Maintaining a Bevel

Glass is much more prone to chipping at the edges for sharp angles (such as 90 degrees), so to protect the mirror I need to keep the edge beveled. When I was trying to get my tile tool worn down without changing the radius of curvature, the edges got ground more than usual and my bevel was almost completely ground away. To maintain the bevel, a sharpening stone (for knives) is drawn across the edge as the glass is slowly rotated. After one revolution the mirror and stone are both washed, and the whole thing is repeated. It took a little over an hour (or two Dr. Who episodes) to restore the bevel to an appropriate size.