper time later on.

To obtain the pattern for the upper and lower return mouldings,
proceed in precisely the same manner as explained in connection with
returns B and D in Fig. 303.

In Fig. 306 are shown the plan and elevation of a gable moulding
in octagon plan. This problem should be carefully followed, as it
presents an interesting study in projections; and the principles used in
solvmg this are also applicable to other problems, no matter what
angle or pitch the gable has. By referring to the plan, it will be seen

SHEET METAL WORK 226

that the moulding has an octagon angle in plan ab c, while similar
points in elevation a' b' c' run on a rake in one line, the top and foot
of llie moulding butting ag^nst the brick piers 6 and A.

The method of proceeding with work of this kind is explained in
detail in Fig 307, where the principles are thoroughly expldned. Let
A B C D E represent a plan view of the wall, over wliicb a gabU
moulding is to be placed, aa shown by G H IJ, the given juofiU of thf

Fig. 307.
moulding being shown by L M. Divide the profile into equal spaces
as shown by the figures 1 to 8. Parallel to I H or J G, and through the
figures mentioned, draw hnes indefinitdy as shown. Bisect the angle
B C D in plan, and obtain the miter-line as follows : Vfith C as center,
and any radius, describe the arc N O. With N and O as centers, and
any radius greater than C N or C O, describe arcs intersecting eadi
other at P. From the point C, and through the intersection P, draw
the miter-line C Q. Transfer the profile L M in elevation to the posi-

SHEET METAL WORK

tion shown by R S in plan, dividing it into the same number of spaces
as L M. Through tiie figures in the profile R S, and parallel to D C,
draw lines intersecting the miter-line C Q, as shown. From tiie inter-
sections on (be miter-line, and parallel to C B, draw lines intersecting
the surface B A. Now, at right angles to C D in plan, and from the

Fig. 308.

inteisections on the miter-line C Q, draw vertical lines upward, int»v
secting lines of similar numbers drawn from points in profile L M in
elevation parallel to J G. A line traced through points thus obtained,
as shown from I' to 8', will be the miter-line in elevation.

For the pattern for that part of the moulding shown by C D E Q'
in plan, and H G S' 1' in elevation, proceed as follows: At right
angles to 1 H in elevation, draw the line T U, upon which place the

SHjsET metal work 227

stretchout of the profile L M, as shown by the figures 1 to 8. At right
angles to T U, and through these figures, draw lines, as shown, which
intersect with lines of similar numbers drawn at right angles to 1 H
from intersections on the miter-line 1' S' and from intersectioDs
against the vertical surface H G. Lines traced through points thus
obtained, as shown by V W X Y, will be the pattern for that part of
the gabie shown in plan by C D E Q' of Pig. 307.

In Fig. 308, on the other hand, the position of the plan is changed,
so as to bring the line A Q horizontal. At right angles to 6 C draw
the vertical line C £, on wliidi locate any point, as K. In the same
manner, at right angles to C B, draw the vertical Une.B J indefinitely.
From the point E, parallel to 6 C, draw the line E 8', intersecting
the line J B, as shown. Now take the distance from S" to J in deva-
tion. Fig. 307, and set it off from S" toward J in Fig. SOS. Draw a line
from J to £, which will represent the true rake for this portion of the
moulding. Now take the various heights shown from 1 to 8 on the
line Z Z in elevation in Fig. 307, and place them as shown by Z Z in
elevation, 1%. 308, b^ng careful to place the point 8 of tiie
line Z Z on the line 8' E extended. At right angles to Z
Z, and from points on same, draw lines, which intersect
with lines drawn at right angles to B C from intersec-
tions of dmilar numbers on C Q in plan. A line traced
dirough points thus obtained, as shown by D E in eleva-
tion, will be the miter-line on C Q in plan.

From the intersections on the miter-line D E, and i
parallel to E J, draw lines, which intersect with lines '
drawn from intersections of similar numbers on A B in '
plan at right angles to B C. A line traced through points
thus obtained, as shown by F J, will be the miter-line ^- ^^■
or line of joint against the pier shown in plan by B A.

Before obtaining the pattern it will be necessary to obtun a true
section or profile at right angles to the moulding F D, To do so, pro-
ceed as follows: Transfer the given profile L M in elevation in Fig.
307, with the divisions and figures on same, to a position at right angles
to F D of Fig. 308, as shown at L. At right angles to F D, and from
the intersections in the profile L, draw lines intersecting those of simi-
lar numbers in F D E J. Trace a line throu^ intersections thus ob-

SHEET METAL WORK

t&ined, as shown from 1 to 8, thus giving the profile M, or true sectbns
at right angles to F D.

For the pattern, proceed as follows: At right angles to F D,
draw the line H K, upon which place the stretchout of the profile M, as
shown b;* the figures. At right angles to H K, and through the figures,
draw lines, whidi intersect with those of similar numbers drawn at

Fig. 310. Fig. 311.

right angles to F D from points of intersection in the miter-lines D E
and J F, as shown. Lines traced through points thus obtained, as
shown by N O P R, will be the pattern for the raking moulding shown
in plan, Fig. 307, by A B C Q'.

In Fig. 309 is shown a view of a spire, square in plan, intersecting
lour gables. In practice, each side A is developed separately in a
manner shovra in Fig. 310, in which first draw the center line through
the center of the gable, as E F. Establish points B and C, from which

SHEET METAL WORK

229

draw lines to the apex F. At pleasure, establish A D. At right angles

to F E, and from B and J, draw the lines B H and J K respectively.

For the pattern, take the distances B K, K A, and A F, and place them

as shown by similar letters

on the vertical line B F in

Kg. 311. At right angles s

to B F, and through points

B and A, draw lines as

shown, making B H and B

H' on the one hand, and

A N and A O on the other

hand, equal respectively to

B H and A N in elevation in

Fig. 310. Then, in Rg.

Fig. 312. Fig. 313.

311, draw lines from NtoHtoKtoH'toO, as shown, which repre-
sents the pattern for one side.

In Rg. 312 is shown a perspective view of a drop B mitering
against the face of the bracket C as indicated at A. The prindples
for developing this problem are explained in Fig. 313, and can be ap-
plied to similar work no matter what the profiles of the drop or bracket
may be. Let A B C D E represent the face or front view of the bracket
drop, and F H G I the side of the drop and bracket. Divide one-half
of the face, as D C, into equal spaces, as shown by the figures 1 to 7
on either side, from which points draw horizontal lines crossing H G
in side view and intersecting the face H I of the bracket at points 1' to
7'. In line with H G, draw the line J K, upon which place the stretch-
out of the profile B C D, as shown by 1 to 7 to 7 to 1 on J K. At right
angles to J K, draw the usual measuring lines as shown, which inter-
sect by lines drawn parallel to J K from similarly numbered interseo-
tioos on H I. Trace a line through the points thus obtwned. Then

^ Dun... ,AiOOglC

230 SHEET METAL WORK

will J K L be the pattern for the return of the drop on the face of the
bracket

In Fig. 314, A shows a raking bracket placed in a gable moulding.
When brackets are placed in a vertical position in any raking moukling,
they are called "raldng" brackets. 6 represents a raking bracket
placed at the center of the gable. The patterns which will be develop-
ed (or the bracket A are also used for B, the cuts being similar, the only
difference being that one-half the
width of the bracket in B is
formed right and the oUiet half
left, the two helves being then
joined at the angle as shown.

In Fig. 315 are shown the
principles employed for obtain-
ing the patterns for the side,
face, sink strips, cap, and returns
for a raking bracket These
prindples can be applied to any
^' ' form or angle in the bracket or

gable moulding respectivdy. Let S U V T represent part of a
front elevation of a raking cornice placed at its proper angles with
any perpendicular line. In its proper position, draw the outline of the
face of the bracket as shown by E G M O. Also, in its proper position
as shown, draw the normal profile of the side of the bracket, indicated
by 6-Y-Z-15; the normal profile of the cap-mould, as W and X; and
the normal profile of the ^nk strip, as indicated by 10 10' 15' 15.
Complete the front elevation of the bracket by drawing lines par-
allel to E O from points 7 and 9 in the normal profile; and establish
at pleasure the width of the sink strip in the face of the bracket, as at
J K and L H. To complete the front elevation of the cap-mould of
the bracket, proceed as follows: Extend the lines G E and M O of the
front of the brackets, as shown by E 6 and O 6, on which, in a vertic^
position as shown, place duplicates (W', W*) of the normal profiles W
and X, divided into equal spaces as shown by the figures 1 to 6 in W
and W*. From these intersections in W and W, drop vertical fines,
.^ch intersect by lines drawn parallel to E O from similariy numbered
intersections in X, and trace lines through the points thus obtained.
Then will R E and O P represent respectively the true elevations, also

Bu ,,A-oo!;lc

SHEET METAL WORK 231

the true profiles, for the leturns at top and foot of the cap of the raking
biacket.

Now divide the nonnd profile of the bracket into equal spaces, as
shown by the figures 6 to 15, through which, parallel to E O, draw lines
intersecting the normal ank profile from lO* to 15' and the face lines
of the bracket EFG, JH, KL, and ONM, as shown. To obtain the

Fig. 31 S.
true profile for the side of the bracket on the lines OM and GE, pro-
ceed as follows : Parallel to OM, draw any line, as Y' Z' ; and at right
angles to OM, and from the various intersections on the same, draw
fines indefinitely, crossing to the line Y' Z* as shown. Now, measuring
in each instance from the line YZ in the normal profile, take the various
distances to points 6 to 15 and 15' to lO", and place them on aimllariy
numbered lines measuring in eadi and every instance from the line
Y* 7>, thus obtaining the points 6' to 15' and 15" to 10", as shown.
Trace a line through the points thus obtuned. Then will Y* 6'
7' 0' IC 15' Z* be the pattern for the tdde of the raldng bracket,

SHEET METAL WORK

and IC 10" 15" 15' the pattern for the sink strip shown by the
lines K L and H J in the front.

For the pattern for the face strip B, draw any line, as A' B', at
right angles to G M, upon which place the stretchout of 10 15 in the
normal profile, as shown from 10 to 15 on A' B'. Tlirough these
points, at right angles to A' B', draw lines as shown, whidi intersect
with lines drawn from similar intersections on the lines F G and H J.
Trace a line through points thus obtained as shown by F* G° H° J°,
which will be the pattern for the face B, B.

For the pattern for the sink-face C, draw C D* at right angles to
GM, upon which place the stretchout of 10' 15' in the normal profile
aa shown from 10' to 15' on C D', through which, at right angles to
C D', draw lines, which intersect by _^

lines drawn from similar intersections
on K L and H J. Trace a line through
the points so obtained as J° K° L° H",
which in the pattern for the sink-
face C.

The pattern for the cap D and
the face A will be developed in one
piece, by drawing at right angles to
EO the line E' F». At right wigles

Fig. 316. Fig. 317.

to E' F', and through the figures, draw lines, which intersect with lines
drawn at right angles to EO from similarly numbered intersections on
REF and NOP. A line traced through the points thus obtained, as
shown by R" E" F° and N° 0° V° will be the pattern for D and A.

For the patterns for the cap returns R E and O P, draw any line
at right angles to 1 1 in the normal profile, as H' G', upon which
place the stretchouts of the profiles R E and O P, being careful to carry
eadi space separately onto the line H^ G', as shown respectively by
6' 1'' and 6* 1'. Through these points draw lines at right angles to
G' H*, whidi intersect by lines drawn at right angles to 1 1 from

SHEET METAL WORK

^milar numbers in W and X. Trace lines through the points thus
obtEuiied. Tien will N^ O* R' S' be the pattern for the lower return
of the cap, R E; while J* M' L' K* will be the pattern for the upper re-
turn, PO. .

In Fig. 316 i$ shown a perspective view of a gutter or eave-
trough at an exterior angle, for which an outside miter would be re-
quired. It is immaterial what shape the gutter has, the method of
obtaJning the pattern for the miter is the same. In Fig. 317 let 1 9
10 represent the section of the eave-trough with a bead or wire
«dge at afc c; divide the wire edge, including the gutter and flange, into
an equal number of spaces, as shown by the small divisions d to 1 to 9
to 10. Draw any vertical line, as
A B, upon which place the stretch-
out of the gutter as shown by simi-
lar letters and numbers on A B,
through which, at right angles to
A B, draw lines, which intersect by

I'ig. 318. Fig. 319.

i'nes drawn parallel to AB from similar points in the section. Trace
4 line through the points thus obtained. Then will C D E F be the
pattern for the outside angle shown in Fig. 316.

If a pattern is required for an interior or inside angle, as is shown
in Fig. 318, it is necessary only to extend the lines C and F E in the
pattern in Fig. 317, and draw any vertical line, as J H. Then will J D
E H be the pattern for the inside angle shown in Fig. 318.

In Fig. 319 are shown a plan and elevation of a moulding which
has mo re projection on the front than on the side. In other words, A B
represents the plan of a brick pier, around which a cornice is to be
constructed. The projection of the given profile is equal to C, the
profile in elevation being shown by C*. The projection of the front
in plan is also equal to C, as shown by C. The projection of the left
side of the cornice should be only as much as is shown by D in plan.
This requires a change of profile through D, as shown by D'. To ob-

234

SHEET METAL WORK

ttun this true profile and the various pattems, proceed as shown in
Fig. 320, in which A B C D t^resents the plan view of the wall, agtunst
which, in its proper position, the profile E is placed and divided into
equal spaces, as shown hj die figures 1 to 12. Through 1 2, par-
alld to C D, draw G F. Locate at pleasure Hie projection of the re-

Flg. 320.
turn mould, as B H, and draw H G parallel to B C, intersecting F G
at G. Draw the miter-line in plan, G C. From the various divisions
in the profile E, draw Hues parallel to C D, intersecting the miter-line
C G as shown. From these intersections, erect vertical lines indefi-
nitely, as shown. Parallel to these lines erect the line K J, upon whidi
place a duphcate of the profile E, with the various divisions on as^cae,
aa shown by E*. Through these diviMons draw horizontal lines in*

SHEET METAL WORK

tersectiog the similarly numbered vertical lines, as shown by the in-
tersections V to 12'. Trace a line through these points. Then will
F* be die true section or profile on H B in plan.

For tiie pattern for the return H G C B in plan, extend the line
B A, as B M, upon whidi place the stretdiout of the profile P, bang
careful to measure eadi space separately (as ^ey are unequal), as
shown by figures 1' to 12' on M B.

At right angles to diis line and through the figures, draw lines,
whidi intersect by lines drawn at right angles to H G from ^milar
points on C G. Trace a
line through the points
thus obtained. Then
wiU H>G>C'B' be the
pattern for the return
mould.

The pattern for the
face mould GCDF Is
obtained by taking a
stretchout of the profile
E and pladng it on the

vertical Une P O, as shown by similar figures, through which, at
right angles to F O, draw lines intersecting similarly numbered lines
previously extended from C G in plan. Trace a line through these
intersections. Then will 1 B' C 12 be the miter pattern for the face
mould.

In Fig. 321 is shown a perspective view of a gore piece A joined
to a diamfer. Tliis presents a problem often ariui^ in ornainental

236 SHEET METAL WORK

sheet-metal work, the development of which is given in Fig. 322. Let
. A B C D show the elei'ation of the comer o'n which a gore piece is re-
quired. H 7' E in plan b a section through C D, and E F G H is
a section through X I, all projected from the elevation as shown. The
profile 1 7 can be drawn at pleasure, and at once becomes the pattern
for the sides. Now divide the profile 1 7 into an equal number of
spaces as shown, from which drop vertical lines onto the side 7' E
in plan, as shown from 1' to 7'. From these points draw lines parallel
to F G, intersecting the opposite side and crossing the line 7' 1"
^ (which is drawn at right angles to F G

from 7') at 1' 2* 3' 4' 5* 6". Draw any
line parallel to C D, as K J, upon which
place all the intersections cont^ned on 7'
1" in plan, as shown by 1° to 7° on K J.
From these points erect perpendicular lines,
which intersect by lines drawn from simi-
larly numbered points in elevation parallel
to C D. Through the points thus obt^ned
trace a line. Then will l'^ to 7^ be the true
profile on 7' 1" in plan.
For the pattern for the gore, draw any vertical line, as A 6 in Fig
323, upon which place the stretchout of the profile 1' 7'' in Fig. 322,
as shown by similar figures on A B in Kg. 323. At right angles to AB,
and through the figures, draw lines as shown, Now, measuring in
each instance from the line 7' 1' in plan in Fig. 322, take
the various distances to points 1' to 7', and place them ■
in Kg. 323 on similarly numbered lines, measuring in
each instance from the line A B, thus locating the points Fig. 324.
shown. Trace a line through the points thus obtained. Then will
F G 7 be the pattern for the gore shown in plan in Fig. 322
by F G 7'.

In Fig. 324 is shown a face view of a six-pointed star, which often
arises in cornice work. No matter how many points the star has, the
prindples which are explained for its development are applicable to
any ^ze or shape. Triangulation is employed in this problem, as
shown in Ilg. 325. lirst draw the half-outline of the star, as shown by
A B C D E F G. Above and parallel to the line AG. draw JH of
similar length, as shown. Draw the "ection of the star on A G in plan.

SHEET METAL WORK

as shown by J K H. Project K into plan aa shown at I, and draw the
miter-lines B I, C I, D I, E I, and F I. As K H is the true length on
I G, it is necessaiy that we find the true length on I F. Uang I F as
radius and I aa center, draw an arc intersecting I G at a. From a
erect a line cutting J H in section at t. -

Draw a line from b to K, whidi is the
true length on I F,

For the pattern, proceed as
shown in Jig. 326. Draw any line, '
as K H, equal in length to K H in Fig.
325. Then, using K b as radius and
K in Fig. 326 as center, describe the
are b b, which intersect at a and a by
an arc G G struck from H as center
and with F G in plan in Fig. 325 as
radius. Draw lines in Fig. 326 from
KtoatoHtoatoK, which will be the pattern for one of the points
of the star of which 6 are required.

When bending the points on the line HK, it is necessary to have a
stay or profile so that we may know at what angle the bend should be
made. To obtain this stay, erect from the comer B in Pig. 325 a line
intersecting the base-line J H at c, from which point, at right angles to
J K, draw c d. Using c as center, and c d as radius, strike an arc inters
secting J H at e. From e drop a vertical line meeting A G in plan at
d'. Set off i B' equal to i B, and draw a line
from B to d' to B*, which is the true profile
after which the pattern in Fig. 326 is to be
bent. If the stay in Fig. 325 has been cor-
rectly developed, then d' B' or d' B must equal
e a in F%. 326 on both sides.

In Fig. 327 is shown a finished elevation
of a hipped roof, on the four comers of which
a hip ridge A A butts agtunst the upper base B
and cuts off on a vertical line at the bottom, as C and C. To obtun
the true profile of this hip ridge, together with the top and lower cuts
and the patterns for the lower heads, proceed as shown in Fig. 328,
where the front elevation has been omitteii, this not being necessaiy,
as only the part plan and diagonal elevation are rsquired. First draw

PATTERN FOR

SHEET METAL WORK

the part plan as shown byABCDEFA, placing the hip or diagonal
line F C in a horizontal podtion; and make the distances betwera the
lines F A and C 6 and betwera F E and C D equal, because the roof
in thb case has equal pitch all around. (The same prindples, how-
ever, would be used if the roofs had unequal pitdies.) Above
the plan, draw die line
G H. From the poiots
F and C in plan, erect
the lines F G md C I,
extending C I to O so
that I C* will be the re-
quired height of the root
above G I at the point
C in plan. Draw a line
■Fbont elevation '^ from G to C, and from
C* draw a horizontal and
vertical line IndeSnitely,
u shown. Then will I G C be a true section on the line of the
roof on F C in plan.

The next stq> is to obttun a true section of the angle of the roof at
right angles to the hip line G O in devation. This is done by drawi&g
at rig^t angles to F C in plan, any line, as ab, intersecting the lines
F A and F E as shown. Extend a b until it cuts the base-line G I in
devation at c. From e, at right angles to G C, draw a line, aae d,
intersecting G C at d. Take the distance e d, uid place it in plan on
tiie line F C, measuring from i to d'. Draw a line from a to tf to 6,
whicli is the true angle desired. On this angle, construct the dew«d
shape of the hip ridge as shown by J, eadi half of which divide into
equid spaces, as shown by the figures lto6tol. As the line GC rep-
resents the line of the roof', and as the point d' in plan in the true angle
also represents that line, then take a tradng of the profile J with the
various points of intersection on same, together with the true angle
a d' h, and place it in the devation as shown by S^ and a' d" b', bong '
careful to place the point d" on the line G C, making a' b' parallel to
G C. From the various points of intersection in the profile J, draw
lines pardlel to F C, intersecting B C and A F at points from 1 to 6.
as shown. As both sides of the profile J are symmetrical, it is necessary
only to draw lines through one-halt

SHEET METAL WORK

In similar manDer, in elevation, parallel to G C, draw Ones
chiougb the various intersections in J*, whidi intersect hy lines drawn
at right angles to F C in plan from similarly numbered points on A F

Emd BC. Trace a line througli the points thus obtiuned. l^en will

K L be tile miter-Une at the bottom, and M N the miter-line at the top.

For the pattern, draw any line, as O P, at right angles to CrXS

240 SHEET METAL WORK

upon which place the stretdiout of J in plan or J' in elevation, as shown
by the figures lto6tolonOP; and through these numbered points,
at right angles to O F, draw lines, which intersect by lines drawn at
right angles to G C from similar intersections in the lower miter-line
K L and upper miter-line N M. Trace a line through the points thus
obtained. Then will R S T U be the desired pattern.

In practice it is necessary only to obtain one miter-cut — rather the
top or the bottom — and use the reverse for the opposite side. In other
words, U T is that part falling out of R S, the same as R S is that part
which cuts away from U T. The upper miter-cut butts against B in
Fig. 327; while the lower cut requires a fiat head, as shown at C. To
obtain this flat head, extend the line I G in Fig. 328, as I W, upon
which place twice the amount of spaces contained on the line A F in
plan, as 6, 3—5, 4, 1, 2, as shown by similar figures on either side of
6 on the line V W. From these divisions erect vertical lines, which
intersect by lines drawn parallel to V W from similarly numbered
intersections in the miter-line
K L G. A line traced through
the points thus obtained, as
shown by X Y Z, will be the
pattern for the heads.

Where a hip ridge is re-
quired to miter with the apron
of a deck moulding, as sho^i'n
in Fig. 329, in which B repre-
sents the apron of the deck cornice, A and A the hip ridges mitering
at a and a, a slightly different process from that described in the
preceding problem is used. In this case the part elevation of the
mansard roof must first be drawn as shown in Fig. 330. L«t ABC
K represent the part elevation of the mansard, the section of the
deck moulding and apron being shown by D B E. Draw E X par-
allel to B C. EX then represents the line of the roof. In its proper
position, at right angles to B C, draw a half-section of the hip mould,
as shown by F G, which b an exact reproduction of B E of the d^
mould. Through the corners of the hip mould at Y and G, draw
lines parallel to B C, which intersect by lines drawn parallel to B A
from V, W, and E in the deck cornice. Draw the miter-line H I,
which completes the part elevation of the mansard.

Dg,l,:^..,,G00glc

Fig. 329.

SHEET METAL WORK

241

Before the patterns can be obtained, a developed surface of the
mansard must be drawn. Ilierefore, from B (Pig. 330), drop a vav
tical line, as B J, intersecting the line C K at J. Now take the dis-
tance of B C, and place it on a vertical line in Fig. 331, as shown by
B C. Through these two points draw the horizontal lines B A and
C K as shown. Take the projection J to C in Fig. 330, and place it as

Pig. 330.
shown from C to C in Fig. 331, and draw a line from C to B. Then
will A B C K be the developed surface of A B C K in Fig. 330.

As both the profiles B V W E and F Y G are similar, take a tracing
of either, and place it as shown by D and D' respectively in Fig. 331.
Divide both into the same number of equal spaces, as shown. Bisect
the angle A B C by establishing a and b, and, using these as centers,

342

SHEET METAL WORK

by describing arcs intersecting at c; then draw d B, which represents
the miter-line. Ilirough the points in D and D*, draw lines paralld
to their reapecdve moulds, as shown, intetseding the miter-line B d
and the baae-line C C.

For the pattern for the hip, draw any line, as E F, at right angles
to B C, upon which place twice the stretchout of D, as shown by the
divisions 6 to 1 to 6 on EF. llirou^ these diviaons draw lines at

Fig. 331.
right angles to E F, intersecting sunilarly numbered lines drawn at
right angles to B C from the divisions onhd and C C Trace a line
through the points thus obtained. Ilien will G H J L be the pattern
for the hip ridge.

When bending this ridge in the machine, it is necessaiy to know
at what angle the Une 1 in the pattern will be bent. A true section
must be obtmned at right angles to the line of hip, for which proceed as
shown in Fig. 330. Directly in line with the elevation, construct a
part plan L M N O, through which, at an angle of 45 degrees (because
the angle L O N is a right angle], draw the hip line O M. Establish at
pleasure any point, as P' on O M, from which erect the vertical line
into the elevation crossing the base-line C K at P and the ridge-tine
C B at R. Parallel to O M in plan, draw O' P, equal to O P', as
shown. Extend P* P* as P' R*, which make equal to PK in devatton.

SHEET METAL WORK

' Draw a line from R' to O'. Then O' R* P represents a true section on
OP' in plan. Through any point, as a, at right angles to OM, draw
be, cutting L O and ON at fc and e respectively. Extend b c until it
intersects O' P at d. From d, at right angles to C R', draw Ae line
d e. With d as center, and de as radius, draw the arc e ^, intersecting
O' P at e*, from which point, at right angles to OM in plan, draw a
line intersecting OM at e". Draw a liP5 from t to e" to c, which repre-
sents the true section of the hip after which the pattern shown in Fig.
331 is formed.

The pattern for the deck mould D B in Fig. 330 is obtained in the
same way as the square miter shown in Fig. 277; while the pattern for
the apron D> in Fig. 331 is the same as the one-half pattern of the hip
ridge shown by » H 1 6.

In Kg. 332 is shown a front elevation of an eye-brow donner. In
ttiis view ABC represents the front view of the dormer, the arcs bdng

Fig. 332.
struck from the center points D, E, and F. A section taken on the
line H J in elevation is shown at the right; L M shows the roof of the
dormer, indicated in the section by N; while the louvers are sb.own in
elevation by O P and in section by RT.

In Fig. 333 is shown how to obt^n the various patterns for the
various parts of the dormer. ABC represents the half-elevation of the
donner, and EFG a side view, of which EG is the line of the dormer
£F that of the roof, and GF the line of the pitched roof agunst whidi
the dormer is required to miter.

The front and side views being placed in thar proper r^ative
positions, the first step is to obtun a true section at right angles to EF.
Proceed as follows: Divide the curve A to B into a number of equal
spaces, as shown from 1 to 9. At right angles to A C, and from the
figures on A B, draw lines intersecting E G in side view as shown.

L.u-.,..L.oo;;lc

SHEET ME'l'AL WORK

From these intersections, and parallel to EF, draw lines intersecting
the roof-line GF at l\ 2*, 3*, etc. Parallel to EF, and from the point

7 fi 5 4 3 2

ONE HALF PATTERN

FOR SHAPE OF
OPENING IN ROOr

Fig. 333.

G, draw any line indefinitely, as G H. At right angles to EF, and
from the point E, draw the line £H, intersecting lines previously drawn,

SHEET METAL WORK

245

at 1', 2", 3', etc., as shown. Now take a duplicate of the Una E K, with
the various intersections thereon, and place it on the center line AC
extended as KJ. At right angles to KJ, and from the figures 1', 2^, 3*,
etc., draw lines, which intersect with those of similar numbers drawn
at right angles to CB, and from similarly numbered points on the curve
A 6. Trace a hne through the points of intersection thus obtained.
Then KLMJ will be one-half the true profile on the lire E H in side
view, from which the stretchout will be obtained in the devdopment
of the pattern.

For the pattern for the roof of the dormer, draw at right angles
to EF in side view the line N O, upon which place the stretchout of
one-half the true profile on the line EH as shown by the small figures
l^ 2*, 3*, etc. Then, at right angles to N O, and through the figures,
draw lines, which intersect with those of similar numbers drawn at
right angles to EF from intersections on EG and GF. Trace a line
through the points thus obtained. Tlien will PRST represent one-
half the pattern for the roof.

To obtain the pattern for the shape of the opening to be cut into
the roof, transfer the line GF, with the various intersections thereon,
to «iy vertical line, as UV, as shown
by the figures 1', 2», 3«, etc. In
similar manner, transfer the line
CB in front view, with the various
intersections on same, to the line
ZW, drawn at right angles to UV,
as shown by the figures 1, 2, 3, etc.
At right angles to UV, sad from
the figures, draw lines, which in-
tersect with those of similar num-
bers drawn at right angles to YZ.
Through these points, trace a line.
Then will UXYZ be the haJf-pattem for the shape of the opening
to be cut into the mfun roof.

For the pattern for the ventilating slats or louvers, should they
be required in the dormer, proceed as shown in V]g. 334. In this
figure, A B C is a reproduction of the inside opening- shown in Fig. 333,
Let 1, 2, 3, 4, 5 in Fig. 334 represent the sections of the louvers which

HALF W.TTEI»N FOR
LOUVRE '4-

Fig. 334.

ibtainmiT the pat-.

SHEET METAL WORK

tenis for all louvers are alike, the pattern for louver No. 4 will illus-
trate the principles employed. Number &e various bends of louver
No. 4 as shown by pcnnta 6, 7, 8, and 0. At right angles to A B, and
from these points, draw lines intersecting the curve A C as 6', T, 4', 8*,
and 9*. On B A attended as E D, place the stretchout of louver No. 4
as shown by the figures on ED. Since the miter-liue AC is a curve,
it will be necessaiy to introduce intermediate points between 7 and 8
of the profile, in order to obtain this curve in the pattern. In diis
instance the point mailed 4 has been added.

Now, at right angles to DE, and through the figures, draw lines,
whidi intersect with those of similar numbers, drawn parallel to AB
from intersections 6* to 9*
on the curve AC. A line
traced through the points
thus obtained, as FKJH,
will be the half-pattern
for louver No. 4. The
pattern for the face of
the dprmer is pricked
onto the metal direct
from the front view in
Fig. 333, in which A 8
B C is the half-pattern.
In laying out the
patterns for bay window
work, it often happens

,^^

Fig. 335.

that each side of the window has an unequal projection, as is shown
in fig. 335, in which DEF shows an elevation of an octagonal base of
a bay window having unequal projections. All that part of the bay
above the line AB is obtained by the method shown in Fig. 290, while
the finish of the bay shown by ABC in f^. 335 will be treated here.
In some cases the lower ball C is a half-spun ball. A* B* F* is a true
section through A B. I.t will be noticed that the lines Ca, Cc, and Cd,
drawn respectively at right angles to ab, be, and cd, are each of different
lengths, thereby making it necessary to obtain a true profile on each
of these lines, before the patterns can be obtained. This is cleaiiy
espluned in connection with Fig. 336, in which only a half-elevation
aiul plan are required as both sides are symmetrical. First draw the

SHEET METAL WORK

247

center line AB, on which draw the half-elevation of the base of the
bay, as shown by CDE. At right angles to AB draw the wall line
in plan, as FK ; and in its proper position in relation to the line CD in
elevation, draw the desired half-plan, as shown by GHIJ. From the
comers H and I draw the miter-lines HF and IF, as shown. As DE

Fig. 336.
represents the given profile through FG in plan, th«i divide the profile
DE into SSI equal number of spaces as shown by the figures 1 to 13.
From these points drop vertical lines inteilsecting the mitep-line FH
in plan, as shown. From these intersections, parallel to HI, draw
lines intersecting the miter-lines IF, from which points, parallel to IJ,
draw lines intersecting the center line FB. Through tiie various
points of intersection in DE, draw horizontal lines indefinitely right
and left as shown.

24S SHEET METAL WORK

If for any reason it is de«red to show the elevation of the miter^
line FI in plan (it not bdng necessary in the development of the pat-
tern), then erect vertical lines from the various intersections on FI,
intersecting similar lines In elevation. To avoid a confuston in the
drawing, these lines have not been shown. Trace a line through
points thus obtained, as shown by D* 13, which is the desired miter-
line in elevation.

The next step is to obtain die true profile at right angles to HI
and IJ in plan. To obtain the true profile through No. 3 in plan, take
a tracing of J F, with the various intersections thereon, and place it on
a line drawn parallel to CD in elevation, as J' P, with the intersections
1 to 13, as shown. From these intersections, at right angles to J' P,
erect lines intersecting similar lines drawn through the profile DE in
elevation. Trace a line through the points thus obtwned, as shown
by 1' to 13', which represents the true profile for part 3 in plan. At
right angles to IH in plan, draw any line, as ML, and extend the va-
rious lines drawn parallel to IH until they intersect LM at points 1 to
13, as shown.

Take a tracing of LM, with the various points of intersectioo,
and place it on any horizontal line, as L^ M', as shown by the figures
1 to 13, from which, at right angles to L' M', erect vertical lines inter-
secting amilariy numbered horizontal lines drawn through the profile
DE. Trace a line through the points thus obtained. Tlien will
1"— 13" be the true profile through No. 2 in plan at right angles to HI.

For the pattern for No. 1 in plan, extend the line FK, as NO, upon
whi(i) place the stretchout of the profile DE as shown by the figures
1 to 13 on NO. At right angles to NO, and from the figures, draw
hnes, which intersect with lines (partly shown) drawn parallel to FG
from similar intersections on the miter-line FH. Trace a line through
the points thus obt^ned; then will 1 P 13 be the pattern for part 1
in plan.

At right angles to H I, draw any line, as T U, upon which place
the stretdiout of profile No. 2, bang careful to measure each space
separately, as they are all unequal, as shown by the small figures 1" to
l."}" on TU. Through these figures, at right angles to TU, draw lines
as shown, which intersect by lines (not shown in the drawing) drawn
at right angles to I H from similar points on the mitci^lines HF and FJ.

SHEET METAL WORK 249

Trace a line through the points thus obtained. Then will V W X be
the pattern for part 2 in plan.

For the half-pattern for part 3 in plan, extend the center line A B
in plan as B R, upon which place the stretchout of the true profile for
3, bdng careful to measure each space s^arately, as shown by the
figures 1' to 13' on BR. At right angles to B R draw lines through
the figures, which intersect by lines drawn at right angles to J I from
similar points of intersection on the miter-line F I. A line traced
through points thus obtained, as 1' S 13', will be the half-pattern
for part 3.

DEVELOPMENT OF BLANKS FOR CURVED MOULDINQS

Our first attention will be ^ven to the methods of construction,
it bang necessaiy that we know the methods of construction before
the blank can be laid out. For example, in Fig. 337 is a part elevation
of a dormer window, with a semicircular top whose profile has an ogee,
fillet, and cove. If this job were undertaken by a firm who had no
circular moulding machine, as is the case in many of the smaller shops,
the mould would have to be made by hand. The method of construc-
tion in this case would then be as shown in Fig. 338,
which shows an enlai^ed section through a fr in Fig,
337. Thus the strips a, h, and c in Fig. 338 would be
cut to the required size, and would be nothing more
than strjught strips of metal, while d d'would be an "^
angle, the lower side d' being notched with the shears
and turned to the required circle. The face strips e,
f, and h would represent arcs of circles to correspond
to their various diameters obtained from the full-sized
elevation. These face and sink strips would all be
soldered together, and form a succession of square angles, !
which theogee, asshownbyi;', and the cove, as shown by m, would be
fitted. In obtuning the patterns for the blanks hammered by hand,
the averaged lines would be drawn as shown by kl for the ogee and
n for the cove. The method or principles of averaging these and
other moulds will be explained as we proceed.

In F^. 339 is shown the same mould as in the previous figure,
a different method of construction being employed from the one made
by hand and the one hammered up by machine. In machine work this

SHEET METAL WORK

mould can be hanimered in one piece, 8 feet long or of the len^ of the
sheets in use, if such length is required, the modiine taking in the full

Fig. 338. Fig. 339.

mould from A to B. The pattern for work of this kind b averaged
by drawing a line as shown by CD. This method will also be ex-
pluned more fully as we proceed.

SHOP TOOLS EMPLOVED

When working any circular mould by hand, all that b required
in the way of tools is vahous-sized raising and stretching hammers,
square stake, blow-horn stake, and mandrel including raising blocks
made of wood or lead. A first-rate knowledge must be employed
by the mechanic in the handling and working of these small tools. In
a thoroughly up-to-date shop will be found what are known as "curved
moulding" machines, which can be operated by foot or power, and
which have the advantage over hand operation of saving time and
labor, and also turning out first-class work, as all seams are avoided.

PRINCIPLES EMPLOYED FOR OBTAINING APPROXIMATE
BLANKS FOR CURVED MOULDINGS HAMMERED BY HAND

The governing principles underlying all such operations are the
same as every sheet-metal worker uses in the laying out of the simple
patterns in flaring ware. In other words, one who understands how to
lay out the pattern for a frustum of a cone understands the principles
of developing the blanks for curved mouldings. The prindples will
be described in detail in what follows.

Our first problem is that of obt^ning a blank for a plain flare,
shown in Fig. 340. First draw the center line A B, and construct the
half-elevation of the mould, as C D E F. Sxtend D E until it inter-

SHEET METAL WORK

251

sects Hie center line A B at G. At right angles to A B from any point,
as H, draw H 1 equal to C D, as shown. Using H as center, and with
H 1 as radius, describe the quarter-circle 1 7, whitji is a section on
C D. Divide 1 7 into equal spaces, as shown. Now uang G as center,
with radii equal to G E and G D, describe the arcs D 7' and E E°.
From any point, as 1', draw the radial line 1' G, intersecting the inner
arc at E'. Take a stretchout of the quarter-section; place it as shown

Fig. 340. Fig. 341.

from I' to 7'; and draw a line from?' to G, intersecting the inner arc
at E°. Then will E' 1' 7' E* be the quarter-pattern for the flare D E
in elevation. If the pattern b required in two halves, join two pieces;
if required in one piece, join four pieces.

In f^. 341 is shown a curved mould whose profile contfuns a cove.
To work this profile, the blank must be stretched with the stretching
hammer. We mcTtHon this here so tkal the student wiU 'pay atiention
to ike rule for obtaining patterns for stretched ■movlda. First draw the
center line A B ; also the half-elevation of the moulding, as C D E F.
Divide the cove E D into an equal number of spaces, as shown iXQW.

SHEET METAL WORK

ato e. rnirough the center of the cove c dr&w a line parallel to e a,
extending it until it meets the center line A B at G, which is the center
point from whidi to strike the pattern. Take the stretchout of the
cove c e and c a, and place it as iown by c e* and c a'. When stretch-
ing the flare a' e', c remains stationary, e' and a' being hammered to-
wards « and a respectivdy. 'Rierefore, from c erect a vertical line
intersecting H I, drawn at right angles to A B, at 1. U»ng H as center
and H 1 as radius, describe the arc 1 7, which divide into equal
spaces as shown. With G as center,
and radii equal to G a', Gc, and G e',
describe the arcs e* «*, 1' 7', and a'
a". Draw a line from e" to G, inter-
secting the center and lower arcs at
1' and o'. Starting from 1', lay off
the stretchout of the quarter-section as
shown from 1' to 7'. Through 7' draw
a line towards G, intersecting the in-
ner arc at a"; and, extending the line
upward, intersect the outer arc at «*.
Then will if ^ (^ <f be the quarter-
pattern for the cove E D in elevation.
If the quarter-round N O were re-
quired in place of the cove E D, then,
as this quarter-round would require to
be rused, the rule given in the former
Instruction Paper on Sheet Metal
Work would be applied to all cases of nused mouldings.

In Fig. 342 b diown a curved mould whose profile is an ogee. In
this case as in the preceding, draw the center line and half-elevation,
and divide the ogee into a number of equ^ parts, as shown from a to A.
Through tlie flaring portion of tiie ogefe, as c «, draw a line, extending
it upward and downward until it intersects the center line A B at G.
Take the stretchouts from a to c and from e to A and place them re-
spectively from c to o' and from e to A' on the line A' G. Then, in work-
ing die ogee, that portion of the flare from c to e ronains stationary;
the part from e to A' will be stretched to form e k ; while that part shown
from c to a' will be raised to form c a. From any point in the station-
ary flare, as d, erect a line meeting the line H I, drawn at right

Fig. 342.

SHEET METAL WORK

angles to A B, at 1. Using H as center and H 1 as radius, describe
the quarter-section, and divide same into equal spaces, as shown.
With G as center and with radii equal to G o', G d, and G h', describe
the arcs a" a", 1' 7', and k" k". • From h' draw a line to G.
Starting at 1', lay off the stretchout of the section as shown from 1' to
7'. TTirough 7' draw a
line to G, as before de-
scribed. Tlien will k" a'
a" ft" be the quarter-pat-
tern for the ogee E D.

In Fig. 343 is shown
how the blanks are de-
veloped when a bead
moulding is employed.
As before, first draw the
center line A* B' and the
half-elevation A B C D.
As the bead takes up J
of a drcte, as shown by
ace/, and as the pat-
tern for / e will be the
same as for e c, then will
the pattern for e e only
be shown, which can also
be used for e f. Bisect
a c and c e, obtaining
the points b and d,
which represent the
stationary points in the
patterns. Take the
stretchouts of & to a and
fc to c, and place diem ^ ^*^-

as shown from b to a' and from 6 to c*; also take the stretchouts
of d to c and d to e, and place them from d to e' and from d to c' on
lines drawn parallel respectively to ac and c e from points b and
d. Extend the lines e' c' and c' a' until they intersect the center
line A' B' at E and F respectively. From the points b and d
erect lines intersecting the line G 1, drawn at right angles to AJ

2S4

SHEET METAL WORJC

B', at 14 and 1 respectively. Using G as center, and with radii
equal to G 14 and G 1, describe quarter-sections, as shown. Divide
both into equal parts, as shown bom 1 to 7, and from 8 to 14. With
£ as center, and with radii equal to E c', £ d, and £ e', describe the
arcs e" c", i (T, and e" e". From any point on one end, as e",
draw a radial line to £, intersecting the inner axes at if and c". Now
take the stretchout of the sectkm from 1 to 7, and, starting at <f , lay
off the stretchout as shown from 1' to T. Through 7' draw a line
towards £, intersecting the inner arc at c" and the outer one at e".
Then will c" e" e" c" be the quarter-pattern for that part of ttie
bead shown by c e, also for

t« /, in elevation. For the Je

pattern for that part shown
by ac, useP as center; and
with radii equal to F a', F h,
^. 344. and F c', describe &e arcs
o" a", h' b', and c" e". From any point
on the arc b' b', as 8', lay off the stretch-
out of the quarter-section 8 14, as
shown from 8' to 14'. Through these
two points draw lines towards F, in-
tersecting the inner arcs at a" a" ; and
extend them until they intersect the
outer arc at c" and c". Then wiU
c" a"- a" c" be the desired pattern.

In Pig. 344 is shown an illustra- *

tion of a round finial which contains ^'

moulds, the principles of which have already been described in
the preceding problems. The ball A is made of either horizontal
or vertical sections. In Fig. 345 is shown how the moulds in a finial
of this kind are averaged. The method of obtaining the true length
of each pattern piece will be omitted, as this was thoroughly covered
in the preceding problems. First draw the center line A B, on either
side of which draw the section of the finial, as shown by C D £. The
blanks for the ball a will be obtained as explained by the devel-
opment shown on page 106 of this volume. The mould b is
av^aged as shown by the line e f, extending same until it intersects
the center line at A, e / representing the stretchout of the mould

SHEET METAL WORK 255

obtained, as already explained elsewhere in the text. Using k as
center, with h / and h e bs radii, describe the blank b".

In the next mould, c c', a seam is located in same as shown by
the dotted line. Then average C by the line i j, extending same until
it meets the center line at h; also average c' by the line I m, extending
this also until the center line is intersected at n. Then i j and / m
represent respectively the stretchouts of the mOuld c c', the blanks c*
and c' being struck respectively from the centeis k and n. The mould
6' 6" also has a seam, as shown by the dotted line, the moulds being
averaged by the lines p o and a t, which, if extended, intersect the
' center line at r and m. These points are the centers, respectively, for
striking the blanks b° and 6^. Ilie flaring piece d is struck from the

y^r

Fig. 346.

center x, with radii equal to a; w and x v, thus obtaining the blank (f*.

By referring to the various rules given in previous problems, the
true length of the blanks can be obtained.

The principles used for blanks hammered by hand can be applied
to almost any form that will arise, as, for example, in the case shown
in Fig. 346, in which A and B represent circular leader heads; or in
that shown in f^. 347, in which A and B show two styles of balusters,
a and b (in both) representing the square tops and bases. Another
example is that of a round finial, as in Fig. 348, A showing the hood
which slips over the apex of the roof. While these forms can be
bought, yet in some cases where a special design is brought out by the
architect, it is necessary that tb^ be made by band, espedally when
but one is required.

The last problem on handwork is shown in I^. 349 — ^that of
obtfuning the blanks for the bottom of a circular bay. The curved
moulding A will be hammered by hand or by machine, as will be ex-

SHEET METAL WORK

plained later on, wliile the bottom B is the problem before us. The
plan, it will be seen, is the arc of a circle; and, to obtain the various
blanks, proceed as shown in Rg. 350, in which A B C is the elevation
of the bottom of the bay, UK being a plan view on A C, showing the

Pig. 347.
curve struck from the center H. In this case the
front view of the bottom of the bay is given, and
must have the shape indicated by A B C taken on the
line IJ in plan. It therefore becomes necessaiy to
establish a true section on the center line S K in
plan, from ^^ch to obtain the radii for the blanks or

Fig. 349. Fig. 348.

patterns. To obt^n this true section, divide the curve A B into any
number of equal parts, as shown from 1 to 6. From the points of
dividon, at right angles to AC, drop lines as shown, intersecting the
wall hne IJ at points 1' to 6'. Then, u^ng H as center, and radii
equal to H 6', H 5', H 4', H 3', and H 2', draw arcs crossing the
center line D E shown from 1" to 6". At any convenient point

»u .,A-oo;;lc

SHEET METAL WORK

257

opposite the front elevation draw any vertical line, as T U. Extend
the lines from the spaces in the profile A B until they intersect
the vertic^ line T U as shown. Now, measuring in every instance
from the point S in plan, take the various distances to the num-

Fig. 860.
bered points in plan and place them upon lines cf
similar numbers, measuring in every instance from
the line T U in section. Thus take the distance
S K in plan, and place it as shown from the line
TU to K>;then again, take thedistance from S to 2*
in plan, and place it as shown from the line T U to 2* en
line 2 in section. Proceed in this manner until all the points
in the true section have been obtained. Trace a line as
shown, when 1* to 6' to Y will be the true section on the
line S K in plan. )

It should be understood that the usual method for '''

making the bottom of bays round in plan is to divide the profile of
the moulding into such parts as can be best raised or stretched. As-
suming that this has been done, take the distance from 1* in plan to
the center point H, and place it as shown from 1' to L in section.
From the point L, draw a vertical line L M, as shown. For the pat-
tern for the mould 1" 2*, average a line through the extreme points,
as shown, and extend the same until it meets L M at N. Then,
with N as center, and with radii equal to N 2" and N 1", describe

2S8 SHEET METAL WORK

the blank shown. The length of this blank is obtained by measur-
ing on the arc 1' 1' in plan, and placing this stretdiout on the arc 1'
of the blank. Tie other blanks are obtained in precisely the same
manner. Tlius P is the center for the blank 2* 3*; R, for the blank
3* 4"; O, for the blank 4' 5"; and M, for the blank 5» 6'.

The moulds 1* 2*, 2" 3', and 3" 4' will be raised; whfla
the bluiks 4* 5* and 5" 6^ will be stretched.

APPROXIMATE BLANKS FOR CURVED MOULDINOS

HAMMERED BY MACHINE
Tlie prindples employed in avera^^ng the profile for a moulding
to be rolled or hammered by machine do not differ to uiy material
extent from those used in the case of mouldii^ hammered by hand,
f^. 351 shows the general method of aver-
aging the profile of a moulding in determin-
ing ihe radius of the blank or patton. It
will be seen that A 6 is drawn in such a
manner, so to speak, as to average the in-
equalities of the profile D C required to be
made. Thus distances a and b are equal, as
are the distances c and d, and e and /. It is
' very diflScult to indicate definite rules to be
^B observed in drawii^ a line of this kind, or,
^' ^^' in other words, in averapi^ the profile.

Nothii^ short of actual experience and intimate knowledge of the
material in which the moulding is to be made, will enable the operator

Fig. 352.
to dedde correctly in all cases. TTiere is, however, no danger of
maldng veiy grave errors in this respect, because the ci^acity of
the machines in use is such, that, were the pattern less advanta-
geously planned in this particular than it should be, still, by passdng
it through the dies or rolls an extra time or two, it would be brou^t
to the required shape.

SHEET METAL WOUK

In Fig. 352 is shown a part elevation of a circular moulding as it
would occur in a segmental pediment, window cap, or other structure
ari»ng in sheet-metal cornice work. B shows the curved moulding,
joining two horizontal pieces A and C, the true section of ^1 the moulds
being shown by D.

In this connection it may be proper to remark that in practice,
no miters are cut on the circular blanks, the miter-cuts Hrang placed on
the horizontal pieces, and the circular moulding trimmed after it has
been formed up.

In Fig. 353 is shown the method of obtaining the blanks for
mouldings curved in elevation, no matter what their radius or profile

-i^-

Fig. 353.
may be. First draw the center line A B, and, with the desired center,
as B, describe the outer curve A. At right angles to A B, in its proper
position, draw a section of the profile as shown by C D. From the
various members in this section, project lines to the center line A B,
as 1, 2, 3, and 4; and, using B as center, describe the various arcs and
complete the elevation as shown by A B C in F^. 352, only partiy
shown in Fig. 353. In the manner before described, average the
profile C D by the line c d, extending it until it intersects the line drawn
through the center B at right angles to A B , at E. Then E is the center
from whidi to strike the pattern. Centrally on the section C D, estab-
lish e on the tine c d, where it intersects the mould, and take the
stretchout from e to C and from e to D, and place it as shown respec-
tively from e to c and from e to (2 on the line c d. Now, using E as

2U0

SHEET ME-i AL WORK

Fig. 354.

center, with radii equal to E tf , E e, and E c, describe the arcs d' d',
e' e*, and c' if. Draw a line from c' to E, intersecting t!ie middle and
inner arc at e' and d'. The arc e' «" then becomes the measuring line
to obtain the length of the pattern, the length
being measured on the arc 2 in devation,
which corresponds to the point e in section.

In Fig. 354 is shown the elevation of a
moulding A curved in plan B, the arc being
struck from the given point a. This is apt to
occur when the moulding or cornice is placed
on a building whose comer b round. To ob-
tain the pattern when the moulding is curved
in plan, proceed as shown in Fig. 355. Draw
the section of the moulding, as A B, A C be-
ing the mould for which the pattern is desired.
C B represents a stnught strip which is at-
tached to the mould after it is hammered or rolled to shape. In
practice the elevation is not required. At pleasure, below the sec-
tion, draw the horizontal line E D, From the extreme or outside
edge of the mould, as b,
drop a line intersecting the
horizontal line ED at E.
Knowing the radius of the
arc on b in section, place it
on the line E D, thus ob-
taining the point D. With
D as center, describe the
arc E F, intersecting a line
drawn at right angle to E
D from D. Average a line
through the section, as G
H, intersecting the line D F,
drawn vertical from the cen-
ter D, at J. Establish at
pleasure the stationary
point a, from whici drop a line cutting E D at a'. Using D as
center, and with D o' as radius, describe the arc a' a", which is the
n:easuring line when laying out the pattern. Now take the stretch-

Fig. 355.

SHEET METAL WORK

261

out£ from a to b and from a to c, and place them on the averaged
line from o to G and from a to H respectively. Using J as center,
with radii extending to the various points G, a, and H, describe th-
arcs G G', a a'", and H H'. On
the arc a' a"', the pattern is
measured to correspond to the
arc a' a* in plan.

In Fig. 356 is shown a front
view of an ornamental buU's-eye
window, showing the circular
mould A B C D, which in this
case we desire to lay out in one
piece, so that, when hammered
or rolled in the madhine, it will
have the desired diameter. The
same principles can be applied
to the upper mould E F, as were
used in connection with Figs.
352 and 353. ^- ^^^■

To obtain the blank for the bull's-eye window shown in Fig. 35P
proceed as shown in Fig. 357. Let A B C D represent the elevatio'
of the bull's-eye struck from the center E. Through E draw the hor

zontal and perpendicular lines shown. In its proper position, draw a
section of the window as shown by F G. Through the face of the
mould, as H I, average the line H' IS extending it until it intersects

2S2

SHEET METAL WORK

the cmter line B D at J. 'Where the average line intersects the mould
at a, establish this as a stationary point ; and take the stretchouts from
a to I and from a to H, and lay them off on the line H' P from ato F
andatolfrespectivdy. As 1
5 in elevation represents the
quarter-cirde on the point a
in section, divide this quarter-
circle into equal spaces, as
shovn. Now, with radii equal
to J I', J a, and J H', and with
J in Fig. 358 as center, de-
scribe the arcs H H, a a, and
I I. From any point, as H,
on one side, draw a line to J,
intersecting the middle and in-
ner arcs at a and I. Take the stretchout of the quarter-circle from
1 to 5 in elevation in Hg. 357, and place it on the arc a a as shown
from 1 to 5. Step this oS four times, as shown by 5', 5", and $'".
From J draw a line through 5'", intersecting the inner and outer lUcs
at I and H. Then will H a a H be the full pattern.

Fig. 358.

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PRACTICAL PROBLEMS IN MENSURATION
FOR SHEET METAL WORKERS.

A square tank, Fig. 1, is required whose capacity ahonld be
200 galloDB, the aides h a and a c each to be SO inchea; how high
must c (Z be, BO that the tank will hold the desired quantity i

Suppose the height c <2 is to be 61^ inches, and the tank is to

}

CAPACITY
ZOOGAUjONS

Fig.l.

hare similar capacity, and one side c iz is to be 20 ioches wide,
how long must the alternate side a 5 be, so that the tank will
hold 200 gallons %

A round tank, Fig. 2, is to be constracted whose capacity
should equal 510 gallons, and be 5 feet high from c to a; what
must its diameter (t & be, so as to liold the desired capacity \

Suppose the diameter of
the tank is to be 60 inches
as a h; what mast its height
<z <; be, so that the tank will
hold 610 gallons t

A large drip pan, Fig. 3, is
to be constructed whose ca-
pacityshouldbel65gal]on8,and whose top measurements a & and^o
are 60 X 40 inches respectively, and bottom measQrementB d c and

Fig. 8.

2 PROBLEMS IN MENSURATION

«^34 X 54 inches respectively; what must its height m nhe, bo
aa to hold the desired volame 1

A round tapering measure, Fig. i, is to be coDstructed whose
volome will equal 42 quarts; its bottom diameter a b ia to be 14

Fig. 4.

Fig. 5.

inches, its top diameters d 18 inchee; what muBt its height e/he
to hold the desired quantity J

An elliptical tapering tank. Fig. 5, is to be constructed whose
major axis m h is 24 inches, and minor axis c d \^ inches at the
top, while at the bottom the major axis «yi8 20 inches, and minor
axis g h 10 inches; the capacity of the tank should equal 44
quarts; what mnst the height m n be, so that the tank will hold
the desired amount ?

A tank, Fig. 6, is to be constructed with semicircular ends

ta. ^b 4

-_4,.^ « -=*

CAPACITY 30 GALLONS

Fig. 6. Fig. 7.

whose capacity should equal 30 gallons; the length a & to be 20
inches, and the diameters of c and d to be each 10 inches; what
must the height efhe, so that the tank will hold the desired
quantity %

Suppose the height ef is to be 24 inches, the diameters c and
d each 11 inches; what must the length of a d be, so that the tank
will hold 30 gallons 9

PROBLEMS IN MENSURATION 3

In Fig. 7 is shown a fitting used in Tentilation piping; the
diameter a b ib 11^ Inches and it is desired that the oblong pipe
on the opposite end shall have an area similar to the roand pipe a B ;
if eymust he 5 inches, what must c (f be so that hoth areas are alike ?

Suppose the pipe is to be square in place of oblong, what must
the length of each side be, so that both ends have similar area !

In Fig. 8, a h ia 10 inches in diameter; and each one of the
branches c, d, and e are to have equal diameters, what must the
diameter of the branches be, so that the combined area of c, d,
and e will equal the area oi ab^

If is 10 inches in diameter, d 13 inches, and e 8 inches,
what must be the diameter of a b, to have the combined area of
the branches !

Fig. 9 shows a transition piece from a round pipe a to an

Figo 10.

elliptical pipe d, both sections to have similar area, if the round
pipe is 21 inches in diameter, and the major axis of the elliptical
pipe must he 82 inches, what must the minor axis of i be so that
the area at b will equal the area of a ?

If the minor axis of Ms to be 16 inches and the major axis 35
inches, what must the diameter of a be, so that both sections will
have similar area!

In Fig. 10, a is 20 inches in diameter and forms a transition
to an oblong pipe with semicircular end; the semicircular ends
are to be 10 inches in diameter; what must the length at c d he,
so that the area of b will be equal to the area of a ?

If the pipe b measured 40 X 11 inches, having semicircular
ends, what must the diameter of a be, so that both sections are
equal in area ?

If a is 20 incht's in diameter and the upper section was to be

FBOBLEUS IN MENSURATION

rectangular in shape, 8 inches wide, what would the length of the
upper Beet ion be 1

Suppose the upper section b was desired to be square, what
must the length of each aide be, to have an area similar to a f

In Fig. 11 is shown the iUnstrstion of an ordinary steel square,
and the method is giren of obtaining accurate diameters of pipes,
round or square, without stay computation whatever, the rale being
based on the geometrical principle that the square of the hypothec
nuse of a right angle triangle ie equal to the aura of the squares
of its base and altitude. To illustrate the rule. Fig. 12 has been

12 3 4 9 7 8

17 loo iO 21 2£i3M

Pig. 11.

prepared. Let A represent a round or square pipe, 30 inches across,
and S a round or square pipe 13 inches across; it ia deBired to
take a branch from the main so that the two branches B and C will
eqaal the area of the main A. What must the size of C be 1

The size of is found by simply taking a rule 20 iuchea
long and placing one end on the arm of the square in Fig. 11, on
the number 12, when the opposite end of the rule will touch the
number 16. Then 16 is the required size of the branch C in Fig.
12. We can prore this by computation which, however, is not
necessary in practice. The area of a 2D-inob round pipe equals
814.16 in.; area of 12-ih. pipe = 113.098 in.; area of 16-in.
pipe = 201.002 in.; and 113.098 in. + 201.062 in. = 314.160 in.
The area of a 20-in. square pipe = 400 in.; area of 12-in, square
pipe = 144 in.; area of Id-in. square pipe = 266 in.; and
266 is. -i- 144 in. = 400 in.

Dun... ,AiOo;;lc

FBOBLEMS IN MBNSCBATION

Suppose any two branches are given as B and in Fig. 12,
what must the size of A be bo that its area will have the com-
bined area of the two branches 1

Simply set the rule on the numbers 12 and 16 on the' two
^ - arms of the square respectively, and the length
y^T"-^ from a to bin Fig. 11 will measnre 20 inches.
If A, Fig. 12, were given, and two branchee
were required, so that B and C were both of
equal size, then simply set the rule 20 inches
long, on both arms of the square so that the
distance from O to o and O to d wonld be
eqaal, as shown in Fig. 11, which woald be
foand to measure 14^ in. plus a least triSe.
This rule can be used to advantage for any size round or square
pipe in blower, blast, heat, and ventilating piping, saving time and
trouble in computation. Where no square is at hand, one can be
drawn on paper and used for work of this kind.

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INDEX

Appro^mate developments 22

Architectural sheet-metal work 193

Architrave 194

Bare for skylights 136

Bath tub 32

Bead-mould 203

Bed-mould 194

Cavetto mouldini; 203

Conical boss 27

Construction of articles from sheet metal 3

Coppersinith's problems , 105

brewing kettle 116

circular tank 107

curved elbow 113

sphere ' 105

Cornice work 193

construction 193

mouldings, shapes of 202

pattema 200

tools 200

Corrugated iron roofing 158

Corrugated iron roofing and aiiling, , , 182

laying 186

tables 184

Corrugated siding, laying 190

Crown-mould 194

Curved mouldings, development of blanks for 249-262

Cyma recta moulding 202

Cyma reversa moulding 203

Dentil course 194

Developments, approximate 22

Developments by triangulation 15

Dividers 163

Double-pitch skylight 142

Dripa 194

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EohinuB moulding 203

Elbows 44

five-pieced 46

four-pieoed 46

tapering two-i»eced SO

tlwee-pieced 4S

Elevation, definition of 106

EmeraoD ventilator 41

Entablatun ,. 194

flashing chimney 187

Flat extension skjrlight 142

FIat-«eam roofing 167

table 159

Foot-moulding 194

Friese 194

Funnel strainer pail 3fl

Heavy metal problems 116

boiler stack 117

conical piece connecting two boilers 128

gusset sheet on locomotive 126

scroll sign 128

tljree-pieced elbow 122

Hip bath 30

Hipped skylight 143

development of patterns for 144

InterMCtions and developments S

eylinder and octagonal prism S

hexagonal and quadrangular prism 7

quadrangular prism and sphere 13

two cylinders of equal diameters at right angles 9

two cylinders of unequal diameters at angle of 45° 11

Jack bar 160

Light gauge metal problems 76

curved rectangular chute 82

cylinder intersecting conical surface 100

hopper register box 85

oblique piping 75

offset 88

rain-water cut-off 77

Xiight gftuge metal problems F>sa

tapering flange 97

three-way branch 90

two-branch fork 94

Maliet 163

Metal roofing 168

tables 169-161

tools 163

Metal slates and shingles 162

Micrometer caliper 4

Miter, definition of 196

Miter cutting 204

angular pediment with horizontal returns 219

eye-brow dormer 243

gable moulding intersecting a pilaster 216

gable moulding mitering on a wash 217

gable moulding in octagon plan 224

gore piece joined to a chamfer 235

gutter or eavetrough 233

hip ridge 237

horizontal moulding butting against pitched roof 207

moulding which miters at an angle other than right 212

panel or face miter 209

raking bracket in gable moulding 230

segmental pediment with upper and lower horisontal returns 223

six-pointed star 236

spire, square in plan, intersecting four gables 228

square return miter '. 205

turret with four gables 219

two mouldings having different profiles to miter together 213

Modillion course ■. 194

Mouldings 202

cavetto 203

cyma recta 202

cyma reverea 203

echinus 203

torus 203

Notching machine 163

Oblique piping 75

Panels 194

Pitched BkyUghts 134

Planceer 194

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266 INDEX

Problems, coppers mi th 'a 105

Problems in heavy metal work 116

Problems in light gauge metal 76

Problems in eheet-metal work 26

bath tub 32

elbows 44

Emerson ventilator 41

faucet, joining of to eheet-metal tank 27

funnel strainer pail 36

hip bath 30

sink drainer 26

Rain-water eut-off 77

Raising sash 139

Raking mouldings 196

Roman mouldings 202

Roof mensuration 163

Roofing 158

corrugated iron 182

flat-seam 167

table 159

standing-seam 177

table 160

tin plate data 161

tools 163

Roofing folders 163

Roofing tin 168

S ■

Scraper 163

Shears 163

Sheet-metal comiceB 193

Sheet metal work

coppersmith's problems 105

heavy metal problems 116

light gauge metal problen;s 76

miter cutting 204

plates 75-79, 133-135

roofing 158

skylighta 133

Shop tools ; . . 4

Single-pitch skylight 141

Sink drainer 26

Skylights 133

bars, various shapes of 136

construction 1 33

curbs, various shapes of 137

,,*<_iOO^^IC

Sk^ights Pi«e

double-pitch 142

flat extension 142

hipped 143

ralring sash 139

shop tools 136

single-pitch 141

Soldering 172

Soldering copper 163

Standing-Beam roofing 177

table 160

Stretch-awl 163

T
Tables

angle iron, weight of 74

cast iron, wrought iron, copper, lead, brass, and tine, weight of 62

corrugated sheets, measurements of 184

flat rolled iron, weights of 6ft-71

flat-seam roofing 169

iron bars, square and round 72, 73

rough glass, weight ot, per sq. ft 135

sheet copper 63

sheet iron and steel, standard gauge for 65

sheet zinc 64

standing-Beam roofing 160

tee iron, weight of 74

tin plates, net weight per bo.x 161

tin plat«8, standard weights and gauges of 161

Terne plat« 168

Tools required by metal roofers 163

Tools used in cornice work 200

Torus moulding 203

Triangulation, developments by 15

Turret sash 152

Workshop pmblems. .

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U book may be kept

FOURTEEN DAYS

.,-.-iT-- liie o( TWO CENTS Kill be chBTged

"■'"*"'»'•"» each day the book ij kept overtime.

e/-,. ■ > i

;

Ko. »1-B

HM.WMWM.

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Full text of "Sheet-metal work; a manual of practical self-instruction in the art of pattern drafting and construction work in light and heavy gauge metal, including skylights, roofing, cornice work, etc"

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