On Sun, 13 Dec 2015 10:33:02 -0700, Don Y
wrote:

It "keeps" well enough (as in, retains it's effectiveness).
It just doesn't "stay inside" the container (toothpaste-style
tubes). Particularly the hardener.

Tubes were opened a little less than a month ago. Hardener
is noticeably "soiled" on the outside (yes, I put the caps on
tight).

As adhesives go, the epoxy based stuff seems far more robust than most
after you open it. poly urethane glues like Gorilla glue will go bad
in the factory sealed container and once you open the clock is
running. The same is true of silicone sealants

I've always praised JB Weld. It fixes a lot of stuff, and has always
held up well.

However, I can not offer as much praise for their company. Some years
ago, I wanted to coat the entire bottom of a metal livestock tank which
was rusty. Those tanks are costly, so it was worth doing. I bought 5
tubes of JB Weld at a local farm supply store. Apparently it had been on
the shelf too long, and was very stiff and hard to get out of the tube.
In fact it was so hard, I had to press down on the tube with my shoe to
get it out. Then it was very hard to mix and to spread. After using 3
tubes, and cussing the whole time, I bought several more tubes elsewhere
and that worked fine. I tried to return the 2 remaining tubes to the
farm store, and they told me they said that it "cant be bad", and
refused to give me my money back.

I called the JB Weld company, and offerred to mail them the unused tubes
and those I had used too. (after explaining the situation). They told me
I would not have to mail them, and that they would send me 5 new tubes.
That was 4 or 5 years ago. I still have not gotten them in the mail.