To make a pad of convenient size for polishing, fold a piece of old, soft cloth, free from lint, and fill it with cotton waste; or the end of a roll of cloth may be covered by the piece which is to do the actual polishing. Provide a cup of moderately thin shellac and another of boiled oil, of which about one quarter is turpentine; or better, a cup of sweet oil without turpentine. Dip the pad into the oil and allow it to soak in completely, then do the same with the shellac. Now dip the pad again into the shellac, and with the finger put on a single drop of oil, and rub lightly upon the work, with a circular motion, or if the work is large enough, the stroke may be longer. If the work is done with a straight stroke, do not stop at the end of the stroke, as the instant between the end of one stroke and the beginning of the return may be enough to allow the shellac to stick and make a hole in the surface, which will be difficult to repair; begin and end the stroke with a sweeping motion. The idea of this method of polishing is to bring the shellac to a polish, using as little oil as possible for lubricating, as the less oil used, the better will be the polish.
76. Brushes.—(A.) If brushes are to be used for stain or for filling, a cheap brush of any suitable size will do, a flat brush being preferred upon ordinary work. For shellac and varnish, the finer the brush, the better the results usually obtained. Ordinarily it is the best practice to use as large a brush as the nature of the work will permit, as it will hold more, and cover more surface, than a smaller brush, and have fewer “laps.” Chisel-pointed, flat brushes, from 1½” to 2½” in width, will be found satisfactory for the work of schools and amateurs, but upon professional work, brushes from 3½” to 5” often are used.
(B.) The care of the brushes is an important part of the work of those who use them, as neglect or carelessness may destroy a valuable brush overnight. Unless a brush is going to be used again the next day, it is always best to clean it thoroughly. If a stain, filling, paint, or varnish brush, use gasolene or turpentine, but if a shellac brush, use wood alcohol, cleaning off all the small particles. To obtain the best results, all brushes should be washed in hot, soapy water, and afterward rinsed in clean water; in general, however, this latter precaution may be dispensed with, unless the brushes are to be laid away indefinitely. Unless the above precautions have been taken, care should be taken that shellac and varnish brushes are not changed from one to the other. Never allow a brush to stand on its side for more than a few minutes at a time, as a wrong direction is easily given the bristles, and the brushes may be quickly destroyed by a little carelessness or negligence.
Old brushes, well broken in and cared for, will give better results than new brushes; therefore they should be treated with every possible consideration.
Varnish brushes often are left in the varnish pot, and if they are hung up so that they will not rest upon their bristles, this is the best way to keep them when they are in almost constant daily use.
Suggestive Exercises
69. Why is wood filler used? Describe paste filler. Describe the process of spreading filler and of rubbing it off. Describe liquid filler and the process of spreading it.
70. Why do we stain wood? What is the difference in the results of staining and filling and of filling alone? How may stains for open-grained woods be mixed and used? Describe a simple cherry or mahogany stain. Describe black walnut stain. What is the objection to a water stain? How may a rich mahogany stain be mixed? How may woods be darkened? Describe the composition of a rich brown stain; of a good green stain; of a brownish black. Describe ebonizing. For what purposes are shellac and lampblack and black varnish used?
71. Of what does shellac finish consist? What is the source of supply of shellac? Compare shellac and copal varnish. Demonstrate the application of shellac. Are thin or thick coats of shellac the better? Why is rubbing down necessary? Demonstrate. What precautions should be taken in regard to oily rags? Why? What should be guarded against in rubbing? What is a convenient size for a piece of sandpaper? Describe and demonstrate patching.
72. Describe the preparation of wax finish. Describe and demonstrate two methods of applying wax finish.