This is a concept for a flamethrower, where you basically strap a candle to an aerosol can such as hairspray. I designed a 3D printed component in Solidworks that allows the candle to be (somewhat) securely attached to the can.
WARNING: Fire is dangerous, don't do anything stupid.
Step 1: Print the Part
3D print the STL file. I don't know a lot about the type of plastic used, but the guy who printed this for me said he used a plastic with a higher melting temperature. This is helpful if you don't want it to melt.
Step 2: Collect Materials
The following will be needed:
-Flammable aerosol (Hairspray, bug spray, etc.)
-Rubber bands (at least 2)
-Tea light candle
Step 3: Assemble
The candle fits snugly into the circular depression. Place the rubber bands on the two ridges, one above and one below the candle.These are used to attach it to the can.
Step 4: Testing
Make sure to test this in a safe environment, such as concrete. Another thing to keep in mind is feedback. The theory is that the flame will feed back to the source of the accelerant, making the can explode. this never happened to me, but it could happen to you.
Ignite the candle, hold the can away from you, and spray. I had the problem of the spray not igniting because the candle was too low. It worked pretty well otherwise. It shot a flame about 18 inches.
Video Coming soon!