Essentials of woodworking

by Ira Samuel Griffith

Fig. 123.

64. Sandpapering.

—To know when to use and when not to use sandpaper is as much the sign of a good workman as to know how to use the tools.

Sandpaper should never be used until all tool work has been done as well, and carried as far as is possible. Sandpaper is, as its name implies, sand paper. In sanding a surface, this fine sand becomes imbedded in the wood and should an edged tool be used thereon it will be dulled. Slovenly work should never be done in expectation of using sandpaper to fix it up. This practice is dishonest. Sandpaper should not be expected to do the work of edged tools or disappointment will follow. The sandpaper sheet, for use, is usually divided into four parts, one of these parts being of good size for large work.

Fig. 124.

For flat surfaces these pieces are placed on a sandpaper block. This block is but a piece of wood squared up to a length equal to that of the piece of paper and to such a width that the edges of the paper will extend far enough up the edges of the block to allow the fingers to grasp them firmly. [Fig. 124]. Do not waste the paper by wrapping it around in such a way as to throw part of it on top of the block. The block should be held flat upon the surface when sanding near an arris, otherwise the arris will be rounded. The arrises should be kept sharp unless on a table leg, arm of a chair or something similar, in which the sharp arrises would be likely to injure the hand or become splintered through usage. In such cases the sandpaper may be run along the arrises once or twice, just enough to remove the sharpness. Sometimes the plane is set shallow and drawn over the arris after the surfaces have been squared, to remove the sharpness.

On curved surfaces, the sandpaper is held free in the hand, no block being used. [Fig. 115] illustrates the manner of sanding the convex curve of the coat hanger. The sandpaper should be rubbed along the grain and the rubbing should proceed only long enough to smooth the piece and to bring out the grain clearly.

On the back of a piece of sandpaper will be found a number. This number indicates the relative coarseness of the sand sprinkled upon the glue covered paper. 00, 0, 1, 1¹⁄₂ and 2 are the numbers commonly used; 00 being finest and 2 relatively coarse. On table tops and surfaces which are not very smooth to begin with, the coarse sandpaper is first used, this is followed by the next in coarseness and so on until the finest is used.

Never attempt to sandpaper surfaces or parts which are to be put together later on to form joints, the edge tools alone must be depended upon to secure proper smoothing.