Re: [ATM] A very rough surface mirror

[Guy Brandenburg <gfbrandenburg@yahoo.com>]

What Dale says here is usually right. However, in some cases, there is lots and lots of grack on the mirror which will grind into the surface. A good cleaning with water and detergent and your bare fingers (so you can feel the little particles of grack with your fingertips), followed by pouring on a mixture of hydrochloric (aka muriatic) acid and a little Copper II sulfate crystals dissolved therein, will remove the coating with great speed and without further etching the surface, which will be the result if you use strong alkaline substances, in my experience, and in the experience of others who have reported to me on this list.
Guy

Dale Eason <atmpob@yahoo.com> wrote: No need for any chemical measure to remove the coating
if you are going to polish it anyway. Standard
polishing will remove it in just a few strokes.  At
least it always has for me.

Dale Eason

--- "Francis J. O'Reilly" 
wrote:

> Dale,
> 
> I would think that it was the result of a very hard
> lap, too fast stroke and 
> very poor pitch lap to mirror contact. That being
> said, with a new lap of 
> good quality, use 1 tablespoon of aluminum hydroxide
> oxide to one quart of 
> water for about an hour then rinse throughly, (Note,
> this I politely 
> disagree with Guy on this matter) to clean the rest
> of the aluminum coating 
> 




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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