Black Metal Oxide

[Dietzen]

I've been looking through the archieves and can't find anything on this. It's probably Listed under something else. Is this the preferred method to blacken your blade? If so, where can I get information on the process, or if not, what is preferred?

 

[peter nap]

I don't know if this is what you are talking about, but it's the closest discussion I can remember.
http://www.bladeforums.com/forums/showthread.php?t=299519&highlight=phosphate

 

[ddavelarsen]

This isn't what you're asking about but one thing that I read in some old machinist's book is to bake on oil. Works pretty good, is fairly hardy and does prevent rust; and it's almost black.

 

[indian george]

To black my blades I use Tool Black and MSC sells it as well as other supply houses.

 

[Dietzen]

Who is MCS? I just read (in a machinists handbook) the oil process. FYI-take motor oil and rub it onto the blade and place it into an oven at 350 for ten minutes. I try it and we'll have to see just how black it gets.

 

[Anthony Chaney]

an etch in muratic acid will darken high carbon steel and also help protect it from rust. It doesn't take very long either.

 

[faramir]

Works pretty good, is fairly hardy and does prevent rust; and it's almost black.

It "prevents rust"because it IS rust - it is a layer of ferrous oxide (not sure whether it's FeO or Fe3O4). It is not brown/red rust. It is made on purpose in big boiler installations and maintained to prevent pipes from corroding (my mom works in a lab when one of the things they check is quality of that black rust coating too). I don'trecall exactly how it is made, i do remember that hydrazine (highly toxic) and ammonia are involved. I can ask for further details if you want me to.

http://en.wikipedia.org/wiki/Iron_oxide