Cork insulation; a complete illustrated textbook on cork insulation ...

282 CORK INSULATION
To prepare Asphalt cement for use with corkboard to walls
and ceilings requires a large kettle, several small kettles and
an equal number of gasoline torches, and several buckets.
Set up the large kettle outside the building and melt down
sufficient Asphalt cement, or odorless asphalt, computed at
three-quarters of a pound for each square foot of corkboard
surface to be coated, using wood as fuel under the kettle, and
the fire protected from possible wind by a sheet-iron shield.
Do not overheat the asphalt. Transfer the molten asphalt in
buckets to the small kettles, or pans, located close to where
the corkboard is being erected. The pans should be about 18
inches wide, 42 inches long and 8 inches deep, should be
rigidly constructed, and should be kept hot by the gasoline
torches.* To the molten asphalt in these pans, add approx-
imately 8 per cent, (by weight) of cork dust, or cork flour,
and stir in thoroughly. The admixture of the cork dust
stiffens up the molten asphalt just enough so that the proper
quantity clings to the corkboards when dipped.
To prepare Asphalt cement for use with corkboard on
floors and bottoms of freezing tanks, proceed as outlined in
the foregoing paragraph, except no pans are ordinarily needed
and no cork dust is mixed with the molten asphalt.
Ordinary wire nails should never be used in erecting cork-
board <strong>insulation</strong>, because they will soon rust away, although
they are sometimes employed by careless and disinterested
erectors. Galvanised wire nails having large heads and of
proper length should always be used where specified, but do
not use galvanized wire nails where wood skezvers are speci-
fied and can be employed instead. Wood, even hard hickory,
is a far better thermal insulator than metal, and consequently
galvanized wire nails should never be used where wood
skewers will serve the purpose, for there is always danger of
frost following in along nails or forming on wall finishes over
nail heads underneath. Hickory skewers should be used in i
preference to softer woods, to diminish the chances for damage
to the hands of workmen from splintering and breaking of the
skewers when being driven into the <strong>insulation</strong>.
*CAUTION—Gasoline torches have been known to explode if not properly constructed,
not kept in proper condition, or not properly operated. Charcoal pots are
less applicable, but safer. See Appendix for description of Oil-Burning <strong>Cork</strong> Dipping
Pan.