In preparing any of the tinctures used for staining, it is of importance to powder or mash all the dry stuffs previous to dissolving or macerating them, and to purify all the liquids by filtration before use. Their coloring powers, which mainly depend on very accurate combinations of the requisite ingredients, should always be carefully tested before a free use is made of them, and the absorbent properties of the materials intended to be stained should be tested likewise. It will be better for inexperienced hands to coat twice or three times with a weak stain than only once with a very strong one, as by adopting the first mode a particular tint may be gradually effected, whereas, by pursuing the latter course, an irremediable discoloration may be the result. Coarse pieces of carving, spongy end, and cross-grained woods, should be previously prepared for the reception of stain; this is best done by putting on a thin layer of varnish, letting it dry, and then glass-papering it completely off again. Fine work merely requires to be oiled and slightly rubbed with the finest glass-paper. Thus prepared, the woody fibre is enabled to take on the stain more regularly, and to retain a high degree of smoothness. When stain is put on with a flat hog-hair tool, it is usually softened by a skilful but moderate application of a badger-hair softener. The steel comb is chiefly employed for streaking artificial oak, and the mottler is used for variegating and uniting the shades and tints of mahogany. Flannels and sponges are often used instead of brashes, but the implements most serviceable for veining or engraining purposes are small badger sash tools and sable pencils. The effect produced by a coat of stain cannot be ascertained until it has been allowed sufficient drying period.
This process may be used either for improving the natural color of wood or for changing it so completely as to give it the appearance of an entirely different kind of timber. Thus a light mahogany may be greatly improved by being made darker, and there are many other kinds of timber that are greatly improved by a slight change in their color. The following notes will be of use in the latter direction:
A solution of asphaltum in spirits of turpentine, makes a good brown stain for coarse oaken work, which is only intended to be varnished with boiled oil.
The naturally pale ground and obscure grain of Honduras mahogany is often well brought out by its being coated first with spirits of hartshorn, and then with oil, which has been tinged with madder or Venetian red.
Grayish maple may be whitened by carefully coating it with a solution of oxalic acid to which a few drops of nitric acid have been added.
Half a gallon of water in which 1/2 lb. of oak bark and the same quantity of walnut shells or peels have been thoroughly boiled, makes an excellent improver of inferior rosewood; it is also far before any other of its kind for bringing out walnut.
Raw oil, mixed with a little spirits of turpentine, is universally allowed to be the most efficacious improver of the greater number of materials. Beautiful artificial graining may be imparted to various specimens of timber by means of a camel-hair pencil, with raw oil alone, that is, certain portions may be coated two or three times very tastefully, so as to resemble the rich varying veins which constitute the fibril figures; while the common, plain parts, which constitute the ground shades, may only be once coated with the oil, very much diluted with spirits of turpentine. The following are a few useful stains: