Posted 01/19/2012 12:05 am
It may depend on the chemistry of the 30 year old Whitman album. Have they changed the materials used in their maunfacture over the last 30 years?
It is normal for a manufacturer of anything to improve the quality of their products over the years.
An acetone bath for the coin is the first resort to turn to. Perhaps some glue has evaporated out and condensed on the coin. Some acid reaction with the copper component of the 90% silver alloy may have also taken place.
As an analogy is that older cars can suffer from evaporative gassing out (especially in hot conditions), of the plastic materials used in their interior. This gassing out shows up as fogging up of the interior glass surfaces of the windows, which often needs a mild solvent to remove.
It is normal for a manufacturer of anything to improve the quality of their products over the years.
An acetone bath for the coin is the first resort to turn to. Perhaps some glue has evaporated out and condensed on the coin. Some acid reaction with the copper component of the 90% silver alloy may have also taken place.
As an analogy is that older cars can suffer from evaporative gassing out (especially in hot conditions), of the plastic materials used in their interior. This gassing out shows up as fogging up of the interior glass surfaces of the windows, which often needs a mild solvent to remove.
