Over a day later and not apparent progress. Is there a chance it is lamination? It looks to me like opaque hardened glue. Also is a fingernail likely to scratch a silver coin? What would you use to lift the surface issue?
Time to see the coin, I think. There are many substances (hardened epoxy comes to mind) that acetone won't cut; maybe we're dealing with something like that.
Oh, dear Lord, NO!!! DO NOT PUT WD-40 ON A COIN!!!!! Acetone is proven to be acceptable to most coin collectors. Do NOT rub. Just soak and rinse with distilled water.
There are 3 major groups of normal glue, and the solvents are different. I would try water ( distilled if you want), 91% isopropyl ( walmart pharmacy area) and then the acetone. After that, it is more difficult such as epoxy ( I doubt in your case), often, a resistant adhesive will crack if frozen and allow solvents to get between the metal and the substance.
I put it in the freezer, just the coin, then dropped it back into the acetone. Do I need to leave the whole container with the coin in the freezer?
No, the theory is that the coin will expand faster than the glob of glue, and crack the glue, so drop into room temperature ( as I would not warm acetone with a hood).
I got around to imaging the coin with the adhesive or laminate. What leads me to believe it is adhesive is there are tiny scratches underneath the apparent glue. Coin has pl surfaces.
Doesn't look like adhesive to me, more like metallic reaction. Might have to use a dip treatment as a last resort.
Would NCS be able or willing to do the job? The coin looks pl to me and could go Unc., unfortunately conservation and grading eat up $40-$50. What you can't see is that the substance is layered, it definitely sticks up off the surface.
Some adhesives/gooey substances react better to aromatic solvents and/or very non-polar solvents. If you have any toluene or xylene around give it a try.
Don't have xylene or toluene around, probably could get a small container at Home Depot, etc. for under $10, which is better? Anyone know what the currency conservation people do for stains or glue on currency?
I picked up some xylene at HD for $8 or so. I started soaking the coin in it immediately, will share results. I guess toluene and xylene increase octane in muscle cars, maybe I will be able to do so with my econobox car?
Pure xylene and toluene are "aromatic" hydrocarbons that burn very hot if you have enough oxygen. Many coin collectors prefer xylene because they think toluene has too much odor, having a lower boiling point.
Are you guys sure this is not a struck thru? OP, is the large whitish spot on the surface or into it. Show a magnified photo of just the spot! If the surface is rough, it is not glue!
I walked it into a shop where the dealer is helpful this morning; looks like someone had tested it with acid, looked through 60X and saw that it was damaged. As a long time collector and sometimes seller/dealer, should I ask the small show dealer for money back? It was only around $50-$60 and I assume as a damaged pl vam 8 it is not worth that much.