We'll, in the interest of safety, I've switched to an outside bevel. It will be interesting to see how this change affects performance.

Can any one tell me about how many times you can use a BBQ sparker before it stops sparking? I'm taking my cannon out of town this weekend and want to know if I should bring a spare, or maybe just put in a fresh one before I leave.

Thanks!

Hi I have built a lovely ABS combustion cannon. The muzzle knife is beveled along the inner edge of the barrel. I did it that way because I figured it would be less likely to split the potato and make a good seal, but I recently read a post by a guy who said his cannon blew up because he made it the...