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 Replies: 20 / Views: 21,565 |
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Pillar of the Community
United States
1767 Posts |
One month ago yesterday, there was a question about 'preserving coins'
in vacuum sealed bags. I took this opportunity to test this... for I only use the
vacuum method for mailing multiple coins. Please Note: The bag is dated 4/28/07 and it should have been 3/28/07. I am surprise that no one caught this error. This is the before 3/28/07 (4/28/07) This is one month + one day later- 4/28/07 The Washington $ and the cent one month later looks 'foggy' the natural luster is gone. I conclude the the vacuum sealing method is NOT advisable for long term storing. mila_
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Pillar of the Community
United States
1626 Posts |
Great test Mila_cent. Thanks for sharing the results. I agree. The GWD looks a little foggy and even the penny looks a little darker.
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Pillar of the Community
United States
1151 Posts |
The changes may be the results of what the bag is made of. I know they are food grade materials, but what about coin grade materials?
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Pillar of the Community
Australia
853 Posts |
I agree with collect4fun......have you tried milar plastic rather than what I assume is PVC or similar
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Moderator
 United States
6563 Posts |
You gonna keep em in another month? I'm curious to compare all the results.
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Pillar of the Community
United States
2600 Posts |
Be darned if I am putting my spaghetti in there.  Jim |
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Pillar of the Community
United States
834 Posts |
Food bags should not have pvc in them, or at least that is what I was led to believe.
Bruce.
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Valued Member
United States
194 Posts |
Thanks for the results. I unfortunatly learned the hard way not to do this. Not only does it dull them, but the seal a meal bags with the horizontal lines, will leave marks on the coins. And will also fog them up. Unfortunatly I put my proof silver quarters in one, and you can guess how I felt when I took them out. Phoenix  |
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Pillar of the Community
Belgium
2078 Posts |
Food bags are made of polyethylene which means ethylene might be left I have not the foggiest idea what ethylene would do to a coin Generally two plastics are safe Mylar and Acrylic used in Capsules ( there may be others ) http://www.universalplastic.com/food.htm |
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Pillar of the Community
 United States
1767 Posts |
collect4fun, Bigfella... the reason I tested this was because another member questioned about a vacuum sealed bags to preserves their coins. I was not sure if this method was safe for long term storage.
I myself use the vacuum seal method for mailing purposes only. So it got me thinking and I decided to test it since I have this vacuum sealer device.
graceoutcast....sorry to disappoint you but, no. Wasn't planing to continue.
Jim1953...The bags are safe for foods. As I said previously, this was only a test out of my own curiosity when the question was brought up on it's safety for coins.
mila_
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Pillar of the Community
United States
1203 Posts |
From what I've been told and understand about plastics, is that no matter if it's Mylar, Acrylic or plane old polyethylene, they all out-gas to some extent. So actually the vacuum only placed the coins in an invirment that wasn't best for coins.
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Bedrock of the Community
United States
20753 Posts |
More unscientific experiments I presume. To many items left out of these tests. For example what was the ambient temperature inside when sealed and outside during the test? Was it a complete vacuum? Was there any possibility that air filled with moiture and carbon dioxide where on the coins itself when sealed? Exactly what type of plastic was used and how old was the plastic?
The experiment appears to show that something was sealed in with the coins.
I have been putting my Whitman Classic Albums in freezer type bags with as much air squeezed out as possible. I've been doing this for more years than most people have been collecting coins and no adverse reactions of any kind yet. I keep my house dehumidified and my basement even more so. I do not move coins from one invironment to another oftem enough to accumulate foreign substances. Again, none of my coins look any different than they did the day I first got them. Some have been with me for well over 60 years now.
Of course for very long term conditions that may change. For example in another few hundred years my coins may start to fade and if they do I'll let you know.
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Moderator
 Australia
16808 Posts |
It does depend on the plastic used. I know there's one German-based coin dealership, Mietens & Partner, that vacuum-seals the uncirculated coins they sell. I've bought coins that have been sitting in "Mietenspak" wrappers for years, and the coins are OK. They claim on their website to have done lots of trial and error to find the best plastics to use to allow safe, long-term storage. quote:
OldDan said:
From what I've been told and understand about plastics, is that no matter if it's Mylar, Acrylic or plane old polyethylene, they all out-gas to some extent. So actually the vacuum only placed the coins in an invirment that wasn't best for coins.
That's correct, though whether it damages the coin depends entirely on what the gas that's coming off actually is. Acidic vapours like hydrochloric and acetic acid can damage or discolour a coin. 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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Pillar of the Community
United States
891 Posts |
I think there must have been some moisture or something sealed into the bags as others have stated. I have tried this before also. I had some sealed up to a year with no ill effects to the coins. It got to the point it wasn't worth the hassle of sealing them up. One thing I did notice that a few of them had slowly lost the seal after a few months. Hard to get a good seal.
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New Member
United States
48 Posts |
Okay, so what you're actaully trying to say is that this experiment really sucked... |
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Pillar of the Community
United States
7123 Posts |
Mila cent
How about some pictures of the coins once removed from the bag ?
even mint cello makes the coins look hazy,, but when they are removed the coins are fine and the haze is in the cello.
its possible that the plastic having been stretched over the coins is what has hazed not the coins.
If I remember right the vacum bags are not exactly clear anyway!!
Metalman
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Replies: 20 / Views: 21,565 |
Posted 04/29/2007 1:40 pm
