Combustion Or Pneumatic?

[Mac_User]

Your pressure tank on the cannon should probably by made of copper as Harpoon said. Solenoid valves are also great replacements for ball valves.

[julz]

ill try cleaning the valve. also ill was the inside of the chamber so the dust is removed. how exactly does the dust stop the phram drom closing properly?
anyway, thanks for ur help and i hope it doesnt happen again.
---Julz