Re: ATM How many times do I need to do this??!!

["Bob May" <bobmay@nethere.com>]

I rarely let anybody go back to grinding to fix a problem with their mirror.
The last three times it was to refine the ROC of a mirror that the guy
wanted exactly to a particular radius and they were just too far off to get
there by polishing.
Thus, my recommendation to you is to keep on polishing and don't stop unless
the surface is hoplessly off.
TDE can be eliminated by the proper stroke in time and a bit more quickly by
using a small subdiameter polisher and polishing just inside the edge area
down to the rest of the curve.
For the apparent holes you presently have, make a good warm press and see if
that gets things working better.  Remember that if you use short strokes,
you won't be able to average things out as the lump in the pitch won't be
moving very far and you end up eventually making a ring in the mirror that
is deep and is about the length of your stroke.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net