doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com cyanide case coloring also provide hardening?

I'll profess my ignorance on Cyanide Case Coloring. I've had more the one gun done with Case Color hardening, but never looked or considered Cyanide Case coloring. That said, I'm now looking at redoing a Fox that was built in the mid 20's and Cyanide was the method then.

Accordingly, I'm assuming the action has to be annealed and the engraving chased, then its sent to whomever for cyanide case colors. When those case colors are applied does that harden the action the way traditional bone charcoal case coloring does? Would assume yes, but I don't know. I know that the new Browning low walls have cyanide coloring, but I think that is more of a dipping process with low heat and the metal is already 4140 I believe.

Appreciate thoughts/comments. Just trying to get smarter on the process itself.

PS. Below is a Browning Low Wall that I had case colored using the same company in Montana that does their actions:

I know that cyanide coloring is much lower temp than bone charcoal. But other than that, I know little about it.

I have wondered myself what the process is.

I look forward to some answers.

If it is case hardening, the temperature required will be the same, whether it is done by charcoal or cyanide. The steel has to be taken above the critical temperature, about 1500 degrees, for any hardening to be done, then quenched in water. The colors are a byproduct of the hardening. If the object is only colors, then I expect it could be done at lower temperatures.

Tom is quite correct. Cyanide can give a nice hard outer surface just like bone and charcoal if the proper procedure is followed. Many older tools built by Starett etc used this process. Once I learned how difficult handling and disposing of the stuff was I pretty much lost interest in it as a viable process for me to use. Pete Mazur has used this process extensively in the past and is very knowledgeable about it. I do not believe he offers it currently due to regulations regarding it. You will likely get the best information from the company that is offering the service. I'll bet they could tell you if you will get a hard outer skin on mild steel using the process they use.

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I had always figured that Cyanide, when done right would have to give a surface hardness similar to bone charcoal. If not then the steel used would have needed to be changed and for sure the malleable iron guns never would have been colored and harden enough for use by cyanide process.

What I wondered was why the change from bone charcoal to cyanide? Handling the materials and disposal, which was not a major thought 75 years ago, has to be more complex with cyanide based materials. Bone charcoal process were well known, with "secrets" being passed down from one generation to the next. So it must have been a cost cutting measure and perhaps more predictable color outcomes. Marginal improvement in hardness would not have caused all the makers to go down this route. In fact I suspect they would have accepted a reduction in surface hardness as long as they thought it to be below critical level.

Profit margins were razor thin on doubles so cost reduction must have been the driving force. What was the cost difference, fifty cent per gun? Maybe it was once one changed they all had to "keep up with the Jones" or be perceived as using the old system when a better, newer one, more modern one, was in use by their competitors.

Beauty is in the eye of the beholder but I always found the Cyanide colors to be too harsh. Perhaps there are ways to tone them down but time and "sunshine" don't seem to affect them as much as some bone colors. Maybe it's just the fact that they are newer. The water color colors of some of the Remington 1894s are as pretty as any painting I have ever seen.

The H&R single barrel guns were also Cyanide colored. It would be hard to believe that production cost was not one of the factors considered when the decision was made to use the process.

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Only asking, it's just carbon added to the surface. What makes the steel formed in the cyanide process different so that it gets harder?

I believe the advantage of cyanide hardening is purely economics. Numerous frames can be "dipped" simultaneously while bone and charcoal hardened items must be packed individually. The end result is the same with minor variations in process accounting for different coloration and color distribution.