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Black oxide conditioning treatment


Ultra Member
Premium Member
Just a followup to some discussion started here about how I kind of stumbled on getting better blackening results by spraying them with WD-40.

I subsequently blackened my little vee block & tried different oils on different parts to see any difference. Hard to photo but hopefully you can see relative to common cap screws. My conclusion is that it doesn't really matter what kind of machine oil. I think ideally a lighter weight because I think it penetrates the otherwise dry chalky texture of the oxide & somehow helps lock it down. I tried WD-40 again, motor oil, light instrument oil... no discernible difference. It doesn't hurt to just let it sit there oily, in fact I'll do that next time & just leave it over night & the give it a rub. I'm not sure if the WD-40 was soaking in more or evaporating.


John Conroy

Well-Known Member
Premium Member
I don't know if this compares to what you use Peter but I use this stuff. I would call the results "not bad". What product do you use?


I also get a chalky finish and then treat with WD40. The replacement part I made (charging handle for a CZ512 rifle) on the left is made from cold rolled steel, the original on the right is plastic.


This handle I made for a Remington 597 is colored using the same stuff. As you said, it's hard to get a good picture. Using a flash seems to make it look less dark.



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Super User
Premium Member
I use "Jax" Iron Steel and Nickel Blackener for patinas on a lot of artistic stuff I do. In the sample it was purposely removed to just blacken certain parts. But if you dunk it, it blackens the whole part in seconds...the longer you leave it the blacker it gets. Comes in small and large sizes. I get mine from Mona Lisa in Calgary, but you can order online as well.

Not sure how it would work long term on contact parts—I've only used on aesthetic stuff and then clear coated afterwards. It makes a surface oxide, but does not penetrate. Sure works well though.



Ultra Member
Premium Member
Jax is the same stuff I'm using. I bought it from Kens Gems in Calgary. The jewelry supply places typically carry the name because the same company makes all sorts of metal finishes. I thought I paid about 25$ at the time for a pint which seems about right. KBC sells a quart for $79 so thats closer to $40/pint. I think the gun supply places were even more on a volume basis but haven't done the math. Pretty sure its the same generic chemical.

you can get a gallon for sculpture supply canada, but not sure on shipping
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Ultra Member
Premium Member

JAX Iron, Steel and Nickel Blackener Gallon (801844)
Produces an antique metallic black finish on iron, steel and nickel. Color:Blackener Size: Gallon

  • Metal surface must be cleaned of all lacquer, oil, wax, and grease.
  • Gloves should be worn to prevent surface contamination.
  • JAX Iron, Steel and Nickel Blackener should be tested on metal surface to determine surface suitability and reaction.
  • Will not affect stainless steel. Will not prevent rust from forming on metal surface.
  • JAX Iron, Steel and Nickel Blackener must be applied as a cold patina, do not coat heated or hot metal surfaces.
  • Apply patina to surface with a bristle brush. Optionally, dip the entire object into the solution. JAX Iron, Steel and Nickel Blackener will react quickly with the metal surface. When opting to perform a dip patina, the solution may be diluted with distilled water to neutralize the reaction intensity. Dilution ratios can vary depending on desired darkening effect. Do not dilute with water if brushing the solution onto metal surface.
  • Leaving the patina for an extended period of time on the metal surface will result in the JAX Iron, Steel and Nickel Blackener to rub off the metal easily.
  • Once the deisred darkening has been achieved, rinse the metal well with distilled water and dry surface.
  • Steel Wool or 3M Scotch-Brite Ultra Fine Pads can be used to alter the intensity of the patina darkness on the metal surface as desired. Additional Iron, Steel and Nickel Blackener solution may be re-applied should you need to re-darken the metal surface.
  • Oil, wax, or lacquer sealer may be applied to metal surface. JAX Iron, Steel and Nickel Blackener may also be left untreated if desired.
  • Although JAX products do not expire, they must be stored at room temperature in tightly sealed original containers.

Tom Kitta

Active Member
Is this thing going to easily rub off or is it somewhat permanent? I.e. commercial or near commercial level results? Or does it rub off much easier?


Ultra Member
Premium Member
Well its not a deep penetration so probably even a .002" gouge or abrasion will show through as shiny metal. But in terms of staying power, resisting oils & cutting fluids I am ok with how its hanging in there. My carriage lathe stop sits on my vee full time by the chuck so sees the typical chips & swarf & fluid. So no it has not rubbed off if the application was successful. Some of my other parts are showing a slow dullening or maybe wear on the corners if they were sharp. Like Johns gun part example, lots of guys use this black treatment or variations that are blue, same stuff I think. I mean if you want a more resilient protective coating that would be like a high end catalyzed finish. But now those systems have buildup film thickness several thou thick from typically primer/sealant & paint so doesn't lend itself to accurate contact surfaces & tooling. I do it so it looks a bit purdy & doesn't rust. Technically the black oxide IS a form of rust... just black rust LOL.

I think (but I dont know) that the industrial blackening is either nastier chemical or its a hot oil dipping like bolts & things. I've seen people do 'blueing' just with heat but you need controlled temp & maybe even controlled environment. I cant image the color penetration is much different though. This 'cold' method is quite easy.