I need a simple HV circuit

[H2SO4]

Im making a propane cannon (like a potato gun, but i will shoot anything that fits) and ive already built the barrel and fuel intake and air mix blah blah blah parts. So i was going use a simple piezo igniter from a barbeque to light this but it seems that is very inadequate and troublesome. I cant seem to lihgt my mixture of gas with this! I miniturized the thing (meaning i put propane in a 1 inch Cu pipe and sealed one end with a hole for the ignitor wires) and even thouygh its spars inside it seldom is successful in ignition. I weant something relieable. Im thining if i can make maybe a 12 kilovolt PSU i could just use a solid arc for an ignitor and that would be a sure fire. But i dont have a 12kv psu. i cannot even find a schematic for a very simple one. I have a 500v psu from a small flourescent light for a gameboy accessory so im wondering if i can further step that up with a transformer to get my voltage. I would like to just build somehting with minimal parts. Maybe a 7.2 v batery and two transistors and a cap and a transofmer. Would a trigger coil provide me with the neccessary voltage? I jst need to build a cheap HV supply.

[Rocket Man]

firstly, don't.

if you want to make a spud gun, go pneumatic. theyre way more reliable and far safer.

other than that, pneumatics are versatile. how many combustion guns can be converted into water guns that rival a garden hose.

 

i had to build a miniature for an in-class physics demo. really light, compact and sturdy, i could reliably strike a falling target from 6 metres.

however, i built it modular. it behaves like a mortar in one configuration and a water rocket in another.

i have never seen a combustion spud gun that can fly further than mine.

 

i used a 600ml soda bottle, sprinkler solenoid and a valve from a bike tyre assembled using 25mm pvc pipe (mains rated) and an assortment of heavy duty glues and O-rings

(my teacher commisioned a duplicate)