The Blackening Process: Insta-Blak A-385
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.
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 deoxidize the parts prior to beginning the blackening process.
Recommended Cleaning Products:
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.
Some experimentation will be required to determine the optimal concentration and length of immersion for achieving the depth of blackness desired. Begin with a 1:1 solution of Insta-Blak A-385 concentrate and water and adjust as needed to achieve desired depth of blackness. The parts should be immersed for the shortest period of time possible, which should be approximately 30–90 seconds.
Alternatively, Insta-Blak A-385 may be applied with a swab-on technique. Complete steps one and two first. Use a swab, brush, or sponge to apply the solution generously and at full strength. The blackening reaction may take up to 90 seconds.
If Insta-Blak A-385 isn't quite what you’re looking for, consider these similar products:
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 and rust-preventative 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-Tec 504 is a solvent-based oil that leaves a dry film.
- E-Tec 521 results in a waxy and glossy finish.
- E-Tec 520 is a water-based lacquer that leaves a hard, dry finish.