[ATM] Back of my blank

[david.a.stevens at gm.com (david.a.stevens@gm.com)]

Since this is not a "thin" mirror go ahead and grind your curve into the
mirror with 80 grit and if you want turn the mirror over and grind the
back. I did this with a 12.5" and I just followed the grits sequence for
both sides of the mirrror. By the time I was at five micron both sides of
the mirror were ready for polish and let me tell you that you will have a
better surface on the back side of the mirror than you do now. However it
is double the work,but it looks real pretty. The only drawback that I could
find is when you are foucualt testing you will get a double reflection and
you have to make sure it is the concave surface that you are looking at.
But you will always have that other relfection that you will just have to
ignore.

Hope this helps,

Dave