[ATM] problem with mirror blank

[Jarvis Krumbein]

Horace, ignore the imperfection and continue.  You will probably find
that you will have ground it out by the time that you have gone through
the grits.  If not, continue on with polishing and after the mirror is
figured and coated, a little dab of black will take care of it.  You will
never notice the difference.  The old Pyrex blanks had lots of bubbles
and it was not uncommon to grind through them with no harm to the
finished mirror.

Jarvis Krumbein
 
On Sun, 8 Apr 2007 20:08:37 -0400 horace r davis <hrd9 at juno.com> writes:
> i have the 16 inch porthole the mirror glass not the same quality as 
> new
> blank of pirex
> the tool and mirror are mated and i have reached .200 inch in 
> center
> i am getting very close to a small imperfection in the blank i am at 
> .120
> grit know.
> if i hit it do i need to grind through and problem remove at least 
> .02
> from the entire mirror
> or can i have the mirror coated and just cover it up with black 
> paint or
> some thing I don't think it is over .025 in dia
> would like your impute
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 
>