Wooden Nozzles

[mabuse00]

Hi,

 

today I shot my first rocket. 50g KNO3/Sorbitol/Iron Oxide 65/35/+2

 

I used 25mm PVC Pipe. Unfortunately these "Shedule 40" waterpipes mentioned on many american internet sites doesn't seem to be common in europe.

My pipe is more suited for electrical installation. 1,5mm walls.

 

I used Beechwood for the nozzle. I read the some people use sodium silicate to make the wood to fireproof, at least to some extent, but i dont have that stuff around.

 

Anyway, the rocket was a great succes, but I could not find it afterwards to examine:(.

 

 

I'm curious if you have any experience with wooden nozzles.

Is it worth to try further?

Edited August 20, 2010 by mabuse00

[dagabu]

In the clubs I shoot at, PVC tubing and wooden plugs are frowned upon due to the ability of them becoming missiles. Rammed clay and paper tubes are considered the norm for fireworks.

[mabuse00]

Hi,

 

well, I can't imagine what's so dangerous about a wooden nozzle...

Mine weights less than 10g and in case of failure it's most likely to be shot into the ground.

 

 

The thing is, I can produce 10 of them in short time an each one looks exactly the same, so i can reproduce my results.

 

 

 

Today i shot 4 new rockets with the same setup, only the increased length of the rocket, thus also the propellant burning area.

But the rockets didn't seem to have much more power then the first one. After I found two of them i knew why - the nozzles eroded quite bad...

 

Rammed clay

Du u use any spezific nozzle form, or just a simple hole?

[Twotails]

Here's the thing, The nozzle(wood) can be come a prejectile(similer to a bullet, exept wood) and potentaly harm you or bystanders and property. The reason clay is (mostly) used is to provide a nozzle that when ejected would probably desinigrate apon contact with somthing(if im right) much less of a hazard than the wooden nozzle. The reason PVC is NOT used if that apon CATO, when the pressure builds up, the PVC shadders(think sharp, shards of razor-like plastic) thats bad, as it can hurt or kill you or people. Furthermore a wooden nozzle PLUS PVC tube would be even worse! think of it like your rockets, could potentaly turn into a bomb, shooting shrapneal at out at you or others. Now approche that of a Regular paper tubed, clay pluged rocket, its made so that IF it were to CATO, it would reduce the casing to harmless paper shreads, and or blow out the nozzle, someone MAY get hit by flying debree this way, but its much Less lethal than your rockets as-is. Im not saying any rockets safe or unsafe, but theres certin things that should be accepted as fact: Dont used PVC(pipe) in pyro(exept maby for comet pumps, ect), and personaly, dont use ANYTHING you dont want to be picking out of your arm/chest/leg later(if your still ALIVE to pick it out that is)

 

I dont mean to sound over cautious, but we all got eachothers safty in mind(i think!)

 

 

EDIT--

I failed to read the bottom of your post, There are some that use a former(rocket tooling and all that jazz) and theres some that just drill out the hole.

Edited August 23, 2010 by Twotails

[Mumbles]

The clay nozzle should disintegrate upon being expelled from the tube, not upon hitting anything. One of the big disadvantages of PVC tubes, besides being incredibly dangerous, is that blackpowder doesn't stick or adhere to it like it does to paper, which can cause CATO's. Despite the name, you can have CATOs past take off. This is when the wooden nozzle can become a dangerous projectile and hit people or property instead of just the ground.

 

How are you attaching these wooden nozzles to your PVC tubes?

[dagabu]

Another thing to consider:

 

Long years ago when I was first making rockets, I used PVC, when and empty casing came down, a neighbor called the cops and told them it was a pipe bomb. If made from paper, they are much less likely to panic if one drops someplace where the public travels.

[mabuse00]

The dangers of PVC are obvious, but i had the pipe ready, it was light and relativly strong - tempting...

 

I've got some Paper rolls here, but they are a little thin walled, 26mm inner diameter and 2mm walls...

This may sound stupid, but I have trouble to get proper thick walled paper tubes.

 

 

How are you attaching these wooden nozzles to your PVC tubes?

I've got a round stick of that wood that fits exactly into the pipe. With gently pressure I move it an position, about 5mm before the end, than I heat the pipe with an hot air gun and bend the overlapping pvc over the nozzle.

I also glue the nozzle with very thin CA glue that creeps between pipe and wood.

 

I bet the PVC ruptures somewhere before the nozzle gets blowen out.

 

The weakest point is the nozzle itself as it widens quickly and the pressure drops.

 

 

I might try to insert a washer in the wood. I'm really curious what would happen...

 

 

if one drops someplace where the public travels.

I'm shooting them in a very remote field, where I can overview a large area. The risk of hurting somebody else minimal.

I'm more worried about to hit myself if the rocket decides to change its direction...

[patsroom]

I was thinking about what all the others were saying about what if the Rocket were to CATOs. If you or someone else were to be injured with small pieces of PVC from the body of the Rocket, if I am not mistaken, PVC does not show up in X-Rays. This of course would make it very hard if not impossible to remove the PVC from the body......Just a thought.......Pat

 

Edited August 24, 2010 by patsroom

[Mumbles]

That is in fact a false rumor. PVC does show up on x-rays, but still it's not something I want to experience. Getting it out isn't the end of it though, there is still a high infection risk in the weeks following.

 

I can not say this seriously enough. Please don't even think about adding metal washers to those rockets. That would be a fast way to get yourself hurt and banned from the forum. We really can't have people discussing incredibly dangerous stuff like that.