Carpentry and Woodwork

by Edwin W. Foster

After the first coat of shellac, varnish is often used for the remaining coats, but it takes much longer to harden and requires careful handling.

Shellac is a product obtained from certain trees in the Orient. It may be bought in the dry state at paint stores and dissolved in alcohol. Grain alcohol is the best and most expensive, but wood alcohol is cheaper and will answer all ordinary purposes. The shellac may be bought in cans all ready for use, and there are two distinct kinds—orange and white.

White shellac is the more expensive, but should be used on light-coloured woods, such as maple, to avoid spoiling the colour.

Varnish comes in so many grades and kinds that it is best to go to a reliable dealer and tell him just for what purpose you expect to use it. There are outside varnishes, rubbing varnishes, light flowing varnishes, etc.

When by exposure it becomes thick so that the brush drags, it should be thinned with a little turpentine.

There is a great difference in the methods of using shellac and varnish. The former being dissolved in alcohol evaporates quickly, so that it must be put on thinly and as rapidly as possible. Varnish, on the other hand, may take forty-eight hours or more to dry, so that the brush can be drawn over the surface several times to remove air bubbles. It is not possible to do this with shellac. The brush used in shellac should never be laid on the top of the jar or can, as it will harden in a very short time. The care of brushes is an important item. Varnish brushes should be cleaned with turpentine, shellac brushes with alcohol, and when cleaned it is better to keep all brushes in a pail of water than to allow them to become dry.

The jar or wide mouthed bottle used for shellac should be kept covered else a great deal will be lost by evaporation. A jam jar makes a convenient receptacle for this, as it has an opening wide enough to allow the use of a flat brush. Evaporation may be prevented by inverting another jar of the same size over it. The shellac on the rim will hold them together practically airtight with the brush inside.

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.