Glassing Big Tubes vs. Big Glass Tubes??

Just wondering....in general, but maybe moreso in HP...doesn't the cost of glassing cardboard or phenolic tube come close to, or perhaps surpass, the cost of buying a fiberglass tube?

Good epoxy is $$, and as you increase the diam, the area goes up a LOT. Add in the cloth, some people develop vacuum-bag dealies...and of course, the mess/hassle/smell involved, and I can't see the economic advantage.

Is a glassed paper/phenolic tube stronger than a glass one? I can't imagine it's lighter....

Why do so many HP guys use glassED tubes rather than GLASS tubes?

From my perspective...

For the hands on, do it yourself.

'Bout it.

Assuming glass lay-up only, cost to do it yourself is 1/2 to 2/3 assuming your time is worth $0. If you figure in your time, home-glassed tubes quickly become more pricey. If you make/buy vacuum bagging set-up and supplies, making your own is more expensive. If you're doing odd diameter, odd shape or odd length, the only way is to do it yourself.

It is fun to do it yourself, though.

Homemade fiberglass over cardboard or phenolic is certainly thicker-walled and almost always heavier than purchased convolute- or filament-wound fiberglass. Also, commercial nosecones never match tube thickness.

It is messy.

It is fun (did I say that already?). When I get in the right mindset, I like doing it. Carbon or true fiberglass sleeves are the bees knees. Combine that with shrink tape and you get some nice tubes and a sense of satisfaction. Like when you fix the toilet or a broken lamp. Coulda hired someone to do it, but what's the fun in that?

--Lance.

Originally posted by Deandome
Is a glassed paper/phenolic tube stronger than a glass one? I can't imagine it's lighter....

Why do so many HP guys use glassED tubes rather than GLASS tubes?

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I'd have to dig up some numbers to say which one is lighter; that said, though, I would expect the paper/fiberglass tube to be lighter than a full fiberglass tube, because the paper provides some structure that the fiberglass tube has to provide for itself, which means more material, and thus more weight.

Doing it yourself is definitely cheaper -- keep in mind that, regardless of the material you're using, one of the things you pay for is labor. All that labor that you put in for free the manufacturer is going to charge you for.

As you get into larger tubes, the price difference becomes more significant, especially when you're talking about tube sizes where Sonotube is an option as the base on which to do the layup.

The biggest advantage to buying fiberglass tube is the significantly reduced finish time. A fiberglass tube just needs a light sanding and it's ready for paint. A tube that you fiberglass will need sanding and filler work before it's ready for paint.

Provided a pretty finish matters to you....

-Kevin

I've glassed my own tubes, up to 7.5 inches in diameter. (I don't have the space in the work-room of my condo to do anything larger...) I do it because I enjoy doing as much of the work as I can myself. If I had the facilities to make my own motors, I'd probably do THAT as well...

I can speak from about my experince here on this myself. Ive done both ways and even made some of my own glass and CF tube.

Laminating a Cardboard or a Phenolic tube of the same size say 6" diameter vs 6" glass tube (be it filament or convolute) will be heavier then the glass tubes are when all is normally said and done. As Kevin pointed out to finish Glassed tubes you will have to fill and sand a posibly fill and sand some more. Also on a laminated tube most of the epoxy gets soaked into the material and the cardboard/Phenolic thus adding weight with no added benifits of strength. (yea a guys can go out and Vacume bag but even that doesnt always mean better. I use a methoud similar but with Mylar and compression wrap. Anyhow The real strong material to use in Convolute wound glass tube. Here is some ways I can tell you it lighet and tougher vs laminated tubes. On most laminated tubes the glass is only 2 wraps and Glass tubes+ the cardboard under it. I can crush it with my hands. On Glass tube of the same diameter its a entire thickness of 1/8 inch wall of solid fiberglass. I cant crush it in my hands. Infact Ive managed to hit a piece of it with a bat and a golf club and bash it into the ground and some chipping but not breakage. I can do it with the laminated and it shatters. Or cracks badly ruined. And As I buolt my wole L3 project from Convolute glass It weighed in at only 48lbs. Its 6" diameter and its 14ft 6 inches tall. Pretty light for a rocket of that size.

Ive also seen a ejection charges that will blow out the side of a laminated tube and a charge thats 5 grams stronger not touch a Glass tube. So thats my experince. Ive gotten to where when I can I always use Glass tube construction. Not laminated cardboard or phenolic. It is more expensive as size goes up. and only so many sizes are avalible to us. So it depends on what you want to do..

They're both good. It's up to the individual and circumstances at the time.
At this point, I buy fiberglass tubes. The time required to fiberglass my own is not worth it (for me) with other family and work commitments. That may not be true forever however. Once the kids jump ship - I may want to devote the extra time to fiberglassing/cabon fibering my own.
Good Luck with whatever way you decide is right for you.

I was wondering about the filiment wound fiberglass tubes. All you have to do is finish the tube with a little sanding? If thats the case I would venture that way myself just for the time savings. I would still like to learn how to fiberglass an airframe though. I have to be in the mood for sanding LOL!

The bad thing about G10 is the cost. I just picked up some 38mm motor mount tube for a 4" Performance Rocketry Nike Smoke and it cost about $10 per foot.

So glassing your own tubes is a lot cheaper. Which is probably why most folks do it. Deals appear from time to time on materials which can save you money. After that its just a matter taking the time to do it.

One thing I glass cardboard tubes. I don't glass the old style phenolic tubes ; the epoxy doesn.t penatrate well , so the laminations break off easily. The flex phenolic is some what better in taking epoxy. I still prefer to limit my glassing to straight cardboard.

Al

Al, when dealing with material for material the convolute wound glass tube is superior by a fair amout vs laminated product or even Filamentwound glass tube. thus why I can see a reasonable difference. Ive seen convolute airframes that have fallen from 2000+ feet and lived but cant say the same for laminated Cardboard or phenolic. So I belive you really do get what you pay for there. But thats just my belief and experinces. As far as glassing the phenolic it is important to really sand that surface good before lamination with coarse paper and use a slow epoxy and it will penetrate. I also use my methoud of mylar and compression wrap and that helps even more.. Same use as I do with most cardboards.

I have no complaint with the strenght of the glass tubes. My only beef is the cost. Large diameter glass airframe is expensive.

Compare that to cardboard. Loc type 7.5" x 48" airframe about $25. 6oz S-weave fiberglass cloth about $3 per yard. West System epoxy about $100 per gallon. So I can have a 4 foot glassed airframe for about $40 plus time spent. Where can I get a glass airframe for double that?

The fall from 2000' feet. Hopefully we don't have to build for that. Be it as it may ; I've seen Quantum tube survive a fall from 2000' with no damage. I'm not saying its great stuff ; just that it survived. I've also seen a glassed rocket impact the ground under full thrust of a pair of J350's(failed cluster). The 3/16" G10 fin broke. The airframe survived with a few scratches.

Fiberglassed tube is fine within its limitations. Its a useful technique for building a large rocket. I expect my L3 project will be glassed cardboard.

Al
BRS Pres

I have seen the filament wound glass tube at wildman but I haven't seen any convolute wound glass tube. I was wondering about the strength of the filiment wound tube. I tought you might have another step or process to getting it ready to be an airframe. I just started looking into this alittle more as I am Thinking about a project.

Who sell's the convolute tube for airframes. What I have found has been expensive and knew it would be. If I was going to use glass tube I would rather use the better type. I don't know much about fiberglass yet...

Another thing to remember is if you make your own tube you can make it to your specs. For example you could add just a layer of light glass for a little added strength or do 2 or 3 layers of 6 oz and have a high performance tube (mach bustin')... If you consider carbon fiber... making it yourself is one of the only ways, because as far as I know PML and PR are the only people that make it and PR doesnt make enough for the demand... and I dont know much about PML's products. I know I could have spent a bunch of money for some CF tubes for my 54mm rocket... and I ended up spending over $500 on carbon fiber, epoxy, various supplies and my curing oven. But I am happy I took that route. After about 2 hundred dollars worth of screw ups I finally got the process down and now have some very nice tubes. Believe me, the excitment when you unwrap the heat shrink tape to find that the mylar comes off cleanly and the surface is shiny and smooth... and then the tube slides off the mandrel without the slightest force is definetly a great one! Especially after doing the same thing 3 times, only to find a ruined tube.

Originally posted by sandmantoy
I have seen the filament wound glass tube at wildman but I haven't seen any convolute wound glass tube. I was wondering about the strength of the filiment wound tube. I tought you might have another step or process to getting it ready to be an airframe. I just started looking into this alittle more as I am Thinking about a project.

Who sell's the convolute tube for airframes. What I have found has been expensive and knew it would be. If I was going to use glass tube I would rather use the better type. I don't know much about fiberglass yet...

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Actually the Performance rocketry tubing that Wildman rocketry carries is convolute wound. The glass that hawk mountain and Giant Leap carries is filament wound. I bought a 48" section of 6" diameter convolute glass tube for about 65.00 from Wildman. Filament will work very well also but under certain situations it will spiral fracture.

As far as the strenght and the other things ive seen .. Ive see a ejection charge that totaled a guys rocket that was glassed cardboard. he had 2 wraps of glass on it and it was a 6" airframe and needed a larger charge and the same all glass tube had no effect with the same size charge.

Our club did a deal with CTI and Mike Dennett can back me on this we wanted to test not just us but some specifc products. one of wich was Glass tubing. So we did a event called 100K in a Day. 1 rocket many flights over and over to accumulate 100K in feet of flight. After 20+ flights ( infact we went 125k.) the airframe was beat to death. BUT it was also having to land at about 30 ft per sec and sometimes faster and would bounce when it hit the ground back 7 to 8 feet in the air. I can attest that a glassed air frame would never take that abuse. Most rockets I build anymore are all glass construction unless I do CF. But they last longer and handle bigger and better flights then glassed tubes do.

I did go to performance rocketry afterwards and found my statement of where I saw the filiment wound tubing was incorrect.

The testing you did sounds good to me. I am used to haveing to be careful handleing my rockets and figured if I build a large rocket out of fiberglass tubing it would be more forgiving as it is moved around. I think I would keep my landings around 15 fps. though LOL! More than once I have broken a rocket before it gets to the pad.

Hard to keep track of what you find sometimes Very helpful info, thanks

Feel free if you havent to look over my L3 build here on the forum. It was an all glass construction of PR parts bought at wildman.

https://www.rocketryforum.com/showthread.php?s=&threadid=27663

I can attest that a glassed air frame would never take that abuse

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i completly disagree... I think that a glassed airframe can be made just as strong as a pure glass airframe.. the easiest way to look at it would be this... what is the difference between on all glass tube made of 4 layers of 6oz glass and a thin walled kraft tube made with 4 layers of 6oz glass... the difference...? Its time... the tube with the thin walled kraft tube on the inside would be slightly heavier (but stronger) and much easier to make because you dont have to worry about it releasing from the glass.

I am sure you are going to being up filimant or some other form of pure glass (besides a stanard weave) but you should have said something like, "I can attest that a glassed airframe of the same weight would never take that abuse" because I am sure it wouldnt be hard to beat the tube in strength. Oh and just one other fun fact, CF wont help much for landing abuse... it is somewhat brittle and has a high stiffness and tensile strength but very pour impact resistance. Glass is the opposite, it is flexible but takes impacts much better then carbon. As does kevlar... that is why a kevlar/carbon or glass/carbon hybrid weave in my opinion is the best way to go, you have the stiffness of carbon with the added strength and impact resitance of kevlar or glass.

Originally posted by jraice
i completly disagree... I think that a glassed airframe can be made just as strong as a pure glass airframe.. the easiest way to look at it would be this... what is the difference between on all glass tube made of 4 layers of 6oz glass and a thin walled kraft tube made with 4 layers of 6oz glass... the difference...? Its time... the tube with the thin walled kraft tube on the inside would be slightly heavier (but stronger) and much easier to make because you dont have to worry about it releasing from the glass.

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Here is why I belive its stronger and better. For one when you or even most people lay up glass onto an airframe and have to wet out the glass and airframe. not always does it get FULL penitration of the substrate below the glass. seen it happen tons. On a all glass tube it has no need to bond to a weak piece of cardboard or phenolic for that matter nor is it a laminated agent. and im sure that if you look at true convolute glass tubes as I prefer, there is more then just 4 wraps as it is wraped on a mandrel and pulled around and wet out. the wall thickness ends up being 1/8 inch. Im sure with that in mind it takes more then 4 wraps and then while tight on the mandrel it gets an outer wrap and compression then normally baked as it is also a higher tempurature and strength of glass like a G10 or even G12 glass. Thus adding to the entire conformity of no air gaps or bubbles no pin holes nothing. Just pure perfection of a solid tube and it will weigh less then your same size tube with the equal wraps of glass but still will not be equal in strength to weight ratio either.

Originally posted by jraice
I am sure you are going to being up filimant or some other form of pure glass (besides a stanard weave) but you should have said something like, "I can attest that a glassed airframe of the same weight would never take that abuse" because I am sure it wouldnt be hard to beat the tube in strength. Oh and just one other fun fact, CF wont help much for landing abuse... it is somewhat brittle and has a high stiffness and tensile strength but very pour impact resistance. Glass is the opposite, it is flexible but takes impacts much better then carbon. As does kevlar... that is why a kevlar/carbon or glass/carbon hybrid weave in my opinion is the best way to go, you have the stiffness of carbon with the added strength and impact resitance of kevlar or glass.

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And just so you know I never mentioned strengths of CF and doing anything with them. I know it can be brittle but it is also more rigid and has a harmonics difference then glass does and works great for Mach flights and laminating glass with to help dampen those effects say for fin flutter.

I used to laminate all of my stuff (cardboard and phenolic) but after much use and building for sometime now have made the switch to a much more robust and durable glass tubes. My rockets handle more and live longer.

I belive there is a rocketry site that test materials and belive the have data to back what I say. www.rocketmaterials.com. Seems the site may be down as I am having problems loading the page.

Anyhow we can agree to not agree but. I still stand by my belief of such. When I have the numbers to provide I will.

I would like to ask a question, are you stating that a pure tube (wrapped on a mandrel which was later removed) made of several wraps of glass (plain weave glass... like that used to make a glassED tube) is weaker then a pure glass tube that was filimant or covelant wound of the same thickness and/or weight? If so then you have proven me wrong but I know of numerous people that make glassED tubing with a very thin (and VERY light weight) kraft tube as a mandrel and wrap it with glass or some other form of reinforcement. But for simplicity they dont remove it. I made some CF tubing with multiple wraps of carbon. My 3 layer 54mm tubing was a little weaker then the PR carbon stuff (3 layers of plain weave 6 oz) but can take flights well over mach 2 and is MUCH lighter then the 54mm PR CF tubing. A 4 wrap tube I did for a test had no flex on the ends whatso-ever and was still much thinner (most likely lighter as well) then PR CF tubing.

'Glass is NOT required for Mach busting flights. For me personally, 'glassed airframes OR 'glass tubes are more for durability... they 'age' much better than cardboard airframes over repeated flights.
I've had a few rockets run close to 1000mph and they were either 4" LOC tubing stuffed with Couplers (Double walled if you will) or 4" Phlexible Phenolic stuffed with Phlexible Phenolic full length coupler.
All but one of these mach busting flights were VERY straight. One flight in the 4" Phenolic rocket did some serious corkscrewing due to me doing a dumb a$$ thing, but even at those speeds and corkscrewing, it stayed togethe and went 9000ft.
All that being said, most of the new projects I'm planning will be 'glassed or 'glass tubing simply for the longer life afforded and the nicer finish that is attainable over 'paper' or Phenolic tubing alone.

L8R!

Ron

Originally posted by AZ_Ron
'Glass is NOT required for Mach busting flights. For me personally, 'glassed airframes OR 'glass tubes are more for durability... they 'age' much better than cardboard airframes over repeated flights.
I've had a few rockets run close to 1000mph and they were either 4" LOC tubing stuffed with Couplers (Double walled if you will) or 4" Phlexible Phenolic stuffed with Phlexible Phenolic full length coupler.
All but one of these mach busting flights were VERY straight. One flight in the 4" Phenolic rocket did some serious corkscrewing due to me doing a dumb a$$ thing, but even at those speeds and corkscrewing, it stayed togethe and went 9000ft.
All that being said, most of the new projects I'm planning will be 'glassed or 'glass tubing simply for the longer life afforded and the nicer finish that is attainable over 'paper' or Phenolic tubing alone.

L8R!

Ron

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Not only do they age better but they should also hold up better under very wet conditions like say being lost in a pond for 24 hours or more. Not that I have any experience with this...

Tim

LOL... Bummer, BUT... here in Phoenix... There isn't a pond or any body of water within 10 miles of the launch site... except for a few irrigation ditches...

Ron

Hey Tim, maybe you need to set up your altimeter to set off another charge if you go below the original launch altitude. Set it up with flotation devive........maybe a seat cushion.

ROFL!! Maybe a strobe attached to the center of the seat??

Ron

Originally posted by plasticpaul
Hey Tim, maybe you need to set up your altimeter to set off another charge if you go below the original launch altitude. Set it up with flotation devive........maybe a seat cushion.

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I would even be willing to throw in the flight attendant except for those pesky NAR rules

Actually, my rocket survived quite well. It was a PML Explorer built with Quantum tubing. Even the phenolic motor mount seemed to be unaffected by the 24hrs in the water. My local motor vendor (here's the shameless plug for Merlin Missiles) spotted it bobbing in the water the next day and waded in up to his waist to get it - thanks again Lee! I would have to believe that a cardboard bodied rocket would not have faired nearly as well even for just 24hrs.

Tim

that is definetly one of the benifits of phenolic tubing...

Originally posted by plasticpaul
Hey Tim, maybe you need to set up your altimeter to set off another charge if you go below the original launch altitude. Set it up with flotation devive........maybe a seat cushion.

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CO2 device to blow up an intertube?

Al

That's a good idea or maybe Tim needs to develop a minature rescue sub he can use to hunt for his rockets.

This might be a good time for Tim to consider O-rings to seal up his electronics bay. Nasa has no problems landing in the ocean so it would follow that Tim would have no problem with a little pond.

That's a good idea or maybe Tim needs to develop a minature rescue sub he can use to hunt for his rockets.

This might be a good time for Tim to consider O-rings to seal up his electronics bay. Nasa has no problems landing in the ocean so it would follow that Tim would have no problem with a little pond.