PVC on Copper

fathom

Thick PVC coating on this improperly stored Indian Peace medal.

What is the latest most effective removal technique? Acetone soak? Duration? Please advise.

Thanks for your consideration in advance.

lkeigwin

I assume you're not talking about the copper spots.

PVC can be removed with an acetone soak. It has no effect on copper (or other metals) but will remove all organic material acquired over the years. So sometimes appearance will change slightly.
Lance.

edit to add: duration doesn't matter.

ms70

If you do the acetone soak please post a pic of the result.

MsMorrisine

pvc is mint green

those black things are carbon spots

ricko

Those dark spots do not look like PVC..... I would say carbon spots... agree with @MsMorrisine. Cheers, RickO

291fifth

All I see are carbon spots. You are probably best advised to just leave them be. Trying to remove them may just make things worse.

fathom

@291fifth said:
All I see are carbon spots. You are probably best advised to just leave them be. Trying to remove them may just make things worse.

Yes the carbon spots are not going away I agree. I'm referring to a thick coat of PVC on the rim and surface though it's hard to tell from the pic. I will do a soak and repost.

MedalCollector

@fathom said:

@291fifth said:
All I see are carbon spots. You are probably best advised to just leave them be. Trying to remove them may just make things worse.

Yes the carbon spots are not going away I agree. I'm referring to a thick coat of PVC on the rim and surface though it's hard to tell from the pic. I will do a soak and repost.

You’re right - it is PVC - a common fate of these old, large medals. Most collectors think that PVC only manifests as green spots or green gunk, but these large medals are often housed in large PVC flips that coat the entire medal in a layer of thin smooth, substance, almost of an ointment consistency. It generally is most prominent on the rims, edges, and high points, but can also be present in the fields of such large medals.

Be careful using acetone on these large medals as it can sometimes take away an original layer of lacquer (though I’m not sure the Mint was applying it at the time of this medal’s striking).

Additionally using acetone on such a large medal can be tricky, because it is difficult to remove all of the acetone from the medal’s surface before it evaporates, which can then redeposit any organic material back onto the medal.

fathom

Great advice, thanks

MsMorrisine

i wouldn't soak it in acetone

as mentioned it may remove old lacquer protecting it.

gently work the rim with a q-tip. don't rub. just let the acetone do the work.

edit: otoh, if you have pvc it may not have lacquer

fathom

Or I could let our host look at it in hand and make a determination on restoration. Thoughts on this option?