Wood-working for Beginners: A Manual for Amateurs

by Charles G. Wheeler

The shellac should be quite thin. It should flow very freely from the brush. Of the two extremes, it is better to have it too thin rather than too thick. Three or four thin coats give a much better result than two coats of thick, gummy shellac. Never try to thin it with anything but alcohol. Keep the bottle corked to prevent evaporation of the alcohol and to keep out the dust.

Before beginning to shellac, see that the work is free from dust. Pour a small quantity of the shellac into a small dish of glass or earthenware, not of tin. Before applying to the wood, wipe the surplus shellac from the brush on the edge of the dish, so that it will not drip, and then lay on the coat as evenly and smoothly as possible, working from the top or from one end or side, and with the grain, so far as possible.[44] Do not apply the brush at first exactly at the edge of the surface, lest the shellac collect too thickly at the edge, but apply the brush first a little way on the surface and then work from the edge. Work quickly and lightly. Begin and end the strokes of the brush gradually—lighten them at the end—so as to avoid a "lap" when the strokes begin again. Do not work over the coat after it has begun to set or try to patch up spots. Simply lay it on as well as you can and let it go at that. If it is not right you will know how to do better next time.

Give each coat plenty of time to harden before applying another—twenty-four hours is none too long. Do not put on five or six coats in a day as is sometimes done. The outer coat hinders the drying of the shellac underneath, by keeping the air from it,—just as with paints,—and the way to do durable work is not to put on a fresh coat until the previous one is thoroughly dry and hard. Shellac dries very quickly so that you can touch it, but does not get really hard throughout for some time, so do not be in haste to put on a second coat.[45]

If there are holes, cracks, or defects of any kind to be filled up, this is the time to do it—after the first coat is hard. One way to do this is to hold a hot iron close to a piece of shellac directly over the hole, which will be filled with the melted shellac. The surplus can be carefully pared off after it is hard. Another way is to use wax coloured to match the wood. The wax can easily be coloured by melting and adding a small quantity of whatever dry colour—burnt umber, for instance—may be required. Do not use putty in such cases.

When the first coat is hard, skim over the surface with very fine sandpaper (00), to remove any roughnesses, and apply the second coat. This is sometimes sufficient. If not, sandpaper and shellac again, and a fourth time if necessary. When you have a sufficient "body" of shellac on the wood, you can much improve the quality of the surface by rubbing it down with powdered pumice-stone and oil, which will remove the "shiny" effect and leave a softer and finer surface. To do this, take a bit of felt or haircloth, and wet it with thin oil (kerosene will do, or petroleum, or linseed oil thinned with turpentine or benzine, but the latter is dangerous to have around), take up a little of the pumice, and carefully and evenly rub over the surface, with the grain, renewing the oil and pumice as may be needed, or they can be sprinkled on the work. But be careful to rub evenly and not too long on any one spot, for it will be hard to repair the damage if you should rub through to the wood. Wipe the whole off thoroughly with soft cloth. This process will be sufficient for most amateur work. For some work simply rubbing down with the finest sandpaper wet with oil is enough. In using sandpaper for rubbing down nice work, split it—that is, remove the outer layer of paper, which will leave the sanded layer thin and pliable and less likely to scratch or rub through the finish. A handful of tightly squeezed curled hair can be used.

If varnish is to be used over the shellac as in case of a boat, simply sandpaper the shellac and do not rub with pumice and oil.

With fine-grained wood, such as cherry, the process given above is all that will be required, but with coarse, open-grained wood, like oak, a good many coats will be needed to fill the pores and give a smooth surface. Therefore a "filler" is often used to fill the pores of the grain. This is cheap and can be bought in the form of paste (either light or dark), which you can apply according to the directions on the can. Rub it into the wood thoroughly, let it stand until it begins to set, or stiffen, then rub it off with a bit of burlap or any coarse material, across the grain (lest you wipe it out of the pores). After it has become hard enough, sandpaper, and clean off any that may remain on the surface. Then shellac as described. The filler can have the shade of the wood, or sometimes, as in oak, the figure of the grain can be brought out finely by using a filler somewhat darker than the hue of the wood. Be sure to clean off the filler thoroughly, using a tool to clean out the angles and corners, or the finished surface will have a cloudy or muddy appearance.

The general directions given for shell acing apply also to the use of varnish, but varnishing is in some respects harder for the amateur to do well. Consult the dealer about the kind of varnish and the brush best suited to the particular piece of work you have in hand. The final coat of varnish can be rubbed down with pumice or tripoli and water. Rotten-stone used with oil (petroleum is good) is excellent for giving a soft polish.

French polishing is often attempted by the amateur, but it should be learned by taking a lesson from a practical polisher, and not from a book. The general idea of the process is as follows: A wad or pad of wool is made and on this is poured thin shellac, adding whatever alcohol may be necessary. This wet pad is then covered with a piece of clean linen, a drop of oil put on the outside to prevent the shellac from sticking, and the pad is then quickly passed over the surface with a circular motion, or with longer strokes in the form of the figure 8, or in some cases simply back and forth. After doing this for a while a very thin coat will have been deposited. This is allowed to dry for a short time, when the process is repeated, again and again, until a sufficient body of the polished finish has been formed. The details of the process vary with different finishers. It is quite easy to polish a small flat surface or such an object as the arm of a chair, but it is much harder for an amateur to successfully polish a large flat surface, like a table-top, except after much practice. A first coating of shellac applied with the brush and skimmed over with sandpaper will save labour in the polishing process.

Before refinishing old work it should, if the surface is in bad condition, be scraped down to the wood, using the scraper and finishing with sandpaper. A chisel (used like the scraper) is sometimes convenient to remove a thick body of old varnish. If the surface does not need scraping, it should be cleaned, either by washing with soapsuds or it can be scrubbed clean with the finest sandpaper, split, using oil or water as the case may be, but seeing that the work is wiped off perfectly dry before applying a new coat. Pumice can be used, as already described, and a stiff brush, like a nail-or tooth-brush, is excellent for cleaning out corners and carved work.