Anyone ever use PEX HDPE as a rocket tube?

[giod]

this is100 psi rated very lightweight HDPE tube in 3/4" ID.

 

wanted to test some rocket motors in it. Anyone try it?

 

Comes in Red WHite and Blue

Edited September 17, 2013 by giod

[Carbon796]

Pex is rated at a specified pressure relative to a specific temperature. The higher the temp, the lower the pressure rating. It will also change according to pipe size. Are you sure its rated at 1000psi? I don't think the 3/4"Pex I use at work is rated anywhere near that. Pex can get extremely soft, melt, and also catch on fire. Depending on how hot it gets. It's also pretty slick, you probably wouldn't get a traditional nozzel or bulkhead to bite into the wall.

[giod]

Oops one HUNDRED psi.. According to the print. I've made some hummers with it, didn't catch fire, got soft though, vent hole by widened by double after 3 second burn. Bentonite held fifty percent of the time. I think for single use it will work. Still playing Edited September 17, 2013 by giod

[Arthur]

The UK retail market has some rockets in which the motor is pressed into a plastic tube but this is then pressed into a typical paper tube for mounting the stick and label. Some of out bigger rockets are made in a metal tube, again this tube is pressed into a card tube.

[Dodad]

I had Pex tubing installed earlier this year. I bet you could use it for a small rammed sugar rocket, providing you can get the nozzles to stay in. You would'nt need to worry about shrapnel with this stuff. Roughen up the inside diameter where the nozzle goes to help it stay put. Paper tubes would be better tho. That plastic will persist in the enviroment for a long, long time.

[Col]

I use pex tube for launching rockets but i wouldnt use it to make the motors. Some of the small commercial whistle rockets use a very rigid, clear plastic tube. From memory, the plastic was similar to polycarbonate with a good 2 - 2.5mm wall thickness.

[psyco_1322]

I actually work at a plant that make PEX pipe just like that. I will state that we do melt and extrude it at under 350F. It does not take much heat to soften the stuff up. Then again, it's only rated for ~100psi of water pressure. On a good note, it is polyethylene and you won't get any shards of death from it.

[Dodad]

I actually work at a plant that make PEX pipe just like that. I will state that we do melt and extrude it at under 350F. It does not take much heat to soften the stuff up. Then again, it's only rated for ~100psi of water pressure. On a good note, it is polyethylene and you won't get any shards of death from it.

 

Still, for a simple cored rocket the burn time is so short I still think it would hold up. I wish I had some 1/2" Pex, I would test it.

[dagabu]

While I don't like plastics of any kind littering the ground, lakes and rivers, PEX is a great solution for the new rocketeer that doesn't know if they will be in the hobby long or not. A stick of PEX is pretty cheap and cuts easily. It takes pressure well with ramming and shows stress by bulging the case. Nozzles lock in nicely but still blow out if the burn lasts more than 1/2 second.

 

For nozzleless rockets, the PEX case works well for a pound-and-fire BP rocket but please remember to police your litter.

[Dodad]

I just tried some PEX tubing. It will not work with my 4oz rocket tooling. The inside diameter is 0.470", my tooling is 0.510"