Ern’s blog

Sharpening: honing a skew turning chisel

A skew has been described as a finishing tool.

The more refined the edge the cleaner and easier the cut so honing isn’t a bad idea and you don’t need a Tormek to do it.

This is what works for me and in very little time I have an edge polished to 8000 grit.

1. Hollow grind on a dry grinder.

Here I’m using a cheap platform with a mitre gauge. I’ve used a square to draw a line on the wheel face at 90* to the side. I line up the skew edge with this and set the mitre angle.

Normally I ink both bevels but this skew’s been through the process.

This kind of platform is a little prone to flexing so modest consistent pressure will give a consistent bevel.

You can of course do this with your choice of jig.

2. Hone.

This is easier than it looks and quicker than it takes to describe.

You press the bevel down on a waterstone with one finger and cradle the shaft with the other hand. You can feel it register properly after you lower the handle a little so the tool pivots on the bevel bottom and then raise the handle til the edge contacts the stone.  Draw the bevel down the stone. Skewing the edge on this stone produces a smooth glide.

This stone is 15 micron, about 700 ANSI or 1000 JIS rating.

The object is to hone out the scratches left by the wheel in order to produce a refined, ie. less jagged, edge**.  That was 80 grit or about 300 micron so it’s quite a jump. But about 10 strokes on each bevel does it. You’re only taking a small amount of steel off at the cutting edge and the bevel bottom and creating two new co-planar micro bevels.

I repeat this on 4 micron and 1 micron stones for a polished cutting edge. These stones were laid in for another purpose but perform well for this. The first honing after hollow grinding only needs about 4 strokes of each side on the 4 and 1 micron stones. Inking the micro-bevels at the cutting edge helps you see if it’s working. All you’re doing is polishing out the scratches from the previous grit.

When next you have to sharpen, ink the micro-bevels and just hone instead.

Over time the bevels get wider and honing takes more strokes. When you run out of patience, hollow-grind again.

If I was starting over I’d just settle for a 15 micron and a 2 micron (6000 JIS) stone and then go for a coarser stone as a refinement to speed up the first honing step and remove minor edge damage.

(4 micron is about 4000 grit JIS, and 1 micron 8000 JIS)

Another option to refresh the cutting edge is to hone with an extra-fine diamond paddle; but I find it a little harder to use than the bench stones.

….

As posted elsewhere, I have a concern about cash-strapped woodies shelling out over a grand for a Tormek and jigs when there may be alternatives. I don’t believe that you need a wet grinder for HSS tools, but jigs and a honing system are close to essential. I’m working on two options for putting jigs in front of powered honing discs.

** Up close the edge off a dry grinder looks like a badly abused wood saw.