Best epoxy for High powered rocket building ?

I use U.S. Composites epoxy

635 resin and medium hardener for lamination. 150 resin and fast hardener for bonding. High quality, good service, and you can't beat the price.

-Tim

snipped-for-privacy@junglevisi> I've been using the West Systems fast epoxy kit and I have been very

GLUE THREAD!!

West Systems is great stuff, no need to change what you're doing.

Joe Michel

I've been using NHP 30 minute with good results. Except when I get the

50/50 ratio wrong. Which leads me to my next question.

With West Systems you use their pumps to get the ratio exactly right, one full squirt of resin and one full squirt of hardener, isn't that correct? Well how much does one squirt of each make? It seems like it would make about a couple of tablespoons. Does that lead to a lot of waste? What do you do when you just need a small amount of epoxy?

J.A. Michel wrote:

I weigh my resin and hardener on a 200g digital scale. It would seem to be more accurate then using pumps. I put an appropriate sized cup on the scale, use the tare feature and then measure out the amount needed in the proper proportions. This gives me a pretty accurate idea of how much laminating resin I've got on the rocket and also let's me know the weight of the adhesive I've used.

Andrew

Jim wrote in news:14DGg.2089$rT5.1195@fed1read01:

Get some oral syringes from the drugstore.They're calibrated. Mark them to positively ID resin from hardener.

5:1 for very small amounts is hard to achieve. RAKA is a good epoxy. Mixes 2:1,like System Three

West Systems has two or three different system sizes. The smallest is okay if you are doing maybe a large 4" or 6" rocket or for laminating fiberglass cloth. Other than that, you'll probably waste a lot. The ideas of weighing the components or using marked syringes are good.

For me, I build lots of big stuff, so the quantity from the pump is not too big and I might even use two pumps occasionally. When I laminate large tubes, I might use 4 or 5 pumps at one time.

Brian Elfert

Any epoxy with a 1:1 mix ratio has got some sort of filler added to something. I may or may not want a filler in my epoxy, and when I do, I'd like to pick what type to use for the application.

I would seriously question the use of any 5 minute epoxy for HPR, LMR, MR, or even Questes type stuff.

West, System3, and Raka are all good. I've not used AeroPoxy.

It can be more accurate, but you also have to make sure you're really doing it right - the resin and hardener almost always have different masses, and the normal mixing ratios are given by volume. Check with the manufacturer to make sure that you're using the right ratios when you are weighing rather than using volumes. I usually use System3, and they have info in their "Epoxy Handbook" about what ratios to use when weighing. Some epoxy/hardener combinations can be *way* out of whack if you use the volume ratios when you're weighing.

I bought a quart of Aeropoxy ES6209 resin and a quart of ES6209 hardener from Giant Leap about five rockets ago and still have at least half a jar left. It says right on the pot to mix ratio by weight 100:100. I have a digital scale that works well for pretty small batches.

It has a long set up time, but once it kicks it is pretty damn strong. John Coker has an epoxy comparison on his website:

Aeropoxy in NOT mixed 1:1. IIRC it's 3:1 by volume or 100:27 by weight.

They are all good products although there might be one that is better than the others for your application. You haven't said what you are doing with it.

Phil

"mix ratio by weight: 100 resin to 100 hardener."

Perhaps you are thinking of a different formulation of Aeropoxy. This stuff is made for structural applications, but they have other products.

The Epoxy would be used for High Powered Rocket construction. For example: Centering ring attachment, motor tube inserting, fin attachment. Level 2 to level 3 applications.

The Rocketeer

I like west but have also used system 3.. system 3 is great because the fillers are pre mixed. great stuff! Just never wanted a pump myself .. because I want to determine how much I need myself for any given task. the pumps are wastefull. so I use a scale the >weight< mix ratio will not be the same as >volume< mix ratio.. thankfully all these companys have the by weight ratio on their sites.

I keep some in squirt bottles for the smaller jobs.just never saw the need for a pump

I use PR2032 Resin and PH3660 Hardner. I just confirmed it is mixed s

3:1 by volume or 100:27 by weight. The moral of the story is always read the directions because Aeropoxy makes more than just these two products.

Phil

For what you are doing, any of those should work. I don't know specifically about Aeropoxy ES6209 but I do know that you would want to thicken the other two if you are using them to attach fins or centering rings. West has a nice tutorial on what product to use to thicken resins I think

also does. Anyway the short answer is thicken with silica and chopped glass. After fins are attached, build up your fillets by mixing epoxy with a fairing filler.

Also, epoxy made by Bob Smith is sold in most hobby shops with a private label - usually the store's name on it. It's already the right thickness for what you are doing.

Phil

Been using the awesome system3 stuff for years. IIRC I still might have one of those $10 samplers in the workshop.

What I've found to be ideal for measuring the stuff is using veterinarian syringes. Perfect for small and even larger jobs.

Ted Novak TRA#5512 IEAS#75

I use the pump but only as a convenient dispensing device. I use an electronic balance to measure. I like Raka epoxy which is 2:1 or

1:0.44 by weight. I use both the slow and fast part B and mix them together depending on the application. I use the West high density filler for many applications and occasionally silica. I also will thin the epoxy with a little 91% isopropanol for certain applications, even though some recommend against this. I like to use it as an aid to penetration on porous surfaces such as cardboard tubes and fiberglass.

Our group at LDRS 2003 built a HPR rocket with 5 minute epoxy for the "From the Groound Up" challenge. It has survived a number of flights.

I wouldn't hesitate to use 5 minute for mid power rockets and smaller HPR.

Brian Elfert

Phil The PR2032 and PH3660 is a structural adhesive not a laminating resin. Really thick, works good for centering rings etc.