"Cow Bone" Blue Process

I recently had an S&W armorer evaluate my 1961 Model 10 Heavy Barrel. I bought this used and was told it had never been fired since leaving the factory. The armorer opened it up and confirmed that everything inside was very clean, original and the gun was fired very little if at all since leaving the factory. Great, I felt better. Then he said the interesting thing about the revolver was that it was the old "Cow Bone Blue" style. He said that was a bluing method at the time of manufacture, but today it is no longer allowed due to some EPA regulations.

Does anyone know anything about that? It is a very deep and rich looking blue.

I recently had an S&W armorer evaluate my 1961 Model 10 Heavy Barrel. I bought this used and was told it had never been fired since leaving the factory. The armorer opened it up and confirmed that everything inside was very clean, original and the gun was fired very little if at all since leaving the factory. Great, I felt better. Then he said the interesting thing about the revolver was that it was the old "Cow Bone Blue" style. He said that was a bluing method at the time of manufacture, but today it is no longer allowed due to some EPA regulations.

Does anyone know anything about that? It is a very deep and rich looking blue.

I believe he was talking about carbona blue.


... and it's lovely!

+1

Well now I feel silly. I obviously misunderstood! Does anyone know what was different about that process?

Look in the forum before this. I believe that there was recently a thread that explains some, if not all, of it.

USFA is doing that with their SAA clones, I have one and it looks really nice, as does your gun.

Thanks to all for the quick response! Also, I hope you all got a laugh out of my mis-pronunciation. Maybe I should get my ears tested.

That is one fine lookin' old Model 10, as crisp and pristine as I've seen. Great catch!

No, I think you have it right. A senior armorer at a large government department described the S&W blueing process as using animal bone. The technique was brought to a close due to government regulation & the environment.

Further, I was told that the newer, dark, soft finish is the result of the elimination of bone during blueing.

I vaguely recall that the bone was burned in the process but don't quote me on that.

Just to add a note regarding the use of "bones". My Great Grandmother and her siblings would gather buffalo bones from the grasslands in North Dakota in their wagon. They'd take them to Park River in Walsh County. The family has pictures of the buffalo bones piled 15' high for 100-200 yards alongside the tracks outside the station. They were told the bones would be picked up and hauled "back east" for medicine and for use in making steel & for bluing.
For years later on our ranch, the "Lazy SS" Hereford Ranch, we would hunt for and find arrow heads and tomahawk club rocks in the same area.

Interesting info here about many bluing methods, including S&W's method from the time of the OP's gun.

http://www.restoration-gunsmith.com/artblue.html

Pretty informative article. Wonder if the story about the widow with the only written carbonia-blueing recipe is true? Pity if it is, but I wouldn't be surprised.

Great article, thanks for the link....

I can't recall where I read this recently, but the old bone and charcoal process for case hardening, used real human bones imported from India I believe it was. That practice was stopped for a long time, perhaps due to the fact that it was human bones, or maybe to prevent poor people from robbing graves to get them and sell for a few bucks. Now apparently Doug Turnbull has a supply of them again. I will look for that article and post it here if I can find it. It was very fascinating reading.

Perhaps the cow bone reference was made to the case hardened parts. Animal bone charcoal can be one of the key ingredients of the secretive recipes used to case harden hammers, triggers, etc. Unfortunately, the term "color-cased" has overtaken the gun vocabulary, implying it's firstly aesthetic. True, it's pretty, but numero uno is a thin, hard wear surface.

We used the same bone char in Carbonia Blueing as we used in the color case hardening operation.
It's nothing secret,,the commercially available stuff from Ebonex Corp (Mich?) that most everyone else in the business uses. In fact, I think on the Ebonex website they list a grade of it specificly for blueing (or they did not too long ago). It is animal bone charcoal, usually cow bones. I'm sure there are some types that work better than others, but you don't have much choice other than 'animal bone char'.

It needs to be of a smaller granular size than usually used in CCH work. The original Carbonia Oil is no longer available, but Mobil Corp provided us with a synthtic grade oil that was in their words,,the equivilent of the original for our purposes. Jet black and near thick as molasses at room temp.

The old American Gas Furnace Co machinery to actually do the blueing was not exclusive to S&W.
Nearly all the mfg used the same equiptment. If you wanted it,,you bought it from them. simple as that.
Winchester used it till they abandon it in about 1938 for DuLite hot salt blueing. Winchester used Whale Oil/Sperm Oil for their 'fine' finishing and either pine tar or linseed oil for their small parts blueing.

The use of Carbonia Oil gave the process it's name but many small parts in the gun industry were blued with less expensive oil (linseed usually).

The hardware mfg industry in the US in the first 1/2 of the 20th century used the exact same system (American Gas Furnace Co equiptment)to mass blue their products. Back then, common fasteners (nuts, bolts, washers, etc) were blued,,not plated like today. They were blued by this method and machinery.

The use of carbonia oil gave the best looking finish and looked very close to the charcoal blueing process it was meant to replace.
It was simply a way to more quickly and efficiently finish metal parts. Charcoal blueing is alot of manual labor for each piece blued.

Hot salt blueing was the next to come along and put the gas furnace method out of business.

While most all the mfg used the same machinery in the blueing process (American Gas Furnace equiptment), the use of the Carbonia Oil is generally accepted as the only 'Carbonia Blue'.
Wether S&W had an exclusive on that particular oil or not I don't know,,some say they did.
What ever the answer, the other makers seemed to have been able to produce some awfully beautiful finishes using a common oil.

Perhaps that is one reason the particular blueing method has a second name,,,machine blueing. They are all 'machine blueing' operations,,but only when using real Carbonia Oil is the finish to be considered 'Carbonia Blueing'.

This is all great information! Thanks for all the responses and clarification.

Whatever the method was, it is a real nice deep blue.

Great thread.
Answered many questions that have come to me
when reading posts here.