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John Reinhart, Claude Godcharles and Sumit Roy
Sharpening

John Reinhart

John learned sharpening techniques at the Krenov school.

John says you can create a mirror polished finish on the back of the chisel or plane iron using successively finer water stone grits all the way up to 8000 grit.

Everone watchinging John

Hand powered grinding wheel

He laps the backside to a distance of about 1/2" to 1" from the cutting edge

The backside gets lapped only once, while the primary bevel gets sharpened repeatedly. When starting to lap the backside, John will often hold the blade at an angle of 30-45 degrees instead of perpendicular to the side of the stone. That way it is easier to tell if the next finer grit has removed all the scratches from the first coarse grit stone. He will often attach a strip of adhesive backed sand paper to a known flat surface and rub the blade against it to flatten the blade backside before moving on to a waterstone.

When grinding the primary bevel, a hand powered grinding wheel has the advantage of turning slow enough to avoid overheating the cutting edge and causing a loss of hardness. Grinding on a wheel creates a concave hollow grind that is followed up with graduated flat water stones.

The hollow grind is considered a timesaver in that the secondary bevel is much smaller than the whole length of the primary bevel.

The secondary or microbevel can extend only 1/64" from the edge of the blade. John says he knows the sharpening is sufficient when a burr can be felt on the backside.

John uses Norton waterstones with 1000, 4000, and 8000 grit. A diamond flattening stone is used to flatten a waterstone that is no longer flat.

The diamond stone grit is between 120 and 180. John uses a Lie Nielsen honing guide, but any honing guide will work to maintain the correct blade angle on the stone.

Claude Godcharles