I found that the jaw faces on some of my F-style bar clamps weren’t flat or square, causing them to slip during use. Not wanting to toss the clamps, I came up with this grinding jig for my disk sander.
The jig starts with a base and runner that fits the sander’s table. The top, clamp rest, and fence align the clamp head parallel to the sanding disk. A couple of light touches are all you need to grind the clamp head square. Just keep checking your progress as you go until the face is square.
