Re coating of the Shane three meter telescope mirror
in February, 2016.
Information on mirror de-coating:
We have been recommended to a mixture of
90 percent Phosphoric Acid
5 percent HCl
5 percent H2SO4
For mirror de-coating.
Also recommended Jasco Metal Enchant from Ace Hardware.
From Paul O.
De-coating at Aluminum Coating
We use a multi step process,
cleaning, first with water followed by paint thinner and finally lacquer thinner.
Then a soak for two days with the mirror surface submerged in printed circuit board etchant.
Then soak overnight in diluted swimming pool acid.
All mirrors get a final cleaning with pure methanol before coating.
While rubbing with a soft abrasive such as talc might help remove
a stubborn coating we do not do that process here.
Polishing and figuring is left to other vendors.
We recommend avoiding the use of Sodium Hydroxide, NaOH and
strong, concentrated acids.
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Page last edited May 9, 2013