In article ,
"Ron Webb" wrote:

I keep a gallon tin of West Systems epoxy in my (room temperature) basement,
for general purpose use. It usually lasts about 5 years. I have never
noticed any degradation in performance as it gets older. The only change is
that the hardener gets a mahogany color after a year or so, but it still
works fine.

I've got some cheap ($30/gal on EBay) stuff down there now that's several
years old. It's still clear and works fine.


That mahogany color is moisture that gets into the hardener. For best
results, heat it to remove the water -- the water reduces strength of
the bonds.