Devcon 5-min Epoxy Doesn't Fully Cure

It doesn't happen all the time, but fairly often it stays pliable and I have to re-do the joint - which can be a messy proposition.

I normally do the mixing on a small sheet of Teflon. Days later, when I peel the leftover epoxy off, it's still gooey underneath. So it seems like I'm not getting a complete cure.

Most of the time, I need only a tiny amount, so I thoroughly mix a small dab of hardener with a small dab of epoxy. It's not perfectly half and half, but I come as close as I can. (Is 50 -50 really the best ratio? Or should I be using more of one than the other?)

When I first started using epoxy, I thought I wasn't mixing the two components enough. So now I go to some effort to mix them completely, but I stilll have the problem.

Ddms

If your having issues w/ it not hardening, I'd be inclined to include a little bit more hardener than catalyst. Just be careful b/c it could dry quicker than you expect.

I use the same Devcon 5 min epoxy all the time, never had any issues. I always try to mix 50/50 ratio and it comes out perfect. If there isn't enough hardener, it will take longer to cure, but we are talking a matter of minutes, not overnight. If yours doesn't cure by the next day I'd say your way off on the ratio or you have a bad batch?

Yesterday I used a bigger dab of hardener. I clamped the joint just in time - it got hard in about three minutes!

That's better than it not hardening at all, because I can just mix up a new batch right away, instead of discovering a day later that the joint is still soft. So I'll continue using just a bit more hardener.

There sure is a lot to dislike about epoxy, but it does make a stronger joint than anything else.

Ddms