5-minute epoxy problems

[Porter Bassett]

I epoxied some stuff last night with 5-minute epoxy. Many hours later, it's still sticky (although a lot less so than it was when I went to bed after a couple of hours last nigh).

Why might my "5-minute" epoxy be lying to me?

[Michael McCoy]

I don't use epoxy much but low temps or old age on the glue might be factors.

[Porter Bassett]

Do you reckon it will eventually harden on its own if I just let it be?

[Bob Slater]

Trying putting it under a lamp might help. Probably past its best before date.

[Michael Faurot]

It could be any of the aforementioned issues, plus the brand. I've had similar problems with epoxy made by LocTite.

[John Schreiber]

If it's in a cold place, it won't cure properly. Moving it to a warm place will help if that's the problem.

If that's not the problem or that solution doesn't work, I'd start scraping it out and start fresh.

[Larry Edgerton]

West System Epoxy.

That is all you need to know, as they will send you a manual when you order their product, and the manual is backed by the best techs in the business.

Hardware store epoxy is for housewives.:)

Temp is very important, did you read the minimum temp on the package? You need to keep that temp up until it is fully cured, not just until it doesn't stick to your fingers. You can not be too far from recomendations or cure times are affected. Keep in mind too that the faster the epoxy the less strength it has, so fast is not always better.

[Dewey Torres]

I am very surprised no one questioned the mix. With any epoxy the mixture of part A to B is very important. Curing problems can be caused by not mixing thoroughly or not using the correct portions of mix. Having said all that it may very well be the temp ...just wanted to point out another possible cause.

[Ken Higginbotham]

My guess is the shelf life expired... What is it generally about 6 months?

[Chris True]

In 20+ years I've never had a shelf life problem, if it isn't crystalized in the bottle it's always cured for me. The mix ratio is important but there is a pretty large degree of tolerance there. If it is supposed to be mixed 1:1 1.1+:1 still cures with a loss of some strength. Cold is the biggee - needs to be around room temp. @ 30-40F it'll take a week to cure.

Even if cold wasn't the issue the first thing to do to solve the problem is get the temp elevated to 80+ for 5 or 6 hours and it may well kick off.

[Ken Higginbotham]

I've had some the didn't harden completely, not sure why. But it was probably more than several years old. Based on this:

Link (http://www.crosslinktech.com/FAQ.htm#What%20is%20the%20typical%20shelf%20life%2 0of%20Epoxy%20and%20Polyurethane%20compounds)

And my experience I was guessing 6 months. It could just be the temp -

[Alan DuBoff]

You sure you mixed it properly? It's 50/50 of the 2 parts.

Should set up in 5 minutes.

[Benjimin Young]

I epoxied some stuff last night with 5-minute epoxy. Many hours later, it's still sticky (although a lot less so than it was when I went to bed after a couple of hours last nigh).

Why might my "5-minute" epoxy be lying to me?

Some epoxies require a little cook time in the mixing tub before being applied although this is not usually the case with a 5 min. The following will not fix your problem but may help to determine what went wrong. If you have some epoxy left, mix two small test batches being really careful to 1) keep the proportions to manufactures specs (not always 50/50), and 2) throughly mix the two parts. Now glue two scraps together with the 1st batch. Wait 2 minutes after mixing the 2nd batch and glue another test together. See if one performs better than the other. If they both do not harden I would guess bad epoxy. If they both harden fine then your original problem was bad mixing or not 50/50.

[Doug Shepard]

I've had problems a number of times with 5-min epoxy and I'll never use it again. Since since taking the plunge with West epoxy a while back, I've never had an epoxy problem.