I made several cannons out of PVC and instead of using lighter fluid like some guys talk about, I tryed using BANGSITE (calcium carbide) with water and to ignite it, I create the sparks with those Piezo lighters. I take the Piezo lighters apart and re-modify them so I can ignite the acetylene gases ...

I never made a PVC cannon before, therefore I don't quite understand how yer system works. If yer using a tire valve, "doesn't that mean you need to use a air compressor" to build up pressure in the tubes? Please explain and or comment about this? I have it in my mind that these air cannons are ...