This is a video of Helios II, my second homemade rocket. It is a 10" long 1/2" diameter galvanized steel pipe with 2 end caps, one having a hole in it. The rocket runs off of rocket candy.  The "A" launch had a 9" long 1/2" diameter rod of rocket candy. The rocket went 100 feet and landed 20 feet from the pad

Helios I was a 2 foot long by 1/2 inch diameter copper pipe. It exploded on the launch pad, but the main tube still went 300 feet up, and landed 400 feet from the pad. I didn't add Karo to the mix so the fuel crumbled, making it somewhat explosive. The recovered part was about 18 inches long and I filled the tube up with 6 inches of rocket candy powder...

Rocket Candy:
65% KNO3 (potassium nitrate, saltpeter, stump remover, fertilizer) - about 4 parts by mass
17.5% Sugar - about 1 part by mass
17.5% Karo Syrup (light corn syrup) - about 1 part by mass

EDIT: Check out the newer and improved Helios 3!!!

Helios II Launch B: the second launch of Helios II. The rocket was loaded with 9 inches of Rocket Candy. Altitude was between 30 and 50 feet.




Helios IIc was filled with 10 inches of fuel.  Altitude was between 30 and 50 feet, but a little be higher that IIb.



Helios IId was the last launch of Helios II. It was loaded with 3 inches of fuel, as that was the last of my KNO3. It flew to 50+ feet, the best all day. Helios III will have wings and a launch ring that will be soldered on, and it will have a smaller nozzle. 

And yes, it really was launched in a downpour!