On 2/13/2010 8:59 AM, Bruce wrote:
On Wed, 10 Feb 2010 09:20:54 -0700, Morris Dovey wrote
(in ):

If it protects metal from oxidation then it would permit using less
expensive aluminum (bonded to an even less expensive substrate) for
concentrator reflectors.

Late followup, but did you consider anodized aluminum?

I didn't because I can get spectral stainless foil in any
thickness/width/length I might need from competing suppliers - and
because the last time I needed aluminum (in a form not available at Ace
or Menards or TruValue stores) I spent three months trying and literally
could not get _any_ US company (neither manufacturer nor distributor) to
talk to me - and ended up having to buy a 25km minimum order from a
Pacific Rim supplier.

[ That supplier was a Japanese firm with a production facility on
Taiwan. Dealing with them was an incredible experience of win-win
negotiation, amiable mutual respect, and complete absence of any kind of
BS. A flurry of e-mails over two days got us to price/quantity levels we
could both accept - I drove to the bank to do an EFT, and when I got
home ten minutes later, there was a "Thank you for your order and
payment" e-mail in my Inbox. Less than two days after that the order had
been produced and was airborne from the factory en route to Des Moines.
It was exactly what I needed and the quality was uniformly excellent. ]

Locally, anodizing services are expensive, and I'm not confident that
I'd end up with the quality I'd need. A single molecule thick SiO2
coating might work if it prevented oxidation, had sufficient longevity,
and could be renewed without degrading the mirrors, but these folks
aren't offering reassurances in any of those directions. Still, it looks
like a technology worth keeping an eye on.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/