Re: [ATM] FW: Figuring flats

["Mitch" <funnybone101@earthlink.net>]

-----Original Message-----
From: atm-bounces@atmlist.net [mailto:atm-bounces@atmlist.net] On Behalf Of
Vladimir Galogaza
Sent: Monday, March 12, 2007 5:03 PM
To: ATM List
Subject: Re: [ATM] FW: Figuring flats

Mike,

>Do you worry about the deformation breaking the glass?

No, I worry that  fast heating of one side will cause bulging
and polishing will remove part of the bulge. When cooled there will be
depression.

Dale demonstrated that short touching with finger of the mirror
surface results in detectable glass bulge.
What will happened at power polishing is very likely beyond
control.
Just a hunch,  but consistent with various observations.
Even slight temperature gradients at night cooling are
causing distortions requiring waiting for temperature equilibrium.
Power polishing is orders of magnitude worse situation, in my
opinion..

Regards
Vladimir

Woops you're right. I forgot this was all about flats; I was just thinking
to make it look nice on the back of a mirror and such. You could do it
perhaps before you start grinding/polishing the other side flat, too late in
this case.

Mitch

_______________________________________________
ATM mailing list http://www.atmlist.net/