Blue over case hardening

tug

I have a Pedersoli rolling block that is exactly what i need. It, however, has kind of a 'mickey mouse' color case hardening on the receiver. Can I blue over that, and more especially can I use selenium blue solution or Birchwood Casey cold blue or similar?

v35

The question is whether the frame is actually case hardened or just simulated.
If it's really case hardened, low carbon steel, you don't want to remove it in order to polish and blue it.
If it's really only decorative, then polish and blue it.
I'd talk with Brownells tech people on what blue to use and what grit to polish the frame with.
Belgian blue via the boil method works well and is durable.
Colt used to sell their Single Action Army revolvers uncasehardened in the white to those who wanted to engrave, nickel plate or blue the whole gun but case hardening adds to surface durability and is desirable.

asphalt cowboy

Unlike a good blue, case Color's offer no protection to the steel at all. It is strictly a surface coloring and does not penetrate into the steel the way case hardening or hot salt blue does. You will find that case color polishes off much easier that blue will.

As for bluing over the case color, I can't advise on that. It may or may not affect how even your cold blue comes out. I've never had occasion to try it.

beantownshootah

V35 has this, I think.

Just to be extra-clear here, there is a difference between case hardening, and case coloring.

Case hardening creates a new surface alloy that physically strengthens the surface of the metal involved. Removing this hardening is not trivial (and its also probably not desirable, since it protects the metal).

Case *coloring* is just a superficial treatment to simulate the appearance of case hardening, but without the hardening. The coloring adds nothing to protect against rust, and can usually be buffed off relatively easily.

I wouldn't try to put any kind of blued (or other) finish over case COLORING without removing it first.

As V35 said, I think its possible to blue on top of case hardening, though personally, I probably wouldn't do it. I know its possible to parkerize on top of case hardening, though that's a somewhat different thing.

The case hardening is probably as functional as simple bluing, and IMO "cooler" in appearance. Just keep it well-oiled (as you might do for a blued finish) and you should be OK from corrosion.

If it really is rust you're worried about, then you're better off with a non-blued finish.

rhmc24

With all the above good advice in mind, why not try it with BC's cold blue if that's what you have. Pick a place that won't show if you don't like what you get. To do a decent job you will have to do some disassembly and cleaning anyhow, so it shouldn't be hard to find a try place.

Bill DeShivs

And then there is "color case hardening" which imparts colors while carburizing the underlying metal. "Case hardening" is simply a surface treatment. It may or may not impart colors. Originally, case hardening was done with organic materials like bone, charcoal, and leather to carburize. These materials imparted the colors-hence it became known as "color case hardening."
Case coloring is just that-coloring.
You can wear or abrade the colors off of case hardening, and the underlying metal will still be hard.