Wanted to see the damage done by this extreme PVC damage. Was an interesting progression to remove it.
Those pics do a good job of showing how it (PVC residue) eats into the surface. I think most folks have heard about it, are aware of it being bad, but I also think most folks don't really realize what PVC residue can actually do to a coin. Those pics show them !
Thanks Doug, it's always talked about but I have not seen anything that shows what to look for when it's removed.
PVC residue is acidic. It corrodes the surface, just as the OP has wonderfully illustrated. You can't fix PVC damage, but you can stop it from getting worse.
Would you be willing to go into a little detail of what you did and used on each of the four steps or progressions?
I soaked the coin for 3 days in xylene occasionally using a q-tip to remove the black from the plastic residue. On reflection I think a day would have plenty if necessary at all considering the next action. On the 4th day I used a diluted 3 parts distilled water to 1 part e-zest speedip. Dip for a few moments, then rub lightly with a new q-tip, then rinse with distilled water. Repeated until the pvc was gone. I had no intention to try to remove it all in one shot. I also had no delusion of the coin being worth anything more than melt. Really just wanted to see the extent of the damage and remove the ugly residue from the surface.
It would be nice if one who is a person who is educated can explain in simple terms the results. The pictures do give great understanding/views of the results over time as shown in pictures. Thanks for this post.
The whole process is fairly simple from beginning to end. In the very beginning the coin was probably stored in a soft vinyl coin flip, but it might have been any of the many coin albums that have vinyl pages and or covers. But in any event it was something made of soft vinyl plastic which contains a softening agent - that's what makes the plastic soft and pliable. And it's that softening agent that ultimately damages the coins. For those who don't understand the process, have you ever opened a brand new vinyl shower curtain - and noticed the smell ? Well, what you're smelling are the gasses being put off by the vinyl as it degrades. And if you ever open a new package of soft vinyl coin flips, and smell it, you'll notice the exact same smell you do with the shower curtain, and it has the same cause. A lot of folks think it's direct contact between the coin and the vinyl that causes the problem, but it isn't direct contact at all that causes it. It's what you're smelling that causes the problem - the gasses being put off by the plastic. Those gasses then condense on the coin and that condensation builds up over time getting thicker and thicker, until it eventually forms a slippery and even slimy film. In the beginning the film is clear, almost impossible to see, which is why many never notice it at first. But with time the film gains color due to aging, it'll go from clear to a very light shade of green, gradually getting darker green with more time. Then it will probably turn a tan color, and eventually brown as it begins to dry out. And it begins to dry out because there are no more fresh gasses being put off. As it it dries out completely it can turn dark brown, or even black in some cases. And these changing colors are also why some folks don't recognize what they are seeing because most of what you read only talks about PVC residue as being clear or green. Hardly anybody ever mentions the darker colors that are inevitable. The damage that is done to the coins is caused by this film, that when it mixes with humidity in the air, turns into an acid and that acid literally eats into the surface of the coin, it corrodes the metal, eats the metal if you will. To remove PVC residue most folks know of using acetone because it will dissolve the film and wash it away. But xylene will work as well, if not even a bit better it is a stronger solvent than acetone. And xylene does not react with copper as acetone sometimes does. But, acetone, and xylene work best on this film before it dries out. Once it becomes dry and hard, it becomes more difficult to remove, but soaking for extended time helps. But when there's still some present on the coin, then one needs something stronger than acetone or xylene. And that means you need to use another acid, to remove the remains of the corrosion caused by the first acid from the film. And that's what E-Z-Est is, a commercial coin dip that contains acid just like all coin dips do. The acid in the E-Z-Est, when diluted, slowly removes the remains of the corrosion, (think of it as silver rust in this case), and it also removes the grey toning that can be seen on the coin. Once the corrosion remains and toning are gone you can easily see where the acid in the film had eaten into the surface of the coin. That's about all there is to it.
Thank you Doug, a perfect explanation. Monty, No idea, traded a friend brass and lead, for silver coins he had inherited and did not want. They were loose in a case containing a old proof set from the British Virgin Islands. He had an old Colt 380 he had also inherited that I cleaned for him and provided a box of ammo to go with it.
I like your post on this. I have seen this on some coins and some of my own in the past. I have used some of what you have said. Your post was very informative. Thanks! I just have not really checked into it deeply enough.
I would add something here. In the group of pics posted by USS656 in his initial post, that 1st pic, the one on the far left - - just because you see dark and or black coloration on a coin, that does not mean it's PVC residue. It very well could be, and often is nothing more than advanced toning because advanced toning often is of the very same color. The key to recognizing that it is or might be old PVC residue is the blotchy, splotchy, nature of the black coloration. Toning almost never occurs like that ! Or, you may be able to see a bit of flaky looking stuff here and there. Dried out PVC residue has that look sometimes. But toning never does. And the easy test to find out if it is PVC residue is to do exactly what Daryll did, soak the coin in acetone or xylene for a while. And if it is PVC residue doing that will remove some of it, just like in the pics you can see that Daryll posted. And you don't have to worry about doing this because, when used correctly, neither acetone nor xylene can ever harm the coin in any way. That said, if using the acetone or xylene does not remove any of the black coloration, then what you're looking at is not PVC residue - it is toning. And you can know this because neither acetone nor xylene can ever remove toning. It should also be noted that when it is dark like what you see on that coin, a quick rinse in acetone or xylene probably isn't going to do anything. It is going to require soaking the coin for at least 24 hrs, and maybe longer, before you can see noticeable results. And as Daryll explained, sometimes the acetone or xylene just isn't enough to get it all off and you will have to take the same additional steps that Daryll did to remove all of it.
the acetone/ xylene soak may also uncover the now white hard residue created by long exposure, under the black. This residue on this coin was not coming off with the 3+ days of soaking in xylene. While I didn't really want to use speed dip, it was less likely to cause further damage I might have done by working the xylene using a q-tip. By using the diluted dip I was able to better control and significantly speed up the removal of the PVC using the acid dip while reducing the further damage that could have been done by too much exposure to the dip.
Thanks for sharing! I've not seen a good example of this before or what it actually does to the coin underneath.
