Spirit of the age. [volume] (Woodstock, Vt.) 1845-1913, 1905-07-29
MAKING GLUE
A Description Of the Process of Its Man
ufAeiure.

Few substances are more generally
useful than glue. At one time or an
other nearly every householder has TO
use II, yet few persons know anything
about the different kinds, or which Is
best for the purpose IN hand,
For ordinary repairs TO articles OF
wood, especially II no severe strain Is
to be placed upon the object, the pre-
pared CLUES are convenient and AIDE
quate. They are therefore often chosen
in preference to the Oid.fashlOned sort.
But for strength and durability, no
glue which Is applied cold can compare
with the kind that Is first melted IN
a glue-pOt and then applied hot; ana
of this kind there are many grades,
which vary greatly in quality.
The manufacture OF hard glue. as
1t is usually called-that Is, glue which
Is to be used hot-is to large degree
the utilization of waste products. The
raw materials are pieces and scrapings
from hides, chips and dust from horn
working factories, pNrings from hoofs,
and best Of all, sinews from animals
klileu lOC loOu III Tue BlVhN SlhhSh'Nt-
houses.
The first process is a soaking in lime
water. made thick enough TO be called
milk of lime" In this bath the Sill
ews and other glue materials remain
for two weeks or more, in order that
all the grease and blood may be eaten
away; but Immediately on removal the
material Is exposed to currents of air,
which allow any adhering lime to alb
sorb carbonlc acid. This checks the
action of the alliai on the animal mat
ter, and makes Il possible to keep
the material in the dry state for an
indefinite period, or until 1t is desired
to use ii.
Previous To pOinns, inc swap 10 asaI"
immersed for twentyfour hours in
bath of milk of lime. 1t Is then placed
in a caldron built on the plan OF the
housewives familiar double boiler
This kind of vessel is necessary to pre-
vent burning on" Water is added,
and the mass is gently boiled until
firm gelatinous liquid results from
cooling.
The clear portion is now drawn off
from the first caIdron into second
vessel, and is known as "6rst run sinew
glue"-the best of all. A small guam
tity of alum dissolved in water is add.
ed, for the purpose of clarifying the
glue by causing it to precipitate its
impurities.
In second double boiler the liquid
remains several hours, till it is perfect
Iy clear, and is then run off into the
congealing boxes, over the bottoms OF
which it spreads out in thin sheets.
The boxes are run into the cooling
rooms, where they remain until the
glue has hardened enough to be re-
moved in sheets, but not enough TO be
brittle. In this state it is ready to be
cut.
The sheets are laid upon boards,
which have previously been wet, to
prevent the glue from sticking. Here
the cutting is done with tightly
stretched brass wires, as a firkin of
butter is cut by the country grocer.
After further drying on revolving net
tings, the sheets are dipped in hot
water and rubbed with brush to give
them a polish. Then then pass to the
kilns for the "stove-drying." This re-
moves all moisture and leaves what APP
pears to be a sheet of translucent yell
lOwish-brown bottle glass. Indeed, the
best sinew glue seems on casual ex-
animation to be nearly as hard as
glass, and quick, sharp blow will pro-
duce q fracture that is clean-cut and
vitreous. The best of this glue is light
The residuum left in the caldrOn
when the first run" of glue was drawn
off is boiled and boiled again, so long
as any gelatinous matter can be ex-
tracted from it. The product is glue
of inferior grades, of course, but use
full as sizing and for other purposes
i'm various arts and industries. AL
though still classed as sinew glue,
these later runs" have not the
strength of the first run. They are
darker and less translucent.
Not many years ago nearly all the
best glue was sold in sheets. To-day
by far the greater part is ground at
the factories to the fineness of ordinary
sawdust. Since in this form it dis
solves more quickly, it Is so preferred
by woodworking factories, which use
large quantities; but as the chances Of
adulteration are greater when the glue
is ground, the purchaser who wishes
TO be sure of strength and durability
will choose the sheets.-Youth's CON-
paniOn.