Spark but no combusting....

[Mihlrad]

I made a mini while i am unable to go to home depo, it has 2 electrodes in it, and when i press the button a spark is clearly formed between the tips of the electrodes, but nothing is ignited... i spray hairspray in it for about a second... and nothing. Its a mini so i figured more then that bad idea... but when i take the cover off, and i hold a flame to the opening, it bursts in flame.

[plumpthumb]

My friend the problem is not enough air and maybe too much fuel. Try mixing in a little air by moving the end in a circle motion before you put the cap on ----or try a little less fuel. I know, it goes against the grain but try it. I have found that minis are real sensitive to fuel/air mix but can be a lot of fun.

[Pete Zaria]

The usual suspects are:

Too much fuel/not enough air (try less fuel, try spraying it in from further away so it doesn't all condense on the sides of the chamber)

Fuel not being mixed properly. Usually you use a chamber fan, but that's not really an option on a mini... shake it hard?

Spark isn't hot enough

Peace,
Pete Zaria.

[Mihlrad]

im using the same ignitor everyone else does though how could it not be hot enough? its a bright blue spark by the way.

[frogy]

Any spark ignites a mini, it doesn't need to be hot when the space is so confined....

To much fuel is %100 your problem....

1 second of hair spray is enough to make medium combustions fire.... to get a mini to fire use Cologne or a drop of Purell

In my Purell mini, it's made out of a Purell bottle and I squirt a spray of cologne in, any cologne with Alcohol 40B will work.... so I spray it in, then tap the Purell bottle on a cloth of anything to get the liquid cologne out, just tap it a lot until the liquid about stops coming out, then put the cap on and fire...

The tapping gets the liquid out, while also forcing air into the mini, causing a good fuel \ air mixture, I get about %90 success rate

[bungalowbill]

I registered to ask that very question...

I built a very basic combustion cannon 2 years ago that has provided me with a lot of fun. It's about a foot of 3" chamber and 2 feet of 2" barrel.

Last year it stopped firing. After some investigation (at some risk and stupidity on my part) I discovered that if I removed the back cap and ignited it, it sparked (and shot flames out the back). I repeated this with the same results several times.

Since the gun wouldn't go until i took off the back piece, I assumed lack of oxygen. I tried less fuel, with no success.

Pete Zaria mentioned that one of the contributing factors is too cold a spark. Do you think this might be my problem?

[Shrimphead]

What kind of ignition are you using? Seems like you might need a new ignitor. That's just my guess. Does it seem to have the same power as before?

[djt]

yeah bbq ignitors get weaker the more you use them. i bought a new one for a medium sized gun and also found an old one we dont use on our grill. the one on our grill was a couple years old and it didnt spark half of what the new one could. if you can get a stungun then those are the best and most reliable thing you can get but personally i like the huge sparks of lantern lighters.

[Benny]

use a butane lighter for fueling.

[boilingleadbath]

Possibly try even less fuel?
Apparently, the spark can ignight a proper mixture, as it did when you removed the endcap.