S&W Bluing Methods

Greetings all, first post, but I have been lurking for a while and have found this to be a great place to get good information on S&W. I have been a S&W fan for practically all of my life.

I'm trying to find out all that I can about S&W bluing methods. I know they used the proprietary "Carbonia" method after WWI (aproximately) but I am really curious about what they did before that. I have generally heard they heat blued using organic carbon sources (eg bone/wood charcoal) but that's about all I know. What did they do 1870-1920?

More than anything I'd like to get my hands on a book or two that provide a lot of details.

I do a lot of my own gunwork and have built and modified a number of firearms. I just picked up a nice 1896 HE that is great except 60% of its finish is gone, but it still has good markings, a good bore, and no bad pits. I figure it would make a nice restoration subject. But I'd want to use a period-correct bluing method.

Any help would appreciated. Except I'm not looking to touch off a "should I refinish or not" debate. I am $150 into this gun and am ok with the possibilty that it's value would be destroyed by my hands. Might feel differently if it was a nicer specimen...

One website I have found that describes different blueing methods used by manufacturers in the past is ronsgunshop.com. I assume the information is correct and I have no association with the business. I was searching for information one day about carbonia blueing and came upon this site. Hope this helps some.

To my knowledge the ronsgunshop info is not entirely accurate -carbonia was a proprietary process using a secret formula and it involved heating to over 500F and is not really directly analogous to charcoal bluing. I do appreciate the effort to help though.

There has to be some book that discusses industrial processes over time. I've heard they used a few different methods before they got to carbonia.

I'll add on a little to my own post...

I hoofed it down to the NY Public Library today over lunch and went through a 1st ed. copy of Smith and Wesson: 1857-1945 by Jinks. I satisfied myself that it does not address bluing beyond stating whether various models were finished in "blue" or "nickel" (or in same cases park).

I don't recall seeing anything about it in History of Smith and Wesson (Jinks) although I don't have a copy here and it's been a while since I read it.

Somewhere, someone has to have compiled this information at some point in time...

One thing that was interesting to note was the use of hardened steel cylinder stop shims in the early hand ejectors and in some of the break-actions. 1857-1945 explained that they stopped using the shims in 1908 because by then they were using a more modern steel that heat-treated better. What is significant is that while Smith was moving to higher carbon steels they were most likely changing their bluing methods -- and perhaps frequently because of issues with how the new steels took the finish.

S&W bluing

In the early 80's I installed a Shilen 1.125 dia bull barrel on my 25-2 revolver and blued the barrel only at my place of employeement. We had a heat treat and bluing facility and we used Heat Bath Corp. products and the bluing tank was kept at 280-290 degrees. The barrel was buffed to a mirror finish and ran through the bath when I installed it on the frame you could not tell it from the original bluing on the 25-2. I think it is in the polishing of the part. The tool holders that were blued in the bath all had a milled finish and all came out black. Jeff

This is from the late Bill Adair's web site:

Bluing Methods, Definitions and Processes
by Bill Adair
[snip]
CARBONIA Heat/Chemical
Now here's one of the most mis-used, least-understood words in the entire bluing lexicon. 'Carbonia' Blue was a S&W proprietary method used in the period from before WWI thru the 1960's. It was also known as 'Smith & Wesson blue'. It was ONLY done by Smith. Never by Colt or any other manufacturer. Carbonia bluing resulted in that deep-black/glossy high-polish finish that Smith was noted for during the years they used it. It's similar to 'DuLite' and Charcoal bluing as far as the process goes, but certainly not the same.
The Carbonia oil (a product of American Gas Furnace Co.) was used by many gun manufacturers in their own versions of 'DuLite' bluing, but the use of Carbonia oil does not make it 'Carbonia Blue' as only S&W did it. DuLite bluing, such as Colt did on their 1918/1919 military model 1911's is an industrial/utility finish. It was generally done over a fairly coarse-polished and/or sandblasted surface, and is a dullish, dark-grey or near-black color when used in that way. It was also far less durable than the S&W Carbonia Blue.
And there's a funny story to go with the S&W Carbonia Blue. I'm telling it like I heard it, and I have no idea if it's true.
The basis of S&W Carbonia Blue was an oil mixture (pine-tar based) made by the American Gas Furnace Company, and they supplied the oil in bulk to S&W, who mixed it with bone charcoal and other 'stuff' to make their own Carbonia product. Years ago, by the way, I contacted the American Gas company for info on the process, and they were kind enough to give me a list of the chemicals/ingredients used by Smith for the process, but it was just a list of chemicals, not a formula.
So, here's the story:
Apparently, only one old-timer at Smith knew the exact formula and he had it in a notebook which he kept. He eventually retired from Smith, and later died. His widow, so the story goes, contacted Smith and offered to sell them the formula in the notebook for $50k. I guess she knew that her husband had the only written copy of the secret formula. Well, Smith had gone into hot-bluing by then, and wasn't really interested in shelling out $50k to her for the Carbonia formula. So, she burned the notebook. And that was the end of Carbonia.
The moral of the story is that all of these companies who now say they do 'Carbonia' bluing, or worse yet 'Colt Carbonia blue', are just you-know-what. Maybe they can do something that looks similar to S&W Carbonia Blue, but it ain't. And Carbonia blue is not Charcoal blue. It's very black the way Smith did it, not blue, and please, Colt never did it.
Carbonia, when applied to a surface that is not expertly high-polished, results in just a so-so utility kind of blue. Time and temperature controls were critical in obtaining the exact color Smith desired.
I've still got the list of ingredients, but there are numerous items on the list, and you'd need to combine them in the correct measures to get the actual S&W formula. I've combined most of the ingredients (or similar ones) in various percentages and at one time did quite a bit of R&D with it, but I never got too interested in pursuing it much further. It was hard enough to find any whale, let alone a sperm whale, so I never had any sperm-whale oil. That was just one ingredient I couldn't locate. American Gas Furnace Company doesn't make the stuff they supplied to Smith any more, so it's a futile pursuit as well as further proof that true Carbonia bluing no longer exists. However, the Carbonia look can be simulated or duplicated by other means.
_______________

I don't think there's any doubt that an exceptional bluing job is 90% polishing and prep. (And I think this is why, in an era of relatively high labor costs, exceptional bluing jobs are rare on factory guns.) As long as you are actually "bluing" the gun -- controlled corrosion of the skin of the metal, to put it simply -- the key to a deep glossy finish is a really, really smooth finish when the process starts.

I am really amazed it is proving so difficult to find out how S&W blued their earlier guns...

Carbonia Blue

I read an almost exact accounting of the S&W Carbonia story on another website some time back.
I will have to look for it as it had more details on period finishes and recipes for those finishes.

Colt offered a limited edition WWI 1911 a few years back advertised with a Carbonia finish.

As the story goes they sent them out to be Carbonia finished outside their factory by a private gunsmith,
So although Colt has offered handguns for sale that were advertised as finished in Carbonia ,
They did not perform the actual finish and because the true recipe was lost the term
"Carbonia Finish" will always be disputed.

This is a side by side picture of their "Carbonia style" finished 1911 next to a parkerized 1911 for comparison.

First, welcome to the forum. In the "Images" book there is a comment that S&W makes all their own polishing wheels and that the originals were made of walrus hide and wood. You can bet that the walrus hide thing is long gone with the tree huggers around today. Also says that prior to 1979 the parts were held in a dry gas oven at 750 degrees with charred bone and carbona wax. The parts were cooled in oil but it does not say what the oil was or how fast the "quenching" was.

Bob

How did they do it??

I would like to know the steps and process used to ready a gun to be blued from assembly through finished piece by S&W. Was any tumbling polish involved? What grits of polish used? For different finishes
M-28 vs. M-27 etc. Was any pickling involved?

The following is a quote from a 2007 correspondence with Roy Jinks: "The bright blue process depends on a very bright finish. It is not the bluing that makes the process bright. The S&W bluing process up to 1978 was a hot dry blue process called carbona. It was a charcoal style of process and S&W started using in in the 1850s. It provided a beautiful color but to keep everything a matching color all parts needed to be done together. S&W did this until 1958. After that they started bluing barrels in one batch, cylinders in another and the frames separate. This lead to slightly different colors in the blue finishes. The new process is a chemical bath process."

This is from the late Bill Adair's web site

Click to expand...

I didn't know that Mr. Adair had passed. This is a great loss for all of us in the shooting/gun community. Knowledge like his needs to be passed on so we may preserve our old firearms.

This is becoming an old thread but I got some additional information and wanted to pass it on.

First, I reviewed a couple industrial/manufacturing books from the first half of the Twentieth Century and determined that carbonia oil was NOT unique to Smith & Wesson. Or even to guns. There were many applications in which manufacturers used carbonia oil in a heat treat/temper furnace to color metal. However, it appears that the specific bluing process used by Smith & Wesson WAS secret and proprietary.

Second, to respond to comments, it is unlikely that the parts were "quenched" in oil...or in anything else. The temperature at which S&W was "cooking" guns was not enough to impart a significant heat-treat effect. Generally stated carbon steel needs to go to the 1400 F or so range and then be quenched (cooled as rapidly as possible) so that the carbon crystalline structure will solidify. Heating to 750 F and quenching wouldn't accomplish that much.

But heating to 750 F and cooling slowly would make a lot of sense. When high carbon steel is heat-treated, it becomes brittle. The hotter the steel is heated and the faster it is cooled, the more significant brittleness is. Generally stated you do not want brittle steel in a gun. While brittle (hardened) steel has much higher tensile and yield strengths than mold steel, it is much more susceptible to dynamic forces. When it fails it is much more likely to fail catastrophically (e.g. shatter/"blow up"). So because of this, the normal practice is to heat treat and to then heat the steel item to a midway temperature (say, 750 F, perhaps) and then let it cool slowly. This relieves some of the internal stresses that developed in the steel during the initial heat-treat and quench, and it gives the resulting steel item more elasticity and resilience (but lower tensile/yield strength than an untempered, hardened piece of the same steel). Normally you consult the data sheets for the steel you are using to figure out how how it should be heated for both hardness treating and tempering.

So the point is -- it would seem that S&W was likely doing 2 things at once here. First, they were tempering the steel. Second, they were giving it a charcoal blue finish, albeit in a "dry" environment.

This begs the question (at least for me), do you need to go to 750 F to replicate this dry charcoal process? Or could you get good results at 500 or 550 F?

BTW - I also reviewed "Smith & Wesson Revolvers: The Pioneer Single Action Models" by John E. Parsons. Nothing about bluing methods. It did mention that S&W shipped out guns for plating (at least in the early days) and it also mentioned that there was a small run of color case hardened No. 1-1/2's (which seemed interesting on a couple levels...).

You seem to have a deep interest in the topic. I suggest you talk or correspond with the Davids Chicoine (Sr & Jr), who restore old S&W's. They are very good.

Here's the website: oldwestgunsmith.com

My underatnding is that for S&Ws they are about the best out there, rather like Turnbull for Colts. I've been well pleased with work they've done for me.

I've been studying firearms metal finishes for a few decades both to do my own for my custom guns and rifles and to write about the subject for magazine stories. Mr. Adair's info shows (may he RIP) that he really didn't know what carbonia bluing was (neither do I) and I don't agree with some of what is posted on Rons gun shop site, from my personal experience.

Here are pix of a single shot I hand-polished to 600 grit and had Steve Moeller (IN) charcoal blue about 20 yeas ago. (I made the custom French walnut grips. It also has gold inlaid lettering and nitre blued screws unlike factory S&W's). The bluing is very close to the original S&W bluing and involves heat at about 600 degrees, charcoal, oil and carding (as with rust bluing). As I understand it, the Am. Gas Furnace process rotated the parts in a both of charcoal and oil at heat , but I am not certain of this.


There are a couple more guys doing this charcoal bluing today including Doug Turnbull (although his is more the bright blue of Colt's) Peter Mazur in CA and Mike Hunter in MO. it is my understanding that Dave Chicoine used a hot blue with salts similar to normal hot bluing with superb polishing. I have achieve a blue very similar to S&W early matte blue (like my Model of 1950, .44 HE) using a rust bluing technique. Original shown.

One fact in the posted info is that preparation, polishing, is absolutely imperative to great results. the early S&W polisheres used huge wheels and this is a completely lost trade in today's firearms world.
In any case, I am also very interested in these processes and hope to learn more, and help if I can.
Best,
Steve

References that may be of interest;

1. Metals Handbook 1939 (American Society for Metals), p.1120 for a description of the Carbonia finish.

2. A History of The Colt Revolver by Haven and Belden (1940), pages 500-503 for a description of the blueing method used by Colt at that time.

The processes are similar but nowhere does the Colt reference refer to Carbonia oil.

Also;

The Custom Revolver, by Hamilton Bowen (a superb !! book).

S&W Sixguns of the Old West, by David Chicoine.

Frank S. SWCA 2052.

"We can't stop growing old but we can choose to remain immature."

Charcoal blueing and Carbonia/Machine Blueing are not the same process though they produce nearly the same,,but not quite identicle finishes. As already stated, any blueing, including rust and hot salt,,the final look depends alot on the prep polish, though the rust blueing techniques will normally knock the gloss down. (There are ways to do glossy rust blueing though)

Charcoal blueing is done in just that,,charcoal. No furnace, no tumbling, no magic mumblings by the 'smith, save for what ever proper wording is necessary to offset the heat, sweat and the occasional burns that you'll receive doing it.

An open hearth, pan, trough or what ever shape container of small pea sized chunks of wood charcoal are brough to heat by a fire under the container,,not in the charcoal itself.
It will start to burn slowly but you do not want it to get to a glowing BBQ type fire in the container itself. The underfire is raked down to control the heat.

Clean parts are buried in the coals and left to heat, then pulled one at a time and quickly carded down. The carding was/is done with anything from wool cloth soaked in oil, burlap, a bit of rottenstone (polishing) added, old recipes talk of 'tow' and oil. Don't use any synthetic cloth as it'll melt on the hot metal and you'll have to start over after repolishing.
The idea is to remove any scale and burnish the remaining blue color and then back into the pit. You work up the color in coats.

Working this can 'be the pits'. It's hot work and can be exhausting if you are doing alot of parts. Obviously cautions against burns and eye protection a must. Early factorys quite often had child labor doing the work overseen by a boss.

The results can be spectacular, especially with a proper polish underneath. Take a look at any mint condition pre 1913 Colt revolver or automatic. That is Charcoal blueing. The first couple of years production 1911's were charcoal blued.

The only production long gun barrel I can think of that was charcoal blued was the Henry rifle IIRC. Quite a few muzzle loading Longrifle barrels were charcoal blued by the 'smiths that made them in what we'd call makeshift settings.

Not hard to see why Carbonia Blue/Machine blue was welcomed as a labor savings device. One machine could turn out hundreds of pieces per/day.

The process was used in other aspects of mfg including the hardware fittings/fastening industrys.
Carbonia Oil was used to impart the fine finishes on firearms and was a propietary finish with that name but the American Gas Furnace (rotating furnace) could and was used by the factorys with other oils including linseed and even pine pitch to impart blue finishes on less important parts like pins, screws, ect (just like the hardware industry used).

Tru Carbonia Oil is no longer available, at least it wasn't when we were trying to reinvent the process, but Mobil supplied a substitute oil that they said was it's modern equivelent. Looked like 5W Tar!

The 'charge' placed into the furnace is ground bone charcoal, as opposed to wood charcoal used in the Charcoal blueing process.
The oil is added in the correct amount after first heating both the char and oil outside the furnace to drive off any water in them,,a definate must do. Then it's mixed and added to the furnace.

The parts are racked up inside or on racks outside and place into the drum. The furnace w/ parts and charge is closed up tight save for a small vent. Enough to allow for continual pressure escape but no free oxygen intake of air from the outside while the process is running.

Any oxygen getting into the chamber during the process, or initial water vapor steaming off oto the parts during heatup will discolor the final finish. Usually a red haze. Chemicly clean of oil, finger prints, etc a must before start also.

Temps and times are part of the 'secret' that each mfg had for themselves and like case color hardening makes each mfg's blue (and case color) look just enough unique to be able to be identified from anothers, though they all reached beautiful results.

At it's peak, the temp will be in the 800F range. There are slight cool offs and heat ups sometimes used. Winchester had problems with color matches and used slight variations in process according to the parts being done.

In the end, the parts are left to cool. It is actually an annealing process at those temps so some though SHOULD be given to the parts, their original heat treating specs, etc. The process may actually weaken the strength of some heat treated parts.

Steel at 800F for a couple of hours and then left to cool slowly inside the furnace is a dead soft annealing for alot of steel.

Hot salt blueing replaced Carbonia at Winchester in about 1938/9.

Frank, thanks for the reference reminder, I read the Colt info and as with many sourses, it lacks detail although interesting in mentioning charcoal, and top heat of 650 degrees. Can't find any specifics on bluing in Hamilton's book, but nice to remember my name in the index (the SAA I worked on is on pg. 160).
Does the Metals Handbook have any specifics about the carbonia process?

2152hq, are you currently offering charcoal bluing? Have you personally done the process, and are you willing to share your experiences?

Thanks much,
Steven Dodd Hughes

The 1930's era New Service was apparently blued at 650!

Thanks to all who have made this one of the most interesting threads I've encountered recently!

Jerry

SDH, beautiful grip work, how many hours do you figure you had in prepping the metal.

Keith