SpudFiles

Built my first gun. Using starting fluid. Has huge bang and nice flame, but when put the potato in..... NOTHING! I have tried everything. Less fuel, more fuel, bigger spud...... fires fine without ammo, but nothing with it? Help?!
Oh. I also tried hairspray, same result.....

Have you been storing your potatoes in sulfur hexafluoride? That might make it harder...

If you put the potato in then fuel try fueling then putting the potato in carefully as to not shoot yourself. You could also try the safer method of metering propane.

Are you loading the potato in before or after you spray in the fuel? Also if you post some pictures, specifically the internals, it might be easier to fing the problem.

I am loading first. I will work on pics n
Tomorrow. Thanks!

It's quite possible you're having fuel-mixing problems. With nothing in the barrel you have more potential for turbulence, as the aerosol spray will tend to draw air in with it. Put a small computer fan in the chamber, or hell, just toss in a couple milk jug caps and shake it around... just for testing. You can get a permanent solution in place later.

Also you could try fueling it with a propane torch. They produce a nice mix so over-fueling isn't really a concern. Just stick the torch nose in the chamber for 15 seconds or so.

Take the guesswork out of the equation.

http://www.spudfiles.com/forums/how-to- ... 22301.html

Try using aqua net hairspray for fuel, also you need to get some pics up so we can try to help you more!!! Good luck!!! 8) 8)

jackssmirkingrevenge wrote:Take the guesswork out of the equation.

http://www.spudfiles.com/forums/how-to- ... 22301.html

I'm quoting this post for reiteration so you don't actually try and use hair spray as a fuel to solve your problems.

Spraying and praying is the exact problem with your launcher, go down to the chemist and pick up a syringe then go find a butane canister and you're pretty much done. $5 and your cannon works better than it ever would with hair spray.

I would need a huge syringe? Chamber is 4" x 18".

Ask for a 60cc syringe. If they ask what its for, tell them its for casting epoxy in. That's how I got mine, and its partially true.

There's your problem.
You seem to think you need a lot of fuel.
It's more likely you are overfueling it.
That is beginners mistake nr 1.
More fuel does not mean more power.The mix has to be exactly right.


The open barrel provided more air, but once you loaded a patato, there's a lot less oxigen.

get the syringe and come back to ask the combustion guys ( not me )
wich volume of fuel you'll need for your chambersize.

That will fix it!
Oh and mention you won;t be needing the needle....else they might suspect you're an addict or on steroids or something....

believe me...a buddy of mine got into trouble that way..

Aharless73 wrote:I would need a huge syringe? Chamber is 4" x 18".

Using butane, 2 x 60cc squirts will do nicely.

Cheap 60cc syringe online

I am a nurse.... So obtaining a syringe isn't a problem! Dumb question though. When "loading" the butane, can I just squirt it in the chamber then close the lid? Or do I have to have some type of loading valve?

Crack the cap a little, just enough so you can fit the tip of the syringe, then inject the butane and close the cap quickly.