Has anyone used this aerosleeves for fiberglassing the airframe?

Hi, Has does anyone have experience with the aerosleeves products for fiberglassing an airframe.

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so, I have a 4 inch ezi-65 which everyone in this group is probably sick of by now, and I would like to fiberglass the airframe in hope that I get a little more bang for my buck in the long run. It is unclear which product is best for my purpose. I want the rocket stronger, but not to weigh a ton. I intend to use an H or I motor plus I will probably be adding some electronics so weight is probably an issue. After reading a review on the product, it seems like the easiest way to get a good result. I am thinking the 4 inch nominal diameter product is correct, but there are three weights to choose from-all of which seem heavier than the weights I have been reading about i.e., 4 oz per sq yard. Also, how is this stuff sold, by the linear yard? So I would need about two yards for a single covering of a 60 inch long rocket? (Rounded to the nearest yard). I have read about the West System epoxy for the bonding, does anyone know a good supplier? Thanks again for all the help.

Reply to
lizardqueen
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Absolutely!

Check this article out about Aerosleeves:

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Reply to
Darrell D. Mobley

Reply to
lizardqueen

I've used Aerosleeves on a couple of rockets, and like it very much. One was fiberglass over phenolic (one layer of medium), the other was all fiberglass, made from two layers of the 'heavy' sleeve, both used West System epoxy. These were my first fiberglassing projects, so this is from the viewpoint of an absolute tyro...

The Aerosleeve material is very easy to work with. Avoiding snags in the material as you put it over the tube or mandrel is about the most difficult part of the process, and that simply requires a bit of patience and care. The finished products are very strong... the fiberglass/phenolic bird suffered a motor failure, in which the forward bulkhead on a 54mm hybrid motor let go, instantly releasing ~600cc of nitrous into the airframe at

800psi. Cleaned out the airframe from the forward end of the motor up... 12" of motor mount and centering rings, recovery harness retention, the works... ripped out the rail buttons, slammed the rocket onto the ground... but the airframe survived relatively unscathed, just a bit of damage where the tube was forced down over the rail standoff. It *will* fly again :)

I haven't yet tried their carbon fiber sleeving, but that will soon be remedied.

Kevin OClassen

Reply to
Kevin OClassen

Don't fibreglass it. There's no real need for it at this level and it just adds weight.

This will probably sound like a heretic view but laminating a rocket with aerosleeve is a dumb way to reinforce it. What you will end up with is a tube that has a massive amount of hoop strength and virtually no more longitudinal strength - the complete opposite of what you want.

Do the job properly using glass cloth and make sure the weave runs parallel to the axis of the tube.

West Systems is very good as are SP Systems and International Epoxies. Aeropoxy is supposed to be excellent but I've never used it myself.

Chris

Reply to
Chris Eilbeck

Hi Chris,

So when do you decide to glass a rocket? It seems to be an issue of extending the life of the airframe that is already strong enough.

Halam

Reply to
Halam Rose

  1. When the stress is likely to cause a break-up in flight unless you reinforce a kit. (see the PML faqs)
  2. When you want something so robust that you're prepared to sacrifice altitude/have to put a larger motor in to achieve a safe altitude.
  3. When only composites can give you the strength you need to meet a fixed mass budget.

I'm happy to replace the odd bit of tube if I ding it on a rock or in the back of the car. Unless it's gonna go well beyond Mach, I'd say you're wasting your time using fibreglass. I've done just that many times with plain phenolic and never had any issues.

Chris

Reply to
Chris Eilbeck

If you have a situation as Kevin described, fiberglass will make a BIG difference.

Phil

Reply to
Philip Stein

I agree with Chris in most respects. For most things fiberglassing phenolic is unnecessary, adds weight, and so on. I do like making my own airframe tubes, and for this application the Aerosleeve products are great-- simply form your tube over a mandrel made of full length coupler. The user has some control over the longitudinal vs lateral strength of the tube by selecting sleeving of greater or lesser diameter than the finished tube. They detail all that on their website.

I'd add that if you fly in cold weather composites seem to hold up better to hard landings on frozen lake beds. Phenolic gets very brittle, especially around the edges.

Kevin OClassen

Reply to
Kevin OClassen

Well that simplifies my level 2 plans, thanks.

Halam

Reply to
Halam Rose

I agree with Chris.

Lizardqueen, why do you want to make the rocket "stronger"? The EZI-65 is designed to fly on H and I motors. I have one, (unglassed, no modifications at all) and have flown it many, many times. H-128, H-123, H-180, I-161, I-357, etc. I think you might be surprised how "strong" it is with no glass. Also, first-time fiberglassers tend to use way too much resin, adding weight unnecessarily. Use this airframe to experiment with electronics, and save fiberglassing for later.

Reply to
Bill

Thanks for the input, I understand there is a mass to strength trade-off. I guess my goal is to us this rocket up to level 2 cert and reinforce it enough to make that possible. According to the following article,

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this rocket has a tendency to shred on J and K motors. There must be some median between creating a massive tank of a rocket and a card board tube. I'm kind of trying to find that line. I saw that according to the Aerosleeves website you can control the longitudinal vs. transverse strength by selecting the correct diameter size. If I do decide to go ahead and glass this thing, I am wondering what experienced users of the product would recommend in terms of size selection and weight selection. I see that Kevin went with one layer of medium. Thanks again.

Chris Eilbeck wrote:

Reply to
lizardqueen

You could still use it for your L2 but use a much smaller J. I've see several EZI65's go up on J350's and none of those EZI's had any glass.

Look at it this way, the glass is more for durability upon landing compared to brute strength on liftoff.

Example: I'm currently working on my L2 bird, a 4" by 80" 4FNC with a

54mm mount. I'm using Aerosleeves but with this rocket it is more for the durability upon landing since it will in fact weigh close to 9 lbs loaded. A 9 lbs rocket landing on soft sod is very likely get a kink in the airframe or even the NC could leave a nick in the fins. I even seen a tangled shock cord to a number on plywood fins.

Personally, I'd leave the EZI65 close to stock and do another glassed rocket for your L2. But that's IMHO.

Ted Novak TRA#5512 IEAS#75

Reply to
tdstr

I disagree. My THIRD flight on an I-161M suffered a short delay and zippered the rocket about 12". Fiberglass reinforcement would have prevented this. LOC tubing is notorious for showing signs of wear and tear, knocks and bruises such as when the nose cone slams back against the airframe. Fiberglass reinforcement would prevent this. Plywood fins can and do break upon impact depending on the angle of contact. Fiberglass reinforcement would help combat this.

Aerosleeves is the perfect way to reinforce the LOC EZI-65 if you use the correct fiberglass sleeve that postures the weave at 45 degree angles to the axis of the tube. In that position, the composite strength is proportional for axial and radial strength. Aerosleeves is a good way for beginners to composite reinforcement to learn the craft.

Reply to
Darrell D. Mobley

Nick at Aerosleeves will give you as much assistance as required. He offers excellent customer service. Just tell him what you are working on and he'll fix you up.

nick at aerosleeves.com

Reply to
Darrell D. Mobley

Please don't do that! It's not a race to get your certs and the build techniques required for L1 and L2 can be quite different. You'll learn a lot more if you do it with at least two rockets. Remember, it's a lot easier to cope with if you get it wrong on a basic L1 kit rather than a L2 kit loaded up with electronics etc.

Chris

Reply to
Chris Eilbeck

This sounds like a good reason to fiberglass. I like building rockets as well as flying them, but I am not enamored with repairing them between flights.

Reply to
Darrell D. Mobley

A proper anti-zipper design would have completely avoided it rather than papering over the cracks as it were.

So junk the damaged bit of tube and replace it.

Again, this is either a fault in the design of the kit or poor rigging by the flyer. Is anyone really still using elastic in their shock cords?

Replacing them with G10 would be even better.

Chris

Reply to
Chris Eilbeck

I think that article shows how to overbuild the rocket, but that's my opinion.

The tube itself will easily withstand the thrust of a J & K motor. At high enough speed the fins may flutter, causing them to break off. So if you think you will reach that speed with this rocket, then a good way to strengthen the fins is to fiberglass them to the body. After attaching the fins and putting down a good fillet, lay fiberglass down one side of one fin, across the body and up the other fin. I don't run the fiberglass all the way up (in fact, you'll get better flutter resistance if you don't) but only about 1/2 to 2/3 the fin semi-span. Even better flutter resistance is to build up a couple or three layers of fiberglass in this way, with each layer shorter (up the fin) than the previous layer. This will give you more strength closer to the fin root, and also change the mass distribution thereby dampening the harmonic vibration.

I use FinSim (earlier version of AeroFinSim) to calculate whether my designs need to improve the fin strength:

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Reply to
Steve Humphrey

True.

Done many a time. Or *could* have been prevented by glassing.

Then that would be a problem for the majority of the kits. Whether elastic, nylon or even a shoe lace for a harness....ALL can, and will, cause a zipper. And demonstrated by me last July :(

True but then why get a kit to begin with?

Ted Novak TRA#5512 IEAS#75

Reply to
tdstr

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