4 replies to this topic

[a_bab]

I'd buy some 1" and 1/2" tubes, but since the shipping is a killer I want to ask if any of you have some negative experience concerning these tubes. I want to use them for nozzle less only rockets, including BP and whistle. They seem to be made or chipboard rather then virgin kraft, so I'm not expecting any wonders here.

While I'm perfectly aware that there are some tests to do in order to reach tune up these tubes to the max, I'd like to know what shoudl I expect from them before buying them.

I know Steve is a member here; I hope this topic is not going to offend anyone because after all we all have the interest to have everything going smooth.


So: any experience with these convolute wound tubes?

[Vic]

I have used steve's ½” tubes they are very similar to some I had from pyro tubes europe I think, some time back. They are fine for bp rockets but I would be wary of using them for whistle with the high loading pressures. They have thicker walls than NEPT but they are softer and are likely to crush and split on the inside when pressing, outwardly they will look fine.
Another thing is they say 1/2” but the metric equivalent can vary.
But as many a hardened tube roller will say, make your own.

[a_bab]

I'm currently investigating the rolling of polyethylene coated paper followed by baking the roll in the oven and so far so good. Still, I'd rather have all the tubes pre-made.

So you say these are chipboard tubes, just as I thought? Meaning the paper is not dense at all, sort of like the paper used for spiral wound tubes, only convolute rolled?

[Steve]

I would be careful using polyethene coated paper, as you will not get a good bond between layers, if you search for polythene glue, you'll find the general answer is 'you can't'. Also, if you're oven baking tubes, make sure you turn them regularly, or they'll come out banna shapped.

With regards to the Inoxia tubes, I havn't made rockets with them myself, so can't comment. I've requested the constructions specs from the rollers, and will post them up when I have them.

[a_bab]

Thank you for the insight Steve.

The PE coated paper works for tubes making, but so far it's giving me nightmares to be frank. It appears that the paper will expand a bit during the "cooking" so the tube will get slightly deformed (ovalised).