The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1905-08-18
BY JAMES RITCHEY

II
Instructor in Woodworking and Pattern
making, Armour Institute of Tech
nology, Chicago)
Copyright by Joseph B. Bowles)
Shellac varnish, or shellac, as it is
commonly called. is solution of shell
lac gum in alcohol Pure grain alco-
hol only is used for the best grades,
wood alcohol being substituted in the
cheaper grades. These cheaper grades
should be avoided. because they de-
teriorate rapidly and do not produce
a good finish, besides being very hard
to spread evenly with the brush.
Shellac varnish must be brushed on
quickly. since the alcohol evaporateS
rapidly. 1t must also be diluted with
alcohol when necessary, until it will
flow freely and spread evenly.
Shellac yarnish alone makes an ex-
cellent finish for either soft or hard
pine or for white maple, without the
use of filler Three to six coats will
be needed, and each ceat, when dry,
must be sandpapered smooth with No.
0 paper before another is applied.
The last coat is not sandpapered but
instead the surface is cut down even
and smooth with powdered pumfce
stone and oil. A good quality of ma
chine or lubricating oil is the best for
this purpose and should be used freely
to keep the pumice stone wet and to
prevent it from gathering into Jumps
ON the rubber or on the surface OF the
work If the surface is fiat use small
block of pine wood. or better of cork.
over which several thicknesSes of can
ton flannel have been wrapped. After
cutting off the higher projections dis
pense with the block and hold the cloth
in the fingers only. The pumice will
cut faster without the block, but greater
care must be taken to avoid rubbing
over and cutting the shellac from the
corners and angles of the piece being
rubbed.
Shellac will not take high polish
like varnish and is usually finished and
polished with the pumice and oil alone
To work rapidly they must be used free
ly and the condition of the surface ex-
amined often during the process by
simply wiping off small section with
the finger or soft cloth.
Patching Varnish.
When rubbing yarnish to an even
and smooth surface, even experienced
rubbers will sometimes rub through
that is. rub or cut off all the varnish
down to the bare wood. To patch such
spots requires time, patience and care.
The first coat Tin recoating) must be
put on so as to cover the bare spots
only, but as the shellac is very thin for
some distance around the spot, the Sec
ond coat must be spread around the first,
and the third still farther on, adding
coat each day. but sandpapering between
coats with great care to avoid scratch
ing the rubbed surface of the shellac,
near by.
Copal Varnish.
Copal. or furniture varnish, as it is
more often called, is made of gum
copal. boiled linseed oil and turpentine,
combined by heat being boiled togeth-
er and strained, after which it is al
lowed to settle and ripen, often for sew
eral months, before it is ready to use.
This varnish, unlike shellac, dries
very slowly, owing to the oil which il
contains, so that each coat requires
from two to four days to dry and harden.
1t must be used quite thin. so that it
will run freely from the brush, turpen-
better, the varnish may be slightly
warmed by placing the varnish cup over
(not in) a vessel of hot water This last
method, when convenient, is greatly to
be preferred, as the raw turpentine
when added will destroy much of the
smoothness and gloss of the va-nish.
Copal varnish is applied directly to
the surface of the filler, and each sue
cessive coat must be sandpapered
smooth with No. paper before anothex
is brushed on. Three, four and even
six coats will be needed, according to
the quality of the finish desired After
the last coat has become dry and hard
the whole is rubbed down even and
smooth with pumic stone. Oil may be
used as described for shellac. but as
copal is an oil varnish, it will resist
much faster if water is used with it in
water, and the pumice stone will cut
place of OIL The surface produced will
be equally smooth, but will have no
polish or gloss.
After cutting. the varnish to smooth,
even surface, all pumice must be care
fully wiped off with moist sponge and
the new surface of the varnish allowed
to dry and harden for one or two days,
after which all remaining particles of
pumice are removed and the new surface
of the varnish is polished by using fine
powdered rotten stone and oil on a
soft wad of canton fiannSl
When polishing with rotten stone
the last or finishing polish is best pro-
duced by small circular strokes of the
polisher, and when the required polish
has been given to the surface, all re-
naming oil and rotten stone is wiped
off with soft cloth, and the final polish
give.i with a piece of soft chamois skin,
continuing to use the circular strokes
in preference to rubbing lengthwise or
in one direction.
When polishing with rotten stone.
linseed oil will produce a finer polish