On Oct 9, 11:53 pm, Steve Hix
wrote:
In article .com,
Fred the Red Shirt wrote:


...

Obviously you have not seen how a telescope mirror ages over the
years.

Guess again.

Well then you should have observed that the transparency increases
between cleanings.


It's easy to recoat the mirror, so it's not so much of a problem,
certainly less of one than dealing with silver corrosion.

While it is not a technologically daunting task, it is not cheap for
larger mirrors especially when you consider shipping. I have a 17.5"
mirror that will need realuminizing when I finally get around to
putting
it into a scope. It has been cleaned exactly once, but the coating
is nearly gone entirely after 30 years in storage.

Offhand, do you know anyone who recoats mirrors that size?

--

FF