The Blackening Process: Ultra-Blak 466
For the longest-lasting, deepest, and cleanest black finishes, we recommend the following blackening process. Please read all safety data sheets and technical data sheets prior to beginning a project.
1. Clean (passive nickel only)
Soils such as cutting oils, coolants, lubricants, and rust inhibitors must be removed from the metal workpiece. Soils can inhibit the blackening process and negatively affect coating adhesion and appearance. Thoroughly clean and degrease the parts prior to beginning the blackening process.
Recommended Cleaning Products:
- E-Kleen 148-E is a low-caustic, low-temperature cleaner that emulsifies oil.
- E-Kleen 163 is a non-silicated, caustic-based cleaner.
*Note that the blackening process for Ultra-Blak 466 varies depending on whether the nickel surface is passive or freshly plated. If the nickel is freshly plated, rinse the parts and begin with the blackening step. If the nickel is passive, the parts will need to be cleaned, rinsed, activated, and rinsed again.
After cleaning the metal parts, rinse them in cold, overflowing tap water; it’s necessary to rinse the parts to remove residual cleaning solution. Parts carrying over un-rinsed film of alkaline cleaning solution would quickly contaminate the subsequent chemicals in use, resulting in a spotty or non-adherent black finish.
Immerse the parts to be blackened for 30–60 seconds.
Immerse the nickel parts in a sulfuric-acid solution (2–5% by volume) for 30–120 seconds.
Rinse in cold, overflowing tap water for 30–60 seconds.
Immerse the still-wet parts in the two-component solution of Ultra-Blak 466 until a deep black color develops. Immersion time will vary from 1–3 minutes, depending on the concentration and temperature of solution as well as the mass and condition of the nickel parts.
Rinse in cold, overflowing tap water for 30–60 seconds to remove residual blackening solution and ensure sealant will not be contaminated.
Seal the black-oxide finish by immersing the still-wet parts in a corrosion-inhibiting, rust-preventative, and water-displacing solution. E-Tec corrosion inhibitors are formulated to rapidly displace the residual acidic solution from the preceding rinse and produce long-term corrosion protection. As the E-Tec is absorbed, it enhances the depth of black, which may take several hours.
Recommended Sealing Products:
- E-Laq 525 is a water-based lacquer that offers a hard, dry finish and corrosion protection.
- E-Tec 504 is a solvent-based, dry-to-touch oil finish.
- E-Tec 522 is a waxy, water-based finish.