Black Oxide?

Just received a shipment of parts. I'm familiar with the brownish-black "black oxide" method of coloring steel, but these came in glossy and coated
almost like a black anodized aluminum part... But not as durable as either anodizing or oxide...
It's not paint... It's more durable than that or even a sharpie marker...
Any clue what the difference is between methods of "blackening" the steel?
Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills: http://www.AutoDrill.com Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
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Our parts always came glossy, almost "waxy"... then we switched vendors and got the dirty, brown, crappy black oxide that comes off on your hands and clothes. The difference appears to be the "sealer"... or lack of sealer on the brown parts. Caswell sells their regular penetrating sealant and a new acrylic "non-oily" sealant.

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On Thu, 15 Jan 2009 10:53:55 -0600, "David Courtney"

How about Iron Phosphate. It is a harder black conversion coating, which when oiled is VERY shiny and quite durable.

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If it feels/looks like anodizing, it might be "e-kote" http://www.metokote.com/coatingTechnologies/electrocoating.asp
The process is about half way between a dip painting and a plating process. Prduces a very good corrosion inhibitor but it is not as durable as paint and does not do well when exposed to UV. It makes a great undercoat/primer for powder coating. Snowmobile (Arctic Cat) and commercial lawn mower (Toro) use E-kote then powder.
Joe AutoDrill wrote:

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Joe AutoDrill wrote:

Sounds like Electro Coating. Basically a THIN paint process that applies the coating using electrostatic spray or dip. Depending on the material it can be a good finish or a crappy one.

--
Steve W.

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On Thu, 15 Jan 2009 10:54:52 -0500, "Joe AutoDrill"

==============Take a look at http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p 640&title=DURACOAT%20PAINTING%20SYSTEM
Unka' George [George McDuffee] ------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
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http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p 640&title=DURACOAT%20PAINTING%20SYSTEM
Maybe... But it was 230 lbs. of small parts. Not likely that they went through all that trouble on small parts.
--


Regards,
Joe Agro, Jr.
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On Thu, 15 Jan 2009 10:54:52 -0500, "Joe AutoDrill"

That sounds like what I know as black oxide. The glossiness is due to a sealant applied after the oxide treatment. There are several variables to control (temp, concentration, time, cleanliness), besides the basic chemistry, so it's not unusual to see variations. One of my customers put in their own line in order to control the process themselves. They use the Penetrate Ultra Liquid on this page, after a very thorough degreasing and cleaning routine. As advertised, the parts come out a very dense black. http://www.heatbath.com/heatbath/products/black_oxide_finishing/black_oxide_for_ferrous_metals
--
Ned Simmons

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