It all started last week when I was spudding with my combustion cannon (50mm barrel, double spark gap, chamberfan), wich has metered butane.
At the end of the spudding session the butane tank regulator thingy screwed up again and refused to give pressure.
Screwing around with the thing, I accedentically injected ALOT of butane.
Maybe like 2 times my chamber size.
The cannon was not loaded with ammo.
I clicked the igniter, nothing happened. I took off the end cap for about one second and put it back. Still nothing.
I went home, and put the cannon up straight into a corner.
The next day I smelled butane, and found out it came from my cannon.
I clicked the igniter (yes, I fire blank shots inside my house) and nothing happened.
Today, one week further I was searching for something and stumbled across the cannon. I thought hey, why not click the igniter?
So I did....
BOOM!
The cannon went off with all its power. The blast of air shredded a poster on the wall into 4 pieces.
In that week enough butane had escaped and I had a good mix in the chamber and barrel.
The barrel was pointing upwards, a bit like this: /
The muzzle end was about 5 inches from the wall.
I think that the reason for this to happen is that butane is heavier then air. And since the cannon was upwards, it couldnt float out so easy. And thus took a week to mix.
Nobody was hurt, and it didnt do further damage. But it could.
So let this be a warning for you.
Always vent your cannon out at the end of a sesion.
That story tickled me in a 3 stooges sort of way... Thankfully no serious damage was done. Your ears were probably ringing after that little episode.
