Epoxy won't set up

[Jeff]

I'm baffled so I need some help and solutions.

I used some Loctite 60 minute epoxy to fill some knots/cracks, etc. I thought that I was pretty close on the recommended 1:1 mix for the epoxy/hardener. However, after 2 days the stuff is still pretty tacky and soft (it'll take a FBI fingerprint). There's no way that it can be cut with a card scraper 'cause it's still too gummy. :help:

I've used it before without any problems so I'm wondering if our NC humidity is having some role in it not curing properly. As a chemist I don't think that there should be any effect on the polymerization process.

What do you folks think and what would you do? I'm gonna use Waterlox as the finish coats so maybe I should just proceed. :dontknow:

 

[DaveO]

How old is the epoxy and did you make sure you mixed it very well? I don't think the humidity would have anything to do with it curing, I believe that is a chemical reaction. If anything the warmer temperatures would have increased the cure rate.

Dave

 

[froglips]

Second what Dave says.

Odds are its old or was was exposed to heat. Some suggest storing epoxy in the fridge.

I've had the same thing happen and the glue never set up.

You should be able to remove it with a solvent. DNA or Acetone. Or, depending on where it is, heat.

Jim

 

[Gofor]

I haven't used the 60 min stuff, but have had good luck with the quicker cure Loctite epoxies, and have used them even in 80+ % humidity. Maybe one of the components is starting to go bad. You did not use lacquer thinner for clean-up, etc, did you? The fumes in lacquer thinner sometimes have negative affect on epoxy hardness and cure times. MEK is better for clean-up. You'll probably have to dig out at least the top layer and redo.

Go

 

[Bas]

I'd clean it out with a chisel/ knife/ awl whatever, and start from scratch. It's a pain in the rump because you lose yet another day, but otherwise it'll come back to haunt you.

Also, I've found that if I mix the epoxy with some sawdust or color filler (like coffee grounds, or cocoa powder) it hardens better.

 

[Sealeveler]

The only problems I have seen with epoxy not curing are not mixed enough,wrong ratio,been frozen or water in the mix.Tony

 

[Jeff]

Thanks folks. Looks like I've got to regroup and redo. Not a big deal, just inconvenient at best. :BangHead:

The Henkel Co. (Loctite) website info reads like this stuff is pretty forgiving: No expiry date listed, store below 100 Fahrenheit. Clean-up with mineral spirits, alcohol, acetone or MEK.

I think I'll pick up a handful of plastic spoons and use them to make sure that the mix is pretty darn close to 1:1 and take extra care to ensure thorough mixing. :slap:

 

[Bas]

I think I'll pick up a handful of plastic spoons and use them to make sure that the mix is pretty darn close to 1:1 and take extra care to ensure thorough mixing. :slap:

Harbor Freight sells a digital pocket scale, perfect for measuring things like epoxy. With a coupon you can usually get it for around $5-$7. I use the small Dixie cups for mixing.

 

[dkeller_nc]

Jeff - One thing you might consider doing is bailing on the epoxy altogether and going to mixture of Titebond III and sawdust. The advatage to the titebond III when filling cracks and checks in walnut is that it dries a fairly dark color (much darker than the glue in the bottle). Not only will it cure without fail, but it then will sand, plane and chisel very easily. You can also add drops of aniline dye to the mixture - the sawdust will take it up, and allow you to choose what color you want for the filler.

 

[CarvedTones]

I would never refrigerate epoxy or hardener. As far as thickening it goes, silica is probably best but if you have to use something from around the house, talc (baby powder) is best with sifted fine sawdust a very distant second, IMO. I mostly use the 2:1 ratio stuff that needs a day to cure and it is pretty forgiving about being slightly off one way or the other in the mix. I usually eyeball it in a graduated cup and don't have problems with it.

Humidity does have some negative effect.

 

[BumoutBob]

It might be the epoxy

I have the same problem with the same epoxy. I glued a column together with it several days ago and the remainder on the card is not absolutely dry yet. I got mine from Ace Hardware here in Hendersonville a week ago. Humidity has been up, but so has the temperature. I have used the 2000lb type in the same sort of applicator and did not have this type of problem.HMMMMM!!

 

[Jeff]

Thanks again for the input and suggestions.

I ended up taking a putty knife and easing off the surface crud. Then wiped it liberally with denatured alcohol and elbow grease; it came out pretty clean. Then a few quick swipes with a card scraper. So far so good. The Waterlox went on fine, but I'll know more tomorrow. Will see how the 2nd or 3rd coat come out with a little light 220g sanding along the way. :evil:

Nothing ventured nothing gained eh? :dontknow: