Epoxy Still Tacky

cliffg · Post by **cliffg** » Wed Dec 06, 2006 3:31 pm

About 3 weeks ago, I mixed up some epoxy to coat the deck core where my new scuppers will go. I am using the West System pumps. It was just over 60 degrees, but it was kind of late in the day so it didn't stay 60 for long. Since then we have had days that are well over 60. The thing is my epoxy is still tacky. Might I have mixed it wrong or weather too cool?

any thoughts would be helpful and any suggestions as to how to fix the tacky stuff now.

Post by **Tim** » Wed Dec 06, 2006 3:59 pm

If it's still tacky after 3 weeks, whatever the temperature, then you have a bad batch for sure.

One thing about those mini pumps is that if they sit for a while without use, the first few pumps may not dispense the proper metered amount. Sometimes, this can lead to a bad mix.

A common mistake is to mix the epoxy with what you think is a 5:1 ratio--that is, five pumps of resin to 1 of hardener. But with the mini pumps, the ratio is built into the pump itself. So for the proper mix, you pump one pump of resin and one pump of hardener, or 20 of resin and 20 of hardener, or 7 of resin and 7 of hardener; you don't have to divide by 5. The pumps do this for you. Might this be what you did?

Fixing the mess is a matter of grinding, scraping, and solvent-washing out the uncured stuff. Hopefully, you're talking about a small area only!

Quetzalsailor · Post by **Quetzalsailor** » Wed Dec 06, 2006 4:53 pm

The West instructions are pretty clear about temperature and cure times. You might have had too low temperatures overnight as well as whatever silly errors enumerated above. My recent error was in mixing use of the white handled pumps with the yellow handled pumps; actually not really my error-who'd have been so unhelpful as to make that change?

I'm now making doors for our house and am using my collection of old, discolored hardeners. The (shower and laundry) doors will be encapsulatd and painted so color is not an issue. The stuff hardens justs fine and our basement is above 60.

Your last gasp before grinding and cleaning would be to put the mess under heat and see if you can drive the cure to adequacy.

Quetzalsailor · Post by **Quetzalsailor** » Wed Dec 06, 2006 5:22 pm

I failed to add comments about the West pumps. They tend to unscrew at the lid and the bottom portion falls into the goo; make a habit of always turning things to the right. The extensions tend to split; periodically check them (you will suck air when the goo level drops below the crack). Beyond that, I've had a little trouble with goo hardening and plugging the spouts, particularly on the hardeners. I simply rod out the plug with a nail and stroke the pump to be sure I don't have any air in it anywhere. If, when pumping, I get a significant bubble, I take a short stroke estimated to make up for what did not come. Errors in counting are easy; more intended strokes tends to reduce the error (missing or misestimating one stroke in three is worse than one in ten). I' ve tried cleaning the pumps: fugeddaboudit! West tells you to do a trial mix of suspect components. I've never liked to waste their gold and have never had a failure caused by old stuff; four or five year old hardener is fine. Smell it; if it prickles the nose like fresh stuff it's still fine.

MikeD · Post by **MikeD** » Wed Dec 06, 2006 9:30 pm

Tim wrote:A common mistake is to mix the epoxy with what you think is a 5:1 ratio--that is, five pumps of resin to 1 of hardener.

Cliff, if I were a betting man... It sounds exactly like the problem I had this summer.

Here's the gory details. It starts about three entries down around the "Oh oh!" one on August 27...

Ariel 414 Blog

The up side is, it wasn't too bad to remove, since you've basically got a bunch of 25:1 resin goo on the area. I scraped off what I could, then wiped the remainder off with acetone. Not a happy or proud day to say the least.

Post by **dasein668** » Wed Dec 06, 2006 10:26 pm

MikeD wrote:a bunch of 25:1 resin goo on the area.

Oof. I remember you bringing this up back when it happened, but ouch! Reading 25:1 ratio really puts it in perspective! ;-D

MikeD · Post by **MikeD** » Wed Dec 06, 2006 11:32 pm

Um, yeah. Darn, I was kind of hoping no one had noticed. :)

cliffg · Post by **cliffg** » Thu Dec 07, 2006 12:00 pm

I must be a bad batch, I did remember to use one pump of epoxy and one of hardener. I will check the pumps because they might be not functioning properly. Oh well at least it wasn't a big batch. The week before I had mixed up a big batch with thickener in it and did some more work on the deck, that worked out fine.

Thanks for all the help.

Columbia34 · Post by **Columbia34** » Thu Dec 07, 2006 1:14 pm

Call west system and talk to there Tech dept. they are great and 100% dedicated to making sure there product works as they say it does. 866-937-8797 I have always talked to Jim Deriks. They will probaly ask for the Batch numbers off the cans, so they know when and how your exact material was made. There should be a sticker on each can.

Scott

A30_John · Post by **A30_John** » Sat Dec 09, 2006 12:04 pm

If your epoxy is "tacky" that sounds different to me than a 25:1 "goo." I guess it depends on your definition of tacky, but I'd be surprised if a 25:1 mix ever reached the tacky stage.

I've had epoxy take weeks to fully cure in cool temperatures. If I were in your situation and thought that I had mixed the epoxy correctly, I'd put a tarp around a sample area and run a heater under it for a day. Run it at 80-90 degrees and see what happens.

Quetzalsailor · Post by **Quetzalsailor** » Mon Dec 11, 2006 10:16 am

Well, after my first previous post, you (and I!) would nor think I'd do this but I managed to mix uses of the white and the yellow pumps again! And there is no information I found in the pump instructions that would let me know whether the result was over or under catalyzed.

First batch was fine (matched pumps). Second batch with a different hardener was applied before I remembered the issue. Third batch I gave it 1/6th more hardener, having noticed my mistake and scurried to try to find info before the first batch went off w/o clamping. I finished my assembly and wrapped the clamped pile with a sheet, stuck a heater under and it appears, 24 hours later, to be acceptable.

I have gone through my 15 years' collection of West and tossed all the white pumps so I will have to be stupid some other way!