How to Repair a Knife Sharpening Stone

Undamaged sharpening stones keep a knife edge in optimum shape.

Stones that are dished, gouged or scratched can be repaired with a few minutes work by flattening the stone on an abrasive surface such as sandpaper. By evenly abrading the surface, you can remove enough material to get rid of the damaged portion, leaving the stone flat and able to sharpen again.

1. Adhere a sheet of 80-grit sandpaper to a flat work surface by spraying the back of the sandpaper with spray adhesive and then placing the sandpaper on the surface, taking care not to wrinkle the sandpaper.

2. Place the damaged side of the sharpening stone on the sandpaper and rub it in a figure-eight motion on the sandpaper.

3. Continue rubbing the stone until the face is flat and shows no signs of the damage.

4. Polish the stone by rubbing it on successively finer grits of sandpaper to remove the sanding marks left by the coarser sandpapers. Most stones will need 150 and 220 grit, while extremely fine stones may require a couple of passes over 400- or 600-grit sandpaper.

Tip

Look for finer grit sandpaper in automotive parts stores as most home improvement centers don't carry sandpaper above 220 or 400 grit.