Re: How to remove mirror coating?

Dean Ketelsen (ketelsen@as.arizona.edu)
Mon, 27 Mar 1995 09:42:22 -0700

The standard way of removing aluminum coatings is to use a 6%-8% concentration of HCL (hydrochloric acid) with a small amount of CuSO4 (copper sulfate) dissolved in it. The blue crystals tint the acid green, perhaps why the mixture is called "Green River Solution"? (I think not!) Anyway, an overcoated mirror will take longer for the solution to penetrate through pinholes, but it shouldn't take very much solution to strip an 8" - use a paper towel to hold it in contact with the surface rather than make a pint of it to dip the mirror into.

-Dean