Buy some vacuum seal bags, and seal up your graded coins in there if you are concerned about moisture infiltrating the holder.
Slabs are not airtight. They do protect the coin significantly, but are not perfectly airtight. Technically, no storage method of coins is airtight either.
I don't think so. It sucks the air. I have coins that is in a Food Saver bag for more than 30 years and it has never toned. Not so true
https://www.cointalk.com/attachments/15305911011011559630091-jpg.794788/ Here is my British Virgin Island coins and I have never opened them for 30 years.
I agree with baseball, Just because a coin is not toned doesn't necessarily mean it is stored in a 100% airtight environment. I am quite sure that a very small amount of air can creep into just about any common coin storage method.
would not the bag lose its tight fit around items, if air is getting back in? That might be a good indicator of a failed seal.
Think maybe Meow will empty out the large pelican case with emergency food, and put the coins in there. It seems to have a pretty good seal.
Pelican are good storage but no protection from trap air that has moisture. Go ahead and try it for just 6 months.
You will immediately know if the bags were not sealed and when that happens, the machine is broken not the bags.
Oooooh, finding silver quarters CRH feels like such a prize! Finding even one of those really makes Meow's day!
Yea, they are not really worth all that much; But they are so hard to find, it is a real treat to find one.