Etex set hard in 10 minutes

[oscarsteel]

I have been useing etex for a long time with almost no trouble. I tryed putting some polyester glitter in my final coat the other night. I may have added to much because when I did I guess it caused a chemical reaction of some kind. The cup I mixed it in became so hot I had to put it down. Then in about ten minutes it was ruined. It set hard in 30 minutes. Has anyone here had this happen before? I have used this glitter before with no problems in less amounts. I was going for a heavy glittered bait and I got a mess instead.........Oscar

[mark poulson]

Weird!

I'd love to know why that happened.

Try emailing the Etex tech support people. Last time I had a question about their epoxy, the woman who replied was both knowledgeable and helpful.

[mark berrisford]

i've had e-tex go off quick but on that occasion i'd warmed it up to much before mixing which seemed to accelerate the curing process so now i very rarely bother to warm it

[mark poulson]

That makes sense. It's a chemical reaction, so heat should speed it up.

Maybe a double boiler ice bath will extend it's working time in the summer.

[BobP]

Oscar, sounds like you found a quick cure polyester hardener for Etex. I'm guessing the Etex solvent broke down some of the glitter and did just that. Epoxy generates heat while curing. The larger the epoxy mass, the more heat is retained and the faster the cure. That's why spreading epoxy on a flat surface extends its work time - the greater surface area allows the heat to radiate off faster, slowing the cure.

[mark poulson]

Ah, so deska! Thank you, Sensei. I'll be spreading my Etex onto a flat, taped surface from now on.

Oscar, sounds like you found a quick cure polyester hardener for Etex. I'm guessing the Etex solvent broke down some of the glitter and did just that. Epoxy generates heat while curing. The larger the epoxy mass, the more heat is retained and the faster the cure. That's why spreading epoxy on a flat surface extends its work time - the greater surface area allows the heat to radiate off faster, slowing the cure.

[RiverMan]

If you get it too warm this will happen. Take some etex and put it in the micro for 20 seconds, pull it out and you will have a diamond! lol

[philB]

i've had e-tex go off quick but on that occasion i'd warmed it up to much before mixing which seemed to accelerate the curing process so now i very rarely bother to warm it

Exactly the same here. Too many mins in the micro and voila rock hard.

[philB]

If you get it too warm this will happen. Take some etex and put it in the micro for 20 seconds, pull it out and you will have a diamond! lol

Does this mean if I put a drying wheel in a microwave I can finish the top coat in seconds rather than 24hrs+ ???

[csob3]

You may have let the etex sit in your mixing cup for too long. If you let it sit still in the cup for 5 min without mixing then it will harden immediately. Etex must breathe in order to slow curing time. Not too sure if it was the glitter?

[mark poulson]

You may have let the etex sit in your mixing cup for too long. If you let it sit still in the cup for 5 min without mixing then it will harden immediately. Etex must breathe in order to slow curing time. Not too sure if it was the glitter?

Oscar,

That's interesting, and not my experience.

I usually mix my Etex, and then let it sit for five minutes to be sure both components have mixed thoroughly, and that most of the air bubbles are gone. I've never had it set up in the mixing cup, but I've had to hit it with a hair dryer during the coating process, if I'm doing multiple lures, because it did start to get a little stiff.

Maybe there are other variables at work?

[csob3]

Maybe you are right? It may be 10 minutes before it started to sit. I left my etex in the mixing cup untouched for about 10min and it hardened immediately...didn't know why but I haven't chanced it since. Maybe it is the mixing cup I was using. I use polyester glitter too and have never had a problem. Weird deal...

[mark poulson]

I don't think I've knowingly used polyester glitter, but that may be what's in the Krylon spray glitter that I use. I've just never had a problem, at least not so far! Knock on wood.

[oscarsteel]

I think now it wasn't the glitter. I have done some baits with it since and not had any trouble. When it done blew up on me I had a full cup for doing a bunch of baits. I think the amount had more to do with it. It could not breath the way it should. I think I will only mix small batchs from now on. I like to fill up my drying wheel when I coat them. I guess I should have made my wheel hold ten baits instead of twenty.

Thanks for all your opinions. I know where to go for good informed answers. :worship:You guys are great. I really appricate all the help.....Oscar

[mark poulson]

Twenty baits! Man, you are ambitious!

I only mix up enough to do four or five jointed lures at a time.

Here's something I thought of when BobP mentioned that heat sets off epoxy.

I know from personal experience that the epoxy cures more slowly in colder weather. In the winter, I use a hair dryer to make my Etex flow more easily.

You might try putting ice cubes and a little water in a larger dish, and setting the epoxy mixing cup into the ice water, to slow down the rate at which it goes off, while you're coating that many lures, to give you more working time.

If it's too stiff, you can hit it with a hair dryer once it's on the lure, to soften it up and make it more spreadable. The ice bath should keep the mixing cup stuff from going off while you're using the HD and brushing out the lures.

Try it once with a small batch to see if it works first. I've never done it myself.

[Downriver Tackle]

I've been formulating paint and coatings for about 15 years. I can guarantee you that ployester flakes are fine. I've used automotive effect pigments cast on polyester films in 2 component epoxies and urethanes, and never seen a reaction. Theoretically and chemically, it's almost impossible.

Honestly, from your description of the heat generated, it wasn't the amount you mixed either. Though, I probably would mix less, as recommended. My theory is that the part A wasn't mixed thoroughly by the manufacturer and you got a shot with excessive accelerator in it. There's an additive we put in the part A of epoxies which controls how fast it cures/reacts. I can make it cure in 10 secomds if I want, or leave it out and it takes hours. It's used in such miniscule amounts, that if not mixed in properly, it can have the same effects you experienced. And when it's used in higher percentages, it does generat tremendous heat. I've melted polyethylene mixing cups when I made a super-fast set epoxy sealant.

[oscarsteel]

Thanks for the info downriver. That may be what happened. I use polyethylene cups for mixing and it didn't melt but it was close to it. I have been using the same bottles of etex with no more problems....Oscar

[mark poulson]

Downriver,

Do you think the accelerator might separate out if it's stored in the heat, like my hot garage?

I now mix my Etex on flat masking tape on my work bench, so I can match the sized of the blobs of resin and catalyst before I start mixing. The more I want to mix up, the wider the tape section I lay out before I start. Masking tape is cheap and easy to peel off and throw away when I'm done, and that way I don't have any unmixed areas, like can happen in the bottom of mixing containers.

I tend to mix really thoroughly, and then let it sit for a few minutes before I start coating. I don't think mixing would make up for a bad batch with too much accelerator, but I've had spots that didn't set up before, and I think it was becuase I didn't mix it enough.

Are Envirotex and Devcon 2 Ton different kinds of epoxy? BobP posted that D2T is sold as a glue, and I know Etex is sold as a bar top coating, so I just wondered if they were different in their chemical makeup.

[rofish]

Mark,

You said you have worked with wood all your life.

If you use masking tape to poor the 2 epoxy components on, for a perfect 50/50% mixing, that's OK, but then it is difficult to mix them on a flat surface.

I would make a kind of hole into a piece of wood, with the shape of, let's say, one third of a sphere, then after having the right quantities on the piece of masking tape, I would transfer that piece onto the hole, for a better and easier mixing.

[Downriver Tackle]

Downriver,

Do you think the accelerator might separate out if it's stored in the heat, like my hot garage?

Are Envirotex and Devcon 2 Ton different kinds of epoxy? BobP posted that D2T is sold as a glue, and I know Etex is sold as a bar top coating, so I just wondered if they were different in their chemical makeup.

Very, very doubtful that it would separate.

Both are what's called Bis-A epoxies. Most on the market are. Where epoxies differ is the harness, elongation %, UV resistance, and tensile strength. Devcon is "junk" epoxy, used for glues. Very hard and virtually no UV resistence. It will chalk and yellow in no time. I couldn't find technical data on the Etex, but I'd guess it's not quite as hard with some UV resistance from the resin itself. Their MSDS makes no mention of inhibitors, so it will probably yellow fairly quickly also. I'd never use the Devcon on a lure. Never tried it, but Etex looks OK. My only concern would be for balsa lures and it cracking over time, and yellowing.

[mark poulson]

rofish,

I trust my eye more to judge the amounts and, so far, it's worked. I used a wooden tooth pick to mix the two halves on the tape, and I'm very thorough. I make sure that, once I've mixed the majority of the epoxy, I move to the outer limits of the epoxy, and mix that back in. It works for me, and there's one less thing to clean up. If I'm mixing enough for four big lures, I may use cups, and then I use a popsicle stick, with the end squared, to mix, and am careful to get down into the little groove at the outside of the bottoms (why do they have to put that there?) so I don't have any unmixed stuff. I measure the resin and the hardener out in separate cups, and add the resin to the hardener, so anything that's unmixed would probably be the hardener in the "corners", and the epoxy will still set up. But for the most part, I use the flat tape and it works great.

Downriver,

I've gone away from D2T for lure coating because it seems to be too hard, and comes off in large flakes when I "kiss" the rocks with my lure, infrequent as that may be.

I find that Etex is softer, and more forgiving.

I just checked and the Etex doesn't say UV protected, or anything about UV, on the package, and neither does the D2T.

I was thinking of using a coat of Krylon Acrylic Gloss, which does have UV protection, under my topcoat, and then I realized that wouldn't stop the topcoat from yellowing. Maybe a sacrificial coating over the epoxy, which could be redone from time to time, would help, but it seems like a lot of work, and I'm lazy.

[Downriver Tackle]

I switched to mixing my epoxy by weight real quickly after inconsistent results. I picked up a digital scale at Cabelas for weighing gunpowder for $70 on sale. I measure it in grains. Watch out though and check the MSDS for density. Sometimes part A is denser than the hardener and your mix ends up being 34 grains:31 grains as an example. A little money and calculations upfront, but the results are well worth it!! Also, a big contributor to any epoxy yellowing is improper mix ratio.

[mark poulson]

How does mix affect yellowing? Does too much hardener cause yellowing? I am guessing that, since too little hardener results in epoxy that doesn't set up.

[Downriver Tackle]

How does mix affect yellowing? Does too much hardener cause yellowing? I am guessing that, since too little hardener results in epoxy that doesn't set up.

Unless polymerized/reacted, the hardener will yellow.

[mark poulson]

So that would explain uneven yellowing. A poorly mixed batch.

On a slightly different note, I've found that, when I've not added enough hardener or mixed it well enough, and I wind up with spots that are tacky, a drop of crazy glue seems to set the resin off and it gets hard, with no tackyness. Why is that?