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 Replies: 42 / Views: 13,526 |
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Rest in Peace
United States
9104 Posts |
Quote:
I've heard recently that the soft vinyl plastic used to make the cardboard 2x2 holders eventually causes PVC damage to the surface of coins. Is this correct? I have rarely seen soft plastic in codbod 2x2s, usually they're mylar, which won't hurt coins. |
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Rest in Peace
United States
9104 Posts |
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I'm curious. Just how do you know those 2x2 flips are PVC. Does it state that on the flips? Is that what the sellers told you? I find it difficult to find that after all the fuss about PVC that any dealer could actually find a 2x2 flip made of PVC. Easy rule of opposable thumb. If you shove the point of a knife through it and it snaps, it's mylar. If it "gives" before breaking, it contains plastic softeners which will deteriorate. Years ago, one company used soft plastic sliders in their albums, but they switched to a hard plastic. |
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Rest in Peace
United States
9104 Posts |
Search gewgil for saf-t-flips
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Bedrock of the Community
United States
20753 Posts |
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If you shove the point of a knife through it and it snaps, it's mylar. If it "gives" before breaking, it contains plastic softeners which will deteriorate.
You are aware of course that PLASTIC is a excessively large variety of products. Actually possibly many thousands of varieties. Some are as you mention and some are not and many are not PVC or anything even close. Some contain softeners and many do not and even those that do not can be made flexible and pliable. Without knowing what the PLASTIC is in a 2x2, it is IMPOSSIBLE to stipulate PVC or not. |
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Rest in Peace
United States
9104 Posts |
Quote:
I could be wrong, but if there is a layer of cardboard and/or mylar between your coin and pvc without the coin coming in direct contact with the pvc, I don't think there is any danger of a pvc 2x2 holder harming your coins. Non-archival codbod contains acid, PVC 2x2s have plastic touching the coin. |
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New Member
United States
10 Posts |
Well, I agree, with a lot of people here, I haven't had any problems with them and it's probably where they are stored and the temps.
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Bedrock of the Community
United States
20753 Posts |
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Well, I agree, with a lot of people here, I haven't had any problems with them and it's probably where they are stored and the temps.
Remember that the method of closing a 2x2 makes them suseptable to air leakage. With air, you also get all sorts of gasses and moisture. 2x2's are no where near air tight but they do come close is sealed on the edges. Many use 4 staples on them to make sure that the coins are sealed well. Also, some place the staples as close to the coin as possible to also help not allowing anything to get to the coins. Yet dispite all such attempts, it is still important to realize that a 2x2 flip is not air tight completely. |
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Moderator
 United States
189117 Posts |
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I have been using 2X2's for almost 40 years and probably over 99% of them have used Mylar windows. Most of that other 1% were even older 2X2's that used cellophane which is also safe. That is my experience as well (minus about seven years). I feel there is often confusion between what is meant by 2x2 and flips, as there is a lot of interchangeable use in the forums. Here are cardboard 2x2s. As far as I know, they have never been made with PVC (but I could be wrong). I have used them long term without any problems. Here are 2x2 flips. Many of them use PVC, but alternatives exist. The alternatives I have used were very fragile and did not last long. I have never used these long term. My only use for them is for holding recent acquisitions (many coin dealers use them for sales). |
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Pillar of the Community
United States
4132 Posts |
It's not just that the construction of 2x2s leave them open to air leakage, so does the material. Plastic is not a perfect barrier to air! Mylar is a much better barrier than most plastics, but some still gets through, slowly. Air-tites are not even air-tight! Ever notice how even metalized mylar balloons slowly deflate, even though they're sealed? Granted, helium is particularly pernicious at going through things, but oxygen will also slowly permeate through plastics (though it's a great deal better than no barrier at all).
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Bedrock of the Community
United States
10635 Posts |
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Non-archival codbod contains acid, PVC 2x2s have plastic touching the coin. Not sure what "codbod" is, but looking at a large batch of 2x2s I recently purchased, they have a cardboard outer surface, but inside is completely mylar, over the opening for the coin and completely covering the edges inside. Then you staple it shut to hold the coin tight within the holder. Are we talking about the same thing here? No cardboard touches the coin... and my original point is, once in this holder, slipping the 2x2 into a possible pvc sleeve shouldn't matter, as it doesn't come in contact with the coin. |
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Pillar of the Community
United States
968 Posts |
JustCarl,
I don't understand why you are so resistant to accepting that there are ways to tell what those flips are made of. It is like saying if you see a coin it is impossible to tell what metal it is made of unless it had the type of metal stamped on it. There are only so many materials these flips are made out of (not COULD be made out of, but are). Even if it is a foreign coin I've never seen before I can be pretty sure it isn't a Uranium, Yttrium, or Erbium coin. The collective experience of countless people that have dealt with the different types of flips while knowing what they are made of (because they have the packages) can lead to some pretty accurate predictions based on experience.
Taking your argument to its logical conclusion would suggest you should never put coins in any type of plastic material because it is impossible to know if it contains any harmful materials.
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Bedrock of the Community
Australia
21788 Posts |
IMO, I think that the Mylar window in 2x2's is so thin that gasses or plasticisers from vinyl album pages will leach through the Mylar, and eventually get to the coin inside. It takes years for this process to be obvious.
That is evidenced by the very gradual blackening of copper coins in such an environment.
What we all need is non vinyl album pages. I think that vinyl album pages are bad news in the long term. They should be banned from long term storage applications.
Museums never store their coins in this way.
Edited by sel_69l
10/12/2011 06:50 am
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Moderator
United States
189117 Posts |
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...and my original point is, once in this holder, slipping the 2x2 into a possible pvc sleeve shouldn't matter, as it doesn't come in contact with the coin. I understand what you are saying and I inclined to agree. I am certain the Dansco 12-pocket 2x2 pages are made from PVC (after all, they are listed as vinyl pages) and I have had no problems with them yet (after about twenty years). |
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Bedrock of the Community
United States
10635 Posts |
Not knowing if Dansco albums (not for 2x2s, but regular albums) has acid-free cardboard is what I'm concerned about... has anyone here read a statement from Dansco addressing this issue? Intercept Shield very specifically states all their materials are acid-free and archival quality... is this true of Dansco too?
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Rest in Peace
United States
9104 Posts |
I would think if it was, they'd be sure to tell people, since that's an obvious selling point.
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Replies: 42 / Views: 13,526 |
First Page
Posted 10/10/2011 7:59 pm
