Music Trade Review -- © mbsi.org, arcade-museum.com -- digitized with support from namm.org
DECEMBER 5,
THE
1925
MUSIC TRADE
REVIEW
46
SUPPLY BRANCHES OF THE INDUSTRY
Dryness of Corestock
Before Laying Veneers
Writer in "Veneers" Holds Corestock Should
Be 25 Per Cent Dryer Than Lumber in Solid
Work
Piano superintendents operating their own
kiln-drying plants are often perplexed by the
question, How dry should corestock be at the
time of laying the veneer? Some have the idea
that if it is as dry as lumber used for ordinary
purposes, such as solid wood furniture, it is
dry enough. Another opinion is held by Carl
B. Burton, who states in the current issue of
Veneers that lumber for corestock should be
dried to a moisture content at least 25 per cent
lower than that of lumber used for solid furni-
ture.
"The conclusion is based on the fact that the
stock will take up considerable moisture from
the glue, and the less moisture the wood con-
tains the more readily will the glue set after
the stock is in the press. During certain sea-
sons, and especially in certain localities, the
stock must be kept in the retaining clamps for
some time in order to allow the moisture to
leave the glue and enter the wood so that the
glue may set sufficiently to permit releasing the
stock from the clamps without danger of the
veneer coming loose. This time is reduced and
the danger lessened by a reduction in the orig-
inal moisture content of the wood.
"Reducing the moisture content of the wood
before the veneer is laid is a time-saving propo-
sition. Ordinary lumber is dried at a higher
temperature than is plywood, and for that rea-
son less time would be required to reduce the
moisture content a further 2 per cent than to
eliminate this same amount of moisture from
the plywood after it leaves the press.
'Another advantage claimed for super-drying
corestock is that it results in less disturbance
to the glue joint in the final drying of the com-
pleted article. The moisture absorbed by the
core from the glue is bound to result in some
swelling of the fibers, and the less moisture
there is to be eliminated after the stock leaves
the press the less shrinkage will there be, with
proportionately less disturbance to the joint.
"When the corestock is overdried to the ex-
tent of 2 or 3 per cent, the crossbanding, or
veneer, should be dried to a point where it is
almost entirely devoid of moisture. Even though
the glue is applied to the core, and the latter
absorbs more moisture from the glue than does
the crossbanding, the crossbanding will take up
a larger percentage of moisture because of its
thinness. Though the crossbanding may be
dried to a lower moisture content than is the
veneer, it may have a larger moisture content
after it leaves the press because of the fact that
less wood absorbs almost an equal amount of
moisture.
"Up to the present time I have laid stress on
the advisability of properly drying veneer in
order to avoid the swelling and shrinking which
result in checking. The idea that the unequal
shrinking of core and crossbanding places a
strain on the glue joint which may materially
lessen its life may not be a new one, but it has
not been given the publicity and prominence
which it deserves. The heavier the wood body
and the greater the shrinkage, the greater is the
strain on the joint. In the case of a crossbanded
core the strain is increased by reason of the fact
that one body shrinks at right angles to that
of the other. In the case of crossbanding or
veneer a lesser strain is imposed on the glue
joint by reason of the fact that the wood gives
way and checks before the strain on the joint
becomes very^ great, but when the heavy core
shrinks the strain is apt to be sufficiently great
to cause a perceptible weakening of the joint.
I am inclined to the opinion that many cases of
failure in which the trouble has been charged
to poor quality of glue have had some other
cause.
"Time and again letters have been received
from people who claimed their plywood warped
although every precaution had been taken in
the drying after it left the press. For a time I
thought they must have been mistaken about
the stock being dry, and in consequence was
led to make some experiments with a view to
ascertaining whether these things are true, and
have reached the conclusion that crossbanded
stock is very apt to warp, no matter how care-
fully it has been dried after leaving the press,
if the units were not properly dried before they
were united. The extent to which this is true
may vary according to the thickness of the core
and crossbanding, but my opinion is that a great
deal of the trouble experienced with moderately
We Are Specialists in
High Grade White Eastern
BAR STOCK
Let us know your requirements
GEORGE LOUCKS
Dolgeville
Write for a sample can of Behlen's
Varnish Crack Eradicator and try it.
Once you learn how much it means to
you in the saving of time on your refin-
ishing jobs by eliminating the necessity
of scraping off old varnish and shellac,
and how much more satisfactory are
the results, because of the better sur-
face it gives to work on, you, like
others, will continue to use it.
Write to-day.
H. BEHLEN & BRO.
Aniline*
Sh«lUea
Stains
Fillers
10-12 Christopher St., New York
V—T
«tk AT*., and 8th St.
New York
thin panels warping can be traced to this source.
Of course, if panels are very thin, with a thin
rotary-cut core, the strain resulting from un-
equal shrinking may be relieved by some, or
all, of the units checking in numerous places.
In the case of a thick core that is strong enough
to avoid checking, there is great danger of the
stock warping after it has gone through the
drying room."
Finishing Market
Generally the prices to which practically all
finishing materials advanced in October are
holding firm and no further advances are ex-
pected. Market experts state that buyers of fin-
ishing materials are safe in keeping stocks for
thirty to sixty days. Turpentine has been fluc-
tuating more than usual this Fall and prices
reached as high as $1.20 per gallon in drum
lots. The outlook for the dollar price is not
promising, and all indications are that present
prices will hold for the Winter.
Foreign reports for a time were to the effect
that the scheme for advancing the price of rub-
ber might be tried on shellac and, following this
rumor, there was heavy buying by the importers
to protect themselves against the artificial ad-
vance. This forced prices up naturally, but a
reaction has set in and the price of 60 to 75
cents per pound, f. o. b. New York City, may
be taken as normal.
F. A. Merriam Honored
SOUTH ACTON, MASS., November 30.—Frank A.
Merriam, senior member of the A. Merriam
Co., manufacturer of piano benches and stools
in this city, has been elected president of the
Acton Agricultural Association at its recent
meeting. This position has considerable local
significance and Mr. Merriam was chosen as a
result of his prominence and activity in Acton
affairs. He is also treasurer of the National
Piano Stool Manufacturers' Association.
Forestry Legislation
WASHINGTON, D. C, November 28.—A survey
of forestry legislation published to-day by the
National Lumber Manufacturers' Association
reveals that twenty-six of the' forty-two States
which had legislative sessions this year adopted
seventy-one important forestry laws.
"The outlook for private reforestation on an
extensive scale," says the forest economist of
the National Lumber Manufacturers' Associa-
tion, "is becoming most hopeful. This survey
shows that the public is beginning to do its
part."
Protect Your Bench With
A SLIP COVER
American
Piano Wire
"Perfected" "Crown"
Highest acoustic excellence dating back to the
days of Jonas Chickering. Took prize over
whole world at Paris 1900. For generations
the standard, and used on the greatest num-
ber o i pianos in the world.
Ssrricst of tor Acoustic Engineer always srailabl*
—free Illustrated books—free
American Steel & Wire
ACOUSTIC DEPARTMENT
208 8. LA SALLE ST.. CHICAQO
Company
Write for Bench and
Cabinet Catalog.
THE ART NOVELTY CO., Goshen,
PHILIP W. OETTING & SON, Inc.
213 East 19th Street, New York
Sole Agenti for
WEICKERT HAMMER AND DAMPER FELTS
GRAND AND UPRIGHT HAMMERS
Made of Welckert Felt