: Most hardener will color as it ages, not really a problem except
: for the color. If it's to be stored for a long time, it's best
: stored in a metal container (lets no oxygen it, like plastic
: can) and in the dark (uv is bad for even un-cured epoxy) and in
: a fairly cool place. Oh yeah, take the pumps out and put the
: original metal caps on the cans.

: Bill H.

If exposure to oxygen is the problem, perhaps it can be prevented by a tip I read once for preserving paint. Put a puff of propane, which is heavier than air, in the can before sealing. That should exclude the air and the oxygen with it.