A room temperature blackening process for die cast and plated zinc surfaces. The very mild acidic liquid concentrate is diluted with 9 parts of water for a 10% by volume working solution. Immersion times of 2 – 5 minutes. Equally effective on cadmium surfaces. 16 fl oz.
Parts that are freshly plated with Copy Cad® or Zinc plate may be moved directly to the Zinc Blackener system, after rinsing in fresh water.
Older zinc die castings (pot metal) should be blast cleaned with either glass beads or baking soda to remove the oxide layer. Some parts may not blacken evenly. In this situation, blast off the defective coating, then ‘etch’ the metal by immersing in a solution of 5% battery acid and distilled water for 60 seconds. Thoroughly rinse in fresh water, then repeat the blackening process.
To blacken the parts, simply immerse in the made up solution until uniformly black. Agitate the parts to remove air bubbles etc.
Rinse the parts in fresh water and allow to dry. Do not handle the parts for at least 1 hour.
Seal the surface with any of the following products.
Penetrating Sealer (from the Black Oxide system)