We are not responsible for any accident caused by Kuromi-do or Rokusho . Mix the solution in a copper pan or Corning ware. Do not use stainless, aluminum, steel, brass, bronze, or enameled steel pans. Work under good ventilation . Finish all forming, soldering, etc.
Coloring is the last process in finishing a piece of metal work.
Remove all firescale before the piece is to be colored. Boil the piece in water to remove any surface grease and oils if it has been buffed. Or use a commercially available cleaner. Fantastik is a good grease remover. Clean in a strong pickle solution.