Elements of woodwork

by Charles A. King

(B.) In buying sandpaper, pass the finger over it to see if the sand is firmly fastened. Be sure that the paper is neither flimsy nor brittle. Coarse particles of sand are sometimes found upon sandpaper which renders it worthless; these can be detected only by use, unless they are very prominent.

68. How to use sandpaper.—(A.) Sandpaper is made in numbers, 00, 0, ½, 1, 1½, 2, 2½, 3. Numbers 00 and 0 are very fine, and are used in rubbing down shellac and varnish. Numbers ½ and 1 are used in sandpapering mahogany and other fancy woods, and number 1½ is used upon all building finish but the finest; the coarser numbers are used upon floors, outside finish, and other coarse work which is to be painted, though for a very nice floor, 1½ is used, rarely anything finer. It is a fallacy to think that the finer the sandpaper used, the finer the job will be, since upon some kinds of woods fine sandpaper will make a glassy surface in spots which will not take the finish like the rest of the work. Sandpapering is as apt to detract from the work as it is to improve it, for unless used very skillfully, the character of angles and small surfaces will be changed, though it may seem that the damage is so slight as to be imperceptible. In using sandpaper, the workman should guard against rounding off square corners or destroying the form of surfaces; a raw corner, however, should be removed with a few light, careful strokes, as a perfectly sharp corner will always be more or less ragged.

The one who knows will always notice the omissions of details of this sort, and will attribute such imperfections to lack of skill or knowledge on the part of the workman. It is for the one who knows, that all work should be done—not for the casual observer—and these apparently insignificant details, rather than the part of the work which may seem of more importance, form the basis by which one workman judges the work of another. In nothing do small things count more than in making or destroying a workman’s reputation.

Fig. 97.—Use of Sandpaper upon a Broad Surface.

(B.) Keep the sandpaper dry, and stored in a dry place, as moisture softens the glue so that the sand may be easily rubbed off. In handling sandpaper, care should be taken that the sanded sides are not rubbed together.

(C.) In preparing to sandpaper a flat surface, or for general work, a sheet of sandpaper should be torn in halves the short way of the paper, and one half should be folded back to back, and held (not tacked) around the block with the hand, as in Fig. 97. The act of grasping the block for the work will hold the sandpaper, and any device for holding the sandpaper on the block is worthless, being considered by the workman as a mark of the novice. The block should be about 3” × 4” × ⅞”, and may be made of wood, cork, fiber, or any material which suits the taste of the workman.

If there is much sandpapering of moldings to be done, it is best to make blocks which will fit the contour of them, as it is very hard on the hands to do this work for very long at a time, though nothing has ever been invented which fits irregular forms as well as the fingers. A piece of sandpaper should never be used on a piece of work until all the cutting by edge tools has been done, as the particles of sand will enter the grain of the wood, and any edge tools used upon it afterward will be quickly dulled. Do not use a piece of sandpaper so large that any part of it will not be under perfect control, as loose ends will scratch the wood, and it has an awkward and unworkmanlike appearance. Always work parallel with the grain, and be sure that all plane marks and rough places are thoroughly rubbed down. In order to do this well, it is often necessary to use considerable muscle. This part of the work calls for good judgment, for unless sandpapered enough, there will be places which will show when the finish is spread on the work, though they may have been invisible before. No one can tell as well as the workman himself when sufficient sandpapering has been done, though it may be evident to any one who knows the signs whether or not the work has been done judiciously. Upon a coarse job it is usually allowable, and sometimes desirable, to sandpaper across the grain, especially if the work is to be painted.

In order to impress it upon the student, we will repeat that too much care cannot be taken in the use of sandpaper, for much oftener will an amateur injure a piece of work than improve it.