How to Sharpen a Block Plane with Sandpaper
Mastered in a Minute: A honing guide and sandpaper adhered to MDF provide effective, no-frills sharpening
A block plane is an essential tool that needs to be sharpened regularly to work properly. Here’s how to do it. (For this procedure, we made our own sharpening “stone” by gluing four different grits of sandpaper—220, 400, 800, and 2000—to a piece of MDF using spray adhesive.)
To start, remove the plane iron from the block plane. If the tool is new or has never been sharpened before, polish the back first. Place the nonbeveled, or flat, side down on the coarsest grit, and use downward pressure as you move the iron perpendicular to its length back and forth across the paper. Only the first inch or so of the back requires polishing. When you’ve achieved a uniform finish, move up to the next-higher grit. Flattening the iron’s back only has to be done once unless it gets damaged or rusty.
To sharpen the iron, use a honing guide to hold it at a consistent angle—typically 25 degrees. Use a screwdriver to tighten the guide’s screw; otherwise it might not maintain the angle you set. Check the angle by eye, and follow up with a few quick pull strokes over a fine grit to ensure the beveled edge makes full contact with the sandpaper. Readjust as necessary until it does.
Use even, consistent pressure on both the pull and the push strokes. If the plane is sharpened regularly, you may only need to hit the finer grits for a sharp edge. If it’s new or dinged up, start at the coarsest grit and work up to the finest. When the bevel has a consistent finish across its surface, move up to the next grit.
After the bevel is sharpened, remove the small burr that forms at the edge by running the back of the plane iron over the highest-grit sandpaper—just as you did to polish the back in the beginning. Reinstall the iron in the plane and you’re ready to get back to work.