Re: us composites the cheapest Poly resin???
I have several gallons of resin which came from a defunct body shop over 15 years ago, I just opened one and used it to build a speaker cabinet with no problems, it worked just fine. The hardener which came with each gallon however had all but vanished, it didn't harden, the tubes were empty and brittle as if it had leaked out and evaporated.
The resin was in steel gallon jugs, stored in a pretty dark paint cabinet. It sat on the bottom near the floor, so the temp probably never got very high.
A buddy of mine also has two 55 gallon drums of poly resin that have been in his shed for at least 20 years, I know he used some of that with no problem only last fall. That stuff has frozen, over and over and still works fine. He had more of it but used most of the third barrel to do a new floor in his boat two years ago. I see no ill effects whatsoever. If I hadn't read it here, I wouldn't have ever thought about fiberglass resin having a limited shelf life.
The cans I have are all marked Duro brand and most likely came from an auto parts store. I got them when the shop I worked for closed up in bankruptcy way back in the 80's. I also found a Dixie cup that I had some resin in sitting on the back edge of the furnace, it had been there for at least 12 years, it was covered over in years of shop dust and over spray but the contents were pretty much still liquid, with only slight gelling or thickening, which was most likely due to the dust mixed in. I mixed in some old resin from a tube that survived just to see what it would do and it heated up and hardened just fine. It actually liquefied once the hardener began to heat the mixture a bit, I used it to fill a crack in the shop floor. The price on each gallon can of resin was marked as $4.49, so that may help to tell how old it was. A gallon can now in the local parts store is about $48 per gallon. I haven't checked Wally world, but I don't think the local store carries it in gallon cans. (They recently dropped even carrying automotive paints and even the little touch up paints, I was pretty upset at that since they used to carry an excellent cold galvanizing spray that worked very well.