How To Make Hard Varnish In Spirit Varnishing
Most polishers are agreed that to obtain a good surface with varnish it is necessary to give the work, where it is possible to do so, a rubberful of polish first, and to thoroughly dry the rubber; but in most carved work the surface is not accessible, and the brush must be used.
Sometimes the carving is extremely coarse, and with an open porous grain, in which case it is best to oil it first and then to fine-paper it down; by this process a thin paste is formed by the attrition, which materially assists in filling up the pores.
Before commencing to use the varnish have ready an earthenware dish or box,—one of the tins used for the preserved meats or fish will answer the purpose,—with two holes drilled so that a piece of wire can be fastened diametrically across the top; this is called a "regulator," and when the brush is passed once or twice over this it prevents an unnecessary quantity of varnish being transferred to the work.
Varnishes.
The ingredients for making varnish are very similar to those for making polish, but the proportions are somewhat different.
Furniture varnish consists of two kinds, viz.: the brown-hard and the white-hard; the former is used for dark woods, such as mahogany, walnut, rosewood, etc.; whilst the latter is used for the light-coloured woods, in conjunction with the white polish.
A few years since the brown-hard varnish was made from these ingredients:
1 gallon of methylated spirit,
40 ozs. of shellac,
4 ozs. of rosin,
5 ozs. of benzoin,
2 ozs. of sandarach,
2 ozs. of white rosin.
The brown-hard varnish which is used at the present time is made differently, and produces a better result; it is made from the following:
1 gallon of methylated spirit,
32 ozs. of shellac,
8 ozs. of rosin,
8 ozs. of benzoin.
The white-hard or transparent varnish for white wood is made with
1 gallon of methylated spirit,
32 ozs. of bleached shellac,
24 ozs. of gum sandarach.
In making either polishes or varnishes, all the 47 gums should be first pounded and reduced to powder before mixing with the spirit, and when mixed they should be occasionally well shaken or stirred, so as to hasten their dissolution.
Brushes and Pencils.
The brushes used for varnishing are either flat, in tin, or round, tied firmly to the handle, and made of camel's-hair; but the small white bristle-tools and red-sable pencils will frequently be found of service in coating delicate carving, or turned work.
Varnish brushes can be obtained from a quarter of an inch to four inches and upwards in width; the most useful brush, however, for general use is about an inch wide.
It is important that brushes should be cleaned in spirits immediately after use, for if laid by in varnish they lose their elasticity and are soon spoiled; but if this preservative principle is ever neglected, the hardened brush should be soaked in methylated spirit, and if wanted for immediate use the spirit will soften the varnish quicker if made luke-warm.
The spirit should be gently pressed out by the finger and thumb.
All varnish brushes when not in use should be hung up, or kept in such a position that they do not rest upon their hairy ends, either in a box or tin free from dust.
Mode of Operation.
It is usual in varnish48ing to give the work three coats, and always allow each coat to dry thoroughly before applying the next.
It should be noted that spirit varnishes begin to dry immediately they are laid on; therefore, on no account should they be touched with the brush again whilst wet, or when dry they will present a rough surface. Always ply the brush quickly, and never go over a second time.
When giving the first or second coats it is unimportant how they are applied, whether across the grain or with the grain, but the finishing coat should always be with the grain.
If the varnish should appear frothy when laid on, it is of no consequence, as it will dry smooth if equally and evenly applied before a good fire or in a warm atmosphere.
Coloured varnishes can be made in exactly the same manner as coloured polishes.
The beautiful glossy black varnishes so admired on Indian cabinet-work, specimens of which can be seen at the Indian Museum, are very difficult to obtain in England, but a description of them may be interesting.
East Indian Varnishes.
The Sylhet varnish is composed of two parts of the juice of the bhela (the tree which bears the marking nuts of India), and one part of the juice of the jowar.
The articles varnished with it at Sylhet are of the most beautiful glossy black; and it seems equally 49 fitted for varnishing iron, leather, paper, wood, or stone.
It has a sort of whitish-grey colour when first taken out of the bottle, but in a few minutes it becomes perfectly black by exposure to the air. In the temperature of this country it is too thick to be laid on alone; but it may be rendered more fluid by heat.
In this case, however, it is clammy, and seems to dry very slowly. When diluted with spirits of turpentine, it dries more quickly; but still with less rapidity than is desirable.
The tsitsi, or Rangoon varnish, is less known than the Sylhet varnish. It is probably made from the juice of the bhela alone. It appears to have the same general properties as the Sylhet varnish, but dries more rapidly.
The varnish from the kheeso, or varnish-tree, may be the same as the Rangoon varnish, but is at present considered to be very different.
The kheeso grows particularly in Kubboo, a valley on the banks of the Ningtee, between Munnipore and the Burman empire.
It attains to such a large size, that it affords planks upwards of three feet in breadth, and in appearance and grain is very like mahogany. A similar tree is found in great abundance and perfection at Martaban.
A poisonous vapour exhales from several of the Indian varnishes, especially from that of Sylhet, and is apt to produce over the whole skin inflammations, swellings, itchings, and pustules, as if the body had been stung by a number of wasps. Its 50 effects, however, go off in a few hours.
As a preventative the persons who collect the varnish, before going to work, smear their faces and hands with greasy matter to prevent the varnish poison coming into contact with their skin.
You may also see :