I can barely tell what they are. I can only make one out that looks like maybe a nazi coin? Would there be a way to save them if they are that corroded? It may be fun to expirement but other than that I don't know if there is much reason to do anything with them.
Unfortunately zinc is quite sensitive to environmental conditions particularly if moisture is involved. IMO if there was ever a justifiable reason for cleaning coins those German WWII coins are prime candidates. But I don't know what would work. Not water; it's part of the problem. I don't think acetone would work. WARNING: Acid would work BUT as reactive as zinc is with acid it would have to be a VERY weak acid. Just remember your high school chemistry class. Hydrogen was generally created by mixing zinc with HCl. The result is a fairly strong explosive. Olive oil might be the solution; it's mildly acidic. Maybe someone in the know will come by and offer another, better solution.
Take them to your local park or beach and Toss one here and there as you walk around. One just might make someones day.
I like that idea. I actually know a guy who owns such a machine. He's in a other country though. Probably too pricey.
Send him a note and ask him if he will be attending any coin shows where he will have the machine with him. Tell him about the crappy coins, and maybe he will cut you a break. Chris
This might be an interesting time to observe the long-term action of olive oil. I once achieved a pretty stupendous result with an IHC so black you couldn't see any detail at all to speak of. This was on a whim, I never expected a good result, and didn't do "before" pics. It only took 15 months to get here.
amazing results on the indian head cent would you get similar results on 1859 copper nickel i have in blackened corroded shape???
I would first try some water and soap for a couple of days soak. Brush with a stiff brush and rinse. If that doesn't do it, toss them in some olive oil in a screw top container and forget about them for a year or so.
