ZnS Rockets

[elliotmotocross]

Has anybody made Zinc/Sulfur Rockets? I wouldn't mind giving them a go. I have made quite a few BP and whistle rockets and they have been pretty good. Whistle I have had a few problems with, but that's to be expected.. right? Anyway does anybody know what a good ratio is and how the rocket should be prepared? Can it be rammed or pressed? Core or endburner?

 

Thanks

[TheEskimo]

General comp is 67.1Zn:32.9S. A simple google search turned this up.

As for their performance, it's not worth building them. Professional rocketbuilders have managed to get ZnS rockets fairly high, but this is with advanced designs and support teams.

I have made them before. They need a core to get them going--too much of a core, as in a candy rocket, will CATO. I have rammed them, but they should probably be pressed.

I LOVE the effect--BIG green/yellow flame, with a huge smoke trail. Unfortunately, with the resources available to the amateurpyro, the ZnS rocket isn't worth the cost, and performance.

My experience with this fuel--EXPENSIVE. I got my Zn for about $14/pound. That means that each pound of fuel is will cost atleast $9.38 per pound, along with the cost of the sulfur. Candy rockets will cost about $1/pound, BP fuel about $.75/lb, and whistle rockets about $1-3/lb. Do you really want to pay this much for a simple rocket? Also, zinc is very dense, and makes up a lot of the fuel. This means your rocket is very heavy. Combine this along with its low isp, and you get a rocket that can't lift a header very far. Even without a header, they don't get very good height.

tl;dr version--Expensive, low performance, not worth it in the long run. Fun to experiment with, though.

Edited April 10, 2010 by TheEskimo

[elliotmotocross]

General comp is 67.1Zn:32.9S. A simple google search turned this up.

As for their performance, it's not worth building them. Professional rocketbuilders have managed to get ZnS rockets fairly high, but this is with advanced designs and support teams.

I have made them before. They need a core to get them going--too much of a core, as in a candy rocket, will CATO. I have rammed them, but they should probably be pressed.

I LOVE the effect--BIG green/yellow flame, with a huge smoke trail. Unfortunately, with the resources available to the amateurpyro, the ZnS rocket isn't worth the cost, and performance.

My experience with this fuel--EXPENSIVE. I got my Zn for about $14/pound. That means that each pound of fuel is will cost atleast $9.38 per pound, along with the cost of the sulfur. Candy rockets will cost about $1/pound, BP fuel about $.75/lb, and whistle rockets about $1-3/lb. Do you really want to pay this much for a simple rocket? Also, zinc is very dense, and makes up a lot of the fuel. This means your rocket is very heavy. Combine this along with its low isp, and you get a rocket that can't lift a header very far. Even without a header, they don't get very good height.

tl;dr version--Expensive, low performance, not worth it in the long run. Fun to experiment with, though.

 

Ah thanks for the help. It's kind of what I was originally thinking. I might give it a go tomorrow but by the sounds of it might not be too successful.

Cheers

[Ventsi]

Just a tip. Cracker sells excellent quality Zn powder at 3.50 a pound.

 

http://www.undergroundgadgets.com/shop/product_info.php?cPath=42_51&products_id=746&osCsid=cbaa292e3c75dc6be417ffa023e43bbb

[TheEskimo]

Hot damn!! I got ripped off, then. But still, even if you got that price for zinc, each pound of fuel would come out to atleast 2.35/lb, making it just as or more expensive as whistle, and having a very poor performance besides.

[TYRONEEZEKIEL]

I have experimented quite a bit with Zn/S rockets and even with High Performance tooling, I was still unable to get any lift out of it. at all!

 

I have read elsewhere that the nozzle requires a burst disk which will allow the pressure to build up in the chamber until it reaches a point that it ruptures the disk which will allow the rocket to gain altitude.

 

I think they make gorgeous fountains, but as for rockets, not really worth it. what you could do is, when making a bp motor, place a section of Zn/S in the motor to give the green flame, while relying on the power of BP or whistle to lift the rocket.

[WSM]

Has anybody made Zinc/Sulfur Rockets? I wouldn't mind giving them a go. I have made quite a few BP and whistle rockets and they have been pretty good. Whistle I have had a few problems with, but that's to be expected.. right? Anyway does anybody know what a good ratio is and how the rocket should be prepared? Can it be rammed or pressed? Core or endburner?

 

Thanks

 

Many years ago (40) a friend of mine came up with a variation on the zinc/sulfur propellant that works very well for small engines (1/4" to 1/2" maximum), end and core burn. The propellant is:

 

53 zinc dust

36 potassium nitrate

11 sulfur flour

 

The composition needs to be well mixed and very solidly consolidated or your rocket may end up as a blue firecracker on a stick! For ignition, use something very hot, like thermalite; or a bit of hot prime on the fuse inside the motor.

 

Let me know what you think after you try it.

 

WSM

[Siegmund]

If the Zn/S mixture has little lifting power of its own ... perhaps the obvious use is as the delay comp after a standard BP thrust? It would have never occured to me to try that. (The subject is much on my mind, after a rocket enthusiast friend asked me for ideas for how to get colored smoke from a delay stage without using chlorate+organic comps...)

[MrB]

Dug up this old thread, since i don't really think it warrants it's own thread...

 

For what ever reason, "Zinkit" rockets has become popular with a manufacturer here in Sweden.

I'm starting to think they know something i don't. These rockets are fuse lit from the bottom, seams to have the burst disc, and generally is finished with a basic salute, or Ti salute. I haven't been able to get my hands on one, that i could take apart, so i have no freaking idea how they make these cheap and cheerful pyro-rockets.

 

Anyone has any clue as to how one would make these in to cheap and cheerful pyro rockets? I was convinced they were to expensive to make, mostly due to construction details, and partly due to raw material cost. The up-shot is of course that it wont go and over pressurize, causing a CATO. Did someone figure out something new with this propellant?

B!

[stix]

I've only read about zinc rockets, and as far as I can tell they are very inefficient. That's not to say that it's not worth trying out.

 

I've made zinc granite and pearl stars, they looked very nice - light aqua with a gold orange tail. I reckon a rocket would look very nice for an effect.

[MrB]

I've only read about zinc rockets, and as far as I can tell they are very inefficient.

 

That is pretty much my understanding as well. Pair that with the fact that it is more complicated to use, having to add the burst disc, it makes me wonder why it's been a crazy lately here in Sweden. Did the company making them figure out something new? Hard to know, of course, but at least it seams there isn't any info floating around that made it obvious.

I'll go away now, scratch my head, and see if i cant get a hold on one of these rockets, to dissect, see what they did. Sadly, they have a requirement for a permit on sale, so i'm not going to be able to straight up buy one, or i would have already.

B!

[schroedinger]

B i would assume that they use a formula that only uses the zinc for the color effect and other ingredients build the main thrust source.

 

Stix yes zinc formulas make an excelent delay formula. Press them with a slightly wet comp. The spreader formula work really good.

 

If you want to get more thrust ouf of a Zn/S formula you can melt the S on a oil bath and melt it together with the Zn. Granulate the comp and press it. These granules can also be used as lift, but you need a lot of it, since Zn is very heavy.

[Maserface]

Have you ever actually hot-cast zinc/sulfur rockets, shroed? Sounds like terribly dangerous advice.

[schroedinger]

No not cast. You set the oil bath to 140ºC. Now you melt the sulfur and add the zinc. With 140 ºC you are way under the ignition temp of the mix. The cooled granules get pressed. Thats what i wrote never wrote anything about hot casting, thats doesn't work, since the liquid is way to viscous and heating it more to reduce viscosity isn't very good.

[Maserface]

Have you actually done that process?

[MrB]

B i would assume that they use a formula that only uses the zinc for the color effect and other ingredients build the main thrust source.

 

It would make sense, and i honestly have no idea, but they behave differently from "normal" rockets in that the fuse is lit, goes in to the casing, after which it feels like a dud, and people want to approach them. At which point they jet of like all hell was chasing. Short (very) burst of energy, and then it coasts until it breaks.

 

B!

[schroedinger]

Masterface yes i did even tried to ignite the fuel by overheating the oil bath. The oil bath sfarted smoking but the Zn and S didn't ignite. But after all ZnS is more a curiosity then real applicable thing. The problem is just that you get no good results from a ZnS rocket, but have a quite expensive propellant that is also quite easy to ignite by static electricity and shock. If you look through rocket sites you can find a lot of reports about accidents with ZnS or micrograin rockets/fuel.