Press lightly the first time you use a new file, until the fine edges of the teeth have been worn a little, as a violent filing on the first strokes may damage the cutting edges of the teeth.
When a file becomes clogged with wood-dust or other substances, soak it in hot water a little while and then brush with a stiff brush. A file-card is useful. A piece of dog-fish skin, if you can obtain it, cuts somewhat like a file or coarse sandpaper, and is useful for curved surfaces where you wish to use the tools after smoothing.
Filing.—See File.
Filing (of Saws).—See Sharpening.
Finishing.—To acquire a high degree of proficiency in finishing indoor wood-work requires long training and practice, but the simpler processes can be undertaken to good advantage by the beginner.
There are a number of ways from which to choose. Simply rubbing thoroughly with linseed oil gives a good, soft, permanent finish, which some prefer to anything else, but you should be sure that all superfluous oil is rubbed off. Do not hang a recently oiled book-shelf or cabinet against the wall-paper of the room, for fear of defacing it. An oil finish, unless rubbed a good deal, has the disadvantage of getting soiled and collecting dust and dirt, but it is easily sandpapered and renewed and is certainly in better taste than a coarse, shiny, cheap varnish.
An old-fashioned way is simply to apply a mixture of turpentine and beeswax, rubbing it as long as your strength and patience will allow. Melt some beeswax in a can or saucepan and, when melted and taken from the stove, pour in enough turpentine to make it the consistency of paste. Then apply with a brush or cloth and rub in and clean off the excess with a stiff brush or cloth, scrubbing the work as you would a stove. This makes a beautiful finish, soft and lustrous. It shows spots, however, and, though it is so easily applied, it requires continual renewing and rubbing to be kept in good condition.
To make a hard and durable coating on the surface of the wood some kind of varnish is required. There is nothing better than shellac for the purpose of the amateur. It is not very hard to use, and there is certainly nothing which gives a finish of nicer quality. The surface dries quickly and the coat hardens more rapidly than most kinds of varnish. For some cases, as a boat, it is well to shellac first and finish with good varnish.[43] Shellac is cut (dissolved) in alcohol, and can be bought prepared, but it is better to cut it yourself, to diminish the chance of adulteration with cheaper substances. Orange shellac will do for most of your work. Into an open-mouthed bottle put some of the shellac (which comes in flakes and looks somewhat like glue) and pour over it enough grain alcohol (95 per cent. grade) to somewhat more than cover the shellac. Cork the bottle and leave in a warm place until the shellac is cut. Shaking will hasten the process. Wood alcohol can be used and is cheaper, but work done with it is not so good. It is a deadly poison taken internally and on account of the fumes it is best not to use it for a long time in a close room. If the tawny tint of the orange shellac is objectionable, white (bleached) shellac can be used, but this it is well to buy already prepared. It is a little harder to use than the coloured kind.
Use a flat bristle-brush and not a soft camel's-hair brush, unless for the last coat. One from one inch to two inches wide will be probably suitable for most of your work. For large surfaces, however, a larger brush is better. After using, always clean the brush thoroughly with alcohol.
Always shellac in a warm, dry place, free from dust—never where it is cold and damp; but on the other hand do not leave the work close to a hot stove or it may blister.