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how to do black oxide at home? Answered

 I have some machined steel parts I would like to black oxide to prevent rust and to make look nice. I would like to know the chemicals involved to make the immersion bath for room temperature black oxide.

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CardiacK (author)2018-04-12

Best way to get a blacked finish on steel is FeCl3 otherwise know as Ferric Chloride. All you are doing is etching the surface to hold oil on the surface .

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xXleslyXx (author)2018-03-03

heat it up to cherry then cover it in oil. any oil will do but linseed is best. Either put some on a rag and wipe it on when its hot or dunk it in oil. it has to be cherry not any hotter or it will harden and not work

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Wisaam (author)2013-02-06

I wouldn't recommend using black oxide because I don't think it would help that much for a long time. Why don't you just paint it with black colour or use black water proof marker.

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ewilhelm (author)2012-11-28

The above comment was copy of the text here:
http://www.finishing.com/faqs/blackoxide.html
and has been removed because it did not link back or provide attribution.

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Alcyon (author)2011-12-27

for they small parts use a black waterproof marker

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The Machinist - Jason (author)2009-12-27

Just remember black oxide will only prevent rust for a short while. If you want to keep your projects from permanetly rusting you need to paint or powder coat it.

Jason

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black oxide turns to rust when exposed to water but it is very porous and adhesive... in history it was used to protect the steel along with oil

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Re-design (author)lemonie2009-12-19

After reading that I think I'd just blue it like a gun barrel.

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lemonie (author)Re-design2009-12-19

That was my first thought for an answer. But then I thought "maybe this / these is/are big, and gun-blue might be an expensive option, so I'll do a quick one (search) for the question they asked."

L

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steveastrouk (author)2009-12-19

If you're in the UK, most engineer's merchants can supply KoldBlak, which is the proprietary process.

I really don't advise making your own.

Steve

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