I haven’t have much experience with high voltage, but wanted to be able to generate a good spark to facilitate ignition of the water rocket. I took the easy way out and picked up a cool little spark generator at (of all places) sparkfun.com. Creates a scary loud mean-sounding continuous spark.
To put the spark in the bottle I used the cnc machine to route a ‘plug’ of sorts to go in the top of the 1/2 pvc pipe. Drilled and tapped a couple holes for stainless steel cap screws I had lying around and I had a pretty good start. I had to bend the left one a bit to ensure they didn’t touch at the top where the caps are.
I probably went a little overkill, but I used some 12gauge house wiring I had for the leads going to the screws. I didn’t want the sparks ‘gapping’ inside the launch tube. I used the mini-torch and soldered the copper wires to the screws and shrink-wrapped them up.
And here was a quick test to see if it was sparking ok. Pretty small, but continuous and hopefully will make ignition happen!