Although the tutorial is in danish, it's so loaded with pics on how to construct the gun, I belive it's pretty easy to follow the instructions.
This is what you need to build the gun:
1. Chamber:55 cm 110*3,0 mm PVC-U downpipe.
2: Pipe: 75 cm 75*2,8 mm downpipe
3: Plug.
4: 110 mm -> 75 mm reduction ring.
5: 110 mm Socket.
- Siliconespray.
- Longnecked lighter.
- Thick gloves (fireproof)
- Hairspray
- Lightergas.
Check-out the picture section on how to discharge the orange gun!! Do not discharge the gun in urban areas,- shooting distance: 200 meters!!
AND DON'T FORGET: I take absolutely no responsibility for the content of the following link. If you decide to follow the instructions on THIS page, and build yourself a Orange Gun, you do so at your own risk.