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View Full Version : Trying to build a welding torch kit.



lbl25a
06-01-2012, 10:42 AM
I already have one of the old Johnson Matthey type microflame welders but the largest size nozzle that it uses is No. 20 with about .9 litres per minute HHO. Fine for small modelling work but I would also like something bigger.
I bought a second hand set of electrodes 24 stainless steel plate about 2 inches by 9 inches with about 1.6mm spacing and connected +-+- to be used as a single wet cell.
I have now arranged the plates in a housing to hold about 1 litre of electrolyte and connected the plates to a 20 Amp 12V battery charger but the output is too low.
Using distilled water as an electrolyte and controlling the power output of the charger through a dimmer switch connrcted to the mains supply I can vary the current up to 20 Amps at which point the voltage across the cell was 2.4 volts. I get more output by increasing the current to 30 Amps but the overload cut out on the charger then trips.
Do I need to change the plate configuration or just use more power ? I have another 20 Amp 12v charger but don't know whether it would be safe to connect them in parallel.

whear
06-02-2012, 12:01 AM
If you're only using distilled water as electrolyte, you should add some NaOH or KOH.

Also, a wet cell creates a lot of steam and not too much HHO.

If you want to see real improvement, you need to build a dry cell.

lbl25a
06-02-2012, 03:49 AM
If you're only using distilled water as electrolyte, you should add some NaOH or KOH.

Also, a wet cell creates a lot of steam and not too much HHO.

If you want to see real improvement, you need to build a dry cell.

I tried using KOH as electrolyte as I had some over from when I last replaced the electrolyte on the microflame welder. It didn't make any difference. As I understand it KOH is added to increase the current flow in the cell but since I can easily draw 30 Amps or more with distilled water, do I need it?

Steam does not seem to be a problem but with a welding torch the cell is not running continuously as in a car. 10 to 15 minutes max for most of the jobs I would use it for. For the same reason overheating should not be a problem.

Perhaps I just need a higher power source. Thinking of using an arc welding transformer but this would need a change in the plate configuration to get the voltage right, also possible a variac in the mains current supply to control the output?

hhoconnection
06-03-2012, 10:10 AM
Go with a dry cell, forget the wet cell. Maybe this will give you some ideas:

<iframe width="560" height="315" src="http://www.youtube.com/embed/36lEXocd1BM" frameborder="0" allowfullscreen></iframe>

aceras624
06-03-2012, 10:44 AM
I already have one of the old Johnson Matthey type microflame welders but the largest size nozzle that it uses is No. 20 with about .9 litres per minute HHO. Fine for small modelling work but I would also like something bigger.
I bought a second hand set of electrodes 24 stainless steel plate about 2 inches by 9 inches with about 1.6mm spacing and connected +-+- to be used as a single wet cell.
I have now arranged the plates in a housing to hold about 1 litre of electrolyte and connected the plates to a 20 Amp 12V battery charger but the output is too low.
Using distilled water as an electrolyte and controlling the power output of the charger through a dimmer switch connrcted to the mains supply I can vary the current up to 20 Amps at which point the voltage across the cell was 2.4 volts. I get more output by increasing the current to 30 Amps but the overload cut out on the charger then trips.
Do I need to change the plate configuration or just use more power ? I have another 20 Amp 12v charger but don't know whether it would be safe to connect them in parallel.

seems like youve made a unipolar reactor that runs at 12 volts. this is quite INnefficent so youre wasting a lot of current on making heat. maybe you could consider making a dry cell bipolar reactor to increase efficency or a few more unipolar reactors run in series to drop the voltage. either way you should really start making a dry cell. theyre just better in every way :)