Whats the best way to install the ignition into the combustion chamber of a cannon?

Question

I'm making a potato cannon. the ABS parts are fully assembled but I need to install an ignition. basically the combustion chamber is a 4" diameter 2' long ABS tube, that will be sparayed with hairspray and then sealed with a 4" male plug. I was considering installing a barbeque lighter's sparker but I'm concerned that if I drill a hole in the chamber it will lose too much pressure when I fire the cannon. Heres the basic idea:

http://youtube.com/watch?v=t7jR9Kgv-9A&feature=related

any suggestions for an ignition?

Answer 1

the BBQ lighter works great, you can seal the hole with glue or caulk. you might need two holes, one for the ground wire, unless the sparker has one already

Answer 2

Hmmmm...the bbq sparker is quite ingenious.....I would substitute starting fluid for the hair spray though...heh .....heh....heh.