SpudFiles

What i the best stuff to use to ignite?? Aqua Net?

If you are using an aerosol fuel, right guard deodorant is the propellant of choice. Very powerful and doenst gum the chamber up.

also starting fluid, though you need the smallest amount really, its very powerful, so if you did something stupid and unsafe like put a bbq ignitor right in the cannon you shouldnt use it, if all of your pieces are SCH40 NSF-DWV or NSF-PW and the pipe is pressure rated you're fine, if you used cellular core or thinwall you shouldnt use it, hell, i'd throw the damned cannon out, because it'll blow eventually

I used ABS....and i am adding a BBQ igniter into it.... But the ingtinter will be out only the spark will be in. So no starting fluid?

ABS is fine, if you're using 2 screws attatched to wires on the bbq ignitor you're fine, if you putting the ignitor IN the gun then i wouldnt use it