PVC as a high power airframe

Ok so I'm starting to think about what I want to build for LDRS 34. Yesterday my parents cleaned out our attic and they came across a large piece of "PVC" type material. I immediately thought rocket. It fits a 4" LOC nose cone but I would have to build up the base of the nosecone with fiberglass a little to make it line up well. First thing I though was if it was if it was going to be strong enough and if it could up to the hot ejection charges. It is extremely light much lighter the a fiberglass tube but a little more heavy then a paper tube. What I did for the heat was hold a lighter to it for 20 sec inside and out. The results were great nothing happened and even hot it wouldn't flex or change shape. the second test was to decide wether it would be strong enough or not. I decided the best way to do was to sit on it suspended between two "chairs". It passed this test as well with minimal flex. So far it has passed everything I thought would be a problem but I want to here from others wether I will be fine to build with this or any other problems that you may think I will face.

Thanks


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It works as long as you avoid Mach.

Coupl'a things:

First, yes PVC can be used with some considerations (one that Chuck pointed out). Others have built great rockets with this as a material. The most obvious examples would be Eric Foster's Badazz offerings. He would be a great resource for info/tips/etc.

Second, glue is a particular concern. Not all "PVC type" materials are the same, and standard epoxies may or may not be appropriate. Bonding "PVC" requires proper glues made for this. So it would be important for you to find out exactly what you DO have, as opposed to something that is "PVC type".

Build it and fly it. And make sure you post pics/stories/vids/etc. about the process and flights.

s6

Thanks I had thought about the glue I will check to see what it really is. I will certainly make a build thread.


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One problem with pvc is that if a shred, cato, or other violent failure were to occur, pvc will shatter into small, sometimes sharp pieces. From what I know this is the main reason people stay away from it.

Eat said:

One problem with pvc is that if a shred, cato, or other violent failure were to occur, pvc will shatter into small, sometimes sharp pieces. From what I know this is the main reason people stay away from it.

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This is theoretical and I have never hear of it happening. PVC when it shreds has very little momentum because of its light weight. You have to be pretty hard close to catch a shard.

cwbullet said:

This is theoretical and I have never hear of it happening. PVC when it shreds has very little momentum because of its light weight. You have to be pretty hard close to catch a shard.

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PVC shattering is the justification TRA has for forbidding PVC motor cases at research launches. It may be an entirely theoretical problem even with motors, but to ascribe it to airframes is ludicrous. The other ludicrous claim is that PVC pieces are invisible on X-rays, so if you get those "small, sharp pieces" embedded in soft tissue, they are impossible for doctors to find and remove.

I have built a number of rockets with PVC airframes, including my L3 ship. PVC bonds well with solvent-type cement. I use filler-free solvent--the water-thin stuff, rather than the thick adhesive you get at the hardware store. Hardware store PVC cement is optimized for filling gaps and creating water-tight "fillets," rather than for shear strength.

https://www.rocketryforum.com/showthread.php?58482-Ari-s-6-quot-PVC-sewer-pipe-tube-fin-L3-rocket

Ari.

Thanks for all of the advice. Turns out that the pipe that I have now is ADS and that there are no glues that will stick to it. I am going to get som regular 4" PVC and will start a build thread. Thinking a 54mm motor mount and 10-13 ft tall


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If ya fly this at LDRS34, I will find a way to drag race you...

blackbrandt said:

If ya fly this at LDRS34, I will find a way to drag race you...

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that's the plan your on!!


P.S a 10ft length of 4'' PVC is 5$ at lowes....

You are on.

conman13 said:

Thanks for all of the advice. Turns out that the pipe that I have now is ADS and that there are no glues that will stick to it. I am going to get som regular 4" PVC and will start a build thread. Thinking a 54mm motor mount and 10-13 ft tall


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You do not want regular PVC ....way too heavy, unless larger than normal motors are used for the size.

Try and find the thin wall version.

blackjack2564 said:

You do not want regular PVC ....way too heavy, unless larger than normal motors are used for the size.

Try and find the thin wall version.

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Yes that was what I was planning on doing. Going to try to go to lowes tomorrow.


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Be sure it is straight before investing time and money.
many pieces are bowed.

M

conman13 said:

Yes that was what I was planning on doing. Going to try to go to lowes tomorrow.

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Around here at least, Lowes and Home Depot only carry sch 40 PVC. The thinwall stuff I use in my rockets comes from a specialty plumbing supply store a couple of towns over.

I have built a rocket out of Lowes ABS pipe that flew very well. ABS sewer pipe has thick walls but they are a kind of sandwich. Inside and outside surfaces are solid, but the inside is foamed up. This decreases weight per foot.

Ari.

This stuff??? Looks very thin and it's only 1 cent

https://m.lowes.com/product?langId=...=3133147&store=1784&view=detail&nValue=SEARCH


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iter said:

Around here at least, Lowes and Home Depot only carry sch 40 PVC. The thinwall stuff I use in my rockets comes from a specialty plumbing supply store a couple of towns over.

I have built a rocket out of Lowes ABS pipe that flew very well. ABS sewer pipe has thick walls but they are a kind of sandwich. Inside and outside surfaces are solid, but the inside is foamed up. This decreases weight per foot.

Ari.

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It's called foam core and is also available in PVC. Different parts of the country use different pipe.

The other stuff with the bell hub on it is SDR 35. As far as I know it's only available in PVC. It's usually green and is used as underground sewer pipe.

I'm actually working on a (much smaller) PVC rocket. It would be about 3ft long out of regular PVC (hence why it is smaller) and fly on 38mm motors. I don't know what you are using, but I am just using a PVC endcap. View attachment Smaug.ork

I was going to use a 4" LOC nose cone built up with fiberglass at the base to match the outside diameter of the pvc. here is what I have so far.


View attachment big boy.rkt

iter said:

The other ludicrous claim is that PVC pieces are invisible on X-rays, so if you get those "small, sharp pieces" embedded in soft tissue, they are impossible for doctors to find and remove.

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There have been a few cases of bones harvested from bodies and replaced by PVC pipe and fittings. They use X-rays to find it.

conman13 said:

Turns out that the pipe that I have now is ADS and that there are no glues that will stick to it.

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Epoxy will stick to ABS, but you have to rough it up first. Same thing we do with PML quantum tube.

codysmith said:

I'm actually working on a (much smaller) PVC rocket. It would be about 3ft long out of regular PVC (hence why it is smaller) and fly on 38mm motors. I don't know what you are using, but I am just using a PVC endcap. View attachment 179941

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This stuff is 2" and has a much thinner wall than schedule 40 PVC.


https://www.centralvacuumonline.com...ationparts/4-feet-of-central-vacuum-pvc-pipe/

Binder Design said:

Epoxy will stick to ABS, but you have to rough it up first. Same thing we do with PML quantum tube.

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No ADS Advances Drainage system pipe.

I dont know if someone has seen this yet, but this guy did his L3 using a PVC rocket, but it looks like he might of used a sandwich of materials, but worth a look.

[video=youtube;U6JBVRkGq-s]https://www.youtube.com/watch?v=U6JBVRkGq-s[/video]

That was a great video

Not a big fan of PVC (personal preference). I like the night rockets made with it. I would avoid sch 40/80 due to weight and safety. Thin-walled as others suggested would be lighter and less dangerous if a bad cato occurred. I can't imagine PVC having that much energy left if proper safe distances are maintained.

I do have some Quantum tube - PVC? Thin stuff - not cheap though.

cavecentral said:

Not a big fan of PVC (personal preference). I like the night rockets made with it. I would avoid sch 40/80 due to weight and safety. Thin-walled as others suggested would be lighter and less dangerous if a bad cato occurred. I can't imagine PVC having that much energy left if proper safe distances are maintained.

I do have some Quantum tube - PVC? Thin stuff - not cheap though.

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Yes that's the great part of the PVC compared to quantum tube and others alike is the large price difference. (Also no spirals to be filled)


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conman13 said:

Yes that's the great part of the PVC compared to quantum tube and others alike is the large price difference. (Also no spirals to be filled)


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Price is nice. If you have cones and other parts that fit too, it is a big plus. If you have thick tubes, the nose cone shoulder would be tiny by comparison.

If you like ~3" airframes, window tint tubing is another alternative. Like Quantum Tube...but free.

conman13 said:

No ADS Advances Drainage system pipe.

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ADS is not a material it is a company name. Generally , if the pipe is black, it is ABS, if it is white, grey, or green, it is PVC, if it is a hybrid drain pipe, it will be black inner and outer, with white in the middle like an OREO cookie.....

No matter. Just rough it up first.