Spark system for a metal combustion

[douggie]

I am currently in the proces of making my 2nd spud gun but this time im making it out of metal!!!
I found an old grease gun to use for the chamber..
One end has a hole in it so u can pump the gun so i filed this out big enough to fit a piece of gall pipe that i found(a bit bigger than a average marble)
i have welded the gall to the now end cap (took a bit of effort but it has came up alright)
Now i am going to jsut weld a base on it wih a bit of 4mm steel i found..
But before i do this i need to put the spark in it.. I only wont something simple preffibley a bbq ignitor nothing fancy..
Will the sparker work in metal chamber i want to put two scewrs in it like my oother 1..

[Moonbogg]

You have to isolate to wires. If they are shielded just run them in the chamber and keep the spark away from the chamber walls.

[mark.f]

You can use one wire that is insulated as the "hot" wire, and then use the chamber walls as the "ground".

I.E. - one wire is well insulated from the chamber walls (via rubber coating, epoxy, etc.... or you can use a spark plug), and the other wire is simply soldered to a spot on the metal chamber. The spark will jump from the hot wire to the chamber wall, or in the case of a spark plug, the electrode to core.

[starman]

Why is this in the Cannon Showcase??