Wood-working for Beginners: A Manual for Amateurs

by Charles G. Wheeler

Fig. 685.

Truing Surfaces.—To true a curved or warped surface, as of a board, lay it on the bench with the rounded side down and wedge it firmly underneath to make it as nearly level as possible. Then scribe a line with the compasses across each end of the board at the height of the lowest point of the surface (Fig. 685). Cut a depression or kind of rabbet at each end down to this line (Fig. 686). Next, by the use of winding-sticks placed on each of these rabbets you can easily see whether they are in line (see Winding-sticks). Alter the rabbets if necessary to get them in line. Draw lines on each edge connecting the bottoms of the rabbets, and plane away the superfluous wood down to these lines. When this is done the top of the board will be true or in the same plane. Test it by placing the straight-edges in different positions on the surface and sighting as before, correcting any errors. One side of the board being made true in this way, the other can be made parallel by gauging a line all around the edge, measuring by the thinnest point of the board, and planing off the superfluous wood in the same manner as the first side.

Fig. 686.

You can sometimes facilitate the process of planing off the superfluous wood by making cuts with the saw and removing part of it with the chisel, or by planing across the grain (the jack-plane is good for this purpose), or paring across the grain with the chisel, or any such method, always being careful not to cut quite as deep as the intended surface, so that all the marks and cuts can be removed by the final planing. See Plane, and also page 179.

Try-Square.—See Square.

Turning-Saw.—See Saw.

Turpentine.—See Finishing and Painting.

Twist-Drill.—The twist-drill is much better than the gimlet-bit. It makes a good hole, bores easily, is not easily dulled, can be used upon metal, and one kind in common use can be easily kept in order by simply sharpening the ends. There are various patterns. A little care is necessary, however, particularly in hard wood, as they are liable to be snapped by bending. See Bits.