I know quite a few people stash unopened rolls and bags away long-term. But as I've recently discovered, they are most definitely NOT safe storage.
Rolls not only have exposed ends, but the paper itself is permeable, and the coin edges WILL corrode, then it will spread onto the faces of the coins.
Ziplock Bank bags, while safe (they're made of LDPE - Low-Density PolyEthylene, marked as recyclable category 4) all have holes in them to allow air to escape. Which also allows air to enter, of course. :(
Security Bags, also made from LDPE (but modified to tear easily in one direction), have a cut through the seal which allows air into the bag.
Therefore all these require additional protection to prevent the contents degrading over the years. The best way is to heat-seal the bags or rolls into LDPE bags. Coin bags will do, just make sure there are no holes for air to enter. You can gently align coins inside a sealed bag to align the coins into a roll. Alternatively, you can seal them into the large LDPE sacks which Armaguard uses, in which case you can just toss them in as they are, without the need to align coins.
The CoinSafe sacks which you can get from most banks are not safe, because they don't seal properly. They're designed to prevent tampering, not exclude air. So if you use these you do need to heat-seal them as well.
And of course calico sacks are not safe either. Air will circulate quite freely through them. Anything you store in these sacks should be sealed first.
I wonder if you put the rolls into a Mylar banknote slip and then heat sealed it would be a good idea. :angel:
Quote from: 'trout' pid='36439' dateline='1386367421'I wonder if you put the rolls into a Mylar banknote slip and then heat sealed it would be a good idea.
Any of the safe plastics are fine. LDPE, HDPE, PP, BoPET (Mylar) or whatever. The main reason for using LDPE is its very easy to get, and free. ;)