reading a few back threads i saw some dicussion on cleaning pvc residue. my first question is where does the residue come from? Second has anybody used an ultrasound cleaner like what is used for jewlery. would that damage the coins?
The greenish slime that leeches out is a plastic softener, and it is corrosive to metal. Acetone desolves, and removes oily, gummy substances like PVC residue. I don't know about ultrasound, but I wouldn't think it would be as good.
mdev: 1) pvc residue is from the degrading of the plastic over time. It is not inert, meaning that it stays the same and does not degrade. 2) an ultrasound will/can damage the coin. 3) and, no, I have never used it, although it may be good for metal detecting coins.
I would like to get an ultrasound cleaner and experiment with it. It seems that as long as you are careful about the solution in it, it may be one of the safest ways to clean coins. But keep in mind that this is an opinion and not based on experience.
I use a ultrasonic cleaner mainly for my ancients that are encrusted in crud, and so far not done any noticable damage
