Miniture (spud) gun help!!!?

Question

i have recently made a mini (spud) gun and wired it with a peisio electric igniter but when it is sparked it fails to ignite the butane in the gas chamber and (sparks perfectly though) i can't for the life of me figure out why

Answer 1

is the thing sealed right!!! also try hair spray for the fuel!! spray in a shot ... insert spud .... push in spud,,,,,, ignite,,,,,, BOOOM ..... there goes spud..........!!!!!!!!!!!!!!!!!

Answer 2

Gases such a butane will only ignite when there is a correct gas to air mixture.  Natural gas for example will only burn when it is 9-14 % gas and the rest air.  Perhaps you used too much butane for the amout of air that is in the chamber.

Answer 3

You may be putting too much gas in the firing chamber, if there isn't enough air to mix with the butane it won't reach the KFB range(ker-freakin-boom).  You will have to air out your chamber and start small with a second of fuel and try, thats what we had to do with ours and now we know the sweet spot and can launch spuds for blocks!