I noticed something strange about old pvc flips. . .

NYCcollector

Maybe 5 to 7 years ago, I bought a bunch of nice raw white coins, all from the same dealer. Many were in flips, some in regular, pvc-laden flips, others in safety flips. Just today, I got around to putting them in Kointains (I know, I was negligent to wait this long). I noticed something strange. I expected pvc damage from the regular flips. Oddly (thankfully), they all seemed fine. But the safety flips were another matter. Many of them had developed sort of brownish rim-toning. Not unattractive, but unexpected, since I would have thought even these generic safety flips would have provided better protection.

Anybody else ever encounter anything like this?

JohnZ

Yes, but what was the composition of the coins? Copper and and silver are very reactive, gold is mostly inert, and different alloys have different characteristics.

Some darkside compositions, like iron, are impervious to PVC, but highly susceptible to rust. Other darkside coins made of aluminum or zinc have their own share of issues.

lordmarcovan

I've had that happen, though I didn't notice it vis-a-vis safety flips versus soft flips. In my case, the rim toning is caused by sulfur in the air. There are several paper mills around here and their emissions must contain a lot of sulfurous fumes. Sure smells like it. Additionally, there is a lot of sulfur in the groundwater here (I live on the coast, just north of the GA/FL border). So there are a lot of things that could cause that. Cigarette smoke is another cause. While I'm a smoker, I no longer indulge my filthy habit inside the house.

It's interesting that your coins in the PVC flips stayed white while the others didn't, but I'm not sure what to make of that.

PS- John, since he said "white", I'm assuming he is referring to silver coins, though different compositions certainly could react differently.

lordmarcovan

OK- here's a harebrained, totally worthless theory:

The PVC-laden flips are soft flips, right? I've noticed these get really soft when it's hot, and they even adhere a bit to the surface of the coin. Maybe this prevented your coins in the soft flips from toning, just because of that ever-so-slightly tighter fit.

With the inert flips, the pockets stay open a tiny bit more, since the plastic is usually a bit stiffer. This allowed for a little more air circulation and therefore allowed your coins to start to tone a little.

A lot of the silver coins in my detector find album have toning like you mentioned- mostly brownish-goldish and not too bad looking, starting at the edges. A few even picked up some iridescence along the way. These coins are mostly cleaned, as they had to be, after coming from the ground. After a few years in flips, they've toned nicely.

NYCcollector

Thanks for your insights. Lordmarcovan, you may be on to something. Now that you mention it, some of the safety flips had cracked. So maybe it was just that the safeties allowed more air to get in than the pvc flips. (They were silver coins.)

JadeRareCoin

NYCcollector, just because your coins that were in the flips do not show signs of damage, it does not mean that you are out of the woods. If you take a coin out of a PVC flip and then put the coin to your nose, you will usually smell PVC on the coin. That's because some of the oil has leached onto the coin and it will eventually damage the coin. That's my experience and my opinion. Any thoughts from other forum members??

NYCcollector

Interesting point about the ability of the pvc softeners to continue their corrosive work, even after the coin has been moved to a "safer" environment.

Any thoughts about how to handle this? I'd hate to apply anything to these blast-white coins if I didn't have to. I can't smell anything on the coins, but who knows. Would an application of MS70 make sense, or could that compromise the coins?

Conder101

If the coins in PVC were in a very dry environment no damage would occur. The oil has to be able to absorb moisture from the air for the corrosive compounds to form and damage the coins. In the absence of moisture, the oil may just cover the coin an atually help potect it by keeping it away from the air.

As for the saf-flips, I find that many silver coins that I have in the develop rim toning expecially at the opening of the flip becaus the stiffness of the flip holds it open allowing air in. Any "toning ompounds" that enter there react with the leading edge of the coin and are thus depleted protecting the rest of the coin from toning.

NYCcollector

Thanks, Conder 101; that's a helpful explanation. Any thoughts as to whether I should "wash" (with MS70? Some other cleanser?)these coins before putting them in Kointains? Again, these are white coins, with no visible signs of pvc damage, but they have been in regular flips for 5 to 7 years.

NYCcollector

Thanks, Conder 101; that's a helpful explanation. Any thoughts as to whether I should "wash" (with MS70? Some other cleanser?)these coins before putting them in Kointains? Again, these are white coins, with no visible signs of pvc damage, but they have been in regular flips for 5 to 7 years.

291fifth

Because they are stiff (no PVC, a plastic softener) the safety flips allow more air to reach the coins. This allows toning to occur rather quickly.

lordmarcovan

I don't think I'd use MS70, as that would be dipping them.

While I have very limited experience in removing PVC from coins, I have heard acetone recommended.

ccr

This is one that I`ve had for about 25 years and still to this day in it`s original flip that I bought it in. It has a film that covers both sides.

Conder101

I would not presume to advise you what to do with your coins, but if they were mine, and they had been stored in PVC flips for some time, I would give them a rinse with acetone before I stored them away.