What do you mean by "exposed". Are you saying there is ugly green residue on the coins? Or are you simply saying your coins were stored in PVC flips for some period of time? If it is the latter then I wouldn't do anything. Some of my coins were stored in PVC for 20 years and only one had PVC damage. I washed that one in acetone and after a while I was able to get the residue off. The rest of the coins I simply transferred to a non-pvc flip.
I understand your confusion about cleaning. 99.9% of the time it is true that you should not clean your coin in any way, shape, or form. However there is a small number of situations where a very specialized type of cleaning is acceptable. We usually call that type of cleaning "conservation" to differentiate it from the bad types of cleaning. Acetone is an acceptable form of conservation so long as you know what it can and cannot do, and how to use it safely. Acetone will remove PVC, but keep in mind that you might end up with a splotch coin afterward. Not because of the acetone itself, but because the PVC residue may have prevented toning on the portions of the coin under it. So if the rest of the coin has continued to tone and those areas didn't, you will see the difference when the PVC is gone.
Posted 11/04/2011 10:29 am
