.The barrel is a 75 mm OD PP drain pipe. I am NOT afraid it will explode; that plastic is really tough, much better than PVC. Only problem is, it is nearly impossible to cement
The barrel will desintegrate at 10 bar.
Trust me.I 've blown up a nearly identical cannon at 9, wich had a 75 mm pressure rated barrel.
Because of ice, I know, but drainpipe can NOT take that kind of pressure without the addition of ice.
video of it in action at 9 bar before it blew:
Original thread here:
http://www.spudfiles.com/forums/chappy- ... t2999.html
Later it was upgraded to 75 mm.Never had the sweet second piston valve though!