blackpowder

[jackhammer]

I was wondering what people thought the best otc substitute for sulphur would be in a KNO3/charcoal/sulphur blackpowder mix. Thanks for any help.

[Bert]

Why would you NOT want to use Sulfur? Primes for chlorate stars excepted?

[dogbone103]

Im not sure what you could use as a substitute but you could try using a sulfide such as antimony sulfide.

I have heard that black powder could be made with sodium nitrate, is this true? Is their any way I could test sodium nitrate to see if it really is sodium nitrate?

[jackhammer]

Why would you NOT want to use Sulfur? Primes for chlorate stars excepted? Mostly because I just ran out, but I still have a ton of KNO3.

[Bert]

Mostly because I just ran out

Sulfur is widely available, cheap and shippable. It should not be difficult to obtain.

[Mumble]

You could always make Sulfurless BP. It still burns decently. It will be harder to ignite. The sulfur brings down the ignition temp. If you didn't figure it out, sulfurless bp doesn't have sulfur in it. The ratio is 3:1 KNO3 to C.

[T_Pyro]

Sulfur is widely available, cheap and shippable.
Cheap, yes, but widely available and shippable, not always. For example, its sale is illegal here, making it difficult (though not impossible) to obtain.

jackhammer, worst come to worst, you could always make some sulfur on your own by the reduction of SO2 by H2S:
SO2 + 2H2S -> 3S + 2H2O
Also,
Na2S + 2HCl -> H2S + 2 NaCl
NaHSO3 + HCl -> SO2 + NaCl + H2O
Na2S and NaHSO3 should be easy to obtain.

[Bert]

They don't use agricultural Sulfur in India? That would amaze me. Soil acidifier, fungicide... Cheap.

[T_Pyro]

Agricultural sulfur is sold not to individuals, and not in small quantities. Co-operative societies can source sulfur (with prior approval of the regulatory agencies) if they want, but in bulk. An individual farmer with the neccessary resources could do so, too. I, on the other hand, am not interested in buying sulfur by the ton, nor do I have the capital to do so even if I wanted to. Match factories can obtain sulfur because the Indian Explosives Act has a special provision for them, and fireworks factories can do so if the have a license.

[Bert]

Damn, I extend my condolences. Even in the US they haven't tried to keep ordinary individual gardeners from buying Sulfur.

[T_Pyro]

Your statement "even in the US", I think, is a malapropism! I'm still waiting for the day when amatuer pyrotechnics will be classified differently from "terrorists" and "bomb makers" in the country. At least you can order your stuff online!

[dogbone103]

can black powder be made from sodium nitrate instead of potassium nitrate?

[blindreeper]

Yes it can however it will not perform nearly as good and it will be hydrgoscopic.

[Bert]

can black powder be made from sodium nitrate instead of potassium nitrate?

In the US "B" grade blasting powder is/was made with Sodium nitrate. "Chile saltpeter" as it was known was cheaper than Potassium nitrate, it was mined from near surface deposits called "caliche" in Chile and used without conversion to Potassium nitrate for blasting powder where a heaving effect rather than a shattering one was wanted. It was often pelletized rather than granulated and put up in waxed paper cylinders to prevent it from picking up too much atmospheric moisture. Before cheap Ammonium nitrate took over, it was also used as the oxidizer dope of choice in active base dynamites (Soda dynamite). I made BP with Sodium nitrate when I was a kid. It will not work well if you're in an area of high humidity, and the ratios are a bit different (Sodium atomic weight about 23, Potassium atomic weigh about 39).
It burns with a distinctive yellow flame...

[PsYcHo]

T_PYRO ,
I've been living in Bangalore, India for a few years, got a few months left. You said that sulfur is illegal but not impossible to obtain, is there any way that you know of to buy sulfur?
Me and a friend are constructing a rocket, but we need some bp as a charge to blow the nose cone off at apogee. We made some sulfurless bp with 80% KNO3 and 20% C, however it burned too slow to be of any use.

[Bert]

Me and a friend are constructing a rocket, but we need some bp as a charge to blow the nose cone off at apogee. We made some sulfurless bp with 80% KNO3 and 20% C, however it burned too slow to be of any use.

2 questions-

If not BP, what is your rocket fuel?

Can you get other oxidizers than KNO3, or can you get sulphides such as Iron pyrite?

[PsYcHo]

Maybe I should have made it clear what type of rocket I was constructing, we are not making a pyrotechnic rocket, its like the estes rockets you can buy in US, UK. Only our rocket will hopefully be more powerfull. The bp is only needed to blow off the nosecone, it should ignite inside the body and pressurize the body, thus forcing the nosecone off to pull out the parachute.

The propellant we are using is a 'candy' fuel containing 55% KNO3, 31% sugar, 1.5% FeO3, 9% water (which evaporates while making the fuel), and 3.6% corn syrup, which sort of acts as a binder. We did have a few problems with the rate of combustion, but the FeO3 has solved that. Today i have found a good source for chemicals :D , including sulphur, and i assume sulphides, any suggestions for a better oxidizer, or a better propellant would be much appreciated.

Thx

[Bert]

The propellant we are using is a 'candy' fuel containing 55% KNO3, 31% sugar, 1.5% FeO3, 9% water (which evaporates while making the fuel), and 3.6% corn syrup, which sort of acts as a binder. We did have a few problems with the rate of combustion, but the FeO3 has solved that. Today i have found a good source for chemicals :D , including sulphur, and i assume sulphides, any suggestions for a better oxidizer, or a better propellant would be much appreciated.

Thx

Gosh, this takes me back! I was 8 when they landed on the moon, and I'd allready lost a couple of Estes rockets to the local trees. Get yourself a copy of October Sky (http://www.amazon.com/exec/obidos/tg/detail/-/0440235502/104-9213592-8162332?v=glance) If you haven't allready. It was only later in life I discovered the joys of replacing the recovery system with flash powder and stars...

Rocket candy is an excellent beginning fuel. It has moderately low Isp and doesn't keep long, but it is non-toxic and CHEAP, with easily available ingredients. A few modifications, such as Sorbitol replacing the Sucrose help a bit, but aren't necessary for having a fun time and a good flight if you can't get them or afford them.

I'd finish your first project, then try BP which is a little trickier. Avoid Sulfur/Zinc, it doesn't have a great benefit in Isp and is much more dangerous and difficult to work with IMO. I knew kids who ended up getting skin grafts and surgery for shrapnel from playing with this. Avoid metal cases until you know EXACTLY what you're doing and are using fuel/chamber pressures that specifically require them. If you're in India, Ammonium perchlorate composite fuels may be difficult to source ingredients for... The components can't be exported from the US due to their usefulness in rocket weapons. If you want to see "state of the art" for homebuilt engines- Get Experimental Composite Propellant (http://www.experimentalrocketry.com/book.html) by Terry Mcreary.


e-mail me off list if you want an introduction to the rocketry/black powder list. You will find a huge number of posts of interest there, and much information on alternative fuels.