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Posted by Robert May on January 10, 2003 21:36:37 UTC

I presented the path you are on because you have indicated that the mirror is almost to the correct shape but needs some local work. This is what I'd do if I had a mirror that was 1/10th wave except the edge which was turned up.
The thing is that where you press on the glass as you polish is where the glass is taken away. If you have gotten the inner point out of the incorrect slope, keep on working further out and you will get that edge down in compliance with the rest of the surface. Don't be afraid to hang the tool over the edge but remember that the forces are going to be higher so be careful that you don't roll the edge over.
After you have things right, do a press with the full lap and do about 5 strokes and then see what happens. Hopefully, that little bit will smooth out any irregularities that may have been put in by the small lap.

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