Scratch- - 5-3-2005 at 16:45
http://www.lateralscience.co.uk/AtomicH/atomicH.html
I think this would be quite possible to build. You could store up quantities of hydrogen from electrolysis of water. Your voltage source could be a
electrostatic generator designed to output the appropriate voltage and Leyden jars made out of buckets, water, and aluminum foil. Since a capacitor
wouldnt give you continuous voltage you could have a spinning wheel with contacts on it. When a fixed contact touches the spinning wheel it switches
which capacitors are discharging quickly, giving you continuous power. I think this could be a very cost effective way of melting/vaporizing/cutting
anything you need! 
neutrino - 5-3-2005 at 18:19
What you’re trying to build is a high-energy torch, but you’re designing something else entirely. The welder only needs a couple hundred volts but
a lot of amps—the article said 300V, 20A. What you’re designing would produce thousands of volts and almost no current, therefore giving you
<b>much</b> less power. Still, this would be an interesting project.
[Edited on 6-3-2005 by neutrino]
Scratch- - 5-3-2005 at 20:03
Thats what the Layden jars are for, but your right. An electrostatic generator is probably not the best thing to build this out of. A transformer
would be better. Capacitors store up amps not volts, which is why it would take a while to charge. I was just thinking of using a high voltage source
because I have one on hand, what I dont have is a transformer capable of supplying voltage even near 300V.
a_bab - 7-3-2005 at 09:36
I once wanted to make this device. I saw in a book an easy adaptation, using a simple lass tubes for the hidrogen streams and a simple electrical arc.
The point is that even if Langmuir had 20A/300 V (that's 6 Kw, meaning the power of around 6 washing machines, or 30 average computers!), you
just need an electrical arc. 300V can kill you, so if you find the way to create an electrical arc, you are set. The electrostatic discharge is not
enough here.
One can use N2 instead of H2 and it will still work, by the same principle: combine two atoms to gen a molecule of N2 and some energy.
The high amperage is needed for a stable arc, so that the hidrogen flow doesn't "brake" it, and the voltage is for a easy start, and a
longer lenght. Welding machines operate usually between 60-100V and the arc can reach 5-8 mm (I'm talking from my experience here).
I know a way to make an electrical arc in a simple way, but I'm too lazy now to describe it. Basically you need two 110/220 transformers, and
diode.
The hidrogen stream is more difficult to obtain, as creating it from Al foil and NaOH or HCl/Zn doesn't sound too good to me, unless you want
just to create a 4000 degrees C flame for the sake of it and not to actualy start welding the car.
[Edited on 7-3-2005 by a_bab]
Hermes_Trismegistus - 7-3-2005 at 13:50
H2 gas in cylinder's is available from most welding suppliers and all glass torch suppliers. (for hotflame applications like quartz, tungsten
etc...
silonyl - 17-2-2006 at 18:06
I've done some reading on this topic, and I find it quite ineteresting as well. The power required is qiute modest when compared with other arc
welding methods (I don't have numbers in front of me... but a couple hundred volts and <20amps seems about right). H2 is readily available in
cylinders, and the technique is dying out in the welding community. I'll probably build a AHW torch in the next few months... PM me if you're
interested in collaboration.