Omaha daily bee., 1908-03-15

An article appearing in this column a
few weeks ago regarding a preparation OF
creosote used by an Omaha contr actor for
making the shingles with which he built a
house resist the weather for two or three
times the ordinary life of a shingle, brought
number of queries regarding the prepara-
tion. Correspondence with the office OF
wood preservation of the forestry service
at Washington brought particulars of the
process from Carl G. Crawford, chief OF the
office. The treatment is as follows;
The preservative treatment of dry
shingles is easily accomplished by immers-
ing them for about one hour In a tank OF
creosote dead oil of coal tar) heated to q
temperature of about 212 degrees Fahren-
heit. In the case of damp or green shingles
IL, is often necessary to prolong this period
In the hot oil. If, at the end of the hot
bath, 1t is found that the oil has not thor
oughly penetrated the wood, the heat may
be shut off and the shingles allowed to
remain in the cooling oil for an hour or
more; or else they may be removed from
the hot oil and quickly plunged into a
cooler bath of the preservative, preferably
at about 10 degrees Fahrenheit.
Staining the shingles can also be accomp-
lished in the same process. Any of the
common colors can be used. They should
be purchased ground in oil, not dry. OF
the reds or browns, about one-half pound
is required for each gallon of creosote.
For greens or blues this quantity should be
lnCIedSeus lie GOlOI SllOulQ be HilAeu win
an equal quantity of boiled linseed oil and
then stirred thoroughly into the creosote,
at a temperature of about l10 degrees Fahr-
enheit.
The shingles should be immersed in the
bath of hot creosote at 212 degrees Fahren-
heit. If they are thoroughly seasoned, one
half hour in the hot oil will be sufficient.
They should then be plunged in the cooler
creosote and color and allowed to remain
for about two hours. In this bath the
shingles must be loose, in order to permit
dpnOgit stain, screen
lattice-work frame will assist in keeping
the shingles under the oil. AS a final step,
the shingles should he spread out to dry.
If no suitable iron watts are available, the
treating tanks may be constructed by a
boiler maker, or sheet-iron worker. The
hot tank need be only large enough for the
immersion of a single bundle of shingles,
unless it is desired to use IT for the treat
ment of fence posts or other timbers. II
derneath, the metal should be heavy enough
to withstand the flame, say three sixteenth
of-an-inch black iron, with the joints
riveted and caulked. If steam coils can be
used. the tank may be of fairly light gal
vanized iron, the Joints being riveted and
soldered. The tank for the cool oil can be
made of light galvanized iron.
The cost of the treatment depends princl-
pally upon the local price of creosote and
the quantity of shingles which it is de-
sired TO treat. If the process Is properly
carried out, however, the Cost OF a creosoted
low-grade shingle should not exceed the
first of a high-grade shingle of the same
kind, nor should the cost of creosote and
staining exceed that of thorough painting,
and It is believed that the results are more
desirable in every way.