The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking. Paul N. Hasluck
his energy, to get better results in both quantity and quality, and to reduce considerably the wear and tear of his tools. A common fault with beginners is that they do not take sufficient care at the commencement of the cut or kerf. The first part of a cut is most important, because if that is not made square through the wood it is afterwards a very difficult matter to get the cut square without twisting the saw, and perhaps spoiling it. Begin sawing by placing the left thumb (see Fig. 312) or forefinger to the line, so as to guide the saw at the commencement of the kerf, then take a few gentle and careful strokes, making sure that the saw enters the wood at right angles. Move the left hand to a more secure position, as indicated in the later figures (Figs. 314 to 316). Then, using nearly the whole length of the saw, take care not to draw it right out of the kerf, or it may be damaged by striking against the work at the return stroke; see that each stroke is regular; and allow a slight pause between each stroke to enable the worker to regain energy for each downward (working) stroke. Short, jerky, and quick strokes must be avoided, for they rapidly produce fatigue, and result in bad work. Do not force the saw: that is, do not press too hard at each downward stroke, as this fault not only leads to fatigue, but also strains the saw. Occasionally test the saw in the cut with a square to see whether it is perpendicular to the surface of the wood (see Fig. 313). The general position to be assumed in sawing is shown in Figs. 314 to 316. As far as practicable, the saw blade, marked line, and saw-cut, the eyes, shoulder, elbow, and hand, should be in one plane, much as shown in Fig. 316, which also shows the head to be over the saw, so that the operator is able to see that the saw-blade is out of winding with, and in the same plane as, the line; this is a very important point. A faulty position for hand sawing is to have the head not over the saw, but some distance to the left of it; consequently the saw leans to the left, and cuts out of the perpendicular. This fault is usually combined with another, namely, getting too far behind the tool, which attitude does not allow the operator to compare the saw with the line, because he is not able to keep his head over it, and he is also prevented from having such full command over the saw as he would have by adopting the attitude illustrated at Fig. 315, where the position is one of much greater freedom, giving at the same time much more power over the saw, with less exertion. By holding the saw in a more vertical position (as illustrated at Fig. 315), there are fewer teeth in contact with the wood at one time, and hence there is less resistance than when the saw is made to slant more nearly to the horizontal. The defect noted is that known a “laying” the saw. With thick stuff it is a good plan to square the lines down each end and line out each side, and then, during the process of sawing, to turn the wood over occasionally, and thus saw from both sides. When, however, it is desired to saw the wood entirely from one side, the blade should be tested now and again with a square, to see whether the saw is at right angles to the surface of the wood (see Fig. 313). After sawing down a foot or two, it will be found desirable to open the cut a little by inserting a screwdriver or wedge, so as to reduce the friction between the sides of the kerf and the saw-blade. Do not open the saw-kerf wide, as this tends to split the wood, and to cause the saw to wobble, thus increasing the difficulty of following the line. It is desirable to lubricate the blade with a little oil.
Fig. 312.—Beginning Saw Cut.
Fig. 313.—Testing Saw with Square.
Fig. 314.—Correct Position when Sawing.
Fig. 315.—Ripping Plank, Front View.
SAWING WET WOOD.
In attempting to cut down a piece of wet plank with a hand saw, great labour and difficulty will be met, and the difficulty will be much increased if the cut is made across the grain—that is, transversely to the direction of the fibres. If the stuff is very thick, the saw blade will stick fast in its kerf. There are two reasons why the saw sticks in soft wet wood. One is that the kerf is not wide enough, and the other that the sawdust cannot get away quickly enough. Hence the remedy is to increase the set and to enlarge the spacing of the saw teeth, which means an increase of the space between the centres of the teeth, with a consequent increase in the sizes of the teeth themselves. In attempting to use the same saw on thin and hard wood, trouble of another kind will be met. The teeth will catch in the wood, the saw will sway too loosely and freely in the kerf, and, if cut across the grain, the timber will become broken or spalted out.
STRAIGHTENING BUCKLED HAND SAW.
A piece of iron with a flat, smooth surface, such as an anvil, or even a flat iron, will be required for straightening a bent or buckled hand saw. If a flat iron is used, it could be held firmly in a vice or a bench screw. Place the saw, with the convex side upwards, on the surface of the iron or anvil, and then hammer, but do not deal heavy blows. After every two or three strokes with the hammer the saw blade should be examined to see the effects. The surface of the hammer should be very slightly spherical, so as to prevent the possibility of leaving hammer marks on the blade. Much care and practice are required for hammering a saw properly. The plate of a hand saw being thin, requires a much lighter blow than steel of stout gauge. If the blows given are too heavy, they will indent and stretch the plate, and in consequence a bad state will be made worse. Fig. 317 represents a saw undulating, or wavy, lengthways of the plate at L, and bent or seamy across the plate at C. It will be seen that at L the blows are delivered across the plate, and at C lengthways of plate, using for the purpose a cross-pened hammer. Figs. 318 and 319 represent a saw that has a bend at the edge; in this case the cross-pened hammer should be used on the convex side, as at B (Fig. 318). and on the concave side, as at B (Fig. 319), after which it should be struck very lightly with a dog-head hammer, as indicated by round marks on both sides. Instead of the cross-pened hammer, the carpenter’s ordinary hammer will answer if the pene is ground a little convex.
Fig. 316.—Ripping Plank, End View.
Fig. 317.—Hand Saw Buckled Lengthways.
Fig. 318.—Buckled Hand Saw.
Fig. 319.—Buckled Hand Saw.