Langridge Oxidising Patina.
To activate your Rust or Verdigris finish simply apply Oxidising Patina and wait.
The longer the oxidising patina stays wet when applied, the stronger the reaction and brighter the final patina will be. Try experimenting to find the effect you want. After approximately 45 minutes when applying to Rust Base a red rust is created. Leaving the surface wet for around 90 minutes will result in a bright orange-yellow colour.