Learning About Fuel

Sunday May 20^th 2007

Today Max D, Myles and I made the first batch of fuel. The setup consisted of:

50g KNO3

25g Sucrose

9.8g Karo Syrup

Melted at 350 C in a tin can, then poured into a tin foil tray to crystallize. Crystallization lasted 1.5 hours and did not finish. The result was some white crystals, some liquid goo, and some brown liquid goo. It burned, but not for very long. If lit, it would burn for a few seconds then go out and had to be re-lit.

Saturday May 26^th 2007

Fuel Batches 2, 3, and 4

Batch 3: 50g KNO3 – 25g Sucrose – 10g Karo (added a little too much)

Added metal camping plate to replace tin foil tray.

Results: Crystallization didn't finish correctly, the liquid was probably too thick in the metal plate. Some was put into a 18cm diameter piece of steel conduit (7cm long). The rest was balled up and stored in an airtight container. The fuel in the conduit motor casing was placed in some dirt by the stream. It burned well and produced a large cloud of white smoke. The result was black stuff coating the inside, probably carbon. The ball of fuel was lit and exploded in my face. Eyelashes were singed: wear safety glasses and don't light balls of fuel.

Batches 3 and 4: 50g KNO3 – 25g Sucrose – 9g Karo

This time the mixture was stirred to reduce water content.

Result: Stirring seemed to work well. When the mixture came out of the pan it was rather liquid, but when packed into an engine casing it burned well. First rocket was made: Engine casing with fuel, paper nosecone attached to top with electrical tape, wooden skewer attached to casing bottle rocket style. The result was that the nosecone blew off the top, and the fuel burned at both ends of the casing. The rocket did not make it off the ground. Do not put a hole through the entire fuel grain. Second rocket was made: Engine casing with fuel (hole only ¼ of the way through and also a rolled up paper plug taped in with electrical tape), paper nosecone taped on with electrical tape, metal mandrel attached bottle rocket style. The results was that the fuel was too wet. Half of the fuel burned and the smoke was not as dense as usual. Again, the rocket did not make it off the ground. Make sure that the fuel is cooked fully before adding it to the engine casing.

A used engine casing

The first rocket!

The second rocket