|Arc Torch Circuit|
The torch electrodes are graphite rods from zinc-carbon D-cell batteries cleaned and neutralized with baking soda (the batteries have an acidic paste inside).
|Hot Graphite Electrodes|
The electrode holders are straight 3/8" OD copper repair pipe that you can find in any home improvement store.
Enough heat is created by the torch to do light welding / brazing. Heating is proportional to current, so a step-down transformer would be a good addition to the circuit. Also, controlling the resistivity of the water resistor might make a good Arduino control project. We could measure the voltage drop and add salt or water to the bucket based on the resistance.
|Tack-welded Soup Cans|