RELATIVE ADVANTAGES OF OIL AND WATER STAINS
The merits of these two classes of stains may be stated briefly. Water stains enter more deeply into the pores of the wood because of their lighter body. The hard parts of the surface hold practically none of the stain and constitute the high lights of the finished surface. But water stains raise the grain and make sand-papering necessary to bring the surface flat again. For this reason, some polishers first give a coat of water to raise the grain and when dry sand-paper flat before staining.
Oil stains do not raise the grain, but owing to their heavier body do not penetrate so deeply and more of the stain is lost in rubbing off. Oil has a tendency to darken wood, so that wood stained with oil colours has a tendency to become clouded or muddy with age.
For staining old work, oil stains should be used rather than water stains. Old work has the pores already filled and water has little chance to penetrate.
Some chemicals and aniline dyes are very satisfactory. Bismarck brown, which may be bought at the chemist's as a powder, is soluble in alcohol and gives a rich reddish brown. It is very powerful and a very small quantity is necessary. Bichromate of potash comes in the form of lumps and crystals. It is soluble in water. Put half a dozen crystals in a quart milk bottle of water and allow it to stand over night. Warm or hot water will dissolve the crystals more quickly. It is to be put on with a brush and gives rich brown tints, the shade depending on its strength, the kind of wood and the number of coats. It gives excellent results on oak and chestnut, and is used to "age" bay wood to a dark mahogany, while several coats of it will bring white wood to the colour of natural black walnut.
Each coat must be allowed to dry and then be rubbed flat with fine sand-paper.
This treatment may be followed by two or three coats of orange shellac, rubbed down.
For "antique" finish on oak or chestnut, dissolve lampblack in turpentine, mix with filler and proceed with polishing as explained.
A decoction of logwood is often used to produce dark and even black effects. The logwood extract is cheap and comes in the form of gum or resin. Several lumps of this are boiled in a gallon of water and applied as any water stain.
Acetate of iron, made from iron filings and vinegar, is used for dark browns occasionally. The filings should be allowed to stand for several days in the vinegar. The acid present is acetic. It unites with the iron forming the acetate of iron.