[Figure 34] shows the position to take in grinding
Chisels. Hold the handle of the tool in the right hand and rest the palm of the left hand upon its blade. Then lower the edge upon the stone until the bevel strikes it flatly, and bear down upon the blade with your left hand. Continue the grinding until the bright line of the dull edge has disappeared and an invisible edge has been obtained. Stop when this point is reached or the edge will become feathery and break off, necessitating regrinding. Grind upon the bevelled edge only, and hold the tool in the same relative position, to prevent the bevel from becoming rounded. The angle of the bevel should be about twenty-five degrees. To keep this angle the same, it is desirable to have a rest, consisting of a board nailed to the frame of the stone, upon which to support the handle of the chisel.
Gouges and Draw-knives are ground similarly, the former being rocked from side to side, in order to grind the curved bevel uniformly.
Plane-irons are held with both hands, as shown in [Fig. 35], and ground the same, except that the corners of the smoothing-and fore-plane irons are slightly rounded, while the edge of the jack-plane iron is a little higher at the corners than in the centre, to give it the qualities for removing thick shavings. It is more difficult to keep the line between the bevel and upper part of the iron straight than in grinding chisels, on account of the wider blade.
Fig. 35.—Grinding the Plane-iron.
Knives and Hatchets are ground upon both sides of the blade.
Of course, the edge of a tool is left in a very rough condition by the grind-stone, and must be rubbed up on an oil-stone before it is fit to cut with.