Re: ATM shear in silicone pads

[Aart Olsen <aolsen@prairienet.org>]

"Arjan te Marvelde (ELN)" wrote:

> What i wander in your case is, the CTE may be similar to pyrex, but how about moisture? I'd say that for any wood this is a more severe cause of deformation?

I use well aged wood that's equilibrated and lots of coats of varnish to
minimize short term moisture variation.  As an ATM I like to do star
tests more than I like to look at the stars themselves, so it will be
easy to see if a wooden cell distorts the mirror -- so far so good.

By the way, here is a chapter on the moisture properties of wood, from
the US Forest Products Laboratory Wood Handbook.  It's a 25 page pdf so
you may need Acrobat Reader:

http://www.fpl.fs.fed.us/documnts/FPLGTR/fplgtr113/Ch03.pdf

Aart
-- 
Aart Olsen
aolsen@prairienet.org