Wood-working for Beginners: A Manual for Amateurs

by Charles G. Wheeler

The common way of holding the tool on the stone is the one just described, but it can also be held at right angles to this position, so that, in the case of a chisel, for instance, the grinding action of the stone instead of being from the edge toward the handle is from side to side of the blade. The tool is ground quicker and easier by this means, and it is a good way to reduce the edge to shape, finishing the grinding by the regular method.

You will see that the curvature of the stone will tend to give the bevel a slight curve, in whatever position the tool is held, which is advantageous in the common way of grinding. When held so that the stone grinds from side to side of the blade the tool must be continually turned a little in the hand so that each part of the edge will bear in turn on the stone, as, the tool edge being flat, and the surface of the stone rounding, the tool would otherwise be ground hollowing. It is harder to hold the tool in this way, however, without its slipping or making nicks or grooves in the stone, and you had best learn to grind in the ordinary manner.

Try to grind squarely across the chisel—that is, to have the cutting-edge at right angles to the lengthways edge of the tool. Apply the square at intervals to test the accuracy of the grinding.

The angle for grinding the bevel of such tools as the chisel is about twenty-five degrees, but when used for very hard wood the angle should be slightly greater, or the edge may be broken.

Do all the grinding on the bevel. Do not apply the flat side of the tool to the grindstone. Any slight burr or turning over of the edge on the flat side should be taken off by the oil-stone.

If the edge is badly nicked or broken, you can first straighten or grind it down roughly on the side of the stone or by holding it nearly at right angles to the stone—but with the latter turning the other way—before grinding in the regular way.

To tell when the tool is ground sufficiently, hold the edge in front of you toward the light. If the edge can be seen as a bright shining line it is a sign that the tool is dull. It will not be sharp until this bright line has been removed, and the edge has become invisible, for a really keen edge cannot be seen by the naked eye. Bear this in mind, as it is the final test and the simplest way to tell when to stop grinding.

In grinding on a grindstone and in rubbing on an oil-stone, the great difficulty is to keep the same angle between the tool and the stone, as the natural tendency in moving the tool is to rock it back and forth and thus alter the angle between the blade and the stone. An arrangement can be bought which preserves the desired angle without effort on the part of the grinder. A little ingenuity will enable you to rig up a guide or gauge with a piece of board which will enable you to replace the tool on the grindstone at the same angle.

The plane-iron is sharpened in the same way as the chisel, only, being wider than most of the chisels you are likely to use, it requires more care to sharpen. The plane-irons can be ground to a somewhat more acute angle than the chisels, although the jack-plane, which is used for rough work, may require more strength at the edge.