Care should be taken to protect the top of the bench from injury; it should never be marked by the chisel or cut by the saw. If chiseling has to be done on the bench, place the work on the bench hook or on a board, and in sawing use a bench hook such as is shown in [Fig. 2], that has a side lip that will protect the bench top.
Fig. 2.
The bench hook is made by students as an exercise, and is used to replace those hooks that have become worn out.
The material, which is delivered from the lumber yard in boards or planks, has to be cut up into lengths and widths suitable for the work to be done. The tools used for doing this cutting are the rip-saw and the cross-cut saw.
Now, a great amount of time can be lost in this work by the student, for the reason of his trying to do work with one tool when another should be used, and especially is this so in regard to saws. A saw will cut faster than a chisel in some places, and sometimes make the work as good if not better; so the student should learn to file and to keep a saw in just as good order as any other tool used.
We devote considerable space here to the saw, for we feel that the saw as one of the principal tools is often neglected, and is not used by students in their work as much as it should be. By a judicious use of this tool much time can be saved and a greater amount of ground covered than by trying to use a chisel or a jack knife in its stead.
Saws are either reciprocating or continuous in action; the first being a flat blade and a practically straight edge, making a plane cut, as in mill, jig, and sash saws; the latter either a circular or rotating disc, cutting in a plane at right angles to its axis (see buzz-saw in shop) or a continuous ribbon or band running on two pulleys, making a plane or curved cut with a straight edge parallel to their axis of rotation (see band-saw in shop).
Practically speaking, the teeth are a series of knives set on a circular or straight line, each tooth cutting out its proportion of wood, and kept from cutting more by the teeth on either side of it. Each tooth should cut the same amount and carry out the chips or dust, dropping it to the side or below the material being sawed. Different kinds of woods require teeth different in number, angle or pitch, and style of filing.
The perfect saw is one that cuts the fastest and smoothest with the least expenditure of power; to do this it is evident that each tooth should be so constructed and dressed as to do an equal proportion of the work, for if any of the teeth are out of line or shape they are not only useless themselves but a disadvantage to the others.