Millheim Journal. [volume] (Millheim, Pa.) 1876-1984, 1880-08-26
Protection of woodwork.

1t Is well knswn that the sap of wood
contains substances like albumen, gelatiRe,
gum, etc, which easily undergo decomposi-
ton, and under certain circumstances, such
as favor fermentation, and in warm damp
air, are able to destroy very rapidly the
stronger woody fibers. The more sap
there is in the wood, that is
to say the greener it is, and the
sooner the evaporation OF this sap is stopped
by an alright cover, the quicker the fer
mentation will set IN, and with it the decay
of the woody fiber. These circumstances
are correctly understood by practical men,
who prescribe that the timber be felled in
winter, and try to obtain free circulation
of air through the structure. They think
they avoid the disadvantages above men
toned if they, further, demand seasoned
wood" because it is clear that there is less
danger of decomposition IN such wood
than IN fresh or green stuff. But here we
at once stumble on this difficulty, namely,
of determining what degree dryneSs in the
wood to be tested seems most advantage
Gus for its use, and the time required for
this is much longer than is generally sup
posed. The appearance Of the wood is
very seldom a reliable guide, and people
are accustomed to think that the wood is
much drier than it really is. The compar-
atively important changes which the wood
undergoes during the first year from
shrinkage enables us to measure approx
mately the time necessary to destroy the
last evil effects of Its interior life. Not un-
til it has reached this stage, which requires
four to six years, unless artificial seasoning
is resOrted to, is the timber benefited by
covering it with Il protecting coat of paint
AT this time the paint must have a benefi-
clal effect IN protecting the wood, for it
prevents atmospheric moisture penetrating
ing INTO the wood to serve as a reagent to
decompose the albumen, which is now
dried and coagulated as well as less abun-
dant. Owing to the position of the lum-
Der yards and the urgency for materials to
build with it is seldom possible to obtain
well seasoned lumber and wood. Sauer-
vein, therefore, proposes the following
process The most rational and sensible
process for large, heavy timbers is the i'm
pregnation, as for railroad ties, with chic
ride of zinc under SIX to eight atmospheres
of pressure, where this can be done.
(Fresh green wood is best for this. No
arguments are necessary In defense of the
value of this method; it cannot be too
strongly recommended, nor is the expense
great-about 81 per cubic meter. When
there is no opportunity for impregnation
the woodwork should be left two or four
years unpainted. In my experience, says
SauerweIn, wood tar is better than coal
tar, because it penetrates in the wood more
easily, and, containing larger amount of
antiseptic substances, its effect is more per-
manent. Although wood tar is considera-
bly, dearer it is to be preferred. It's color
being somewhat similar to wood color, it
can be used on small unimportant buildings.
Its cost is only one-fourth that of oil paint
and can be applied by common workman.
Planed and worked surfaces should be
merely oiled three times) not painted
Besides having better appearance, this
oil varnish Is necessary tO'prevent crack
ing and drawing of thin parts like doors
and windows. 1t does not interfere with
the gradual drying out of the wood. After
the expiration of three to five years the OIL
ing may bs replaced by protecting coat
of paint to prevent water from penetrating
into the wood work. 1t should be added
that it seems advantageous to mix about
one part of elutriated chalk with three
parts of the white lead which is used with
the special color for all oil paints. This