spark but no boom

[Opossum]

i have bbq grill ignitor with electrodes in the chamber. i used hairspray that has propane in it also i used starting fluid with ether in it. i was getting good consistent sparks. i also played with air to fuel combinations. all day trying and got 3 crap shots. my chamber is 4"x15" barrel is 2"x48"

[hi]

You have to much fuel in it. Dont use hair spray, it is the worst thing you can possibly have. Try using axe, that works well.

[willarddaniels]

probably too much fuel. If you spray it in, then let it sit for 2 minutes to allow for evaporation, maybe wave the chamber around to help it along.
This is one reason we use chamber fans as a hop-up.

[Opossum]

i tried to air it out. when i took the cap off with the starting fluid and clicked my sparker it flamed like crazy the i did with the cap on and nothing even nothing in the barrel. if i hit the electrodes will that get them "wet" and they won't spark?

[hi]

dont spray the electrodes. Are you using starting fluid or hairspray? If its starting fluid then you only need about 3/4 second spray, maybe even less.

[Opossum]

it worked with starting fluid when it was in for a while and i uncapped it and it made a big fire. last summer it worked fine with hairspray i just had to sand the electrodes.

[itwentboom]

Hairspray sucks. Right Gaurd still works just bought a can today.

[Opossum]

Never mind it was shorting in random places and the electrodes were dirty. I cleaned it up and used starting fluid and it works perfectly.

[the c3h8er]

hairspray stinks it mostly just manages to gum up you gun.

[Bubba05]

Yeah I found that with hair spray too?
I use deoderant for S@#Ts n giggles but i use stuff called "Start ya Bastard" Witch is like airo start? Goes really good!

Bubba

[DasGestapo]

try ventilation
blow out the entire chamber, and put in like a 2 second shot of old spice deoderant.

on my first cannon, i originally used way too much of the stuff. you need less than you would think!!
also, make sure to keep the tips of the electrodes clean.

NEVER USE HAIRSPRAY
i know its a ghettofantabulous classic, but it makes your chamber look like a sewer

[pimp]

try putting the potato in first if u didnt cuz the fuel probulay is escaping

[potatoman85]

the problem is that the chamber is to small. a good rule of thumb in combustion style potato guns is that the chamber should be 1.5 times the volume of the barrel. I've always had good sucsess with it, getting at least 300 yards or more every single shot.

[jimmy101]

the problem is that the chamber is to small. a good rule of thumb in combustion style potato guns is that the chamber should be 1.5 times the volume of the barrel. I've always had good sucsess with it, getting at least 300 yards or more every single shot.

Actually, a good rule of thumb is that the volume of the chamber is 0.8 times the volume of the barrel.

And, that must be a pretty big gun (barrel more than 6' long) to be getting >300 yards.

[lukemc]

Hairspray sucks. Right Gaurd still works just bought a can today.

right gaurd aniti persperant works (first ingredient is butane) but it leaves a white film inside the chamber. regular right gaurd uses dentured alcohol and will almost never