Instructables

Oxy-Propane Potato Gun on Steroids

video Oxy-Propane Potato Gun on Steroids
This Oxy-Propane Potato gun is on Steroids.  Not only do you get a much more explosive mixture with straight Oxygen than air, but, because of the pressurized delivery, you can force more fuel into the chamber.  And, you don't have to steal your wife's hair spray.   It is made of all steel instead of PVC for safety, and to give it that bad-ass look :)  My wife thought I was going outside to battle aliens.  Complete build steps included in video.
DanTDM2 months ago

So awesome, but if you want power, build a hybrid. I am. If you use oxygen, only use green oxygen teflon tape and oxygen valves.

ajensen1910 months ago
You guys are getting crazy with explosive mixtures in potato guns. What's next? Nitroglycerin lol. Check out the mini potato gun I made. The miniature ones have some advantages over the big ones such as being more portable and cheaper.
HowToLou (author)  ajensen1910 months ago
Most are over 6 feet. This one is pretty portable at only about 2 feet long, but the compressed oxygen and propane mixture help it pack a huge punch, for its size.
This is awesome !
PS1181 year ago
Would MAP gas make an even bigger boom or does it just burn hotter as a torch?
HowToLou (author)  PS1181 year ago
Yes! MAP has more punch by volume. They also have Acetylene tanks which, when combined with Oxygen, is a standard metal cutting mix. That would be the ultimate way to crank up the boom. Also, put a bigger (longer) potato in the barrel to make a better cork. This will allow you to turn the valves on for a longer period of time and compress more gases into the chamber. More gasses mean more boom. My demo, as strong as it is, is just the beginning of what that gun can do.
EnigmaMax1 year ago
I'm guessing the potato seals the gases before detonation. A great idea, but higher pressures or other projectiles might not seal tightly. Maybe include some kind of piston or valve behind the barrel?
HowToLou (author)  EnigmaMax1 year ago
You are EXACTLY right! The potato is the payload, but more importantly, the seal that keeps the gasses in, before you pull the trigger. You can use another "piston", but be prepared to lose it, because it is going with the payload.

PLEASE don't use a valve. You will fill the chamber with gas behind the closed valve. If you pull the valve before the spark, the gas will escape and explode outside the gun. That is not too bad, BUT.... If you spark the gas behind a closed valve, the entire metal gun could explode like a pipe bomb. Just use a longer potato to get a better seal. Potatoes are cheaper than surgery :)