Artists often embrace chance and unpredictability in metal sculptures to create dynamic, one-of-a-kind pieces. One common method involves allowing natural oxidation or rust to develop organically, giving the sculpture an evolving texture and color. Some sculptors incorporate found objects or scrap metal, letting irregular shapes dictate the final composition. Others use heat or chemical reactions to introduce random patterns, such as torching metal to produce unpredictable burn marks or applying acids for spontaneous etching effects.

Welding techniques can also introduce randomness—artists might drip molten metal onto a surface, allowing gravity and temperature to shape the outcome. Kinetic metal sculptures take unpredictability further by relying on wind or movement to alter their form. By surrendering partial control, artists infuse their work with a sense of spontaneity, making each piece a collaboration between intention and accident. This approach challenges traditional notions of precision in metalwork, resulting in sculptures that feel alive and ever-changing.