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Etex set hard in 10 minutes
39 replies to this topic
Posted 17 July 2008 - 06:15 PM
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.
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.
Posted 17 July 2008 - 06:31 PM
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.
Posted 17 July 2008 - 09:13 PM
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.
Posted 17 July 2008 - 09:26 PM
Unless polymerized/reacted, the hardener will yellow.
Posted 17 July 2008 - 09:41 PM
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?
Posted 17 July 2008 - 09:53 PM
That would be the reason for your problem.
Because you're creating a polymer blend and getting additional hardness and a faster set from the crazy glue. The epoxy isn't reacting any better because there's nothing in the crazy glue for it to react with. The crazy glue will have little affect on yellowing and may cause chalking. If you've ever used crazy glue outdoors, you'll notice that it turns a frosty white after a while.
Posted 17 July 2008 - 09:57 PM
I have noticed that moisture makes it chalk up and flash, not curing all the way through. I use the brush on crazy glue on the boat, for lure repair, and let it dry a minute before I get it wet, and it seems to be fine.
Posted 17 July 2008 - 10:09 PM
Crazy glue is Isocyanate loaded with a tin accelerator, and it reacts with hydrogen and oxygen molecules. Mosture on the surface makes it react really fast on the surface and cure, thus sealing off the underlying material from fully reacting. Mositure makes it form larger crystals than it reacting with gas-phase molecules and gives you that chalky look. Chalking over time is from UV degredation.
Edited by Downriver Tackle, 17 July 2008 - 10:16 PM.
Posted 20 July 2008 - 11:01 AM
My fishing buddy says acrylic paints react with the kind of plastic used in soft, making them gooey over time.
Are you familiar with any such problems?
I do want to try that clear acrylic top coat with the UV protection over my Etex, but I use screw on plastic tails on some baits, and don't want them to melt.
Posted 20 July 2008 - 11:57 AM
It's not the acrylic, it's the solvents in it. Good auto grade acrylics are all cut with ketones and other strong solvents. You might want to give some of the exterior acrylics for wood a try, like Minwax or similar. Those are cut in mineral spirits generally and should be fine and have UV protection. Always spot check the materials in question first. Another option is waterborne acrylic or urethane.
Posted 20 July 2008 - 12:59 PM
If I do decide to put a UV resistant clear over my Etex epoxy, would I need to scuff the epoxy for a bond, or do you think the acrylic would stick?
Posted 22 July 2008 - 10:32 AM
I'll give you guys a little tip for measuring out your epoxy. Get yourself some syringes. DO NOT get them from a medical supply store...the kind with the rubber plungers. Most of these are lubricated with silicone and will cause all sorts of problems. The ones you need, you can get from Flexcoat, a rodbuilding finish company. You may be able to get them directly from flexcoat, or you can order them from Mudhole.com. Anyway, drill a hole in the cap that the syringe tip (nipple) will fit into snugly. Then, the syringe itself becomes the cap because you will never have to take the cap off again. Just turn the bottle upside down and draw out what you need. Just make sure that you don't share syringes between bottles. I promise you guys, this method is the absolute fastest and best thing since sliced bread for mixing epoxy from a bottle. You will never weigh it out or pour it out in puddles again.
Posted 22 July 2008 - 02:13 PM
Downriver, it's nice to have someone around who knows chemistry! Speaking of yellowing, I haven't seen any significant yellowing on > 100 baits topcoated with Devcon 2T. Some are more than 5 yrs old. 95% of the problems I see or hear about regarding D2T not hardening result from poor measuring or inadequate mixing - especially the latter. I mix it like crazy, until it looks milky with air bubbles, then add a FEW drops of denatured alcohol to help it release bubbles while I'm brushing it on the lure. No failures for a couple of years now.
Posted 22 July 2008 - 03:27 PM
Mark, they will last a long time. If you want, you can clean them with denatured alcohol after each set of bottles if you want. Also, when you do get a new set of bottles, don't drill holes in the new ones, just replace them with the old caps that already have the hole.
Posted 22 July 2008 - 03:36 PM
I think I'll try the rod building syringes.
I've had yellowing, both with D2T and Envirotex. I wonder if it's really the paint underneath yellowing through the clear. I use Krylon spray on glitter over my paint jobs before I clear, and the can says archival safe, but it doesn't say anything about UV. I've also use pastel fixative between coats on some lures. As soon as I get some free time, I have to repaint and re coat some lures that had the D2T flake off. When I do, I may do one with glitter, and one without, and see if it makes a difference. I haven't had either yellowing or flaking on cranks I've repainted, only on wooden swimbaits. Weird.
Posted 22 July 2008 - 05:30 PM
That's good to hear. It must hold up for a few if so many people are using it. If you don't leave your customs out in the direct sun, yellowing takes a long time, even with Devcon, if it's mixed correctly. I used it repair a support for my boat cover and it was visibly yellow in a week or so in direct sunlight all day. After a year it was amber, cracked, and fell off.
I'm still a stickler for weighing epoxies. I made a chart with the proportions for however much I need and use yorker caps to dispense it. Takes about 60 seconds longer, but it's peace of mind having zero doubt that it was proportioned correctly and can ship lures tomorrow morning.
Posted 30 March 2009 - 09:01 AM
What brand are you using?