From: Daniel Fundo 
To: Chuck Taylor 
CC: ATM Archives 
Reply-To: Daniel Fundo 


<< Assuming a good quality to begin with (it is a Televue) how big a
chip would you estimate you could have on the mirror of a refractor style
diagonal before it would affect the flatness of the mirror?  >>

It doesn't matter how big the clip is!  It's how its placed on the holder
that will affect flatness.  If the clip isn't designed correctly (to just
clear the thickness of the mirror) then any over tightening will induce
strain on the mirror.  Generally, a thin peice of felt is attached to the
part of the clip that is over the surface to avoid scratching.  A slight
compression of the felt will not affect the mirror, unless it is very thin.

Several of us on the list still believe in mechanical attachment of all
mirrors to their cells/holders, but for a secondary, especially a small
one, I believe that silicone adhesive, in moderation, is acceptable.

*****-----
Dan F.
Secretary/MAS
Memphis, TN

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