Auburn Rust instantly begins the rusting process on most types of steel. A multitude of decorative rust effects can be produced in a relatively short time span, ranging from several minutes to a few hours. The actual difference between the Rust Oxidizers is pretty subtle.Contact time, humidity, alloy temperature etc. determine the final color and texture. This unique formula combines a foundation of copper with the look of rusted steel. With these safe, easy to use formulas, scores of ornamental rust finishes can be created. Simply alter the humidity, temperature or rusting time and alter the final finish. With Auburn Rust, ornament ally rusting ferrous metals has never been so fast, easy, and safe.