When storing gas for mowers, etc., should a plastic gas can be sealed or allowed to vent? With E0, I normally loosen the collar to allow venting. However, with E10, I'm not sure that's a good idea, as it promotes water absorption. I believe it's safer to vent, but better for the E10 to seal. If this is just short-term storage of E10 (say, a month), is it fine just to vent the can?
Plastic Gas Can: Seal or Vent?
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I have left a sealed can of E10 in the trunk of the car, out in the sun, etc. The sides bulge but it has never leaked. It is one of the Sceptre cans derided in another thread and currently sold at Wal-Mart. They seal up very tight (I don't even smell gas while it is in the trunk) and withstand pressure inside. There is an approval process for this.
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Why would you want to let the can vent? It might blow up a little bit when it gets hot but when the can cools back down then there's nothing to vent off. By letting all the volatiles evaporate you're seriously degrading the octane of your gas.
You should always seal every gas can. If it bulges, that's great!
Positive pressure will keep bad stuff like moisture out.
There's nothing unsafe about a bulging gas can, they're engineered to take it. Just don't go to extremes like in a 120' building in front of a window, or in the hatchback of your car.
Positive pressure will keep bad stuff like moisture out.
There's nothing unsafe about a bulging gas can, they're engineered to take it. Just don't go to extremes like in a 120' building in front of a window, or in the hatchback of your car.
I use plastic cans non vented. I just bleed the pressure before using. Their stored in the hot Texas garage. Every three months I dump them in my truck and get fresh. I use stabilizer as well.
The EPA requires it not to vent on it's own as of 2009. That is when all the 
y cans started hitting the shelves.
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y cans started hitting the shelves.
Collapsing Gas Cans, EPA Regulations, Why does my gas can collapse
Have you ever gone to use your gas can, only to find that it has collapsed in on itself like the picture above? For some of you, you may think this is a defect and that you got a bad can. You may have even contacted the manufacturer and asked for a replacement. Did you know that this is not a...
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Wow it is news to me that you shouldn't vent even the mower gas can. I have all old both metal and plastic cans. For years I have always put a plug in the end of the spout to keep it clean, but sure wouldn't hold any pressure. The OLD 2.5 gallon metal can I have been using the last few years the large lid doesn't seal up so definitely is vented. And the gas never gives me any problems.
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I've seen the gas can contracting in the winter and expanding in the summer. Never had a problem. If it bothers you, you can equalize the pressure when it happens, but I would keep it sealed.
Also makes it harder or impossible to start a cold engine.
Write or wrong I vent my can’s when stored. I close the vents during transit to avoid spilling. I’ve not seen any issues with my OPE that were a result of venting. All the old gas cans were vented including my favorite can I got from my mom when she sold her house. The new ones aren’t vented for safety reasons.
Just my $0.02
Just my $0.02
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that is what I do also.
Do you think your local gas station "vents" their cans? When you vent a gas can what you will lose are the most volatile parts of the gasoline. The lightest, most easily evaporable parts of gasoline are the most desirable for your engines. Leave a can open long enough and you'll be left with a thick sludge of varnish. Close your cans up tight.
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I never had a need to buy a new one so this is news to me.
I am using vented older plastic gas can from 25 years ago when we bought our first house and keep it sealed although it has a vent hole on one end. I can see it bulging slightly in summer and normal shape in winter . Next time I buy one of these newer EPA mandated-designs, I will be better informed when it collapses with temperature/seasonal change. Good to know.
I am using vented older plastic gas can from 25 years ago when we bought our first house and keep it sealed although it has a vent hole on one end. I can see it bulging slightly in summer and normal shape in winter . Next time I buy one of these newer EPA mandated-designs, I will be better informed when it collapses with temperature/seasonal change. Good to know.
