Just starting to spud and wonder how long your barrel should be? Want to know how to build a better cannon? This is just the place! If you think your question is one of a newcomer, please post it in here. If your question is posted elsewhere, and it's a newcomer's type question, it will be moved in here.
I never used propane before only hairspray, and i was wondering if i could just let some propane in the chamber as i would when i used the hairspray, like 1-3 seconds of spraying??
The exact amount you need differs per cannon, but just tinker with it and you'll get the hang of it. Give it a few seconds, try, and if it doesn't work then keep messing with it. Propane torches let out very little at a time, so they're pretty easy to start out with.