The back-saw, Fig. 31, is used for both ripping and crosscutting upon fine work. The blade is made quite thin and is reinforced by means of a back piece.
Fig. 31. Back-saw.
The handsaw or crosscut-saw and the rip-saw are used mainly upon coarser work such as the cutting out of stock. In such a case the penciled lines are placed so as to lay out the piece somewhat wider and longer than the dimensions desired for the finished piece. Here the saw is placed so as to "straddle" the penciled line. In accurate sawing, as with a back-saw, a knife line is used, being placed at the exact location desired for the finished piece. The saw blade is then placed so as to bring the kerf entirely upon the waste wood, but with no wood left between the kerf and line, Fig. 32. The proper starting positions for the back-saw are shown in Figs. 33 and 34. Upon a narrow piece the saw maybe started from one side only, usually the far side. As with the other saws, the beginning strokes are short, light, easy ones, increasing in length as the sawing proceeds. The handle is gradually shifted as the newly formed kerf provides a guide for the blade, until the back is in a horizontal position. In manual training work the back-saw is often used for rough cutting off of small stock, the kerf being made with reference to the knife line as in Fig. 35, the surplus stock remaining, being removed with a plane. In such sawing the stock should be placed flat side up, not edge up, a back-saw blade cannot be twisted as can the hand-saw and rip-saw to make it follow the line.
Fig. 32. Accurate Sawing to Line.
Fig. 33. Starting Position in Backsawing.
Fig. 34. Alternate Starting Position.
Fig. 35. Sawing Parallel to Line.