Hello everybody, I was reorganizing a bunch of inherited coins and there was one thing I loved so much about it. I like to call them ghost coins as you can see the transparent shape of the coin and I think they are so beautiful.
I'm afraid I find them a little terrifying. Most of those flips have a ghost impression that's greenish -- and that implies that they've been corroding the coins they held! If you look at the coins you took out of those flips, you'll likely find that a lot of them have some green discoloration. They may have sticky spots. This is active PVC damage, caused by chemicals used to make the plastic soft. It's damaging because the sticky stuff contains an acid that corrodes the coin's surface. To get rid of it, you can soak the coins in pure acetone, the kind that comes in a can at a hardware store (not fingernail-polish remover, which often contains other stuff as well). Soak each coin for a few hours (in a sealed container), then take it out, dip it in fresh acetone to rinse it, and stand it on edge on a glass or metal surface (not plastic) to let the acetone evaporate. Do all this in a well-ventilated area, away from flame. Of course, I could be misinterpreting your photo, and everything could be fine. But those look like flexible (soft) flips, and that means they're likely to be PVC. If I were you, I'd check the coins very carefully. Good luck!
That is a very bad sign. Your coins probably got messed up with PVC. I hope they are all transffered to 2X2 mylar holders.
Glad you posted the ghost holders. Seriously though it appears some of the coins may be suffering from PVC and that can seriously damage them for life. Please have all those coins checked out asap and welcome to CT.
Thank you all and Jeff especially for the information it was very helpful. Still new to this but I did get all the coins into new 2x2s. I did notice a lot of the coins with a stickyish coating but I assumed it was some sort of old olive oil sealant from long ago. I didn't clean any of the coins as i heard it could damage value but this is dire it seems. Let me know if I should still unpack my coins and clean them up with acetone. Took me a while to get them together and id rather not do it again but I will do what I have to, to save my grandfathers coins.
Cleaning coins improperly damages them. Soaking them (no rubbing) in acetone isn't improper, and won't damage them. (Some here believe it can change the color of copper coins; if you're concerned about that, another solvent, xylene, should also work, and everyone agrees that's safe for any metal.) After you do soak them, be sure to put them into new 2x2s, and throw the old ones away. The old ones will now have the sticky stuff on their inner surfaces, and if you reuse them, you'll just put the dangerous stuff back onto your coins. Good luck!
One more question. How fast does this PVC erode coins? I want to get an idea of how nice these coins must've looked when my grandfather first got them.
I'm not sure we can answer that. It depends a lot on how they're stored, especially temperature and humidity. If you're lucky, they can go decades without a problem; if you're unlucky, they can get corroded in weeks or months. If you can get good, clear, in-focus pictures of some of the coins, we might be able to give you a better idea. I have an example of a modern quarter that I posted here a few years ago -- it was toned in a rainbow of colors. I left it in my office on an anti-static work mat, which apparently is made of PVC. When I came across it a few weeks ago, I picked it up, and found that it had stuck to the mat; there was a green circle where it had been, and the coin's reverse was sticky and corroded. When I have time, I'll post before-and-after images.
A couple years ago based upon CT chatter, I also dumped all the soft PVC coin flips I had coins in and replaced them with the hard plastic flips. I had the same "ghost" flips that you have .. well over a hundred of them. Many of the silver coins were slightly toned / hazed too and they were probably stored in a much more stable environment than most peoples.
An excellent question. If I had to guess, I would say that it's not the DOP decomposing; it's the PVC somehow yielding free hydrogen chloride, which the DOP then carries into contact with the coin. But there are several steps there where I don't have a good model for the process.
I had some info that gave the breakdown of the plasticizer in the presence of H2O to form HCl as one of the reaction products. I'll have to dig deeper, but it may have gotten lost during a computer change. FWIW, the reactions made sense to me (my organic chem is limited). Sorry, I can't provide the details so consider this a "trust me" response .
Actually decomposed DOP would give phthalic acid which might damage the metal. Or, as @-jeffB sez, PVC can produce HCl on degradation. It happens and I won't lose too much sleep over it.
In my experience it doesn't necessarily erode them in the traditional sense. I had a Morgan dollar, bought in 1974 in a PVC sleeve. After about 40 years in the PVC, it was covered in green haze, leaving a "ghost impression" like your coins. However, after just a few hours in 100% pure acetone (hardware store grade), the PVC came right off without a trace. There might be some underlying damage to the trained eye, but to me the Morgan looks like a nice BU coin now.
I suppose it wasn't too bad this time as many of the coins are still in good condition besides average wear and tear. good to know thank you. Then I will not rush to clean up my coins as I spent a lot of time reorganizing them. I will definitely get to it soon though.
