Post Treatment Solution is a water displacing rust preventative. It is designed to provide rust protection for ferrous metals which have been treated with Zinc or Manganese phosphates. Due to its incredible water displacing properties, it can be applied to parts while they are still wet, eliminating drying operations. Post Treatment Solution may be applied by brushing or dipping. For maximum protection, dipping is recommended. This product, being a favorite among traditional firearm enthusiasts, is also a very effective "after-bluing" oil and rust preventive. Notes: Solution is designed to provide rust protection for ferrous metals which have been treated with Zinc or Manganese phosphates. Solution may be applied by dipping or brushing.