SpudFiles

Well I'm new to combustion cannons so I made a mini combustion out of an oxy pad bottle with a lighter igniter and pen tube for a barrel. But alot of times when i ignite it, the top with the barrel just goes flying off, and a few times its shot a wad of tissue around 40 feet. How come the top goes flying off? it just explodes out about 20 feet.

You probly didn't put it on tight enough. Could you post a picture?

well im afraid if i put it on too tight, the whole thing will just blow up

Unlikely.

Something with a pen tube for a barrel doesn't sound as if theres a huge combustion chamber and even so you're not talking uber high pressure. A fizzy drink bottle can handle the pressure for a deoderant based combustion.

yea the bottle is a 2" by 2" square . thanks.

Yeah it won't blow apart

you got to watch out some of the pill bottles have brittle plastic