Re: how to make electric arc furnace
Been there, done that (well not the blind/burn/kill part).
Simplest form is a set of carbon electrodes connected to AC mains, with a very low resistance (=high wattage, think water boiler, 2kW heater) in series. When the electrodes touch, the series resistance limits current but the electrode tips & nearby air heat up quickly. When pulled apart slowly, you get a plasma arc in between the electrodes.
Extremely bright, white light (including UV!) & temperatures high enough to melt small pieces of glass or even nickel, produce ozone and other bad fumes. At optimum distance 1/2 the power goes into the series resistance, the other 1/2 into the arc. And obviously not safe to touch anywhere (read: using isolated tools to grab / move stuff) due to direct AC mains connection.
When I'd do a repeat these days, I'd use at least isolation transformer, professional electrode material & more precautions / safety gear. Equipment
meant for such uses is even better...
Please be carefull, UV radiation due to arc, can make you blind. High currents can burn you and kill you.
You forgot ozone, nitrogen oxides, liquid metals, open fire, 1000+ °C sparks & objects that decide to fall apart @ such temperatures... :razz::shock:
Gasses & UV can do severe damage you won't notice until later.
In other words: think before you act, and
use all protection available!