This is the old way, and is still used for all common work. But for fine painting, as carriage work, a filler is now used first, because a priming to be durable should unite with the wood, grasping the fibers and filling the pores, so that after coats cannot sink in. The object is to cement the surface. Priming is often called "rough stuff." The old way did not do this, with the result that the oil separated from the lead and kept soaking into the wood. The princ.i.p.al makers of paints now recommend a filler before any white lead is added.
TOOLS AND MATERIALS FOR WOOD FINISHING
Brushes. It is well to have several varieties to help keep them distinct. For varnish and sh.e.l.lac, the best are those with the bristles set in hard rubber. For ordinary purposes, brushes one inch wide are satisfactory. For stains, cheap, tin-bound brushes are good enough, and are easily replaced.
Cups. Half-pint enameled steel cups are cheap, satisfactory, and easily kept clean. For the care of cups and brushes, see Chapter VI, The Equipment and Care of the Shop.
Steel wool. This consists of shavings, turned from thin steel discs set together in a lathe. It comes in various grades, No. 00 to No. 3.
The finest, No. 00, is coa.r.s.e enough for ordinary purposes.
Sandpaper. Use No. 00 smeared with boiled oil. Pulverized pumice stone and pulverized rotten stone, both very fine, are used to rub down inequalities and to give a dull finish to sh.e.l.lac or varnish. Use with oil on sh.e.l.lac and with oil or water on copal varnish. Horsehair and soft wood shavings are often used to rub down varnish. French felt, medium hard, is used for rubbing down copal varnish with pumice stone.
Cotton waste is the cheapest available material for wiping.
Cheese cloth is better for some purposes, but more expensive.
Soft cloth without lint is necessary for French polishing. "Berkeley muslin," "Old Glory," and "Lilly White" are trade names. A fine quality is necessary. The starch should be washed out and the cloth dried before using, and then torn into little pieces, say 4" square.
Fillers consist of silex or of ground earths mixed with oil, j.a.pan, and turpentine. Their object is to give a perfectly level and non-absorbent basis for varnish covering.
Oils. Raw linseed oil is very fat and dries slowly. It is used for interior work.
Boiled oil is linseed oil boiled with litharge (PbO) and white vitriol, which removes much of the fatty ingredient and gives it drying quality.
Turpentine is a volatile oil from the sap of long-leaf pine. It is mixed with oil in painting to give further drying qualities.
Benzine is a cheap subst.i.tute for turpentine. It is a highly inflammable product of coal tar and evaporates quickly.
Drier is an oil in which resin has been dissolved. It is mixed with varnishes and paint to make them dry quickly. It is also sometimes used as a varnish itself.
j.a.pan is a varnish-like liquid made of sh.e.l.lac or other resin, linseed oil, metallic oxides, and turpentine. It is used as a medium in which to grind colors and as a drier.
WOOD FINISHING
REFERENCES:[*]
(1) Stains.
Hodgson, II, pp. 25-59, 155-164.
Van Deusen, _Man. Tr. Mag._, 6: 93.
Maire, pp. 46-64.
(2) Fillers.
Hodgson, II, pp. 7-25.
Maire, 65-72.
(3) Oil Finish.
Hodgson, II, pp. 99-103.
Maire, p. 117.
(4) Wax.
Hodgson, II, pp. 93-99.
Maire, pp. 112-116.
(5) Varnish.
Sh.e.l.lac.
Maire, pp. 73-80, 101-111.
_Journal, Soc. Arts_, 49: 192.
_Ency. Brit._, Vol. XIV, "Lac."
Hodgson, II, pp. 66-93.
_Inter. Encyc._, Vol. X, "Lac."
Oil Varnish.
Hodgson, II, pp. 59-66.
Clark, pp. 1-69.
Maire, pp. 81-100.
_Encyc. Brit._, Vol. XXIV, "Varnish."
(6) Paints.
Brannt, p. 134-152.
_Building Trades Pocketbook_, pp. 357-360.
For detailed directions for the treatment of different woods, see Hodgson, II, pp. 112-153, Maire, pp. 124-141.
[Footnote *: For general bibliography see p. 4.]