Sharpening Jig for Jointer and Planer Blades
I’ve tried several different shop-made jigs for sharpening my jointer and planer knives but this one has proved the simplest to use and make.
When making this sharpening jig it’s important to make the slots at the correct angle so the bevels of the blades lay perfectly horizontal. This way the sandpaper will have even contact. My jointer blades required a 38-degree angle but check yours because it may be different.
I also had to saw the angled slots with the board on its edge. That’s because my tablesaw (like most) tilts to only 45 degrees. This is not far enough for the slot to be cut with the board laying flat. Cutting it on its edge solves this problem. Take a look at your saw and you will see what I mean. Double-check the angle of your jointer knives and saw the slots to match. I added a blade guard to keep things safe.
For the sanding block I used chunks of 3/4-in. MDF with sheets of silicon carbide sandpaper attached with spray-on adhesive. I started with 220 grit and worked my way up to 600 grit for a final honing.