Re: ATM "frozen" liquid mirrors

[Aart Olsen <aart@uiuc.edu>]

Why solid epoxy?  I'd try a molded concrete substrate covered with just a
thin layer of spin cast epoxy.  That way you would benefit from the
stiffness and low temperature coefficient of the concrete.  If you use a
good mold for the concrete (e.g. that convex tool you have lying around)
you could perhaps get by with a heavy varnish -- the stuff used to finish
bartops -- because you'd need just a millimeter or so for polishing and
figuring.  Painting the rest of the concrete surface with polyurethane will
prevent it from outgassing when aluminizing.  It should be easy to cast
ribs into the concrete to save weight, and it would be handy to embed some
bolts for mounting too.


Aart M. Olsen         mailto:aart@uiuc.edu          217-244-4688
Library Systems Office      Univ of Illinois at Urbana-Champaign