Sending out your jointer knives for sharpening is not only inconvenient, it could be a gamble. Canadian woodworker Hendrik Varju has been unhappy with the results he's seen from commercial sharpening outfits and decided to devise his own method for sharpening jointer knives in-place, without having to remove them from the cutterhead.

Varju's DIY sharpening method won't completely replace the need for a sharpening service, but it will greatly increase the time between sharpenings and allow you to fine-tune the job done by a service in those rare instances when you do send them out.

Key to this method is the ability to lock the tool's cutterhead in-place. Varju does this by using a simple shop-made jointer locking jig. It's nothing more than a small block of hardwood cut to fit into the jointer's rabbeting ledge. A hardwood dowel sticks out of the block, thus keeping the cutterhead from turning. With the cutterhead locked down, Varju uses a series of diamond plates to hone a microbevel that yields perfect cuts.