Trondak U-40 review update

[Fishwhittler]

I got my first airbrushed lure completely finished, and I really like the way it turned out. What do you think?

On this lure I used Trondak U-40 LS Supreme High Build as topcoat instead of Flex Coat Ultra V. I'm doing a review of U-40, and this is the first part.

Trondak U-40 LS Supreme High Build review- Part I

Note: I bought the High Build version of U-40, not the regular. Whenever I say "U-40" in the following report, I'm referring to U-40 LS Supreme High Build. The same thing for Flex Coat: when I say Flex Coat I'm talking about Flex Coat Ultra V High Build.

I read somewhere that a lot of the epoxies out there are the same thing, only in different packaging. This cannot be said of U-40. The resin component is much thicker than the resin in Ultra V, while the catalyst is slightly thinner. While mixing, I also noticed that U-40 has a stronger smell than Flex Coat.

Mixing: I did a little experimenting, and so far U-40 seems to mix best when I mix it the same way I mix Flex Coat. My technique is mix 1 minute, heat, and then keep mixing, heating at intervals of 45 seconds until you have mixed for a total of 4 minutes. Do not count the time heating as part of the four minutes. After mixing, heat the epoxy one final time and then cover it and let sit for ten minutes.

Viscosity: U-40 is considerably thicker than Flex Coat, and so you can probably use fewer coats. For example, if you use three coats of Flex Coat, you can probably use only two coats of U-40.

Bubbling: In my limited experience, U-40 appears to bubble more than Flex Coat. But on the package, it says to pour the mixed epoxy on a piece of foil, and I haven't been doing that. I will pour it out in the future to see if that fixes the bubbles.

Heating: U-40 doesn't react to heat the same way Flex Coat does. Heating Flex Coat while mixing will pop a lot of the bubbles, and at the end of the ten minutes most of the bubbles are gone. When I heated U-40 a lot of the bubbles would pop, but I still had quite a few bubbles in the mixed epoxy. More of the bubbles popped when I was brushing the epoxy on, but it for me it hasn't been as bubble-free as Flex Coat. Also, heating U-40 after it's on the lure doesn't do much to remove bubbles; it will pop some of them but it will also generate more.

Dry Time: U-40 sets up faster than Flex Coat, and is dry to touch in 4-6 hours. Flex Coat takes longer, usually 6-8 hours to dry. However, Flex Coat appears to cure faster than U-40, and after two days of cure time for each Flex Coat is a little harder than U-40 mixed on the same day. On the package it says that U-40 takes 5 days to fully cure, so I'll see how hard it is then.

Appearance: U-40 gives a beautiful, glossy finish very similar to Flex Coat.

Yellowing & Durability: I haven't had U-40 long enough to know how well it resists yellowing and teeth marks, but I'll try to post info in the next part of my review. That could take several weeks, so stay tuned.

[Steven Ladner]

Good review. That lure is beautiful 

[NateFollmer]

Man I would be afraid to fish with something that nice looking. How did you make the body of this lure? If you did that by hand then you are just not human

[Fishwhittler]

Thanks!

I didn't carve this bait; I'm not anywhere near good enough!  It's a Lucky Craft RC 2.5 knockoff from predatorbassbaits.com.

U-40 review part II: Hardness

After more than 5 days of curing, U-40 is still not as hard as Flex Coat after the same period.  In fact, Flex Coat is harder after eight to ten hours.  I'm not sure whether this is good or bad, as the greater flexibility may be an advantage in resisting scratches.  The difference in hardness is not much, but U-40 is slightly softer.

Still to come: Yellowing and tooth marks

[NateFollmer]

Yeah, the softness might be a slight advantage as you said. This crank looks amazing. Every time I look at these threads I want to go buy an airbrush Have you been using an airbrush for awhile or is that your first try? If it is, I'll keep my statement that your not human haha.

[whittler]

Nate, I don't think we have seen anything yet, Ben has a lot of talent.

Testing is the only way to decide on topcoats and you are doing it right. Nice work by the way.

[Fishwhittler]

Thanks all you guys! 

@ NateFollmer, this is my first airbrushed bait.  I got a cheap airbrush/compressor combo from amazon.com and so far I'm very pleased with it.

Trondak U-40 review part III: Fish Teeth Resistance

I took this bait fishing today to test the durability of the U-40.  I caught four fish in one hour, plus two other strikes that I missed.  The U-40 held up well to the fish teeth, and it still looks very good.  Scratching was about the same as Flex Coat, so if there aren't any issues with yellowing I think I'll switch completely to U-40.  Below are some pics of the bait after I fished it.  There is one small tear in the topcoat where the hook point stuck in and then tore free, but this could happen to any topcoat and so is simply not part of the equation.

[Fishwhittler]

More pics.

[BIG M]

Good report

[Crookedneck]

Killer bait!  Great work!  Reading your post I've got a couple of questions for you.

1)  You have been using Flex coat.  But it yellows?!  More of a statement, really, I have been using flex coat light and high build for my rods.  I have decided to change as I noticed it yellows.  It yellows while still in the bottle actually.  And there is nothing worse than spending hours on an intricate wrap only to have it turn yellow...

2)  You are trying the U40?  I have never tried it myself, Have you ever tried Thread Master finish?  I haven't used it yet...But, it was recommended to me by another rod builder named Billy Vivona (if you haven't heard of him look him up, one of the best out there right now) I will be using it when my order gets in.  If you are interested in how it works for me I would be glad to pass it on.  Billy says it doesn't yellow, and has great leveling properties.

Food for thought!

Mike

[Crookedneck]

P.S.  pouring your finish onto foil will greatly decrease the bubbles no matter what finish you use.  It spreads the finish out and I use a straw to blow the few remaining bubbles out.

Make sure you pour the finish onto the shiney side of the foil.

Mike

[BIG M]

I've been using flex coat ultra v for almost 2yrs with not yellowing.   The old stuff would yellow pretty quickly but then so did devcon.

[Fishwhittler]

Killer bait! Great work! Reading your post I've got a couple of questions for you.

1) You have been using Flex coat. But it yellows?! More of a statement, really, I have been using flex coat light and high build for my rods. I have decided to change as I noticed it yellows. It yellows while still in the bottle actually. And there is nothing worse than spending hours on an intricate wrap only to have it turn yellow...

Thanks!

I've got some yellow double and triple-jointed swimbaits... not fun. 

Note: I bought the High Build version of U-40, not the regular. Whenever I say "U-40" in the following report, I'm referring to U-40 LS Supreme High Build. The same thing for Flex Coat: when I say Flex Coat I'm talking about Flex Coat Ultra V.

Flex Coat Ultra V does not yellow.  I also got the old version of Flex Coat once, and it yellowed inside of a month.  I switched to Ultra V after that, and I haven't had any problems since.  I've got some baits coated with Ultra V that are over a year old and they still show no sign of yellowing.

The only reason I would want to switch to U-40 is it's cheaper.  I have zero problems with Flex Coat Ultra V and the price isn't bad at all, but if I can save a little using U-40 then I will. But if U-40 yellows, I'm going back to Ultra V.

2) You are trying the U40? I have never tried it myself, Have you ever tried Thread Master finish? I haven't used it yet...But, it was recommended to me by another rod builder named Billy Vivona (if you haven't heard of him look him up, one of the best out there right now) I will be using it when my order gets in. If you are interested in how it works for me I would be glad to pass it on. Billy says it doesn't yellow, and has great leveling properties.

Food for thought!

Mike

I haven't tried Threadmaster (yet!).  I'm definitely interested in hearing how Threadmaster works for you!  I'm always looking for a better topcoat.

Ben

[S Hovanec]

All I use is Thread Master on my rods. I did coat a couple beat-up lures with some left-over once. It levels just like it does on the rods and gave fantastic finish....they looked new.

[Fishwhittler]

Well, I've had U-40 for about a month now, and it hasn't yellowed yet. ;D  That isn't very long, but when I tried regular Flex Coat (not Ultra V) it yellowed inside of a month.

I mixed some the other day, and then I decided to try something new: I'd use my finger to coat the lures. I saw a thread on TU about using a finger to spread epoxy and I figured I'd give it a shot. Anyway, it worked great! I got fewer bubbles, and it was easier to completely cover each lure.

Also some more info about mixing: U-40 mixes with fewer bubbles if you mix slowly. Flex Coat can be stirred hard and it will still lose a lot of bubbles when you let it sit, but U-40 needs to be mixed a lot slower.

[jbass]

Don't you love battle scars on a crankbait......nicely done.