RichA
New member
I picked up an old WW2 telescope lens in a brass mount at an antique sale. The lens had fungus which had apparently eaten into the lens. Would not come off with methyl alcohol, acetone or lens-cleaning fluid. So I tried some Peek metal polish. It worked! The lens hadn't been corroded, but the fungus had gone rock hard and had to be polished off. The lens is now clean. This lens had no coatings, it's possible doing this to a lens with coatings would effect or abrade it.