[peachpearplum]

I am relatively new to rocketmaking as a hobby and was wondering if there was any way of preparing rocket fuel for small miniature rockets without the use of potassium nitrate. The rockets that i make are around 4/5 inches high and weigh around 100g. The reason that I dont want to use KNO3 is that the stores that I know of that supply me with it have all slowly stopped supplying it due to bans and are forced to re-stock.One store does sell a fertilizer with soluble potassium oxide and nitrogen but thats as close as it gets to pottasium nitrate

I'm hoping to use more simpler and more common household ingredients to be more independent of garden stores and pharmacies.

Any ideas? Thanks for your help,

Andrew

[hermanntrude]

I'm sorry, but we can't really tell you how to make explosives. I can tell you that you can buy solid-fuel rocket engines in some model stores. I used to buy them in london

[peachpearplum]

oh. Ok, well I just though that it was a pretty normal question to ask lol.

thanks anyway, do you know where else can I find out?

[CaptainPanic]

Yup. The same people who came up with the brilliant idea to ban KNO3 from stores probably also want to monitor the internet... which is a good reason to ignore the topic of explosives on this forum. Explosives are (in the minds of some people) closely related to terrorism... such people don't realize that our economy runs on explosives (think about a car engine and space flight). Also, they only see dangers, and don't realize the added value of people who self-educate themselves by experimenting at home.

In short: it's the year 2009, and it's safety first - regardless of any benefits of risks being taken.And I think it's a wise decision of this forum to play it by the rules.

[gbg112]

CaptainPanic said:

In short: it's the year 2009, and it's safety first - regardless of any benefits of risks being taken.And I think it's a wise decision of this forum to play it by the rules.

I laughed for like ten minutes after that because it is just so true.

Have you considered using no oxidisation , e.g. Sodium bicarbonate and vinegar.

or you could try , carbon and hydrogen peroxide.

[ammonium nitrate]

gbg 112, you said carbon and hydrogen peroxide, the specific carbon is magnese dioxide, also, it needs some form of alchahol or other flamable liquid to the mixture but from a different compartment so you can light the methanol and then release the oxygen created by the magnese dioxide and hydrogen peroxide, if your interested, thats how the v2 rocket that germany used on london in world war 2 worked, also you could try impregnating some sodium chlorate int a paper towel and then wrapping it in tin foil with an appropriately sized exaust hole, also you can use any nitrate salts in rockets and if your local chemist sells instant cold packs, which mine doesnt=( some of those contain ammonium nitrate

[Mayday]

Well, the availability of potassium nitrate varies upon location (concerning legal matters), although it isn't your only option to make cheap, easy homemade rocket fuel. Potassium nitrate is an oxidising salt, a nitrate salt to be more specific. There are other nitrate salts, such as sodium nitrate and ammonium nitrate. Sodium nitrate can be bought in various forms. Ammonium nitrate is also easily attainable, as a fertilizer and in Instant Cold Paks (the outer pouch of small beady while balls). Both need purification, although Google and YouTube will help immensely with those matters. There are other oxidizing salts, such as potassium permanganate, potassium chlorate, sodium chlorate, sodium perchlorate, and potassium perchlorate. Potassium permagrate wouldn't work well in rocket fuel, and isn't very easy to obtain or synthesize, however both are possible. Potassium and sodium chlorate can be made easily in the home, by boiling bleach and filtering (for sodium chlorate) and letting the filtered solution to dry, or before the solution dries, you may add potassium chloride (salt substitute, bought easily at a grocery store) and stirring a lot. The leftover dried crystals that went through the filter are what you ate trying to get. An important note: both potassium and sodium chlorate are fairly unstable, and powerful. They might cause your rocket to melt or explode in misproportioned quantities. They are safe to handle without the fuel being mixed or bonded. Perchlorates, both potassium and sodium (and others, there are several) are nasty, and should only be used in explosive blasting caps ore novelty fireworks (flash powder). Nitrocellulose might work, I am not sure, and don't bet anything on it. You can add stuff to your fuel-oxidizer mixture, like powdered aluminum, iron oxide, and sulfur (in minute amounts, less that 30%) Try black powder, it does contain potassium nitrate, but it is sold in WalMart, Bi-Mart, and many other places as black powder for reloading black powdered guns. That's probably your best bet. Remember, fire hurts.

[Enthalpy]

Chlorates and permanganates should be avoided in a rocket because their "pressure exponent" exceeds 1, which means they burn faster at a higher pressure, and this acceleration is faster than the pressure increase - but the mass flow through the nozzle increases only as the pressure. In short: boom. Perchlorates and nitrates (simplifying) don't have this serious drawback.

I strongly warn against hydrogen peroxide, which is very dangerous in usable concentration
http://www.gkllc.com...en_peroxide.pdf

Ammonium nitrate is dangerous, it destroyed the AZF plant ten years ago, a port in 1947, and many more:


Nitrocellulose is commonly used in missiles, as a colloid with nitroglycerine to improve performance. It's dubbed safe - as long as nitroglycerine hasn't crept out. Needs a serious igniter. But mixing with nitroglycerine is nothing for a hobby chemist.

Don't get paranoid, but... Shops around you stop selling potassium nitrate - certainly because police asked them to do so, certainly because police has noticed your activity. Not only because of terrorism, also because of frequent accidents.

Did you consider switching to liquid propellants? At least they don't detonate before use. Liquid oxygen is very efficient with most fuels: liquid natural gas, Diesel oil, turpentine, polyethylene...
http://www.hq.nasa.g...led/1740151.pdf

[Elliott007]

You could try ammonium nitrate which is used in instant cold packs.

[doG]

As an experienced rocketeer I recommend Ammonium Perchlorate Composite Propellant compositions. Aerotech offers reloadable engines and reloads to go with them. Thunderflame offers the materials to make your own but you must take their class first before they'll sell to you. Hunt down a local Tripoli or NAR club and see if there are enough people interested to take the class. I think our local club had to come up with 8 attendees to get a class scheduled. It was well worth it though.