A little problem resolved

[Kittyhawk]

I was about to ask for assistance with a small difficulty that's been bugging me for years but as I began typing I suddenly realised what it was and how to fix it. Tried it and problem solved. You're allowed to say of the solution 'everybody knows that,' well, I didn't.
The problem is with tins of product which I have for a long time and open repeatedly - specifically in this instance tins of epoxy glue.

I use the glue one or two times a week and always clean the lip of the lid with a rag and the groove of the tin with a cotton bud before closing but after some weeks the lid would get harder and harder to open until it eventually got so stuck on that the only way to open it was to rip it off with a plier which pretty well wrecked it completely. This was starting to happen with the current tin. The problem is caused by repeatedly closing a can by tapping lightly around the lid edge with a rubber mallet to seal it. This makes the lid lip spread a miniscule amount but enough for it to finally bind in the groove on the can. The fix takes only seconds and requires just the lightest nip all around the lip of the lid with a pair of pliers, preferably small ones with smooth and narrow jaws. So I gues its push a lid on a can, don't hit it if you like go reopen it multiple times.

 

[AES]

I have similar problems, also with paint tins. I still tap all around lightly with a little hammer, but before putting the lid in position (but after wiping around the edge and the groove, just like you) I take a piece from a fairly thick poly bag and place that over the top of the tin - with an overlap all around. Then tap the lid in position. I seems to work OK - "more or less".