Re: [ATM] Polishing to a sphere

[Gilbert Gagne <ggagne@clearwire.net>]

Vladimir Galogaza wrote:

>>It ultimately will be a "flex" mirror, but first its figure 
>>must be made spherical
>>    
>>
> How do you hold the mirror while polishing MOT?
>
I hold the mirror with my hands around the rim so the heat of my hands 
only affects the rim. This initially caused a turned edge with long 
polishing spells until I changed to short polishing spells of 10 minutes 
or less alternating with 1/2 to 1 hour cold pressing. The drag of 
polishing a 3/4" x 12" mirror is very hard on the hands. I sometimes use 
a 2" thick hollowed out plywood disk that applies pressure only to the 
rim and to the outer 1" of the mirror, still MOT while polishing. This 
eliminates hand heat from affecting the glass and is much easier on the 
hands. I still restrict polishing spells to 10 minutes or less for fear 
that applying pressure only to the rim might distort the glass, but so 
far, the turned edge hasn't returned.

I appreciate your comments and am anxious to finish this miror.
Gil Gagne
Port Orange, FL
_______________________________________________
ATM mailing list http://www.atmlist.net/