A Way To “Color Case Harden” At Home

Some time ago, I wrote an article about completing a black powder revolver kit from Dixie Gun Works. Upon completion, the frame still needed to be refinished as it was just bare steel. I mentioned that I hadn’t yet decided on what finish to use on the frame, but wanted something that at least looked like color case hardening, as this is the finish the original Colts had. A reader suggested Steel FX patinas, as they have a finish that gives the appearance of color case hardening without actually having to heat treat the steel. So, I looked into it and decided to give it a try.

The problem for the average home builder with color case hardening is that it requires some expensive equipment and some special skills. In a nutshell, color case hardening is basically carburizing (adding carbon to the surface of the steel) and hardening steel. Case hardening was used into the 1900s for parts such as revolver frames and receivers, and the “coloring” was a byproduct of this process. These days color case hardening is primarily done for aesthetic reasons, such as recreating the original finish on older firearms (though I have seen some more modern firearms refinished in this manner as well). Obviously, most homebuilders do not have the capability to heat treat steel in their garage. This method gives a similar appearance, and you only need polishing materials, the Liquid Patina, and the Renaissance Wax.

The first step is to completely disassemble the frame or whatever parts you’re working on. If you built a revolver from a kit like this one, then you should be familiar with this process. Then, you need to polish the frame or parts you want to finish. If you’re working on a “kit” revolver like this one, you might have already done a chunk of this when you did the clean-up work on the frame. But I’m going to go over the polishing process some anyway, just in case you didn’t or are using this process on some other project.

You need to have all of the major defects or extra material removed (in the case of this kit revolver). Use a file for this. Obviously, the more substantial the work needed, the coarser the file you should use, going finer as you go. Then once you have the file work done, it’s time to polish the surface with an abrasive cloth. It is important to remember that paper-backed abrasive is for wood, and “cloth” backed is for metal. Use something as a backer whenever you’re using abrasive cloth (unless it’s a truly round surface that you can use the “shoeshine” method on), to prevent rounding off corners or other features. I use a file for flat surfaces (wrapping the paper around the file). For other surfaces, I cut a piece off and wrap it around a rubber eraser. I keep it in place with a push pin. Whatever you use, tear or cut the cloth so that it doesn’t hang over the edge so that you keep better control.

I polished the surfaces to a 400 grit finish. You start with a coarser grit cloth. If it’s a filed surface, I typically start with something like 80 or 120 grit. Then once you have the surface polished to that grit go to the next finer and so on, polishing the polish marks out from the previous grit. When you change grits, polish in a different direction as this makes the polish marks stand out (making them easier to polish out), particularly as you get to the finer grits. You will be tempted to overlook some small flaws (polishing is rather tedious), but don’t. The finishing work won’t hide surface imperfections, actually making them stand out instead. After you’re done polishing, clean all of the leftover abrasive off. And then you need to completely degrease the frame prior to applying the chemicals. Avoid handling your parts with your bare hands from here on out.

Next is the actual metal coloring process. Applying the liquid patina is a two-step process. You apply the Surface Activator, and then the Gunsmith Special itself. The Gunsmith Special will only react with the surfaces that have the activator on them-meaning the surface has to actually be wet with the applicator. I found this actually helps you keep control of what specific area you want to work on. Then you let the chemical sit on it until it is the color you want. Then wash it off, and blow it off with compressed air to completely dry it. I found that it’s best to do smaller areas at a time, as it’s easier to control how it all looks. I also found that the surface tension of the liquid tended to keep it away from the edges, so it took a couple of tries to get everything colored with no bare spots.

Now that everything is the color you want, it’s time to apply a protective coat. I chose Renaissance Wax, as it’s what SteelFX recommended when I called them, though they mention in the directions that other clear coats could be used. You apply the wax in thin coats and polish it with a clean rag.  Apply a little and buff it, repeating this until the whole part is coated. Once this is all done, reassemble the parts and you’re finished.

The Gunsmith Special solution from Steel FX offers a way for the home gunsmith to apply a finish that resembles color case hardening without expensive equipment and special skills. It’s a great way to finish a revolver kit project like this one. It’s fairly inexpensive and pretty easy to apply. I’m really happy with how mine came out. Until next time, Happy ‘Smithing!

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