What am I doing wrong?

[ryguy]

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.

[Flying_Salt]

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

[ryguy]

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

[Hotwired]

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.

[ryguy]

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

[Flying_Salt]

Yeah it won't blow apart

[singularity]

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