Color Case Hardening

[lynnl]

Thrud, in another posting (CRS vs HRS) mentioned color case hardening. I just got MBR1&2 from Guy Lautard and read his description and recipe.
I'm wondering if Thrud uses that recipe, or Kasenit, or what? Does the Kasenit process produce good coloring? I haven't done any of that (intentionally that is).
Also, is the coloring effect highly dependent on the type of steel used?

[JCHannum]

Kasenit and similar compounds leave the metal a grey to black in the hardened ares.

Color case hardening is dependant to a degree on the steel, but more on the combination of materials used in the procedure, and how they are arranged.

Color case hardening is usually done with a combination of wood charcoal, bone and leather charcoal and a couple other secret ingredients depending on the operator. Some of the early guys used to pee in the pot, so it depended on what they drank the night before.

There is a lot of black magic associated with color case, but main ingredients of various charcoals, and cooling as quickly as possible in aerated water with minimum exposure to air seem to be the key to success.

[SGW]

Commercially I believe it's done with potassium cyanide, but that's not something to mess with at home.

[Thrud]

SGW is right about the commercial version - those of us who don't want to die avoid cyanide compounds - even if they do color case harden quite well!

Guy Lataurd's brew works well, in the following editions he recommends the bone charcoal - this works the best. Just follow his instructions (when he tells you not to reuse ingredients believe it) and you should like the results - lots nicer than Kasenit but not as easy. I have not been able to get Kasenit for years - nobody wants to sell it here.

[JimH]

I visited Ballard Rifles in Cody, Wyoming over the Xmas holiday. What a fun experience. They do their own case hardening on the receiver. They use the bone charcoal. Did not mention if they had a secret ingredient or not, but basically said they follow the old way of doing it.

An interesting side note was that they had a CNC mill set up to exclusively rough out the stocks. Mount the blank in a jig and away it went.

Good folks all around.
J

http://www.ballardrifles.com

[Herb W]

I'm familiar with case hardening, but after reading the posts above, still not clear on color case hardening.

Is this done when you need to case harden the part anyway and want also to have an attractive finish?

What colors can you achieve?

How durable / corrosion resistant is the finish & do you need to protect or seal it with anything?

[This message has been edited by Herb W (edited 03-23-2002).]

[JCHannum]

Take a look at the BAllard link posted above. The receivers are color case hardened.

Many gun manufacturers used it for its decorative, as well as mechanical functions.

Starrett and others used to use it on a lot of tools, parallel clamps, surface gagas etc. Think they still use on some.

A large range of colors, mostly blues and reds can be obtained depending on materials and methods used. It is quite attractive.

[Rotate]

Thrud,
I too have been unable to source Kasenit in Canada. Is this banned in Canada? Will I have trouble mail ordering from the States?

Why can't you use finely crushed activated charcoal to do surface hardening?

Albert

[mark]

Brownells has both the kasenit and bone charcoal.

[Thrud]

Herb

Starrett's #56 Hardened Steel Surface Gage is color case hardened. The Bone Charcoal gives the most vibrant colors (red, blue, greys, etc.).

Albert

I do not know why this is so, no one can tell me except they cannot get it. I suspect it Agriculture Canada or some other poo-for-brains department that has decided some chemical in it is unsafe for Canadians. Probably the same reason a wrist rocket and some air guns are on the prohibited list.

Dave

[This message has been edited by Thrud (edited 03-24-2002).]