We have reached the seventh cube for the element cube collection: Cast iron! Made from a pair of disc brakes, which was quite a challenge to get melted due to cast iron's high melting point.

As something new the cube is engraved using electro etching, where an electrolyte of vinegar and table salt is used. The power supply is set to 12V and draws around 5001000 mA. Please remember good ventilation when doing this.