Combustion Symptoms

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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CannonCreator
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Thu Nov 29, 2007 9:23 pm

K so thanksgiving weekend I went up to california city ( yes, in california )
to go riding like we always do once or more a month. This is my first time I borught my combustion potato cannon though. t was my first and only combustion, It has worked every time I shot it never any time I pulled the BBQ ignitor and nothing came out of it.

I was using the usual hairspray, the only flamable chemical that has ever set into my chamber, same bottle, it was about ahlf why full when I tried using it. Theres no chamber fan, it is a screw off end cap then spray harispray into the chamber kind of cannon.

I want to say it was around 45-55 degrees maybe barely the sixtys, I mean everyone was weraing coats, and jackets but me ( I never get cold). I put the potato in, spray a good amount close it quick... Click, Click, Crap!!! it dosnt work, We were playing around with it for 30 minutes cycling in air, blowing into the camber. We checked the spark gap, it was perfect, better then usual.

I was never aware of this inconcictency in a combustion cannon before. So basically what was going on? Im guessing it was to cold for it to ignite properly, I have never ever had any combustion problems before. What happend?
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homedepotpro
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Thu Nov 29, 2007 9:58 pm

did you stick your face at the end of the chamber and press the sparker, that usually works for me, and then i end up with a head full of burnt hair. jk don't do that.
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jon_89
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Thu Nov 29, 2007 9:58 pm

how big is your chamber?
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Ragnarok
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Thu Nov 29, 2007 10:01 pm

Combustions are always at least a little inconsistent.
50 <sup>o</sup>F is not that cold, so I'd suggest it was another problem rather than temperature.
Does that thing kinda look like a big cat to you?
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Thu Nov 29, 2007 10:26 pm

My combustions tend to play up in the heat not the cold, i find that if i adjust the amount of fuel (up or down, can't remember) i find that it works. After much cursing :)
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CannonCreator
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Fri Nov 30, 2007 12:56 am

I have a 4" dia 17" long chamber. And the next day arounf lunchtime it was around high 60's or 70's and they were shooting consistantly. Thats why I think it was the tempurture.
Spudding Is dangerous, I learned the hard way:
http://www.spudfiles.com/forums/my-eye- ... 15301.html

Guns. As They may Claim lives, they are lives. Our lives.

When Life gives you lemons, through them at somone.

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BigGrib
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Fri Nov 30, 2007 1:28 am

I have found when i get into the fifty's mine acts up too so what i do is leave the barrel empty and dry fire it a few times to get it warmed up and then it will fire consistently
Yea, that's definitely going to get you at least a tazer.
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rna_duelers
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Fri Nov 30, 2007 2:20 am

I seem to find that combustions do not work aswell in the heat and also what the humidity is like,if it's really humid it's a bitch to get going.

They can also be a bitch to get going while drunk...or so a little birdy told me.
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CannonCreator
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Fri Nov 30, 2007 9:32 am

thanks, i never thoguht of heating it up, but i would have to use a torch to ignite it cuase it wasn'y dry firing either. Thanks thats my answer i needed!
Spudding Is dangerous, I learned the hard way:
http://www.spudfiles.com/forums/my-eye- ... 15301.html

Guns. As They may Claim lives, they are lives. Our lives.

When Life gives you lemons, through them at somone.

Live, Breathe, Eat, Paintball
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Fri Nov 30, 2007 11:58 am

I've always noticed much less power in cold days than on warm days on guns that don't have a meter or chamber fan.

It is possible that the cooler air temperature means the fuel does not mix nearly as well as it does on a hot day.

Or, there is a volatile component of the fuel (butane, alcohol etc.) that does not consistently vaporize when the temperature is too low.

My combustion guns with chamber fans really don't care what the ambient temperature is.
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