How durable (resistant to wear) is color case hardening?

Thanks

Not very durable compared to other finishes like bluing but it wasn't originally done for cosmetic reasons. The process is meant to hardent the surface; the resulting colors are just an added bonus.

quote:

The process is meant to hardent the surface; the resulting colors are just an added bonus.

I'll throw, respectfully, a wrench in that- case hardening without colors also hardens the surface, I'd guess hardening with colors was/is done for the cosmetic effect. non-color hardening is a simpler process, as I understand it.

Some of the factories cover the finish with clear coat to protect it.
I have a Rizzini 20ga that has it.

laquer slows the finish wear, but it still wears away incredibly faster than any other finish.

It became a fad over the past few years to case color everything for appearances only. I won't do it. If it is an old shotgun action, hi-wall, or soemthing like that which was originally case colored, then it was a siple steel that was case colored to begin with. And if the action has not been filed or heavily polished, then the case hardening does not need to be redone.

Every time you case color or case harden an action, you screw with the steel's molecular structure. You can only case color something so many times before it is toast. Knowledgable case colorers have told me that it is a maximum of 3 times.

Even on a second case coloring the metal will move some and often crack. Well, "often" when compared to not screwing with it. At any rate, you are upping the risk that the action will have to be scrapped or that the parts need to be adjusted ("hard fit"), and there will be gaps at the wood to metal joints.

I am hoping this is a fad like white line spacers, 45° forearm tips, high polish hot blue finishes, short mags, moly, Blackstar's "secret process", cryo'ing everything, and most other non-traditional guin things. These fads hit the scene are are cool for a decade or so, then folks get back to artistically sound practices.

The hard surface produced by diffusion of carbon into the steel surface and then quenching can be pretty durable, depending on its thickness. It gives a glass-hard skin over the softer steel underneath.

The surface colouring, which is more or less a byproduct of the process (though often the case hardening is in fact done for this decorative effect of course) is not durable at all. It is not part of the hard skin but actually sits on top, as a very thin film of iron oxide - the colours are interference effects much like you get with a thin film of oil on water.

Clear Duracoat or a similar coating seems to be the hot ticket these days....

A lot of the doublegun guys just give the case color a coat of Tru-Oil every year. It gives the colors a warm cast due to its yellow color and is removed with solvent. In lieu of that Behlens Jet Spray is clear and does the same job without the yellow cast.