My local paint supplier has cases "4 - 3 liter cans" of Upol rapid cure "marsilla body filler FOR $56.00, I bought a case today and was wandering how long this filler would store? I would like to have more if it would be good for a few years but don't want to buy it if it will go bad pretty fast, Any of you guys have some input on the filler and how long it could be stored?