metallurgy

A 105-minute film of a West African smith family in Burkina Faso smelting iron from ore, from making charcoal and building the kiln to forging tools. It is a cultural recreation filmed for the camera, not current practice.

A Primitive Technology episode in which the creator builds a bow-drill-driven bark fan to blow air into a fire, using only natural materials. It shows the progression from fanning a fire by hand to a rotary forge blower.

Real Engineering explains the materials science behind metal 3D printing, including crystal structure, laser sintering, and why printed parts develop fatigue cracks. It shows how process imperfections limit the strength of printed metal.

NileRed tries to make a ring from pure purple gold, a gold-aluminium intermetallic that is brittle and hard to work with. The 53-minute video follows the chemistry and many failed attempts before he produces a finished ring.