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Saw specialists have devoted a great deal of thought and time to the matter of hand saw practice. How to Use a Hand Saw
The saw is a unique tool in many respects. It performs its functions by a method that is different from that of any other tool.
Because of this, and because proper use is necessary to get good work from a saw, a short discussion of the theory of sawing seems desirable.
Grasping. -- Consider first that the handle of a saw is a much more important part than is the case with most tools.
The power of arm and shoulder is delivered to the saw through the handle; and accuracy, speed, and production in sawing all depend very largely on its design and location.
The Disston handle is an inset handle. It is built onto the blade of the saw, the metal being shaped to receive it. It is made to fit the hand.
Study the hand a moment. A line joining the bases of the fingers makes a curve almost as regular as the arc of a circle, with the center of this arc in the fleshy mound at the base of the thumb.
Now grasp the handle, and observe how the concave shape of the handle where the fingers close around it produces a "squeeze" that braces the fingers more firmly against each other. This throws the main duty of grasping the handle on to the three last fingers of the hand. As a matter of fact, it makes it both easy and logical to use the thumb and first finger for guiding rather than grasping.
This theory is more readily understood when the saw is put into a cut. It will then be apparent that the point at which the power is applied is across the center of the hand opposite the three last fingers. The curve of the handle helps to maintain the thrust at this point, and the saw runs just as easily and readily if the thumb and first finger are not used for grasping at all after the cut has been started. The lower horn of the handle is useful, as will be noted, to hold the hand compactly and prevent it from spreading.
It is quite possible, in view of the above considerations, to use both the thumb and first finger to guide the saw.
It is essential for good sawing that the saw run in a straight line with the forearm, so that it is practically a continuation of the arm. It is important, too, that the user stand in such position that his elbow and shoulder are in direct line with the saw as in Fig. 14.
The operator usually works with two limiting factors: he must cut along a straight surface line, and he must cut vertically to the surface on which that line is drawn. These results are obtained much more readily when the saw is held as described above.
Fig. 14.-Proper position for arm, hand, and saw for cross-cutting.
Hold your saw with the thumb and forefinger lying extended along the sides of the handle. This helps you "point" the saw along the line. You will find this grip to be easy to acquire, even if you have used another method for years. Students and apprentices learn accuracy with this grip more surely and quickly than with any other.
The handle should be grasped firmly, but not squeezed too tightly. A great deal of fatigue is caused by gripping the handle more tightly than is necessary.
The upper horn of the handle functions on the back stroke, when it prevents the hand from sliding up as the saw is drawn back.
The method of grasping just described is regarded as best for accuracy. Disston handles are of such a design, however, that the thumb and all four fingers can be used to grasp the handle if working conditions or personal preference suggest.
Position. -- In considering the most efficient position in sawing, another factor must be dealt with. The eye must be brought into the same
Fig. 15.-Front view of correct cross-cutting position. Note straight line of action.plane as blade, elbow and shoulder, so that the line of vision is true with the cutting plane. (See Fig. 15.)
The eye follows the progress along the square edge, and the position taken must permit of this. The work may be held or steadied by the left hand. Often, when the work is on a sawhorse, the knee is used also.
Left-handed pupils should learn to adapt these instructions to the left side of the body. We believe that it causes complexity and delays progress for left-handed pupils to be forced to learn right-handed sawing. However, it frequently happens that persons who regard themselves as left handed are actually ambidextrous. A little experimenting will clear this question up in any given case.
Holding the Work. -- Good judgment will provide an answer to most questions regarding holding the work for sawing.
When it is of a shape and size that permits, it is often convenient to hold the work in a vise or on a bench hook.
Fig. 16.-Supporting waste to insure clean cut-off.Sawhorses are usually knee-high or slightly higher, since the knee is commonly used to help hold the work on them.
In rip sawing, and when the waste piece is heavy in cross-cutting, the work is likely to split off as the cut nears completion, unless properly supported. (See Fig. 16.)
The left hand is used to support short waste pieces as the cut nears its end. Mechanical support is necessary when the waste is heavy.
A little experience soon teaches the pupil to properly stabilize his work before he starts his cut.
Starting the Cut. -- The line has been drawn. The pupil has assumed an easy sawing position with the work properly supported.
The middle of the blade edge rests against the far edge of the board to be cut.
Do not attempt to split the scribed or penciled line. Start the cut close to the line, on the waste side. Grasp the edge of the board with the left hand, close to the line, so close that either the knuckle or the end of the thumb will bear against the saw blade and support it vertically. (See Fig. 17.)
Fig. 17.-Supporting blade with thumb to start cut.Raise the thumb sufficiently to prevent its being cut by the saw teeth. Sawing is begun by drawing the blade slowly toward the operator two or three times so as to start a kerf or cut in which the blade will run smoothly. If the first strokes are away from the body the saw will jump to the right or left or split out the wood. Experience teaches that the scoring to, start the cut should be done with a draw stroke (pulling toward user).
Finishing the Cut. -- After the groove has been started, a few short forward strokes will deepen the cut so that the left hand may be moved away free of the blade.
The saw should then be pushed with an easy, free-running motion, making the strokes approximate the full length of the blade, so that each tooth may do a fair share of the work. Short strokes dull the saw more rapidly for the reason that a few teeth do all the cutting.
Impress on your pupils the fact that the cutting angle and the spacing of the teeth control the amount of cutting done by one stroke of the saw. The correct angle for the saw in cross-cutting is about 45 degrees from the horizontal, while in ripping the saw is held more nearly erect, at about 60 degrees. It is unnecessary and tiring to bear down or "ride" the saw: Downward pressure through the wrist is wasted effort. If the saw does not "feed" itself under normal pressure, it is probably out of condition.
Do not try to force the saw if it jams in the cut. When this happens, something needs correcting. Either the wrong saw is being used or the saw is not in proper condition. Stop and find the trouble.
In cutting off the end of a board inexperienced saw users sometimes attempt to remove the waste wood by twisting the saw-blade in the cut. This may permanently crimp the blade, destroy its tension, and render it unfit for use.
The ability to make a smooth vertical cut along a given line is a result of practice in the correct position. Do not permit pupils to try to run the saw at an abnormally flat angle in an effort to follow the line. This will not gain the desired results, for the theory is incorrect, as will be seen by reference to "How a Saw Cuts," elsewhere in this book.
Speed and skill with the hand saw are developments that grow only out of careful practice of the right fundamentals, such as proper grasp, correct, easy position, starting and completing the cut properly.
Above all, of course, it is necessary that the saw itself be properly made, set, and sharpened -- for even the most expert workman must have a good saw to do good work.
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