WHICH GLUE TO USE
The answer to this question depends so largely on the individual
conditions, that only very general suggestions may be given. We have
already suggested the need of experimenting and accurately recording
the results of using various kinds of glue. Once again, your dealer
will give you good advice nine times out of ten--and your own
experience should afford the most valuable check on his suggestions.
In general, the following glues are indicated:
Wood joints--High test hide glues. They make strong, firm joints, which
is extremely important, as joints are subject to more or less tension;
and they set rapidly.
Veneers--A moderately high test mixture of bone and sinew or bone
and hide. The higher test glues set too quickly for this particular
kind of work. If a spreading machine is used, avoid a glue that tends
to foam. Sometimes foaming is caused by its spreading too fast.
Overheating glue also tends to foam it. This can be overcome by the
addition of sweet oil or vaseline, paraffine or wax candle, but it is
objectionable when veneering. It is best to be sure you have a glue
that will not foam. Your dealer can tell you what glue to use.
Sizing--Use a glue free from grease and foam and one that flows freely.
Paper Boxes--A quick-setting hide glue is indicated for setting-up. For
covering, a lower test bone glue is preferred, as it does not set so
quickly. Paper box manufacturers are troubled more or less with foaming
glue and can use the remedy suggested in the paragraph on veneers, as
this will not be objectionable in paper box work.
Belting and Other Leather Goods--Here the principal requirements are
flexibility, resistance to moisture and tenacity. The higher test glues
are generally preferred.
Bookbinding--For pasting covers, a low-grade bone glue answers all
requirements sufficiently well. For rounding and backing, where strain
is exerted, a high-grade hide glue should be used.
For Emery Purposes--Very high-grade glue that has been carefully
prepared to eliminate all acids, alkalies and impurities. A good
emery glue possesses superior water-absorbing qualities. To test a
glue for emery purposes, soak an ounce in about five times its weight
of water at room temperature for 48 hours. If at the end of the time
the water shows discoloration, or if decomposition is evidenced by a
disagreeable odor, the glue is not adapted to emery use; otherwise it
may safely be used. Weigh glue after the operation, to get an idea of
its water-taking properties.
HOW MUCH TO PAY FOR GLUE
While the high test glues cost more per pound, they go farther and do
better work, except in cases when their quick-setting characteristics
are an objection.
How much you can afford to pay for your glue is a question that you
must answer from your own observation and tabulation of results. In
certain lines it would be foolish to use a high-grade glue, where the
work would not benefit in proportion to the increased expenditure. Any
attention given to the subject will be well repaid.
KEEP ACCURATE RECORDS
Always keep accurate records, and base your future purchases upon the
demonstrated comparative results already attained by the various glues
you have used in actual practice.
No glue is good to use unless properly prepared. A 16-cent glue may be
reduced to the grade of an 8-cent glue by overheating. The grade of
the glue at the time it is used is the important thing.
Do not by faulty methods of preparation impair the working quality of
your glue. A glue of moderate high-grade properly prepared is better
for practical purposes than a high-grade glue whose working quality has
been destroyed by excessive or prolonged heating.
WATERPROOF GLUE
Sometimes it is desired to use glue with waterproof qualities. Glue
is rendered practically waterproof by adding a small quantity (about
1%) of ammonium or potassium bichromate to the glue liquid. Upon
hardening, the glue then becomes waterproof. Adding a small quantity of
formaldehyde to the liquid glue will help it to resist the action of
water after it has dried for some time.
Others suggest dissolving glue in an equal quantity of water and adding
about as much linseed oil as water, with the aid of heat, until a
jelly is formed. This mixture is said to be practically waterproof.
A patented process has recently been put out for which the claim is
made that it can be applied to any glue irrespective of grade or make,
rendering it absolutely waterproof. The result is attained by mixing
the glue with certain chemicals in specified proportions, and then
adding a certain amount of formaldehyde. Any amount of glue can be
treated and the process is said to be most effective.
VEGETABLE GLUE
Of recent years efforts have been made to find a substitute for
animal glue. The effort has met with success to a certain extent for
particular kinds of work. Probably the newest addition to the list of
vegetable glues is the mineral glue-silicate of soda. Liquid silicates
were first sold for the manufacture of soap. In recent years certain
forms have been used for light adhesive paper work. It is used in
places where glue is too slow setting.
QUICK SETTING GLUES
When a glue is desired to set very quickly the manufacturer can usually
furnish glue with the setting qualities desired for the particular
work in hand. If this cannot be done, for any reason, remember that
the temperature of the glue is an important factor. A low temperature
aids in quick setting. Some paper box manufacturers have had successful
results in quick setting by adding a small quantity of turpentine to
the liquid glue. Some add silicate of soda.
FLEXIBLE GLUES
Specially made glues are supplied by manufacturers for work in which
flexibility is needed. An easy way to increase the flexible quality of
glue is to add a little glycerine to the liquid glue.
The Republican Publishing Co., Hamilton, Ohio
TRANSCRIBER’S NOTES
Inconsistent hyphenation has been standardized throughout.