Regarding the removal of the scunge, I think this one gets down to the same methods that are used for the restoration of ancient coins.
Spend some time searching the Net, as well as relevant threads in this Forum.
I don't know if it will work, but ultrasonic cleaning at a jeweler's may be worth a try.
Would Verdicare help in this case?
The black scunge looks like copper sulphide.
Experiment with some other nickels first. You have to get the subject coin right first time. With a substitute coin, experimentation with a dilute acid could prove useful. You can control the rate of reaction by controlling the dilution and exposure time with a clock. Strangely, I have seen an ancient silver tetradrachm of Ptolemy X11 recovered in this way.
I understand your motivation in trying to clean it in the face of general advice 'don't clean coins'. Occasionally, there are exceptions; the coin is disappointing as it is.
Posted 04/10/2011 6:41 pm
