A GREAT MANY men who use as common a tool as a plane cannot do a good job in keeping the tool in order. It is quite a knack to sharpen a plane in good shape, especially to set an edge on the plane iron with an oil stone. Figs. 1 and 2 show how to do it, and how not to do it. Supposing the plane iron has just been ground: it is placed upon the oil stone in the position shown in Fig. 1. The bevel of the tool is brought to bear flat upon top of the stone, then the back of the bevel is slightly raised, perhaps two or three one-hundredths of an inch, and while in that position the plane iron is carefully moved along the stone from end to end. The required pressure is applied by the finger, care being taken not to give the plane iron too rocking a motion.
Some mechanics fall into the habit of moving the tool as shown in Fig. 3. This motion is fatal to good work, and makes the bevel of the tool as shown in Fig. 4. The bevel is supposed to commence at a and should run nearly flat to b. Instead of this it is rounded, and as a good mechanic would term it, “is as crooked as a dog’s hind leg.” Fig. 5 shows a tool that has been whetted many times upon an oil stone and is ready for grinding. The bevel proper extends from a to c. The effect of the oil stone is shown from b to c, where the secondary bevel has been formed. This is the correct way to whet a plane iron. It should not be done as shown in Fig. 6, which represents the type of plane iron known too commonly among careless workmen.
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