VARNISHING Before varnishing, the surface should first be " flatted " either by mixing the last coat of paint with turpentine or by rubbing it down with a piece of felt moistened and dipped in pumice stone. For a level surface, tack the felt on a block of wood, or use thick woolen cloth or chamois tacked to u block of wood, or a smooth piece of pumice stone with water. Let dry and brush off the surface to remove the dust. Take care that the air is not full of dust when the varnish is applied.
For a fine quality of work, two to six coats may be spread on, one after the other. Do not lift too much var nish on the brush, but rather take up small quantity, spread it on finely, and rub out well. Rub down the next to the last coat until the gloss is " flatted," and let the last be a flow ing coat, heavy enough to flow out evenly of itself. For a cheaper grade of work, two or three coats are suffi cient, the last coat being flowed on.
To finish varnish, rub down with very finely pulverized pumice stone, and wash off with clear water. Af terwards rub down with rotten stone and sweet oil, applied by means of the bare hands. Finally wipe and polish with chamois.
Killing Knots.—Use for this pur pose only the best quality of pure grain alcohol orange shellac varnish or " knot killer." Apply over this with a brush equal parts of red and white lead ground with water, and mixed with hot glue size at the rate of 4 ounces of glue to a gallon of water. Apply before it cools. And for fine work, follow with a second coat of 3 parts of white lead ground in oil, and 1 part of red lead or litharge.
Or, for cabinetwork, cover the knot with an oil size and lay over it silver or gold leaf.
Or hold a hot iron against it until the pitch stews out so that it can be scraped off. Afterwards corer with gold or silver leaf.
Ingredients of Varnish. — Varnish is a solution of various gums, as the resins amber, copal, dragon's blood, mastic, lac, rosin, and sandarac, in various solvents, as alcohol, wood spir it, oil of turpentine, linseed, and other drying oils. It is used as a decora
tion to produce a hard, transparent, or glossy surface, and also as a pro tection against moisture and air.
Resins.—Resins in general are sub stances that occur in various plants, and which flow from trees of different species when the bark is cut. They are usually yellow and do not crystal lize, but form in drops like gum. They are not, however, the same as gum, although the two words are often used interchangeably.
Amber. — A resin produced from certain extinct coniferous trees. It occurs as a fossil, usually of u pale yellow color, opaque, or transparent. It is mined the same as coal in vari ous parts of the world, especially in the vicinity of the Baltic Sea. Small quantities are found in the United States. Amber was much prized by the ancients and was an object of commerce in prehistoric times. It is extensively used for ornaments, es pecially for the mouthpiece of pipes.
Anime.—A resin which exudes from a certain tree in Brazil. Used as a medicine and as incense. The name is also applied to a resin known in India as copal.
Copal. — This name is applied to several resins used in varnishes. It is a nearly colorless, translucent sub stance imported from tropical Amer ica, India, and eastern and western Africa. Zanzibar copal is said to be the best.
Lac.—A resinous substance caused to exude from certain trees in Asia by the bites of an insect about the size of a louse. The twig punctured by these insects becomes incrusted with lac, sometimes to the thickness of a quarter of an inch. It protects the eggs and supplies food for the young maggots. The mothers are of ten imprisoned and covered by the sticky fluid, imparting to it a lac dye similar to cochineal. The twigs are broken off before the maggots es cape and are dried in the sun.
Stick-lac is the crude product or dry twigs. It is not soluble in water except the lac dye or red coloring matter, which washes out. It is par tially soluble in alcohol, but not in linseed oil or turpentine.