[ATM] coring a lens or mirror

[Guy Brandenburg <gfbrandenburg@yahoo.com>]

I have heard different opinions on when one should
drill the hore in the center of a lens or mirror (eg
Cassegrain or Lurie-Houghton). 

Some sources recommend drilling and beveling before
almost any grinding takes place, and then either
gluing or plastering the glass cylinder back in. I
have heard that this can cause serious edge problems
around the drilled hole.

Other sources recommend waiting until all of the
grinding, polishing and figuring is all done, and then
spray-painting g the entire surface with rustoleum,
drilling out the core carefully, and then removing the
rustoleum with a bath of hot water, which causes the
paint to come off in one piece.

What methods have the assembled experts tried? Which
do you think is better?

Guy Brandenburg

=====
Guy  Brandenburg
Washington, DC
My home page:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
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