On Nov 9, 6:09*pm, trvlnmny wrote:
I do not use polyurethane glue or cyanoacrylate glues very often. When
they are new and I use them they are fine.
What I have a problem with is when I go to use them again at a later
date and they have gone hard.

I've had good luck storing CA glue in the refrigerator.
Polyurethane is catalyzed by hydroxyl (i.e. is water sensitive)
just like most silicone RTV adhesives, and should (I have only
tested with silicones) last longer if you seal the bottle inside
a (for instance) paint can with some dessicant. Maybe even
just a coffee can with a good lid...

By 'dessicant' I don't mean wimpy silica gel, use CaSO4 or CaCl.