ORIGINAL: lildiesel
...just putting a new thin disk of cork in the cap every now and then. I've got a collection of pint and quart cans as well and use them for holding the mixes I want to fly with. They're sort of color coded with a coat of enamel so nobody can ever confuse them with the original product. The fuel gets stored in the basement where its cooler than the garage in the summer.
Good idea. Another way to seal the cap (stolen from Eric Clutton) is to put teflon plumber's tape around the threads. I usually buy fuel in quarts, but I save some cans so if I get a gallon I can dispense it into quarts.
George