Originally Posted by john491

My thoughts would be that it was possibly fortunate that there was a small leak, it may have prevented damage to your storage can. If you have been storing where there are large differences in temperature the can swell and contract if there is no vent ( assuming the storage container was not completely full). Also if that was the only thing venting air into your storage, it is unlikely you moved more than a cubic inch or so of air back and forth, so not much water vapor in there.
If in doubt, filter the fuel into a new container then back through a Mr Filter to remove any remaining water, add fungicide.
John

Originally Posted by john491

When there is a significant volume of air above a liquid, the air will expand or contract significantly more than the liquid, which has no significant expansion as far as this kind of storage. A vent or small leak prevents this. You indicate you are about 2/3 full. I would expect there to be some venting of the air as temps increase, unless stored inside of course. I keep my fuel in the garage which can experience a 20 deg change in a day. I have seen my tightly closed cans swell when capped too tightly. They are polypropylene so flex fairly well, but metal container rolled joints don't like changes in internal pressure. Not a problem if the storage is kept mostly full (ie 90% +).
My biggest concern is leakage if the can were to be turned over.
John