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how can i build an arc furnace from a microwave ? Answered

after wanting to build a tesla coil, but first reading up on how to make a HV output supply from a microwave transformer,
then realising i want an arc furnace to melt pool salt(calcium chloride, or if possible, carbonate) in order to make calcium metal, or calcium carbide, via electrolysis

what do i need to do, to build an arc furnance from a microwave transformer?

clearly it seems very much able to generate an arc, with a significant amoutn of heat, but i dont know how to safely use it to do what i want.
at the moment i already do own a microwave transformer, its fuse clips and all the other junk form the microwave transformer.

i also want to know if its possible to melt lead with an arc furnace, as i want to do some lead casting wihtout using expensive propane.


I can't comment on the furnace as a whole...

but if you think propane is expensive, then the electricity required to run an equivalent electric furnace will blow your mind.

I looked into this a little:
Propane's cost has skyrocketed in the past few years. It is more inefficient to run an equivalent electric furnace, but it's not necessarily more expensive. If propane costs $2.40 per gallon, then electricity from a standard grid would be cheaper to use providing it costs less than 10 cents per kWh. So where I live, it would be less expensive to use electricity, as it costs 8.3 cents per kWh.
It depends on where you live though, and it also depends on whether or not the propane is bought in bulk, and what time the electricity is being used. (it's the most expensive during summer in the day, and cheapest during winter at night)

i now know that using a microwave transformer wont work without rewinding, but now i possess several welder transformers i will use instead.

I read one of your comments below, and I realized:
I hope you don't think that you can run an arc furnace off those 1500 watt solar cells...
Arc furnaces use WAY more power than that.
I found a welder online that runs off a 23 horsepower engine and produces 11,000 watts of electricity!
Be prepared to use that much, especially because light duty welders usually don't cut it for arc furnaces...

Don't forget to factor in the TOTAL cost of electricity including fixed costs and fees (delivery/transmission etc)
The billing price for electricity here is around 10/kWh, but it's almost double when you include the fees.

It's definitely possible. You may want to modify the secondary coil a little though. A good arc furnace operates at voltages between 400v-600v and have as many amps as possible. A typical MOT puts out around 2000v to 2500v. Since you don't need that many volts, perhaps you could re-wind the transformer to get less volts and more amps.
Also, in case you don't know, electrolysis only works with DC. And you can't use a DC power supply to power a transformer because transformers only work with AC. You'd need to pump AC into the transformer, and then rectify the outgoing current with some pretty powerful capacitors and diodes.


7 years ago

General knowledge imparts massive electric currents arcing in a properly
insulated paddock of molten metal guided by carbon arcs to regulate energy.


goodie so it can be done.
this leads to the second question
can i safely electrolyse, while pumping off the chlorine gas generated, the molten salt to aquire the alkali metal?

are there any precautions i should take to ensure the high voltage of the microwave transformer, and the 12vdc of the modded pc power supply electrolysing the salt, dont combine or damage each other?
or will the arcs generated also electrolyse the molten salt?
in theory it should work, but if done incorrectly, could be a catastrophic waste of time, money and time

btw, my friends house, at which i intend to be using this, has several large solar cells taking advantage of the 99% clear skies over ridiculously sunny darwin. these can generate in exess if 1500 watts on a good day which is pretty much everyday ,
plus, where i live, propane is quite expensive, especially the disposable bottles.