School of Woodworking Newsletter

You will need to sharpen the cutting iron. Manufacturers do not usually send their planes out of the factory with finely honed cutting irons; with the exception of Lie Nielsen and Veritas. Most planes will still cut with a dull iron, but obviously a dull iron gives greater resistance and requires more power to push the cutting iron through the fibers of the wood. Sharpen the iron first. Many people get hung up on the sharpening angle thinking that if it’s not exactly 35 degrees it won’t cut. A cutting iron sharpened anywhere between 20 to 30 degrees will cut and cut well, however, there is a compromise. An angle of 30 degrees will give the least resistance but will have a weaker edge, while an angle of 35 degrees will have greater resistance but the cutting edge will be stronger. Begin sharpening on a coarse stone.

I am using diamond stones because they cut steel fast, last long and, most important, they stay flat. In this case I am using an extra-coarse #270 grit stone for establishing the angle I want or to reestablish the angle. On a new iron you should not need to use this coarse grit for the initial sharpening. This coarse grit is my equivalent of the grinding wheel. Once the bevel is established I transfer to the adjacent stone, which is a #270 grit diamond stone, to polish and hone the angle.

With the diamond honing completed the iron is sharp enough for general woodworking, but for fine work you will need to sharpen the plane further. We call this honing. To hone the cutting edge you will need a strop. A strop is piece of split hide glued to a piece of wood and can be any size or shape, depending on what you intend to hone. For sharpening edge tools we use a flat 3” x 10” strop. We charge the strop with a fine abrasive suspended in a waxy substance called buffing or abrasive compound.

Contact me for strops and buffing compound if you need them. With the strop charged, pull the cutting iron, bevel down along the surface of the strop, trailing the cutting edge behind so that it doesn’t cut into the leather. When you strop it’s important that you move the iron in one direction only, otherwise the cutting edge will gouge the leather. Press the iron firmly into the strop and vigorously pull the iron thirty to forty times across the full length of the strop, at the same angle as the grinding bevel. By now the whole of the bevel should have a mirror finish. Turn the iron over and polish the flat face, keeping it flat on the surface of the strop. Do not lift up the iron or you will create a second bevel on the flat face. For all planes it is critical to keep this face perfectly flat.