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?
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...
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.
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. You guys are great. I really appricate all the help.....Oscar
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.
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.
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
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.
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,
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.
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