Rocket Propellants

It is best prepared by melting the potassium nitrate and sugar together, but this is a dangerous operation and could result in accidential ignition during preperation. Dry mixing is possible and much safer but produces lower quality propellant.

Mixture is somewhat hygroscopic. Low impulse propellant.

The burning rate of these rocket fuels depends much less on pressure than that of black powder. This widens the accetable limits of the ratio nozzle area/fuel surface area.

The burning rate of these rocket fuels depends much less on pressure than that of black powder. This widens the accetable limits of the ratio nozzle area/fuel surface area.

Burns very fast, producing lots of smoke. It is not a very effective propellant due to its low energy density.

The propellant has a burn rate of 0.0385 inch/sec at 100psi and a burn rate of 0.04 inch/sec at 300psi. Burn temperature is approx. 1800K. and ISP=180.

Stinks like ammonia when mixed, and hardens faster than normal epoxy curing time. Suggestions for rocket dimensions: 1" rocket tube, 3" fuel length, Durhanm’s water putty nozzle 3/8" thick, and 5/16" diameter. Core in center of fuel about 3/8" diameter through the length.

Loud whistling rockets can be made with this. The author of the text this composition was taken from used it in nozzle-less whistling rockets. The rocket casings were 3/4 inch inner diameter, and 3.25 inch length. The fuel grain ended 1/8" from the rear end of the motor tube.

Preparation:
1. Mix the iron oxide with the potassium benzoate and mill this mixture untill a very fine powder is obtained.
2. Melt the petroleum jelly in a beaker on low heat. Turn the hot plate or stove off. Make sure no sources of heat or sparks are present before proceeding with the next steps.
3. While stirring, add 5 parts of toluene to each part of petroleum jelly by weight. Laquer thinner can be substituted for toluene when pure toluene is not available. Continue stirring untill the petroleum jelly has completely dissolved in the solvent used.
4. Add the petroleum jelly to the potassium benzoate/iron oxide mix and stir the mixture untill it becomes homogenous.
5. Then, slowly add the potassium perchlorate while stirring continuesly with a wooden spoon for several minutes until homogenous. At this point, the mixture usually has a consistency of thick soup and the beaker is warm to the touch. If the mixture seems too dry or thick, extra toluene or laquer thinner can be added at this stage.
6. Spread the composition out in a layer about 1/2" thick on kraft paper over newspapers to dry overnight. It is important that the mixture has thoroughly dried before pressing motors. A slightly damp mix can cause some shrinkage of the propellant grain over a period of days or weeks, causing the rocket to explode when ignited.
7. When the composition has dried overnight, carefully run the mixture through a 20 mesh sieve twice and store in a paper container so that trace amounts of solvent can evaporate. After several days, the mix is ready to press.

The GE silicone II is noted for having an ammonia-like odor, where the GE silicones smell more like vinegar. The dimensions of the rocket made with this propellant were 1 1/8 inch ID, with a 1/2 inch core. Mix the copper oxide, PVC and silicone first, in a plastic bag. Then mix in the ammonium perchlorate. The stuff is said to be somewhat crumbly, and presses well.