Fuel tank vent.. Leave open or closed for storage?

I always kept it closed.. However, I had a crack form along the seam on my previous tank.. A couple gallons ended up sitting in the back of the boat for a few days saturating my paint nicely... I'm assuming the pressure had built up enough to cause a stress crack in the tank.. Anyhow, a little more time and money to throw in my hole in the water and will be good again.. Just wondering what everyone else did....

Open unless I have the tank somewhere like in my garage that is somewhat temperature controlled. You'll get major expansion in the heat.

I left the vent closed on my gas can for the lawn mower in my utility building last week and it looked like a giant tomato when I went to mow Sunday afternoon.

Ususally closed, but it makes more sense to keep it open. I always forget to open it and then wonder why my engine doesn't idle after a long run after fishing all day.... Doh! The tank is sucked in pretty good by then.

Will

I always keep my tank empty, I fill it up before going fishing what I don't use I put in the car.

I learned the hard way to keep it open in the summer. I had to replace a tank that wound up looking like a basketball & wouldn't sit right in the boat.

I keep it open with a plastic bowl over the cap to keep rain off.
I learned the hard way too: Closed it one day on the way home from the bay because it was raining. Forgot to open it up.
The next day, it wsa 95 degrees. By time I got home from work, the tank was rigid and the pressure had forced over 2 gallons of gas around the carb cover gasket and through the carb, into the cylindars & out the exhaust. Big puddle of gas soaked dirt under the prop. Luckily it did not damage the carb or fuel pump.

Sounds like we all went through the lesson then..

I went ahead and replaced the cracked 6 gallon tank with a smaller 3 gallon.. Makes it easier to just pull out and stick in the shed at the end of the day.. Shed is climate controlled to 78ºF so no worries of getting too hot...