I like Rotopax cans for the form factor, although IMO they’re a bit overpriced. I’ve bought all of mine as factory blemished or lightly used so I’ve saved a lot doing that. And I don’t have any of their mounting accessories, just DIY stuff.
This started off with my needing a solid and low profile way to mount Rotopax fuel cans to my roof. It has become for us a versatile crossbar / rack system that gets used on almost every trip. Using the channel strut crossbars we have carried all of the items below, sometimes multiple items at...
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Also, a 2GL one fits perfectly in the wet box.
To reduce the tendency of unvented plastic fuel cans to swell excessively here’s what I do:
I put 3.9 gallons in my 4GL ones, let the fuel warm up (gasoline expands a lot with heat), then cap tightly while pushing in the sides of the can. This minimizes the swelling effect quite a bit. If you acclimate them in this way, they will go slightly concave when they get cold, but it doesn't seem to hurt anything.