Re: ATM Can an 18" mirror be made by hand?

[Lawrence Sayre <lsayre@stratos.net>]

Guy Brandenburg wrote:
> 
> How did the "Candle Holder" mirror work out?
> Guy Brandenburg

Repeatably 1/6 to 1/7 wave via Foucault test if I use the entire 8.6"
surface, and 1/10 to 1/12 wave if I stop it down to exactly 8"
aperture.  I had a bit of TDE that I lost a battle with, so 8" is the
way I intend to use it.   Getting ready to send it to Clausing for Beral
coating.

Overall I would not recommend one to the beginner as the very thick and
heavy ashtray like edges (At least ~1.5" thick) and the thin central
~70% (less than 1/2" after completion) offer problems with getting it to
grind and more importantly figure predictably across the entire
surface.  It flexes easily in the center but not much at all at the
ashtray lip edges. Mounting it will be interesting also.

Lawrence Sayre

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"Man's mind is his basic tool of survival!"
(a quote from the famous 'John Galt'  speech 
in the equally famous book "Atlas Shrugged")
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