View Full Version : Goop Shelf Life?

04-12-2009, 04:26 PM
So I just found some MAS epoxy and hardener that I never opened. I bought the stuff in in September 2002. Is it usable or should I go with fresh stuff to avoid wrecking a project?

The labels say something like, "at least a year " or something to that effect.


04-12-2009, 04:33 PM
Should be ok if well stored and kept sealed. Check for crystals (white layer on bottom) of epoxy jug. If crystals are present, warm the epoxy to dissolve them. ( see the thread on cleaning epoxy pumps for Ray Frechette's comments)

Make up a small test batch if in doubt to make sure it will cure properly under normal conditions.

04-12-2009, 08:46 PM
You may find that the hardener has darkened, but i've had OK luck with old hardener of other brands. A call to the manufacturer would be a good idea.

Frank Wentzel
04-13-2009, 02:56 PM
Epoxy has an almost indefinite shelf life. I have epoxy that is as much as 30 years old that still kicks over just fine. The failure mode, if epoxy did go bad, would be that it would harden on standing without hardener. In other words, if you can still pour it, its still good.

/// Frank ///

04-13-2009, 03:36 PM
It must be good.....whenever I mention that I'd like to borrow baby brothers garage to build another dink I still get some very un christian remarks made ....something about the stuff that I stuck to the floor last time is still there as discoloration, even after grinding it smooth...and it's been a couple of decades....and BIL used some T-88 that was at least 25 years old and it still worked....and I forgot about it. It was stored in the root cellar, dark, cool.....

04-13-2009, 03:55 PM
MAS purchased here in 2004 is fine. Hardener is darker. Mix a 1 oz test batch first.

04-13-2009, 04:45 PM
Good to know My gallon of WEST is about 6yrs old.

Rich VanValkenburg
04-13-2009, 04:48 PM
I have about 2 gallons of resin left that has gone through several(many) freeze thaw cycles and it's still good, reacts the way it's supposed to with hardener. I'd left it in a garage shop that wasn't heated unless I was in it. Even the hardener seems to be ok. I check for that ammonia smell when you mix it. If that isn't there then somethings wrong.