UNIVERSITY OF CALIFORNIA

COLLEGE OF AGRICULTURE

AGRICULTURAL EXPERIMENT STATION

CIRCULAR No. 260
August, 1923

AN ORCHARD BRUSH BURNER

By W. L. ZINK

Brush burner in operation, burning fig prunings.

There has been much demand from California orchardists and
vineyardists for a brush burner that can be built in a substantial
manner at a reasonable cost with the tools and equipment found in the
average farm shop. Furthermore, a burner is desired that can be
built low, that will permit the making of alterations according to
individual orchard conditions, and that is light enough to be pulled
by two horses. Recognizing the importance of this demand, the
Division of Agricultural Engineering at the University Farm, Davis,
cooperating with the Division of Pomology, has designed a burner
with the above requirements in mind.

TYPE OF BURNER

An angle iron frame carrying a suspension or basket-type fire pan
is used (fig. 1). By use of this type of fire pan, the strain placed
upon the red-hot sheet iron is direct tension in place of bending.

Z UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION

Therefore, it is possible to do away with the material usually required
to reinforce the fire pan. By this plan it is also possible to place the
material used in the main frame far enough from the hottest part of
the fire that a light type of construction may be used. Angle iron
runners are used for transportation. In orchard trials the burner
was easily pulled by a team of horses.

Fig. 1. — Sketch of orchard brush burner designed by the Division of
Agricultural Engineering.

MATEEIALS AND COSTS

The materials used have been carefully standardized so that there
is just one size of angle iron necessary (2V2ff by 2%" by %"), one
size and length of braces (20" by 1%" by %"). two sizes of machine
bolts (i/2" by 1" and %" by 1"), one size and length of tie rod (y2"
round) and one gauge or thickness of material for the fire pan.

One burner built at the University Farm, using new material for
the frame and the discarded oil tank shown in figure 2 for the pan,
cost altogether $10.40. Another burner built of new material through-
out (frontispiece) cost $27.22. In both cases the angle iron was
purchased with the necessary cuts already made. Two men with an
average set of tools should be able to build one of these burners in
one to two days.

Circular 269]

AN ORCHARD BRUSH BURNER

BILL OF MATERIAL

No.

Length,

Description of material

Name of part

of
pieces

size,
etc.

Remarks

Angle Iron (2i',x2i"xi")

Skids

2

9'

Bending of ends and
drilling of holes are
same.

Angle Iron (2f "x2§"x£")

Fire pan supports

2

8'

Both drilled alike.

Angle Iron (2A"x2i"XA")

Vertical members

4

2J'

Two right-hand, two
left-hand.

Angle Iron (2§ffx2|*xD

Cross beams

2

5'

Both alike.

Strap Iron (1§"x3/8")

End braces

2

20"

/3/8" holes.

Strap Iron (l±"x3/8")

Cross braces

2

20"

\18" on center.

Tie Rods {\" round)

Diagonal tie rods

2

7f

U. S. Standard thread
for 2" at each end.

Bolts

\" Standard Machine

Connecting angles

12

1"

Use standard machine

3/8" Standard Machine

Braces and fire pan

30

1"

bolts.

Nuts

Fastening tie rods

4

ru.s.s.

thread

Hex nuts will be eas-
ier to turn up than

Washers

Under tie rod nuts

4

square ones.

Sheet Iron

Fire pan

1

\ cylinder

May be made of old

(Not less than 16

8' long by

water tanks, boil-

gauge)

4f radius

ers, corrugated cul-
verts, etc. Black
iron usually cheap-
er and is just as
good. If in small
sections pieces may
be welded or rivet-
ed together.

In some cases it may be possible to buy second-hand material.
However, it is usually difficult to obtain angle iron of the correct size
and weight for good results. It must be remembered that the dimen-
sions for the angles should not vary too greatly. An angle of smaller
dimensions may mean a bent portion on the frame when the burner
is in operation. For the fire pan, however, old tanks, boilers, corru-
gated culverts, or other second-hand sheet iron may often be used to
good advantage. For example, note figure 2, which shows how a pan
for one burner was cut away from an old cvlindrical fuel tank. It is

UNIVERSITY OF CALIFORNIA EXPERIMENT STATION

ver3' important that no material lighter than 16-gauge (approximately
Yin" thickness) be used because of the rapid burning and rusting
effects.

TOOLS NECESSARY

The principal tools required for making one of these burners are
a forge, a drill press, a center punch, a %" point hot punch, a cold
chisel (preferably with handle), and a H" U.S. standard die. A
sledge, a machine hammer, a steel square, a bit brace, and two adjust-
able wrenches are also necessary.

Fig. 2. Using an old oil tank for fire pan. In this case the required material
was cut away by the aid of an oxy-acetylene torch. Usually the material is cut
with a cold chisel.

If oxy-acetylene equipment is available, it can be used with advan-
tage, especially for cutting the air-draft holes in the fire box. It is
also convenient for cutting the angles in case they are bought in stock
lengths. Moreover, it can be used for bending the curved ends of the
skids. With an oxy-acetylene outfit, it is not necessary to have the
forge fire, the cold chisel, or the hot punch mentioned above.

BUILDING THE FRAME
The bill of materials ("page 3) and figures 3 and 4 furnish the
information necessary for cutting the stock for the frame and pre-
paring it for assembly. As a general rule, time and money can be
saved by buying the angle iron already cut to the proper lengths. It
will help greatly in the assembling to get the cuts as square as possible.
In case the angle iron is bought in stock lengths, a hack saw is a good
tool for cutting it. A cold chisel can be used with greater speed but
is not so accurate.

Circular 269]

AN ORCHARD BRUSH BURNER

In making the bend for the curved end of the skid or runner, heat
the angle iron to a white heat at a point approximately one foot from
the end. Hold the angle iron over a solid body such as an anvil (fig. 5)
and bend by striking the overhanging portion with a sledge. As the

a£"*BJ"*i"i8' angle

-12"-

All bolts for angle iron connections
to be £"x I" — Bolts for braces and
fire pan to be $"xl"
round iron diogonol brace rods, 7'/0" lono^ ^J !

Si " x S$ "xj "m 9 ' angle iro,

Fig. 3. — Side view.

angle is bent down, it should be turned sidewise from time to time and
the kink which tends to form along the inner flange straightened
(fig. 5a). Be certain that the bent part of the skid lies in the same
vertical plane as the main part. By holding the long blade of a

U'6jr"

D/agona/ braces
'2$ "a 2i"*f x 6' ong/e iron
//' <tf "

Fig. 4. — End view.

steel square along the bottom of the skid the amount of the bend
can be easily read on the short blade. Bend until the vertical rise at
the end of the skid is five inches. Tt is important to get the skids
curved as nearly alike as possible.

6 UNIVERSITY OP CALIFORNIA EXPERIMENT STATION

After completing the bending of the skids, the holes for the
diagonal tie rods should be punched. These are %" and should be
punched through the corners of the vertical angles at a point 3%"

Fig. 5. — Bending the curved ends of the runners.

Fig. 5a-

-Hammering out the kinks formed during the bending
of the runner.

from the bottom ends. Use a white heat for the angle iron when
punching these holes. The horn of an anvil makes a good support for
the inside of the angle when punching. Do not try to punch the holes
all the way through from one side. Go two-thirds of the way through,
then turn the angle over and finish from the other side. This will

Circular 269]

AN ORCHARD BRUSH BURNER

keep the edges of the hole from burring out. Keep driving the
punch in from one side and then the other until the hole is the correct
size.

Next, locate the position of the remaining holes by center punch
marks. Note here that all holes for bolts connecting angles are %" ;
all those connecting braces or fire pan to angles are %". A little
extra care in laying out these center punch marks will be worth while
when it comes to assembling the frame. The %" holes at the ends of
the curved skids are the on]y ones on the whole frame that should
not be drilled before assembling".

Fig. 6. — Assembly in progress. Frame complete except for one fire pan sup-
porting angle. Draft boles cut and fire pan ready to go on to the frame.

Each side as a unit, including one top rail, one skid, and two of
the vertical angle irons, should be temporarily bolted together. Attach
the upper ends of each of two of the 1%" by %" by 20" end braces
to the vertical angle irons. With the frame straightened by means of
a square, swing the end braces down to the inside of the angle on the
bent ends of the skids and center punch for the holes. The skids may
then be removed and taken to the drill press for drilling the %" end
brace holes.

"With the skids bent and all the holes drilled or punched, every-
thing is ready for putting the frame together (fig. 6). It is a good
plan to slip the bolts into place and turn the nuts up by hand until
all the parts are in position. This will give greater flexibility in fitting
the more stubborn joints. It is important, however, that all the frame
bolts be carefully tightened when once they are in place. Adjust the

8 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION

tie rods until the diagonal distances between the vertical angle irons
are equal. Bring them up at least tight enough that they will not sag.

BUILDING THE FIRE PAN

There are three important points which should be considered in
laying out and cutting the draft holes :

1. They must be narrow enough to prevent the loss of burning coals.

2. They must be low enough on the sides of the fire pan to allow the

ashes to sift through.

3. They must be numerous enough to supply plenty of air to the

fire.

Fig. 7. — Cutting the draft openings, showing tools used for cutting,
sledge, cold eye chisel, and the wood block.

The side draft holes indicated by "x" in figure 6, also by the
dotted lines in figure 1, were added during the latter part of the
pruning season when the brush was full of sap and an extra large
amount of air was needed. It is well not to cut these until the burner
has been tried, for the use to which the burner may be put often
alters the draft requirements. For the same reason it is usually better
to start with the drafts smaller than necessary and, after trial, increase
them to the required size.

If the cutting is to be done with a sledge and cold chisel (fig. 7)
a block of wood (preferably hard wood) should be placed on end
against the portion of the sheet iron being cut. Chalk the outlines of
the desired openings and follow carefully the lines so made. After
the air holes are cut they should be smoothed up with the aid of a
hammer and sledge (fig. la).

Circular 269] AN orchard BRUSH BURNER 0

It is easier to hold the wood block against the sheet iron if the
air holes are cut before the fire pan is fastened to the frame. However,
this is not the case when oxy-acetylene is used. In the latter cas
is perhaps better to cut the draft holes after the pan has been bolted
into place.

To drill the holes for the bolts connecting the sheet iron to the top
angle irons of the frame, lay the sheet iron in place and by means of
clamps over the edges of the angles or blocking from beneath, brine
the sheet iron up to the top edge as shown in figure 1. Remove the
four upper frame bolts and center punch the sheet iron through these

fM

BH ^^^^5

4Sk* if

JBl*^-- ,inMJ

h^i; :

Jfi5*£ ^^^r^^^W

Fig. la. — Straightening edges of draft openings.

four holes. Drill these holes %" and fasten the sheet iron into place.
An ordinary bit brace can be used for operating the drill when drilling
through the sheet iron, if the end of the drill is given clearance from
the iron at all times by driving into the center of the hole occasionally
with a center punch. Once the %" main frame bolts are in place it
is a very easy matter to drill for the %" bolts at the one foot intervals
along the top rail.

MAKING THE HITCH

This burner is so designed that it may be pulled from either end.
By this plan it is possible to get out of a tight place very easily
without trying to turn the burner around and perhaps damaging a
tree. Two fifth chains and a clevis make a very satisfactory com-
bination for connecting the doubletree to the burner. Both ends of
one chain should be fastened to the vertical posts between the cross-

10 UNIVERSITY OP CALIFORNIA — EXPERIMENT STATION

beam and the skids as shown in figure 1 and also in figure 8. Do not
hitch to the end of the skids as this would raise the hitch connection
too high and thereby increase the load for the team. Furthermore,
there would be danger of bending the ends of the angle iron skids
when making turns. The other fifth chain should be hitched from
the center of the first chain to the doubletree clevis or ring. Keep this
chain as short as possible and still not have too much heat for the team.

vgm3

'*#4j ft

v *jj • , *

: **v^

Mil rw mm

Fig. 8. — Preparing to fire up. Old packing boxes, excelsior, or newspapers
may be used to good advantage. Note how hitching chains are attached.

PRESERVING THE FIRE PAN
To prolong the life of the fire pan it is important that each year
after use it be given a coat of waste tractor crankcase oil, or something
of that nature, to keep the material from rusting out so rapidly. A
thin coat of asphaltum is also very good for this purpose. A recent
survey of the burners in use showed that more of them had been dis-
carded because of the pan rusting out than for all other reasons
combined. The design used in this burner makes it comparatively
easy to put in a new fire pan. With ordinary care this burner will
last many years.

FOR VINEYARD WORK

One of the regular orchard burners has been tried in vineyard
work. The indications are that it will prove as satisfactory for vine-
yards as for orchards. No investigations have yet been made, however,
of the most economical width of frame or of the proper size and
placing of the draft holes for vineyard work.

STATION PUBLICATIONS AVAILABLE FOR FREE DISTRIBUTION

No.

253. Irrigation and Soil Conditions in the
Sierra Nevada Foothills, California.

261. Melaxuma of the Walnut, "Juglans

regia."

262. Citrus Diseases of Florida and Cuba

Compared with those of California.

263. Size Grades for Ripe Olives.

268. Growing and Grafting Olive Seedlings.

270. A Comparison of Annual Cropping, Bi-
ennial Cropping, and Green Manures
on the Yield of Wheat.

273. Preliminary Report on Kearney Vine-
yard Experimental Drain.

275. The Cultivation of Belladonna in Cali-

fornia.

276. The Pomegranate.

277. Sudan Grass.

278. Grain Sorghums.

279. Irrigation of Rice in California.

280. Irrigation of Alfalfa in the Sacramento

Valley.
283. The Olive Insects of California.

285. The Milk Goat in California.

286. Commercial Fertilizers.

287. Vinegar from Waste Fruits.
294. Bean Culture in California.
298. Seedless Raisin Grapes.

304. A Study of the Effects of Freezes on
Citrus in California.

308. I. Fumigation with Liquid Hydrocyanic
Acid. II. Physical and Chemical Prop-
erties of Liquid Hydrocyanic Acid.

312. Mariout Barley.

317. Selections of Stocks in Citrus Propa-
gation.

319. Caprifigs and Caprification.

321. Commercial Production of Grape Syrup.

324. Storage of Perishable Fruit at Freezing

Temperatures.

325. Rice Irrigation Measurements and Ex-

periments in Sacramento Valley,
1914-1919.

328. Prune Growing in California.

331. Phylloxera-Resistant Stocks.

334. Preliminary Volume Tables for Second-
Growth Redwood.

BULLETINS

No.
335.

336.

339.

341.
343.
344.

347.

348.
349.

350.
351.
352.

353.
354.
355.
357.

358.

359.
360.

362.
363.

364.

365.
366.

367.
368.

369.
370.

Cocoanut Meal as a Feed for Dairy
Cows and Other Livestock.

The Preparation of Nicotine Dust as
an Insecticide.

The Relative Cost of Making Logs from
Small and Large Timber.

Studies on Irrigation of Citrus Groves.

Cheese Pests and Their Control.

Cold Storage as an Aid to the Market-
ing of Plums.

The Control of Red Spiders in Decidu-
ous Orchards.

Pruning Young Olive Trees.

A Study of Sidedraft and Tractor
Hitches.

Agriculture in Cut-over Redwood Lands.

California State Dairy Cow Competition.

Further Experiments in Plum Pollina-
tion.

Bovine Infectious Abortion.

Results of Rice Experiments in 1922.

The Peach Twig Borer.

A Self-mixing Dusting Machine for
Applying Dry Insecticides and
Fungicides.

Black Measles, Water Berries, and
Related Vine Troubles.

Fruit Beverage Investigations.

Gum Diseases of Citrus Trees in Cali-
fornia.

Preliminary Yield Tables for Second
Growth Redwood.

Dust and the Tractor Engine.

The Pruning of Citrus Trees in Cali-
fornia.

Fungicidal Dusts for the Control of
Bunt.

Avocado Culture in California.

Turkish Tobacco Culture, Curing and
Marketing.

Methods of Harvesting and Irrigation
in Relation to Mouldy Walnuts.

Bacterial Decomposition of Olives dur-
ing Pickling.

Comparison of Woods for Butter Boxes

Browning of Yellow Newtown Apples.

CIRCULARS

No. No.

70. Observations on the Status of Corn 161.
Growing in California. 164
87. Alfalfa. 165.
111. The Use of Lime and Gypsum on Cali-
fornia Soils. 166.
113. Correspondence Courses in Agriculture. 167.
117. The Selection and Cost of a Small 170.

Pumping Plant.

136. Melilotus indica as a Green-Manure 172.

Crop for California. 173.
127. House Fumigation.

129. The Control of Citrus Insects. 174.

144. Oidium or Powdery Mildew of the Vine. 175.

151. Feeding and Management of Hogs.

152. Some Observations on the Bulk Hand- 178.

ling of Grain in California. 179.

153. Announcement of the California State

Dairy Cow Competition, 1916-18. 182.

154. Irrigation Practice in Growing Small

Fruit in California. 184.

155. Bovine Tuberculosis. 188.
157. Control of the Pear Scab. 190.

159. Agriculture in the Imperial Valley. 193.

160. Lettuce Growing in California. 198.

Potatoes in California.

Small Fruit Culture in California.

Fundamentals of Sugar Beet Culture

under California Conditions.
The County Farm Bureau.
Feeding Stuffs of Minor Importance.
Fertilizing California Soils for the 1918

Crop.
Wheat Culture.
The Construction of the Wood-Hoop

Silo.
Farm Drainage Methods.
Progress Report on the Marketing and

Distribution of Milk.
The Packing of Apples in California.
Factors of Importance in Producing

Milk of Low Bacterial Count.
Extending the Area of Irrigated Wheat

in California for 1918.
A Flock of Sheep on the Farm.
Lambing Sheds.

Agriculture Clubs in California.
A Study of Farm Labor in California.
Syrup from Sweet Sorghum.

CIRCULARS — Continued

No.
199.

201.
202.

203.
205.
206.
208.

209.
210.
212.
214.

215.
217.

218.

219.
224.

228.
230.

231.
232.

233.
234.

235.

236.

237.

238.
239.

240.

Onion Growing in California.

Helpful Hints to Hog Raisers.

County Organizations for Rural Fire
Control.

Peat as a Manure Substitute.

Blackleg.

Jack Cheese.

Summary of the Annual Reports of the
Farm Advisors of California.

The Function of the Farm Bureau.

Suggestions to the Settler in California.

Salvaging Rain-Damaged Prunes.

Seed Treatment for the Prevention of
Cereal Smuts.

Feeding Dairy Cows in California.

Methods for Marketing Vegetables in
California.

Advanced Registry Testing of Dairy
Cows.

The Present Status of Alkali.

Control of the Brown Apricot Scale
and the Italian Pear Scale on Decid-
uous Fruit Trees.

Vineyard Irrigation in Arid Climates.

Testing Milk, Cream, and Skim Milk
for Butterfat.

The Home Vineyard.

Harvesting and Handling California
Cherries for Eastern Shipment.

Artificial Incubation.

Winter Injury to Young Walnut Trees
during 1921-22.

Soil Analysis and Soil and Plant Inter-
relations.

The Common Hawks and Owls of Cali-
fornia from the Standpoint of the
Rancher.

Directions for the Tanning and Dress-
ing of Furs.

The Apricot in California.

Harvesting and Handling Apricots and
Plums for Eastern Shipment.

Harvesting and Handling Pears for
Eastern Shipment.

No.
241.

242.
243.

244.
245.
247.
248.

249.
250.

251.

252.
253.
254.

255.

256.
257.
258.
259.
260.

261.
262.
263.
264.

265.
266.

267.

268.

269.
270.
271.

Harvesting and Handling Peaches for
Eastern Shipment.

Poultry Feeding.

Marmalade Juice and Jelly Juice from
Citrus Fruits.

Central Wire Bracing for Fruit Trees.

Vine Pruning Systems.

Colonization and Rural Development.

Some Common Errors in Vine Prunimg
and Their Remedies.

Replacing Missing Vines.

Measurement of Irrigation Water on
the Farm.

Recommendations Concerning the Com-
mon Diseases and Parasites of
Poultry in California.

Supports for Vines.

Vineyard Plans.

The Use of Artificial Light to Increase
Winter Egg Production.

Leguminous Plants as Organic Fertil-
izer in California Agriculture.

The Control of Wild Morning Glory.

The Small-Seeded Horse Bean.

Thinning Deciduous Fruits.

Pear By-products.

A Selected List of References Relating
to Irrigation in California.

Sewing Grain Sacks.

Cabbage Growing in California.

Tomato Production in California.

Preliminary Essentials to Bovine Tuber-
culosis Control.

Plant Disease and Pest Control.

Analyzing the Citrus Orchard by Means
of Simple Tree Records.

The Tendency of Tractors to Rise in
Front- Causes and Remedies.

Inexpensive Labor-saving Poultry Ap-
pliances.

An Orchard Brush Burner.

A Farm Septic Tank.

Brooding Chicks Artificially.