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 Replies: 7 / Views: 1,996 |
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Valued Member
Canada
403 Posts |
I acquired a bunch of silver PL sets (1961-67) in original pliofilm packaging, which were housed in plastic binder sleeves for (presumably) many years. The plastic sleeves housing the sets had all discoloured to yellow, and the sets were actually stuck inside of the plastic sleeves. After destroying the plastic sleeves to free the PL sets from their housing, I noticed the pliofilm surfaces on each set was very sticky. Not sure if anyone has experienced this, but I'd like to clean the surfaces of the pliofilm to remove the sticky substance, but I thought I'd query the forum for advice before proceeding since I'm concerned about a watery/soapy solution (or moisture thereof) inadvertently finding a way into any of the PL sets' individual coin pockets. Thoughts?
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Pillar of the Community
Canada
1747 Posts |
well, if the coins show any significant toning, you will know that they pliofilm is compromised. if there is no toning, I would say a mild soap and warm water, using a soft towel, and drying it after.
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Valued Member
 Canada
403 Posts |
Thanks Ace, that's kind of what I was thinking too. No silver has toned, but the 1¢ has some mild toning on 3 of the sets.
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Pillar of the Community
Canada
1747 Posts |
just be careful not to drown the coins
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Pillar of the Community
Canada
3733 Posts |
is there a smokey smell to the coin sheets. I would say it is environmental damage.most likely smoke, but yes a soft detergent applied to a cloth, test on a corner edge first , just to be safe..
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Pillar of the Community
Australia
7096 Posts |
I would think a soak in acetone would be the best approach to this problem  |
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Valued Member
Canada
403 Posts |
Silverwolf, there's no smokey smell whatsoever. I will try the detergent & damp cloth approach, carefully.
Failing that, perhaps Trout's suggestion will do the trick ;)
Thx all!
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Moderator
 Australia
16829 Posts |
Quote:
I would think a soak in acetone would be the best approach to this problem Assuming you want to make all of the plastic go away (including the pliofilm), then yes, I'm sure this would solve the "problem".  Acetone has a tendency to depolymerize plastic. If you want a spectacular demonstration of this, splash a few drops of acetone onto a block of styrofoam. Do NOT use acetone on any plastic object you intend to keep. Seriously. That being said, I'm not entirely sure the pliofilm is going to be saveable in this case. What we've got going on here sounds like solvent transfer. You may have experienced the phenomenon whereby a coin in a 2x2 sitting in a PVC album page gets "stuck" and needs to be prised out, usually destroying the plastic film of the 2x2 in the process? The same thing may have been happening here. Solvent transfer can happen when two pieces of plastic, one heavily plasticized (the album page) and one not (the pliofilm or 2x2) are held together for prolonged periods - especially if pressure is applied (such as being placed into an album and then have heavy things stacked up on top of the album). Plasticizers and other entrapped solvents inside one of the plastics cross over and infuse into the other plastic. The surface of the second plastic is permanently changed, and no amount of "washing it" with anything is going to make the now-embedded plasticizers go away. Personally, I'd take the coins out, throw the pliofilm away, and be thankful that the plasticizers hadn't diffused all the way through the pliofilm to attack the coins. Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Replies: 7 / Views: 1,996 |
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Posted 06/08/2015 2:41 pm
