Wood Staining 101
If the purpose of staining is to imitate natural wood, it is recommended that you procure specimens of the woods to be imitated. Excellent and most convenient specimens can be obtained at any scroll saw supply house at a trifling expense. Commence by oiling and varnishing the specimen to bring out the color, or apply a darkener if an antique color is required.
As a darkener for cherry, apply with a brush aqua-ammonia diluted with water according to the depth of color required. This is probably the best mixture for all red woods, as it develops the colors to their utmost intensity. Lime-water and lye (potash solution) are also frequently used, although lye should be used cautiously. If applied too strong, it destroys the red color after developing it. Iron filings or shavings boiled in vinegar produce a darkener for oak, and are frequently employed in producing the “darks” or shades in sixteenth century finish.
After darkening with a water solution the specimens should not be oiled, but after having thoroughly dried should receive a coat of shellac, and, when dry, a coat of varnish. Having the colors well brought out, they will be found of great utility in preparing a stain of accurate shade. Now, the secret in preparing a good stain is that it should be perfectly transparent, which may be produced in either oil or water colors.
The latter, however, with a few exceptions, will be found to give the best results, for several reasons. In the first place, it penetrates deeper into the wood, thus producing a more substantial finish. Next, the wood employed is generally hard and fine, and by an application of water stain the grain is raised, whereby the “lights” or veins are more prominently brought out, imparting to the finish a more vivid appearance, which cannot be so effectually produced from oil colors. Still another advantage in water stain is the saving of time in its application. When properly prepared, it can be used for dipping, which is the method practiced in our cabinet shops for staining much furniture.
It can also be applied with a brush, although good results by this method are accomplished only when skill and practice are exercised. In applying it a four- or five-inch flat bristle brush would be found the right size, enabling the operator to cover over any one part or section before the stain penetrates the wood. It will be found less difficult to apply oil stain uniformly with a brush, and it is, therefore, generally employed in staining soft-wood and especially the different species of pine, all of which absorb water stain in spots, giving it a daubed appearance.
The first thing to be considered is the receptacle or vessel in which the water or acid stains are to be prepared. This should be formed of a material which is unaffected by the corrosive action of acid. Porcelain-lined iron or glazed earthenware in the way of kettles or common stew crockery are commonly used. As the latter are often cracked by the heat required in boiling, it is safer and cheaper in the end to use porcelain-lined kettles.
Needless to say, care and cleanliness are two very necessary qualities in the preparation and application of stains, for a good workman is always a careful and a clean workman.
In finishing “rubbing” may be considered one of the most essential qualities, since it gives to the varnish when laid upon the wood a degree of smoothness not otherwise attainable. By the use of the brush alone minute furrows and ridges are left upon the plastic surface of the varnish, and although good varnish possesses in itself a high gloss, the gloss is not nearly so agreeable to the eye as the brilliant polish of which rubbing is the preliminary. The reduction of these ridges and furrows is accomplished by means of finely-powdered pumice-stone moistened with raw linseed oil and applied with a piece of haircloth or other coarse and fibrous material. For rubbing large flat surfaces the haircloth is sometimes folded over a block of convenient size, but this is not practicable for articles of small size or irregular shape.
In rubbing, considerable force must be used, but the stroke must be steady, and as long as possible, and great care should be taken to rub the surface uniformly. If it is rubbed unevenly the varnish is liable to be worn away quite to the wood in some places, and the perfect smoothness that is the beauty of a good finish will thus be impossible. The edges especially are liable to be rubbed bare, and should be carefully treated.
The crevices and hollows of carvings are rubbed by means of hard-pointed sticks of various convenient sizes. The rubbing should be continued until the entire surface appears perfectly smooth and free from marks of any kind. The surplus pumice-stone and oil should all be carefully removed from the surface by means of rags, and the work may then be cleaned up with a little sweet oil well rubbed in, and retouched with a cloth slightly dampened in alcohol, which serves to remove any remaining oil from the surface. If the article has veneered panels they are now ready for the final processes of “polishing,” or “flowing” processes. Whatever the kind of “finishing,” the workman should make it a point where possible to have a suitable temperature. No good finishing can be done under 60 degrees, and it is hard to get the temperature too high for this work. The wood should be warm and perfectly dry, and visitors, flies, dirt, dust and dampness should rigorously be excluded from the room while the work is in progress.
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