Insta Blak Room Temperature Blackening Process Solves Hot Black Oxide Problem

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We recently received some tooling parts in our lab from a major tool manufacturer that was having black oxide coated tool parts turning an orangish-red color on a machined surface area.

Their goal is to make the parts a uniform black. They sent some parts to Mark Kulas, one of EPi's chemical technicians, to develop a custom process for their parts. Here is the procedure that produced uniform black parts:

  1. E-Kleen 148-E 10% by volume, 140F, 3-6 minutes

  2. Cold Water Rinse 30 seconds

  3. E-Prep 258 20% by volume, 70-80 F, 30-90 seconds

  4. Cold Water Rinse 30 seconds

  5. Insta Blak 333 10% by volume, 70-80F, 2-4 minutes

  6. Cold Water Rinse 30 seconds

  7. E-Tec 503 water displacing oil 100% by volume 1-2 minutes

There are other instances where Insta Blak 333 will produce black parts where hot black oxide will not. Steel castings can turn red-black during the hot black oxide process. Take the same parts in Insta Blak 333 and the parts will turn a uniform black color with no red hues. Insta Blak 333 produces a black without the white salting out that hot black oxide will on powdered metal parts. Insta Blak 333 produces a great black color on cast iron, while hot black oxide will have a red hue to it. So when evaluating your blackening choices Insta Blak 333 can produce superior results to hot black oxide.