Grant “The King of Random” Thompson (previously) outlines how he created a makeshift arc furnace from microwave parts, which creates enough power to melt steel in under two minutes when the two repurposed carbon rods are pressed together. In the video, Thompson tries the arc furnace out on all manner of metals and a handful of rocks.
This project can reach temperatures in excess of 3,000ºF (1,648ºC) which is well beyond the melting point of hobbyists. Caution, care and expert planning are required to mitigate risks. Use of this video content is at your own risk.