Rocketpoxy Availability

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The specs look pretty close to Rocketpoxy. The ultimate test is to give it a try. If you do, please let us know how it worked out. It would be great to have a reliable supply of something functionally equivalent to Rocketpoxy for those external fillets at a minimum!
That's what I thought too. There are other threads on TRF that discuss ES6279, but sure I'll report back ;-)

As far as purchasing AeroPoxy products I go directly to PTM&W if I can't find it cheaper elsewhere.
 
Tim Lehr was on Rocket VLOGs tonight, and mentioned that he isn't getting a response on availability inquiries. I'm taking that as "not so good news" for those of us who use RocketPoxy for our external fillets. <cue the funeral music >
 
Tim Lehr was on Rocket VLOGs tonight, and mentioned that he isn't getting a response on availability inquiries. I'm taking that as "not so good news" for those of us who use RocketPoxy for our external fillets. <cue the funeral music >
Yeah, he also said he knows the owner as well as something like "it seems to be dead"
 
A few alternatives have been listed here, and I've done a mini comparison of a few. This is for fillets only, not internal structural. And my choices are probably not appropriate for those doing Mach 4 and 400k meter flights. Or possibly not L2 either.

Criteria: (These are MY preferences. Yours will be different...)
1. Twin piston dispenser, like many of the JB products. I simply don't like measuring.
2. Thixotropic, or reasonably close.
3. Easy to apply, easy to smooth out.
(Sounds like I'm a bit lazy...)

Contestants in "The Epoxy is Right":
1. Devcon 5 minute Epoxy Gel
2. PC SuperEpoxy
3. PC-11

Devcon Gel placed last. It's the consistency of Vasoline, and sticks to what it wants to. In particular, it sticks better to my popsicle stick applicator than to the fin/body tube. Dab it on, pull the popsicle stick away, most of it stays on the popsicle stick. And it wants to stick to whatever you use to smooth it with. I smooth with a tongue depressor dipped in 99% isopropanol, and had difficulties. A gloved finger dipped in IPA worked best.

PC-11 2nd place. The biggest issue with PC-11 is that it is VERY thick, just like bubble gum. Hard to mix, difficult to apply just because of the thickness. But it smoothed out OK with IPA dipped tongue depressor. On the plus side, it has enough working time to do all the fins. I'd use this if I was out of my first choice. Which was...

PC Super Epoxy. Just the right consistency, applied easily, smoothed out well. It flows slightly, just enough to self-smooth, but not enough to run. It does stay put. Downside is the short working time. I couldn't do more than 3 fillets at a time.

Hans.
 
If any of you guys have epoxy that is cloudy or has crystals in the bottom, try heating it up to, say, 140 degrees F for an hour or two. In the summer, leaving it in a car in the sun works well. For small amounts, like an 8 ounce set of Bob Smith epoxy, I'll set it on top of one of the heat circulator pumps in our house's heating system. I also have an old crock pot we never cook with anymore. (The cover shattered, leaving glass in our food!) As I recall, leaving epoxy in that while set on warm will get rid of the crystals. If I'm not mistaken, this is just for the resin, but I'm not sure, so I do both. If there's a way to deal with hardener that's getting old, yellow, and thick, I haven't learned it yet. I have some old Raka epoxy that I originally built a boat with. It's been 20 years or so, and I've had to leave it in the car a few times, but it seems to work fine. I might stress test some samples if I was going to use it structurally, but it does make some very tough fuel. (70 percent KNO3, 15 percent finely ground sugar, 15 percent epoxy). It has to be pushed pretty hard to get it out of the mold!

A couple of the boats I built were "stitch and glue". That means most of the chines are done with internal fillets with glass tape over them, and there are many feet of them. Fumed silica works very well as a thixotropic additive, but I understand it's very bad for your lungs. Maybe work outside on a very calm day. With any breeze, the stuff will blow away before you can use it. Wear a GOOD dust mask or a respirator. If I was using it a lot, I'd ONLY use it with a respirator. One of the things I'd do with the boat was add filler and then a little bit of the fumed silica, which would make it behave better. I think I used "wood flour" quite a bit. Essentially, very fine sawdust. If you want it to be just right, you should probably measure what you use in your mixes so you can replicate it.

IF I was having trouble with fillets cracking and stuff like that, I'd use glass tape over them, which should really increase the strength and stiffness. Using glass tape also means that I could put microballoons in the fillet mix, along with the fumed silica, to make it lighter. Microballoons don't thicken the epoxy nearly as much as fumed silica, so you can use quite a bit. It will seem fairly thick when first added, but when you get it mixed in well, it thins out some. It will sag without the silica, most likely. The stuff I did the other day sagged, but in that application, I wanted it to. I suspect that glass over fillets with a significant portion of microballoons in them will be stiffer, stronger, and lighter than un-covered fillets with fumed silica.

If you are getting bubbles with epoxy over wood, work when the wood is cooling off. This way, the air in the wood isn't expanding and trying to get out. You can warm the wood up just before you put on the epoxy with a heat gun. Also, if you have good ventilation you can warm up the applied epoxy with a heat gun. It will form bubbles, but they'll come out as long as the epoxy hasn't begun to set.

Raka and, I think, the regular West epoxy are general purpose. They will do okay laying up glass and for mixing up glue, but they are a compromise. For maximum properties, I suggest epoxy that's exclusively meant for laminating when you are making composites, and epoxy that's meant as an adhesive when gluing. The adhesive stuff will be a little softer, but that gives it better peel strength. Some time ago, I was putting pre-cured carbon fiber on basswood. Using some epoxy a boat builder gave me, the same as we'd laid up a few of his boats with, the carbon was very easy to peel off, though it worked great with glass. Ordinary, 30 minute Bob Smith stuff, or perhaps something equivalent to it, was much more tenacious. But when I made a carbon fiber peg with the laminating stuff, it was fine. I've heard that if you go back and add more epoxy over some that's been there for only a couple of days, you can get a good chemical bond. Not so much if it's really hardened up. Epoxy that hasn't fully hardened can be worked on with a scraper for much better results than with sandpaper, and vice versa when the epoxy has cured hard. Some general purpose epoxies can still be quite soft after 12 hours, unless they cure under quite warm temperatures. This is ok with me, because that means I have more working time. Slow epoxy is especially okay with me on hot days. A smoking cup of prematurely curing epoxy isn't pleasant to be around.

I haven't bought Raka in years, but they're still selling it. If it's still the same, I recommend it. Their info is a bit sparse, though. For things that will be left in the car, or for you guys that live in hot places, or who like black rockets in the sun, I suggest looking into somewhat more heat resistant epoxy. One of Raka's hardeners is supposed to be a bit more heat resistant, but I have no quantified information on that. Maybe you could pester them for advice. Sometimes, you can increase the heat resistance of epoxy by post-curing. That is, heating it up for a while after the first cure. It's best to follow the epoxy maker's instructions for this, or at least bring it up to temperature slowly, or you'll soften it again. Some epoxies are supposed to stand a lot more heat already. If memory serves, some varieties of JB Weld claim remarkably high service temperatures.

If you're concerned about reliability, I know T-88 is approved for gluing wood in full scale airplanes, and it's quite popular. Probably not a good choice for wetting out fiberglass, though. Nor, according to specs I've seen, is it especially heat resistant.

BTW, when gluing, surface prep is really important. As I recall, West has some good info on this. I admit I haven't tried flame treating plastic much just yet.

Yet another afterthought. I remember liking System Three's general purpose epoxy, but it's expensive. Also, they used to have an epoxy that cured in two phases which was supposed to be tougher than other laminating resin, I think by resisting crack propagation, but it was dropped. I liked it, though I never tested its properties in any formal way. It cured cloudy, and was supposed to.
 
I'm going to call again this week. I'm starting my L3 build and really don't want to use anything else for the external fillets. I'll post their response...

Use the West 6-Ten, perfect fillets, and you can do them all at once. Expensive, but for perfect fillets, totally worth it. Especially because once you’re done, just stand it up in the corner to dry. No sag, just perfect fillets.
 
I'm going to call again this week. I'm starting my L3 build and really don't want to use anything else for the external fillets. I'll post their response...
Please let us know your results.
 
Did I mention the fillets were perfect?:p:p:p
Guess I should have proofread better…
So, I'm building my L3 rocket. I'm going to need large fillets, 1.5 - 2" radius, 30 inches long, 6 total. Will one cartridge be enough? How big a bead can you lay? The static mixer looks like a lays a small bead, a lot smaller than I need. Have you used it on big builds?
 
So, I'm building my L3 rocket. I'm going to need large fillets, 1.5 - 2" radius, 30 inches long, 6 total. Will one cartridge be enough? How big a bead can you lay? The static mixer looks like a lays a small bead, a lot smaller than I need. Have you used it on big builds?

IMG_2329.jpeg

6” Wildman Ultimate Punisher. There was some leftover. I’d probably have two tubes just in case.
 
Please let us know your results.
Called Glenmarc today. They are still trying to source material for making RocketPoxy. The head guy wasn't there, so no specific update on a timeline. I can only guess the missing component is whatever material they use as filler. They make a lot of other epoxy products, so I have to believe they have resin and hardener.
 
Called Glenmarc today. They are still trying to source material for making RocketPoxy. The head guy wasn't there, so no specific update on a timeline. I can only guess the missing component is whatever material they use as filler. They make a lot of other epoxy products, so I have to believe they have resin and hardener.

Tried some Aeropoxy ES3629, as I have an Aircraft Spruce locally so was easy to pick it up. Its pretty much the same consistency as RocketPoxy and in my tests it seems to mix and spread very similiar to Rocketpoxy as far as making filets goes. I did call the manufacturer, Aeropoxy, to ask about product that has a bit higher operating temps.

https://www.ptm-w.com/technical-lib...lletins/ES6279 - 71 & 72 Bulletin 23Aug10.pdf

See below. I'm not recommending, etc, etc. to use, etc. just providing some info/impressions based on my hunt for a replacement for Rocketpoxy

PXL_20240619_140900254.jpg

PXL_20240619_140014056.jpg


PXL_20240619_140906809.jpg
 
I know that the West Systems 610 has been suggested as replacement. Other than it coming in bit smaller packaging and needing a caulk gun, it seems decent.
Its not quite as thick as either Rocketpoxy or ES3629 to me. But it went on as a filet quite well and is holding its shape, so thats good. However I did notice that it has lots of bubbles. Being quite clear, compared to ES3629 or RP with their fillers, its quite easy to see them.
I did three de-gassing passes with a vacuum pot, but still have issues with bubbles.

NOTE: Just to be clear, I did not use on this test sample the mixing tube extension that comes with it. I just squirted some out (is that a term?) and mixed by hand.


PXL_20240619_140853018.jpg
PXL_20240619_140914161.jpg

Again being clearish, you can see the bubbles. I worked it pretty hard to avoid bigger bubbles when applying and smoothing the epoxy.

610 might be useful for some smaller mid and low end high power rockets for me. Think I'll go with the ES6279 for larger rockets at least until I try some Proline 4500 myself.
 
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Tried some Aeropoxy ES3629, as I have an Aircraft Spruce locally so was easy to pick it up. Its pretty much the same consistency as RocketPoxy and in my tests it seems to mix and spread very similiar to Rocketpoxy as far as making filets goes. I did call the manufacturer, Aeropoxy, to ask about product that has a bit higher operating temps.

https://www.ptm-w.com/technical-library/product-bulletins/Adhesives Bulletins/ES6279 - 71 & 72 Bulletin 23Aug10.pdf

See below. I'm not recommending, etc, etc. to use, etc. just providing some info/impressions based on my hunt for a replacement for Rocketpoxy

View attachment 651520

View attachment 651521


View attachment 651522
Awesome. Thanks.
 
Awesome. Thanks.
Tried some Aeropoxy ES3629, as I have an Aircraft Spruce locally so was easy to pick it up. Its pretty much the same consistency as RocketPoxy and in my tests it seems to mix and spread very similiar to Rocketpoxy as far as making filets goes. I did call the manufacturer, Aeropoxy, to ask about product that has a bit higher operating temps.

https://www.ptm-w.com/technical-library/product-bulletins/Adhesives Bulletins/ES6279 - 71 & 72 Bulletin 23Aug10.pdf

See below. I'm not recommending, etc, etc. to use, etc. just providing some info/impressions based on my hunt for a replacement for Rocketpoxy

View attachment 651520

View attachment 651521


View attachment 651522
You name ES3629 but show the tech specs for ES6279. I assume it's the latter since I can't find ES3269 on the internet?
 
Hmmmm. The data sheets of rocketpoxy and es6279 look almost identical. Then combine that with the photos of the product in use (one can clearly shows 6279), I pretty sure they are basically the same. If I finish my tub of rocketpoxy this summer I will be ordering the es6279.
 
Hmmmm. The data sheets of rocketpoxy and es6279 look almost identical. Then combine that with the photos of the product in use (one can clearly shows 6279), I pretty sure they are basically the same.
Thats what I said!! :D

Watching stuff cure.... I did note that the ES6279 does sag about the same amount, roughly, that I experience with RP.

Interestingly enough the 610 seems to hold its shape really well. The glob in the cup which I left hanging, out of curiosity, on the side of the mixing cup basically has stayed almost exactly the same!
 
Thats what I said!! :D

Watching stuff cure.... I did note that the ES6279 does sag about the same amount, roughly, that I experience with RP.

Interestingly enough the 610 seems to hold its shape really well. The glob in the cup which I left hanging, out of curiosity, on the side of the mixing cup basically has stayed almost exactly the same!
Nice detective work. Thanks for sharing.
 
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