The Blackening Process: Insta-Blak 335
For the longest-lasting, deepest, and cleanest black finishes, we recommend the following blackening process. Please, read all safety 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. Clean the parts prior to beginning the blackening process.
NOTE: Mil scale or heat treat scale must be removed prior to blackening in order to achieve the best and most uniform finishing results.
Recommended Cleaning Products:
- E-Kleen SR 148-E is an aqueous alkaline soak cleaner that removes carbon smut from steel and metal parts, resulting in better adhesion and brighter finishes. It’s ideal for soak cleaning.
After cleaning the metal parts, rinse them for a minimum of 30 seconds in a bottom fed overflowing cold water rinse tank to remove residual cleaner.
Immerse the metal parts for 2-3 minutes in 10% by volume solution of Insta-Blak 335.
The shortest immersion time necessary to produce the desired black is between 2-3 minutes, up to a maximum of 5 minutes, depending upon the alloy and surface hardness. Immersing parts for an excessive amount of time will not increase the depth of blackness and may result in the formation of an undesirable smut or rub-off.
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 parts for one to two minutes in a compatible E-Tec water-displacing solution. The 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.
See the rust preventative and sealing comparison chart to find the best E-Tec solution for your needs.
Recommended Sealing Products:
E-Tec 501 is a slightly oily lubricant and rust/corrosion inhibitor for ferrous and non-ferrous metals. It produces 110–130 hours of salt-spray resistance.
E-Tec 503 is a dry-touch and glossy lubricant and rust/corrosion inhibitor for ferrous and non-ferrous metals. It produces 70–90 hours of salt-spray resistance.
E-Tec 504 is a dry-to-touch, hard-film, solvent-based lubricant and rust and corrosion inhibitor for ferrous and non-ferrous metals that produces 50 hours of salt spray resistance.
E-Tec 505+ is a dry, soft-film solvent-based lubricant and rust and corrosion inhibitor for ferrous and non-ferrous metals that produces 96 hours of salt spray.
E-Tec 521 is a low-viscosity, water-based emulsion providing protection for all types of plating.
E-LAQ 525 is a water-resistant, hard (2H–3H pencil hardness), and clear acrylic lacquer finish for coating metal or blackened surfaces.