Forest Green Oak.—Forest green oak is among the best of the green effects in this wood. The stain is made by mixing two parts of chrome green with one part of chrome yellow for the colouring material. This is added to a mixture of three parts turpentine and one of raw linseed oil, with a little white japan. The resulting stain should be somewhat thinner than linseed oil. After this has been applied to the oak surface, rubbed in and dried, it is given a coat of thin shellac coloured with tumeric and a very little green aniline. This should have a wax finish.
Gray Oak.—A gray stain may be given to oak by a solution of iron sulphate, made by dissolving a small quantity of chemically pure crystals in water, and giving the solution a strongly acid quality by adding a little sulphuric acid. This solution is most conveniently used by placing it in a box tank large enough to contain the pieces of wood to be stained, as they must soak in the solution until they are thoroughly saturated. The pieces may be kept separate by stout cords tied around them, and they may be held under the solution by means of weights. When taken out they should be allowed to dry before they are rubbed down.
Weathered Oak.—Weathered oak stain is made by taking two ounces of copperas and the same quantity of dry tannin, dissolving them separately in about a quart of water, and when thoroughly dissolved mixing them together. When applied to oak it gives it the natural weathered tone with a slight bluish cast. It may then be oiled, shellaced and finished with a flat varnish or wax.
Fumed Oak and Chestnut.—But the most satisfactory method of giving a brown tone to furniture or other woodwork, is without question, by fuming with ammonia, though this process is limited to two woods, viz., white oak and chestnut. All other woods, including red oak, are deficient in tannic acid, the essential element to combine with the ammonia gas in the production of the stain. This method requires a fuming box of sufficient dimensions to contain the article of furniture to be fumed. It must be carefully constructed with all its joints made vapour proof by pasting over them strips of paper and covering them with shellac. The top or one side of the box should be fastened with screws, so that it may be vapour proof when the box is in use and yet easily removed. The operation of fuming consists simply in placing the furniture in the box with one or more shallow pans filled with the strongest ammonia—not the household ammonia, which is too weak—screwing the top or cover on, and allowing the apparatus to stand from 12 to 24 hours, according to the shade desired. If the fuming box be provided with small glass windows in its adjacent corners, a good light will be thrown across the furniture so that the development of colour may be observed without opening the box. When the desired shade has been obtained and the furniture removed, it is best to give it a good wax finish which will develop a beautiful velvety texture.
Peculiarities of Fumed Finish.—It will be observed that the toning of quartered oak by the fuming process develops the beauty of the grain far better than any other process of staining; and there should also be noted the still more remarkable fact that the contrasts of tone are the reverse of those given by staining; i. e., the parts that appear lighter in the one case are the darker parts in the other. This gives a certain distinction to the fumed finish and furnishes a means of detecting that which is not genuine.
WHITE ENAMEL
A vivid and very effective finish for furniture as well as for the trim of some rooms is white enamel. It is used on new work and also in re-finishing old furniture and other woodwork. In the latter case the old finish, whatever it may be, must be removed and the surfaces thoroughly sand-papered. But whether the wood be old or not, a satisfactory enamel finish cannot be produced by using the white varnish alone, since, like all other varnishes, it is somewhat transparent. It is necessary, first, to coat the wood with flat white—a paint made of white lead with some zinc oxide for hardening and thinned with turpentine. Oil should not be used in any part of the process. Three coats of this paint will generally be needed to produce the right surface for the final finish. Each of these coats should be allowed to dry and become well hardened. Two or three days, better still a week, should be allowed for hardening between coats, since insufficient hardening leads to cracks in the subsequent coats and develops a tendency to chip off. When a surface is ready for the enamel, only one coat of it should be applied, and that should be given not less than one week to harden before it is exposed to wear. Enamel is simply a good varnish coloured with zinc oxide ground in varnish. It may be thinned, if necessary, with turpentine, and it is applied with a brush like any other varnish.
PROBLEMS
Problems in filling and finishing were developed in the series of furniture making problems in [Chapter VII]. It is only necessary to bring forward the unfinished work there described and apply to it the finishing methods outlined in this chapter. Our problems are, therefore, the following:
The Knock-down Bookcase.—If made up in white wood it may, like its original, be stained in imitation of black walnut and waxed. It may, however, be of oak, ash, or cherry, and finished to harmonize with the furniture with which it is to be used.