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Insta-Blak 333

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Insta-Blak 333 is an immersion blackening solution that results in a smooth, no-smut satin black finish on tools and architectural surfaces.

One gallon of un-diluted Insta-Blak 333 concentrate can coat approximately 400–500 sq. ft. of metal parts.

Learn about EPi's trial kit and the short-run kit.

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How to Use Insta-Blak 333

Insta-Blak 333 is a black-oxide process designed to make in-house blackening simpler, faster, and more effective while still achieving an aesthetically pleasing black finish.

Use Insta-Blak 333 to:
  • Coat metal items with a glossy, grey-black finish
  • Blacken metal parts at room temperature in only 1–5 minutes
  • Achieve clean, smut-free finishes and dimensional stability
  • Reduce heating and energy costs
  • Avoid hazardous caustic fume
  • Blacken cold- and hot-rolled steels, cast iron, powdered metals, tool steels, and sterling silver
Getting Started

EPi offers 2-liter trial kits and 5-gallon short-run production kits for short-term projects. Learn more about what is included in the trial kit and the short-run production kit.​

The Blackening Process: Insta-Blak 333

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

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.

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.

2. Rinse

After cleaning the metal parts, rinse them in cold, overflowing tap water; it’s necessary to rinse the parts to remove residual cleaning solution. However, thicker or heavier parts may chill the blackening solution in step three. In these cases, use a hot-water rinse so that the parts can be preheated. 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.

3. Blacken

Immerse the metal parts for 2–4 minutes at room temperature in a 10–15%-by-volume solution of Insta-Blak 333.

If Insta-Blak 333 isn't quite what you’re looking for, consider these similar products:

  • Insta-Blak 333 GEL is a gel-based solution that result in a no-run, no-drip black finish. It's designed for vertical applications, steel panels, and quick touchups. It's ideal for users who desire a slower chemical reaction.
  • Insta-Blak S-334 is recommended for touchups on scratched or damaged black oxide finishes. It produces a rich black color and maintains an item's structure and dimensions.

4. Rinse

Rinse in cold, overflowing tap water for 30–60 seconds to remove residual blackening solution and ensure sealant will not be contaminated.

5. Seal

Seal the black-oxide finish by immersing the parts for one minute 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 502 is a thin and slightly oily lubricant and rust/corrosion inhibitor for ferrous and non-ferrous metals. It produces 70–90 hours of salt-spray protection.
  • 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

Activation (if needed)

In most applications, cleaning the parts in E-Kleen 148-E or another cleaning solution is sufficient. However, some difficult-to-blacken steel alloys will require activation to make the steel surface receptive to the blackening reaction. When necessary, activation takes place after step two, adding a seventh step to the process.

E-Prep 258 is used at 20% by volume in water at room temperature. Immerse the metal for two minutes after the first rinse. Follow the activation with another cold-water rinse prior to blackening.

Recommended Activating Products:
  • E-Prep 258 is a universal liquid surface conditioner and activator. It also removes smut and rust from steel parts and acts as a conditioner by enhancing the depth of black finishes when the resulting finish is lighter than desired.