62. Whetstones. - (A.) These are used to give to a tool the keen edge necessary to cut wood smoothly. The natural stone in most common use is the "Washita stone," which is quarried in the Ozark Mountains, and is thought by many to be the best natural stone for the general use of the wood-worker; it is fast cutting, and when of the best quality is of even texture.

(B.) Many workmen prefer an "Arkansas stone," as it is finer and harder than the Washita. It is also more expensive, however, and is better adapted to the use of woodcarvers and engravers than to the use of wood-workers in general. It is usually not so fast cutting as the best of the Washita stones, but a finer edge may be obtained by its use. There are other natural stones, but none so generally used as the above. The purchase of a natural stone is to a great extent a lottery, as only about one stone in ten has a perfectly even texture, is free from cracks, and has reasonably good cutting qualities.

(C.) If a stone needs truing, lay a piece of coarse sand paper upon a board, and rub the stone over it until it has been ground down. The best place, however, to true up a whetstone is upon the horizontal stone of a marble worker; this is a large grindstone, several feet in diam eter, mounted on a vertical shaft, upon which are placed pieces of marble to be ground to a flat surface.

(D.) Artificial oilstones, made of emery, corundum, carborundum, and other artificial abrasives, are coming rapidly into use, and, as in the case of grindstones, even tually will supplant all others in many occupations, as they cut faster than any natural stone, may be made of any degree of fineness, and are of absolutely even texture. They are also able to resist many accidents which would destroy a natural stone.

(E.) Slip stones are used to sharpen gouges and curved tools of all kinds, and may be made in any desirable shape. An oblong stone, 8" x 2" x 1", is the size of stone in most general use by the wood-worker, and should be fitted into a box or piece of wood with a cover to keep it clean. It may be laid either flat or on its edge, as suits the workman, though the stone may be kept true more easily if it is set on its edge.

(F.) The use of the oilstone is described under topic 40, A. The oil used should be a kind that will not gum; its purpose is to prevent the glassiness which is caused by the friction of the tool over the stone. Common machine oil is used by many, lard oil by others, and kerosene, or coal oil, is claimed by many workmen to be the only oil suitable for use upon an oilstone. Any one of these oils will give satisfactory results, but kerosene keeps the stone cleaner, thereby adding to its efficiency, and for this pur pose lubricates quite as well as any of those above-men tioned.

63. (A.) Files are used for many purposes by wood workers. An assortment consisting of 4" and 6" slim taper, or three-cornered, files; 8" and 10" flat, or bastard, files; 8", 10", and 12" round files; and 8" and 12" half round wood files and rasps should be in every carpenter's kit. The 4" slim taper files should be used upon the finer saws, and the 6" upon the coarser ones, though the latter are used by some workmen for both saws. Upon jobbing work, it is necessary to have a few warding and knife files to use upon keys and odd jobs, and also to sharpen bits.

Files and rasps are made of every shape and size, and for every purpose. Wood files usually are tempered to stand lead or soft brass, and should never be used upon anything harder.

In drawing a file back between the cuts, do not allow it to drag, as it is injured thereby about as much as when it is cutting.

(B.) There are a great many other tools and appliances used by the wood-worker with which the workman should be familiar, but it is not necessary to describe them, as the above-mentioned are the most essential tools common to all forms of woodworking. There is no im portant principle involved in the construction, care, and use of woodworking tools which is not discussed in this chapter, and the student who becomes thoroughly familiar with the matter treated will have little trouble in learn ing to handle other tools.

64. Saw filing. - (A.) This is an accomplishment which every young wood-worker should master, as its possession will save expense and inconvenience, and add much to his efficiency as a workman.

Fig. 89. - Jointing a Saw.

(B.) The first step in sharpening a saw is to examine the edge carefully to see if the teeth are of an even length; if they are not, they should be jointed. This is done by using a flat file held perfectly square in a block, as shown in Fig. 89. One or two light strokes usually will be enough to make all the teeth of the same length. The edge of the saw should round slightly in the middle, say about 1/8" for a 24" or a 26" saw. If the edge is perfectly straight, it should not be jointed to this shape at once, but a little at each time for several filings.

(C.) After jointing the saw, be sure that it is properly set. This may be done by a saw set, of which there are several patterns in use; these are all of two types, the hand set (Fig. 90), and the anvil set (Fig. 91). Either of these forms is efficient, but as it is more convenient, the hand set is more commonly used. Do not give the saw too much set, or it will not cut smoothly, but will break the wood badly on the back side of the cut; there is also greater danger of breaking the teeth, and as more wood is cut out, more muscle must be applied. The point of the teeth only should be set, and care should be used that the blade of the saw is not sprung, which will be apt to result from setting the teeth too far from the point.

Fig. 90.- Hand Saw Set.

Fig. 91.- Anvil Saw Set.