56. Painting is one of the most important of the trades with which the carpenter comes in contact, and it is the intention of this chapter, not to teach the carpenter to do the work of a painter, but to outline some of the facts which he should know regarding the common use of paint.

(A.) In mixing the priming coat, 100 lb. of white lead to 7 gal. of raw linseed oil and 3/4 gal. of japan drier are the proportions commonly used upon the best work. After this first or priming coat has been put on, all nail holes, cracks, and other imperfections should be puttied; if this is done before the wood is painted, the putty is apt to fall out. For succeeding coats, 6 to 7 gal. of oil to 100 lb. of white lead will give good satisfaction; the drier is usually omitted after the first or priming coat.

Raw oil should be used upon outside work, as boiled oil does not stand so well, though a mixture of 3 parts of raw oil and 2 parts of boiled oil works more easily and dries faster, but is not so durable. However, it is used upon some of the best work. In many localities, boiled linseed oil is used entirely, but the work is not so permanent.

(B.) Ready mixed paints are used by some, but many of them are inferior to white lead and oil, or to white lead, oxide of zinc, and oil, which are frequently specified upon the best work.

In using mixed paints, it is the safest plan to shun all makes which have not stood the test of time. Some ready mixed paints are hardly worth putting on; others will wear as well as the best white lead paint; in fact, the best brands of mixed paints are made of white lead, zinc, and oil, purchased and mixed in large quantities, under the most favorable conditions, and are generally superior to the white lead and oil mixed by the painter, both in spreading and wearing qualities. The price is about the same.

It is poor economy to purchase cheap paint, as paint costing 50 per cent more will often cover from 75 per cent to 100 per cent more surface than the cheaper kind, and give much better service under the same conditions.

(C.) Knots in pine and other pitchy woods should be covered with a heavy coat of brown shellac, to prevent the pitch from frying out.

(D.) Metal work should be covered with black varnish or asphaltum. Before being painted with oil paint, very rusty iron should be scraped and sandpapered to the clean iron. Boiled oil should be used, as raw oil requires so much time to dry that it is apt to be washed off by rain, or to catch the dust.

Upon metal roofs, iron oxide and boiled oil are about as satisfactory as anything which can be used, though there are many roofing paints of more or less efficiency made by different manufacturers.

A good roofing paint should be quick drying, of more body than is ordinarily used, should adhere closely to the roof without scaling, and should not blister in the sun.

(E.) Do not paint a shingled roof, as the paint covers only the exposed wood, and water which runs under the shingles of the course above will not dry out readily, thus causing decay and shortening the life of the roof. Shingles may be dipped in a creosote stain for about 9" or 10" from their butts before they are laid; this will act as a preservative to the shingles and increase their service-ableness.

(F.) Wood adjoining masonry should have a good coat of paint; this is not generally done except upon the best class of work.

(G.) Wet or green wood never should be painted, as the moisture in the wood is thereby confined and the result will be that either the paint will peel off or the wood decay, or both.

(H.) Flat color should be used upon inside work; this is made by mixing white lead with turpentine and a little varnish, together with the pigment necessary to give the desired color. If oil is used, the paint will turn yellow after a few months.

Instead of using a pure white paint, a little black should be mixed with it, or otherwise the white paint will be too glaring; this also prevents to a great extent the dingy appearance which a pure white has after the newness has worn off. Flat color is less transparent than oil color, and will, therefore, cover better, but it is not suitable for outside work.

(I.) It is often necessary to remove old paint; this may be done by burning with a gasoline torch, a method to be used only by a man of skill and judgment, as a fire is easily started while burning around places where the joints have opened and the wood is very dry. Old paint may be removed quite well by using a preparation made of 2 oz. of soft soap and 4 oz. of potash mixed in boiling water, to which is added 1/2 lb. of lime. Apply hot and leave it for 24 hours; wash it off with hot water.

Paint removers are made by paint manufacturers and sold at such prices that it is usually better to use them than to use any homemade mixture. They are generally quicker and surer in their action; some are apt to discolor the wood, but that is not an important matter, unless the work is to be finished in the natural wood.

(J.) In finishing woods with an open grain, as ash, oak, etc., it is necessary that the grain should be filled. Years ago this was done by applying several coats of shellac and rubbing each coat down to a surface with #00 sandpaper, or with pumice stone, but that method is very slow. Of late years the use of a paste filler has done away with the necessity of so much work.

There are several good makes of wood filler upon the market which are generally of the color of light wood; the addition of dry color will make it of almost any desired shade. If manufactured filler is not easily obtained, a fairly satisfactory substitute may be made by mixing cornstarch or whiting with turpentine or naphtha to form a thick paste, and by adding a little oil and japan to bind it together. Any desired dry color may be added after the paste has been thinned to about the consistency of cream by the addition of turpentine, or naphtha which is used by many for reasons of economy.