Re: [ATM] Mirror question

[Guy Brandenburg <gfbrandenburg@yahoo.com>]

Michael,
I think it depends on the aluminum coating; some are easy-peasy to remove by polishing and some are extremely stubborn. We have been using muriatic (aka hydrochloric) acid with some copper II sulfate crystals dissolved in it to remove coatings. Works very fast. PCB etchant seems to me to be hard to find.
Guy

Michael Lindner <mikell@optonline.net> wrote: I got my first mirror back from the coater with the same note (except 
mine said it wasn't fully polished out *and* had lots of scratches). I 
can still see them today, but that scope is *wonderful*, and is my "grab 
and go" scope. The moral of the story - perfect is the enemy of good enough.

If you're going to eventually put it in a scope, why not do so first and 
see how it performs before throwing away so much effort?

Also, if you *do* decide to repolish/refigure, I polished off an 
aluminum coating, and it was a lot of work, and the effort of getting 
all the aluminum off left me with an odd hole that took a long time to 
refigure off. Putting the mirror in some PCB etchant solution takes no 
effort and you can start working on glass right away instead of aluminum.

My $0.02.




Guy Brandenburg, Washington, DC
My home page on astronomy, mathematics, education:
http://home.earthlink.net/~gfbranden/GFB_Home_Page.html
or else 
http://tinyurl.com/r6fh2

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