Heat Sealing Coins And Banknotes In Mylar/Pet Sleeves/Flips

Thanks for your input. Yes, humidity here is quite a problem.

I have a dehumidifier cabinet just for my collection of banknotes and stamps. I put my silver coins in there as well!

I have just order a few hundered mylar sleeves to store my notes, looking for ways to seal and label them.

Well, the issue with PVC is gaseous products getting onto notes and coins. If you heat seal something, I feel it may propagate a bit of gas. I doubt it would be damaging though.

Some places sell food sealer things. That might be worth a try.

I fell in most cases people worry to much about the future of their coins. So much depends on your age. If you are young, naturally you want your coins to look as good as they are now when your old. But then what? If you get to the 70's or 80's, then who are you saving them for? If you have someone to leave your collection to someday, then it may pay to get a bit overboard on coin protection. If not, use the excess money to buy more coins, not piles of stuff to protect them.
I keep allmost all my coins in Albums and then in Zip Lock Plastic Bags. This gets me the ability to look at them and change then as often as I want. Sealing each coin in something makes that difficult.
Reminds me of a car I used to have. Got it new and put seat covers on all the seats. Still looked new when I sold that car. The person that bought that car had kids and dogs in the car all the time. Seats looked like went through a war in no time.