Handbook on Japanning: 2nd Edition | Page 3

coats of coarse varnish (1 lb.
seed-lac, 1 lb rosin to 1 gallon methylated spirit, dissolve and filter).
This varnish, like all others formed from methylated spirits, must be
applied in a warm place and all dampness should be avoided, for either
cold or moisture chills it and thus prevents it taking proper hold of the
surface on which it is applied. When the work is prepared thus, or by
the priming made of size and whiting already described, the japan
proper is itself applied.

SECTION II.

JAPAN GROUNDS.
The japan ground properly so called consists of the varnish and
pigment where the whole surface is to be of one simple colour, or of the
varnish, with or without pigment, on which some painting or other
form of decoration is afterwards to be applied. It is best to form this
ground with the desired pigment incorporated with shellac varnish,
except in the case of a white japan ground which requires special
treatment, or when great brilliancy is a desideratum and other methods
must be adopted. The shellac varnish for the japan ground is best
prepared as follows: shellac 1-1/4 lb., methylated spirits 1 gallon.
Dissolve in a well-corked vessel in a warm place and with frequent
shaking. After two or three days the shellac will be dissolved. It is then
recommended to filter the solution through a flannel bag, and when all
that will come through freely has done so the varnish should be run into
a proper sized vessel and kept carefully corked for use. The bag may
then be squeezed with the hand till the remainder of the fluid varnish is
forced through it, and this if fairly clear may be used for rough
purposes or added to the next batch. Pigments of any nature whatever
may be used with the shellac varnish to give the desired tint to the
ground, and where necessary they may be mixed together to form any
compound colour, such as blue and yellow to form green. The pigments
used for japan grounds should all be previously ground very smooth in
spirits of turpentine, so smooth that the paste does not grate between
the two thumb nails, and then only are they mixed with the varnish.
This mixture of pigment and varnish vehicle should then be spread over
the surface to be japanned very carefully and very evenly with a
camel-hair brush. As metals do not require a priming coat of size and
whiting, the japan ground may be applied to metallic surfaces forthwith
without any preliminary treatment except thorough cleansing, except in
the cases specially referred to further on. On metallic surfaces three to
four coats are applied, and in the interval between each coat the articles
must be stoved in an oven heated to from 250° to 300° F.
WHITE JAPAN GROUNDS.
The formation of a perfectly white japan ground and of the first degree
of hardness has always been difficult to attain in the art of japanning, as
there are few or no substances that can be so dissolved as to form a
very hard varnish coat without being so darkened in the process as to

quite degrade or spoil the whiteness of the colour. The following
process, however, is said to give a composition which yields a very
near approach to a perfect white ground: Take flake white or white lead
washed and ground up with the sixth of its weight of starch and then
dried, temper it properly for spreading with mastic varnish made thus:
Take 5 oz. of mastic in powder and put it into a proper vessel with 1 lb.
of spirits of turpentine; let them boil at a gentle heat till the mastic be
dissolved, and, if there appear to be any turbidity, strain off the solution
through flannel. Apply this intimate and homogeneous mixture on the
body to be japanned, the surface of which has been suitably prepared
either with or without the priming, then varnish it over with five or six
coats of the following varnish: Provide any quantity of the best seed-lac
and pick out of it all the clearest and whitest grains, take of this
seed-lac 1/2 lb. and of gum anime 3/4 lb., pulverize the mixture to a
coarse powder and dissolve in a gallon of methylated spirits and strain
off the clear varnish. The seed-lac will give a slight tint to this varnish,
but it cannot be omitted where the japanned surface must be hard,
though where a softer surface will serve the purpose the proportion of
seed-lac may be diminished and a little turpentine oleo-resin added to
the gum anime to take off the brittleness. A very good varnish entirely
free from brittleness may, it is said, be formed by dissolving gum
anime in old nut or poppy oil,