Hydrogen spud gun

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.
spudnikMK2
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Wed Nov 15, 2006 8:53 pm

Recently I built an electrolysis machine. It seperates water into hydrogen and oxygen gas. Hydrogen and oxygen are highly explosive so I'm going to connect a cannon to it and see what kind of power I get. If anyone has any ideas or tips let me know. I was also thinking that hydrogen would be perfect for a hybrid cannon.
Last edited by spudnikMK2 on Thu Nov 16, 2006 7:44 pm, edited 1 time in total.
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MrCrowley
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Wed Nov 15, 2006 8:56 pm

use metal!
cannon freak
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Wed Nov 15, 2006 9:03 pm

How fast does your machein put out gas?
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frankrede
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Wed Nov 15, 2006 9:09 pm

Do it by remote ignition and have a asfety barricade for the first 10 or so shots.
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noname
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Wed Nov 15, 2006 10:46 pm

Sounds pretty cool. Give us feedback when you test it. And like others said, definately use metal and remote ignition. Hydrogen burns fast at about 12-75% in oxygen, but DETONATES in something like 25-50%.
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sergeantspud2
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Wed Nov 15, 2006 10:54 pm

Im interested in your electroysis machine becuase Im in the middle of making mine... Do you have any pics of it? I wont copy them, I already have my plan I just want to see how yours came out.
:D Always rely on Murphy's Laws :D
4.If you have enough grease & a big enough hammer, you can put anything... anywhere
3.If all else fails, hit it with a big hammer
2.Matter will be damaged in direct proportion to its value
1.If anything simply cannot go wrong, it will anyway
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drac
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Thu Nov 16, 2006 6:12 am

I'd say don't do it at all.
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boilingleadbath
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Thu Nov 16, 2006 10:04 pm

H2-02 accelerates to detonation velocity quickly, and generated pressure will be about 50% higher than propane-air. (pressure estimate: going on my memory of flame temps, and very quick mental calculations)

Use, at the very least, high-rated PVC, and use distributed ignition sources to prevent detonations.
squeaks
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Fri Nov 17, 2006 12:34 am

I think it's a great idea to use hydrogen. I mean, what fuel can be cheaper than water? I agree with leadbath though, you probably would want to use this in sch 80 or metal.
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ammosmoke
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Fri Nov 17, 2006 12:47 am

Sounds kinda scary if you ask me, but it all depends on what concentration of the fuel you put in the chamber.

I mean, in theory there should be 1/3hydrogen to 2/3 oxygen, quite er, explosive. Pretty much the same as oxyacet balloons. BOOM........AWWWK. *DEAD*

Hydrogen is already almost considered explosive as it is.......
cannon freak
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Fri Nov 17, 2006 3:15 pm

Ya know its not dangerous at all if you simply don't stand beside it when firing.



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spudnikMK2
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Fri Nov 17, 2006 6:37 pm

ammosmoke wrote: in theory there should be 1/3hydrogen to 2/3 oxygen....
Its actuly 2/3Hydrogen to 1/3 0xygen, hence H2O. And yes it is highly explosive :twisted: so im going with a metal barrel. i'll post pics when i can but that may not be for a while.
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judgment_arms
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Fri Nov 17, 2006 6:50 pm

One word, Hindenburg…
Oh and when you fire it yell “FRAG OUT”
djt
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Fri Nov 17, 2006 9:07 pm

i hope your going with a metal chamber too...
But with electrolysis you can just collect the Hydrogen and Oxygen in the same place. This mixture will be the perfect e mixture your looking for. Since there is already air in the chamber of the gun that contains oxygen, the mixture will be a little off, but it will be pretty close.
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Hotwired
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Sat Nov 18, 2006 4:43 am

From wikipedia about spudguns:
When using a carbon steel cannon with hydrogen gas as fuel, a process called embrittlement occurs, in which the hydrogen reacts with the carbon to create methane, leaving the metal structurally weak. Embrittlement leaves the cannon severely vulnerable to failure. Hydrogen is also highly discouraged as a fuel because of the extreme risk of accidental ignition.
Copper has a decent pressure rating, well above pvc, you could try that.
Last edited by Hotwired on Mon Jan 22, 2007 8:42 am, edited 1 time in total.
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