By Tom and Kay Benham, Contributing Editors, Lapidary Journal Jewelry Artist
No matter how careful you've been using your sharpening stone to sharpen gravers and other edged tools over the years, one day you will discover that you have developed a low spot in the center of your stone. You don't have to toss it and buy a new one, just renew its surface. To renew the stone's surface to its former pristine condition, tape one edge of 120-grit drywall sanding screen to a flat surface. Rub the worn surface back and forth on the screen until the surface is flat again. Be sure to keep the surface wet with water to prevent the stone from loading up. A few short minutes and you'll have a fresh, flat stone; the workout of the upper body is just an added benefit.