Re: [ATM] Ultrathin Project update

["Arjan te Marvelde" <arjan.te.marvelde@hetnet.nl>]

Richard,

> contact approaches molecular. It is then indistinguishable from a
> solid lump of glass with a concave surface.

OK, so you actually 'glue' suport to the glass, not to part before figuring
is done. Do you think this is thermally stable enough, and zero stress? If
any resiual stress releases when the mirror and support are separated, you
know what the result would be...

> How can it be "off" ?. The plaster has no voids and is in intimate
> contact with the convex surface of the mirror, whatever its shape. The

My assumption was that the support was not attached to the glass. I believe
that in your original post you mentioned something like grinding into shape?

I do believe you need a rigid backer, per your suggestion, only I'm a bit
worried about problems caused by glueing things together. You may risk
forcing the glass in a shape you don't want. It's probably better to use a
thin conforming intermediate layer like pitch, chamois, silicone. The
difficulty is finding the optimal thickness to allow some correction without
causing too much flexure.

  AtM

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