Chisel Sharpening - Jig For A Jig

Yesterday it was time to sharpen my chisels.  I've been doing this by hand on the diamond plates, but I have a tough time getting the cutting edge square to the sides of the chisel.  This is especially true on smaller chisels.

Right side of this 1/2" chisel is shorter

I have a jig for sharpening - the Veritas honing guide - but there are problems with it.  There is no good way to ensure your chisel is set straight in the jig.

Is it straight?  Or is it not?

The other problem is clamping the chisel in the jig to get the right bevel angle.  I eyeball the chisel in the jig against a bevel gauge set at 30°.

Bevel gauge behind honing guide

This works OK, but it's slow and I still have the problem about whether or not the chisel is straight in the jig.  So I made a jig to help in this process.  I took a piece of hardwood and cut stopped grooves of 5/8", 1/2", 3/8" and 1/4" widths.  These grooves are square to the end of the board.  The length of the grooves is equal to the distance the chisel sticks out of the honing guide when it is set properly to sharpen at 30°.

Jig in progress

To use the jig, I set the chisel loosely in the honing guide.  Then set the end of the chisel in the jig so that the sharp end bottoms out at the stopped end of the groove.  This ensures the proper projection to hone at the 30° angle.  Then I make sure the honing guide butts up to the end of the jig (this ensures the chisel is square to the jig) and tighten the clamp.

1/2" chisel bottomed out in groove, honing guide butted up to jig, ready to clamp

This is not perfect due to a little slop in the jig and issues with the honing guide clamp screw, but it works pretty well.  The 1/2" chisel came out perfectly square after sharpening.

That's as square as I'll ever need it

I still plan to sharpen by hand, but every once in a while I'll use this jig with the honing guide to bring things back to square and to the proper bevel angle.