SpudFiles

BLB, I could literally watch graphite flake off of the rod and wither away when I used those electrodes. Stainless steel 316 is the way to go.

I can't remember why aluminum is bad, but it is. Prettymuch anything besides stainless and platinum will corrode and give you crap you don't want.

It doesn't matter too much if you are only collecting the hydrogen, but if you want to collect the perfect mix of oxy and hydrogen you need to use electrodes that wont reacts at all. Otherwise you will not get the desired mixture. And by an undesirable mixture, I mean one that wont even ignite.

Another idea to consider, go to home depot, buy some calcium carbonate, fill your barrel 1/6 of the way full of water, drop in about 6 of the calcium carbonate pebbles, it will trigger a chemical reaction that will expel some flammable gas, just experiment with differant amounts of water and calcium carbonate, also, experiment on best times to wait before sparking your cannon