Epoxy shelf-life and temptation

[tijos]

I've got some half full cans of epoxy resin and hardener that date back to 2001 and am thinking of using it to laminate some paddles.

I've tested it on scrap and it still seems to work fine.

Any of you had experiences with old epoxy that seemed fine at first but then deteriorated in some way?

Am I just asking for trouble?

[AlanWS]

It should be fine. Check to make sure the resin has not crystallized (you'd see solid at the bottom, and if there you can fix it by warming until it dissolves) and the hardener has been closed properly to prevent soaking up crud from the air (it would likely have darkened significantly, which would not be a problem in itself except for color, but would indicate air exposure that might have allowed take up of water and CO2 over time, which could cause some problem. The other risk of old epoxy is that you might forget exactly what ratio of resin to hardener to use for that particular epoxy. You need to have that right.

[Jim Dodd]

I've used old epoxys before, for small things.

Usually the hardeners darken with time.

Some resins seperate, and leave crystals in the bottom. Carefully heating these up by setting the jug in very warm water has worked for me.

The biggest difference I notice with old epoxies, is the pot life is shortened.

I think for paddles, it should be fine !

Good Luck

Jim

PS. this experience is based on System Three resins

[tijos]

Thanks guys, I'll give it a shot.