The protection and preparation of the surface should be the first consideration and should be as carefully planned and carried out for plain painting, staining, varnishing or natural finishing as for more expensive work, as these are often the foundations for a better class of future finishing.
Inside door frames should not be set until after the plastering has been completed, then put in with the other finish, otherwise the mortar will stain the wood badly and these stains cannot be removed without a great deal of trouble. In fact, frames are often ruined by mortar stains and bruises from plasterers removing their scaffolding. These bruises and stains especially ruin the work when it is to have a natural stain or finish.
If the frames are set, they should be protected before the plasterer commences work. If the work is to have a natural finish and the frames are hard wood, they should first be filled with paste filler, then a coat of shellac or liquor filler applied. If the frames are soft wood and are to be stained, they should be given a coat of oil stain; if to be painted, they should be primed. If water or spirit stains are used, cover with a coat of shellac or liquid filler, otherwise the lime water in the plaster will change the color of water stains. A strip should be tacked to the face of the frames to protect them from being bruised or scuffed up during the plastering.
Floors which are to be finished natural or stained should not be laid until after the plastering is done. Floors should be the last work of the carpenter as well as the painter. This requires laying an extra floor. On the best and more expensive buildings this is looked after by the architect in his specifications. However, there are a number of buildings in which the floors are laid before the plasterer commences his work, and as these are to be finished either natural, stained or painted, they should be protected from plastering.
As soon as the carpenter has finished sandpapering and dressing down the floors, they should be carefully swept and dusted off. The cracks should be filled with either a good linseed oil putty mixed with 1-3 keg lead, or a good crack and crevice filler, which is not so likely to be affected by shrinkage of the floors as is putty.
If hard, open-grained wood, the floors should first receive a coat of paste filler, then a light coat of shellac or floor finish.
If the floors are soft or hard pine and to be finished natural, they should receive a coat of shellac or liquid filler of good quality, applied thin. If to be stained, they should receive a coat of oil stain.
When dry, cover the floors with heavy building paper or plain carpet lining tacked down solidly. Sprinkle dry sand around the walls to keep the mortar from soaking into the paper. Allow this covering to remain on the floors until after the painting or finishing is done on the other parts of the room. The floors should be finished last.
Before the carpenter turns the work over to the painter, he should remove from the rooms all blocks, shavings, etc., and turn as much of the building over to the painter at one time as is possible.
The painter should sweep the room clean and thoroughly dust off the work before commencing to paint, stain or varnish.
Putty nail holes, joints, etc., with good putty, one which will not soften with age or turn yellow if white or light tints are applied over it.
If the work is to be painted, soft pine doors and casings should first receive a coat of size to keep them from spotting. This should be a shellac size if the work will permit. Good liquid filler is often used with good results by reducing to a thin consistency and applying a smooth, even coat. Hard drying varnishes, such as copal and hard oil finishes, are successfully used by applying them thin. Glue size can also be used if applied hot and very thin. It should not be allowed to get cold, as it will not strike into the wood but remain on the surface and is liable to break away. It is very hard for ordinary dampness to affect glue size after it has been properly applied and covered with paint or varnish. Where the price of work will not permit of sizing or the specifications do not call for it, satisfactory work can be done by mixing varnish with the priming coat. Varnish and turpentine will, to a certain extent, keep the work from spotting.
The paint for interior work should be mixed with a large percentage of turpentine. Oil will turn the work yellow. If white work, such as flat white, white enamel, is to be done, it is absolutely necessary that the priming coat should be mixed with turpentine, otherwise the work will yellow in a very short time, especially where sizing has not been used. An excess of oil will also cause the work to crack and check badly. Too much oil cannot be used for interior work with safety. Where the work is to be finished with oil paints, more oil can be used in the priming. It should be borne in mind, however, that interior work should always dry hard and firm to insure good results from its present painting, also to allow of satisfactorily repainting.
In giving these directions for the different classes of work, the one principal object has been to caution against the application of too numerous coats. It is not the amount of paint applied to a surface which produces the results, it is the manner of application, the proper mixing of the paint and the preparation of the surface. In enameled or grained work it is especially true that where too numerous coats of ground work are applied, it is very hard to repaint such a surface if at any time a different class of work should be desired.
Throughout the directions for undercoats on all classes of work it will be found that varnish is specified in place of oil and japan. This gives the most satisfactory undercoat surface that can possibly be made, especially if a good grade of varnish is used. The work will remain in good condition for an indefinite length of time; it will not crack or check; the grain of the wood will be thoroughly tilled and with this method of reducing the paint, the number of coats to produce satisfactory work can be cut down.
Mixtures of japan and oil for undercoats are not always satisfactory for interior work. Too much oil makes spongy work which is liable to crack and check badly. Heavy mixtures of oil and japan will do likewise.
The directions given are not new but have been tried out in the most practical ways and have always proved entirely satisfactory.
Sandpaper or smooth the surface with tine steel wool and dust off thoroughly before applying the paint.
Where paint, enamel or varnish are retarded in their drying by weather conditions or other causes, the work can be assisted in drying and hardening by sandpapering or mossing off, killing the gloss and allowing it to be exposed to a free circulation of air. This will harden work in a few hours as much as if allowed to stand for a considerable length of time.
Cheap paint should not be used for inside work any more than on the exterior of the building, if good results are to be expected. It is a mistake to use cheap ochre for priming. The same paint, or something as good, should be used for priming or first coat as is used for the finishing coats or for building up the ground work for enameling, graining and like work.