[ATM] extreme raised edge

[burrjaw at earthlink.net (Jim Burrows)]

At 2004-02-14 23:05 -0300, Matheus Lazo wrote:

>In my new mirror I have tried a HCF lap. It polished very well but the 
>last 10mm
>of the mirror become extremely raised. The curvature of this zone is about 
>100mm
>less than the spherical part. I would like to now how is the better way to
>correct this zone.

As it says in the A.T.M. series, and as I learned to my regret, you can't 
finish off a mirror with HCF - it leaves a rough "non-optical" surface.  So 
it is probably best to switch to pitch (hey! that rhymes!) now that you 
have the mirror polished.  Your high edge can be attacked with a small 
tool, or, also from somewhere in the A.T.M. books (along with the caution 
to be careful and don't dig a ditch), put some rouge on your thumb and go 
around the edge.

         -- Jim Burrows
         -- mailto://burrjaw@earthlink.net
         -- http://home.earthlink.net/~burrjaw
         -- Seattle N47.4723 W122.3662 (WGS84)