Anyone of you had any experience with Zn/S rockets?

I've just started experimenting with them, using a fuel composed of 80% Zn dust and 20% finely ground sulfur.

I guess this mixture might be a little bit harder to ignite than BP, but maybe that can be solved by adding a little bit of BP or similar mix just where the fuse enters the nozzle?

Wonder if a small amount of KClO4/C would be appropriate as a first fire mix? I have plenty of KClO4, but have ran out of KNO3 for the moment...

My experience with Zn/S rocket stays close to the ground :(

Some online documents say it is a way to heavy mix to create a very effective lift, though I've seen rockets that flew on them, and my test mixes were very powerfull too. (nice roar)
I'd stick with KNO3/sucrose or black powder rockets.

PS(1): Why do you complain because you have plenty of good strong oxidiser (compared to KNO3 anyway) ???

PS(2): You made a topic with your second post, so don't expect to hang around much longer ...

Though I've never tried that propellant myself, it is obvious that the relatively high density of zinc will add a lot weight to the rocket thus making somewhat inefficient compared to other fuels.
The composition I know consits of 67.1% Zinc and 32.9% Sulfur and it is also stated that the zinc/sulfur mixture is not a very efficient propellant due to its low specific impulse.
Because of this I think that zinc/sulfur propellants are not the best solution, although it would it would be an intresting experiment.
Ammonium perchlorate propellants seem to be the best choice I think.

Zn/S seems to be a bit harder to use properly than other rocket fuels I have tried, but it's supposed to work real good.

I suppose I still have some experimenting with making a better nozzle design before I'll get it to work properly.

Zn/S burns slower when pressed into a tube, so I guess a real small nozzle design will be required in order to make it take off...

The main advantage is probably that it is less sensitive than chlorate/perchlorate based rocket fuels.

I came here to both share my knowledge and to learn in areas which I have less experience, and I did not intend to break any rules.

My first post was a reply to another thread, my second this thread about rocket design, sorry if I upset anyone, didn't mean to!

Cheers!

Macgyver

I had a very stunning experience with Zn/S. Filled into an empty newyears eve rocket and rammed it. I added a little bit of BP to ensure ignition. When I lit the fuse, the BP ignited and after 2 seconds a very sharp bang hit my ears. When I went to inspect the rocket, I noticed that it had been split in 2 parts, one stayed on the ground, the other one landed 10s later.

However, I must say that this was done with very fine chemically pure Zn powder.

Macguyver, with KClO4 you can make far superior rockets. Also, you can very easily make NH4ClO4 by reacting KClO4 with H2SO4 and NH3.

I haven't yet tried the propellant in rockets but burnt loose powder.. It really burns very fast producing a thick smoke cloud and a nice intense green flash. At least you can make some sort of flash bangs with it...

It might be a bit harder to ignite than bp but you still don't need any prime, single fuse will do. Though it certainly is a more sensitive propellant due to presence of Zn. Yes, the high density of zinc and the low specific impulse are the main drawbacks of this propellant.

Macgyver, you don't need to press it into tubes (especially to ram it!). Packing it gently into a tube provides faster burn rate. The KN ratio is about 4 IIRC so you might want to use relatively big nozzle. The take off will propably still sound more like an explosion than a normal whishhh! <img border="0" title="" alt="[Wink]" src="wink.gif" />

I'm looking forward my holiday when I'll get time to test this stuff in the rockets and I'll keep you noticed how they work..

I've seen some very impressive pictures of Zn/S propellant rockets, but I don't think it's a very good choice for a propellant. Like others said, KNO3/Sucrose or BP would be better for most purposes.

Chemistry-type question: I'm told in the Zn/S propellant the sulfur acts as the oxidizer...how does this work?

It acts as an oxidizer by gaining electrons (from the zinc)

Zn + S -&gt; ZnS

Zn is 2+, S is 2-

Sulfur is nifty in that it can be both an oxidizer or a reducer

Macgyver, this thread will remain open because i think this fuel needs discussing but look at the rules because this has brought you very close to HED.

about the KClO4/C....no offence, but obviously it will be fine. KNO3 is usually used because its cheap and safer thats all. KClO4 will help it burn much hotter so would probably make a better first fire mix. do some research about the chemicals and do some experimentation.

From my experience so far, Zn/S burns much faster as a loose powder than when confined and compressed in a cardboard tube.

But it does need a little BP to insure ignition, and yes I do use very fine Zn powder, about 2.5-4 um grain size.

I'll try to make some more tests this weekend and get back to you with my results...

If you plan on making big Zn/S rockets, fill little tissue paper bags with the propellant and load a few into the rocket motor, rather than having the propellant in one big continuous charge. Otherisw, the Zn has a habit of settling to the bottom, leaving S on top, and this obviously fucks up the fuel. With the bags, it can't settle out as much.
I personally find the common KNO3/sugar cast fuels to be more effective, reliable, and easier to use. KClO4/sugar rockets should be even better.

I just made some rockets with Zn/S fuel (7/3). The results were, one lousy lift up, one pretty loud CATO and one succesful take off.

80mm x 18mm ID cardboard tube (wall thickness about 3mm) was used in each. The first one was nozzleless but in the other two I used 4mm bentonite nozzle. Actually I'm not sure if the second was a CATO or just a god damn loud take off. It was so dark, all I could see was the bright flash and heard the bang. Never find any pieces of the rocket though... In the last one I used a bit thicker nozzle and it flew maybe 50 meters.

I should have made more tests with the bigger motors but I really don't think this propellant is worth of it. One finds much better uses than rockets for these chems...

Just did a test with a Zn/S rocket made out of an used CO2 cartridge.

Worked much better than expected, but took off so fast that you could hardly see where it went except for the smoketrail it left up in the sky.

I used about 30g of Zn/S (80%/20%), and just attached the CO2 cartridge to a stick, but for such a simple design I'd say it worked well...

Where did you come by your Zn powder?

I have heard it to be useful in smoke comps some of which containing hexachlorathane. Another one that comes to mind is roughly 80%Zn/20%S.

From "Svenska Kemi" in Sweden. It's 3.5 um particle size, and works wonderful for Zn/S based rocketfuel.

For hexachloroethane based smoke comps, you don't need this small particle size, but it works wonderful. :D

Try 37.4% Zinc powder, 46.6% Hexachloroethane, 16% Zinc Oxide....

If want a cheaper HCE smoke, try 47% Zinc oxide, 37% Hexachloroethane and 6% Aluminium powder. This one is hard to ignite, but use a small amount of flash or BP, once it starts to burn it burns very good....

I get my zinc powder (very fine technical grade) from a wholesale company that sells many other useful chems as a paint additives. Zn was about €10/kg.

Is that the same place where you get your HCE?

Yes, same place I got the HCE as well as most other chems.

Good quality, fast service & no questions asked...

I did a small experiment about 2 months ago comparing the Zn/S to KNSU (similar to KNO3).
Both of the propellants came in at 25 grams, excluding the 1/4 inch PVC pipe that served as the case, and the rock putty nozzle.
I fired both of them off at the same time but the Zn/S seemed to explode rather than go up, so the KNSU rocket won (probably because I have tons more experience with them).

Overall estimated altitudes where:
KNSU - about 45 feet (wow)
Zn/S - about 10 feet