Electropolish Electropolishing is an electromechanical process similar to, but the opposite of, electroplating. The electropolish process smooths and streamlines the microscopic surface of a metal object. As a result, the surface is microscopically featureless, with not even the smallest spec of a torn surface. Chromate Conversion Chem Film, sometimes called Alodine or Iridite, is a chemical conversion coating that is used to passivate aluminum. It protects aluminum substrates from corrosion and serves as a base for organic coatings while leaving dimensions unchanged. Brass & Copper Bright Dip Bright Dip on copper and brass alloys is an acid based chromate conversion coating used to protect and add shelf life to the base material. The parts are first cleaned to remove the oil and dirt that may be on them from processing and manufacturing. Passivation Passivation remains a critical step in maximizing the essential corrosion resistance of parts and components machined from stainless steels. Passivation returns the substrate back to its original specifications by removing iron particles from the surface.