how can I remove the oxidation from nickel?

Question

does anyone know how to remove oxidation from nickel?
I have old nickel coins that have crud all over them, and I have tried all the conventional methods and most do not work.
now the only things remaining are the harsher acids. thanks

Answer 1

Some nickels contain Silver and the dark crud is not oxidation but Silver sulfide (which is black).

If the coins have no other collector value, clean them with a mild metal cleaner, not acids. But be aware that chemical cleaned coins loose much of their value to a collector.

Answer 2

If you use harsher acids, you would dissolve some of the nickel in the cleaning process. If you really need to remove the crud, you will need to remove it by hand. If the crud is the oxidized material of the coin, the best thing for you to do is to leave it alone.