I've got a spot of PVC (I think that's what it is) on a silver coin and was wondering if there is any way or product to use to remove it without also removing the value of the piece. This coin is also really dark (Does this come from PVC residue also?) Would love to send pictures but haven't figured out how to take them up close with my digital camera yet! (By the way, do most of you use scanners?) Thanks everyone!
The short answer to your first question is acetone. Make sure it is the pure stuff, you can get it at any hardware store (I got mine at Wal-Mart) for less than $10/gallon. After it's acetone bath dunk your coin in distilled water and let it air dry (no patting or rubbing). Repeat as neccessary. As for photos/scans; I think that it is pretty evenly split between those using cameras and scanners. That said, I think that while good photos are more difficult to consistantly produce, they are vastly superior to scans. I say that because scans don't show a coin's luster, making coins look washed out (even though they show details fabulously). Taking good close-up coin pictures can be pretty challenging, but once it is mastered the photos created accurately show off a coin's detail as well as luster. Photography is definately an art, but it does pay off with practice. The best part of digital photography is the ability to easily take a large number of photos and choose the best ones quickly. As for tips, use the macro (close-up) setting on your camera. It is almost universally indicated with a small icon of a flower. Turn the flash off if it isn't turned off automatically. Then ALWAYS use a tripod since the close-up setting has a longer exposure time and that really magnifies any shake in the camera leaving you a blurry photo. Then use the timer delay to take the picture after you have removed your hand from the camera to further reduce the shake. I use a cheap Kodak CX7430 and I can take pretty good photos using the tips I listed. Good luck and keep practicing!
How long? Thanks for your response...One more question: How long do you keep them in the bath? Overnight or just a couple seconds? Does it matter? Thanks PS Slowly figuring out this camera...everything's a little grainy yet.
I would use Acetone too...BUT I and many others think it still lowers the value...sometimes you can tell when its been in Acetone sometimes you can't...I'd rather be safe than sorry and mark the coin CLEANED with a little bit marked off the value...but with PVC you MUST clean it somehow...if you don't...you won't have a coin after awhile...it will eat the coin away. I would leave the coin in for about 30sec.... Speedy
You never stated what type of coin you were reffering to. Is it in fact a Silver coin? What denomination? What date and mint mark? Please note many coins that appear to be Silver are in fact not Silver and do not contain Silve at all. If the spot is indeed PVC, which is Poly Vinyl Chloride, which is doubtful, it will not spread on the coin. More than likely the spot is some other contaminate if on real Silver. In any case the suggestion of using Acetone is pretty good. If it is a good grade of Acetone, it will not leave a residue and will remove most unwanted contaminates without being to much of a considered cleaned coin. If the spot is a form of Silver Nitrate or similar compound, as you remove the contaminate, you will also remove a portion of the Silver since the spot was formed with the Silver and a nitrate. If your coin is in fact a modern coin it may not contain any Silver at all and the Acetone bath will have very little effect on the coin itself but will remove added on contaminates. As to time, try for a few hours first, then longer as required. Even for a day will not effect the coin.
Do a forum search on PVC and read the voluminous threads that have been posted. Just Carl's opinions doubting that your mark is PVC, and suggesting lengthy soaking in acetone are definitely minority opinions. PVC residue forms when coins are left in soft plastic flips for extended periods of time. If it has not already pitted the coin, it comes off very quickly in pure acetone. Good luck!
PVC is actually a fairly stable compound. I've had coins in 2x2's for well into 30 and possibly 40 years. They are not in an invironment that instigates a reation with metals meaning low temperatures and very little humidity. Many of my 50 or more Whitman Classic Albums also contain sheets of plastic covering the coins and they also show no signs of contamination with the plastic. I may be jumping the gun so to speak by not waiting for a few hundred years though.
Just a quick comment because PVC is getting a bad rap. It is not the PVC that causes the problem, it is the plasticiser (sp?) that is added to the PVC to make it more flexible that causes the problem. So if you use stiff flips (or other containers) the potential problem is the physical rubbing, not the contamination layer. It seems this is a classical case of "you can't win for losing".
Could someone please post a photo of a coin with PVC, so everyone knows what you are talking about. Thanks
Neither 2x2s, with their mylar windows, nor the hard plastic slides used by Whitman, Dansco, et al., in their albums, contain PVC, so how many weeks, years, decades or even centuries a coin spends in contact with those plastics is totally irrelevant to PVC contamination. Here is a closeup of the rim on the 50 yen coin in the Japan Mint Bureau's 1975 Mint Set. All mint sets prior to 1984 were issued in plastic folders made with PVC. If you look closely at the rim you will see a dark green color - that's the PVC damage which will eventually pit and corrode the coin.
If the slides used in albums had the plasticizer used in PVC they would be too flexible to slide in and out, or to give "rub" marks to uncirculated coins. Mylar film does not have that plasticizer either, as you can verify from any good chemical handbook on plastics. Sorry, but I can't specifically recall every reference source I have used in the 68 years since I learned to read, but my own personal experience with PVC contaminated coins has taught me that: The residue is easily removed with pure acetone, and If the residue has been on the coin long enough, the surface will be corroded/pitted. If that doesn't satisfy you, let's just agree to disagree, and get on with more important things.
If you looked up what PVC is, PVC has the ever-hating chloride compound in it, which is the active ingredient to ruin anything. But it is only when PVC starts to break down, which gives out the bad chloride compound. Let's put it this way, if you have ever swam in a public swimming pool, you know what is the active chemical compound they use - yes, chlorine. If you have sensitive skin and hair, you know what the effects are, and often you would shower as soon as you get out from the pool. If you see some cases of Olympics swimmers, you can see that some swimmers do have bleached hair, not because they did some sort of hair treatment, but often because of the extensive training periods. Moral of the story: IF you know there is PVC damage in the EARLY stages, you would want to get rid of it as soon as possible. The only exception will be on copper coins as acetone seem to leave some sort of wierd toning on such coins.
Oddly enough I am a chemist. I was a associate professor at a local Junior College in Chemistry. I have degrees in chem as well as electrical engineering. I have an extensive library of chem books, some evendating back to the 20's. Therefore the interest is in not what PVC is or what it can do but where is it stipulated that the plastic in 2x2's or the slides in albums are composed of a specific substance. I also agree with satootoko to let sleeping dogs lie.
Holy cow... I didn't know that. I wonder how many remain in their original packaging. Which makes me wonder - I don't know if this question has ever been addressed: Is it possible to keep PVC stable in certain environmental conditions that would not adversely effect the coins inside? Normally, the question wouldn't be important, but in this case, I would imaging that if they could be stored, say at a near freezing temperature which could possibly slow down the PVC deterioration, my guess would be that the sets would be worth a certain premium. Maybe not. Does PVC breakdown as a chemical reaction to air, or just on its own? I guess, then the sets could be housed in some sort of air tight environment - if a true air tight holder could be made
I've got kind of a related question here. Can a fingerprint be taken off of an Ike dollar? Would acetone do anything for that or am I screwed here? This one has bugged me for a while now, I've got a nice blue Ike in the mint cello with the big blue token and all and there is this huge fingerprint right across his head. I know I'd have to cut it out and all but nobody seems to want it the way it is.
I'm not sure but I think so....some of my coins are stored in a cool place...it is cool all year long and colder in the winter...some of the coins have been in PVC flips for years (not any more though) and they didn't show any signs of PVC.....but then some other coins stored in warmer area had PVC alot. Speedy
Yes, it could be removed if it had only been there for a very short time. But not without doing even more damage to the coin. And if it had been there for any time at all, say a month or more, the coin would likely already be etched permanently. Your best bet with a coin that has fingerprints, toning you don't like - anything at all that you don't like - is not to buy it to begin with. But if you do buy one - then sell it and buy another that you do like.
Usually on the web sites of the companies that make the products. If the products contain no PVC - they will say so. Or they will say something like, archival quality. But it really doesn't need to be. For if the plastics that we are talking about contain PVC you cannot only feel based on the pliability of the plastic - if it's soft and very flexible, it contains PVC; you can also use your nose to determine it. The compound has a very distinctive smell - any plastic containg PVC will smell just like a new shower curtain.
