charcoal bluing again.

[jerrywh]

I have been researching and carrying out experiments on different methods of bluing barrels for about 2 weeks this time.  I did a lot of tests a long time ago besides.  In my research I cannot find anybody who can verify that the American gun makers of the 18th century ever buried the barrels in a pit with burning charcoal. In every case that I have found so far it is only speculation.  In one article on Williamsburg it says that George Suiter developed the method.  He doesn't say it was originally done that way. But for the record I think it probably was done some but not much.  So far that's what I got. I never have found anybody who did it by that method and had it come out without defects.  This is an expensive project so far.

[bob in the woods]

I believe that Eric Kettenburg has done it, with success. You want to try contacting him.....or perhaps he'll see this and post a response .

[rich pierce]

Maybe there are a couple questions in there. First, what evidence is there that colonial rifles had blued barrels?  Both material evidence (remains of finish) and newspaper adverts support blued barrels. Second, how were they blued?  Most figure charcoal blueing preceded browning for barrels, and boiled blued barrels (browned then boiled) came later, IIRC.

[jerrywh]

 I know Eric did it but they came out blotchy or irregular. So has Jack Brooks and I think Ron Scott has also.  I know that some originals had blued barrels or that that they showed evidence of that but nobody has ever presented any evidence of how it was done. The methods described so far have all been speculation. In my research the term [charcoal bluing]
 has at least three different meanings. It can refer to color or to the fact that charcoal was somehow used in the process. The pit method is crude and gives irregular results. Also at times causes warping.\
 every bond fire pit isn't equal.  So far I have found three or four different methods that produce different results.

[Mark Elliott]

In a number of his articles on "black" guns, Wallace Gusler has reported evidence of what he called charcoal blue on the inside of butt pieces and the underside of barrels.    You will need to talk to him about where he got the idea of charcoal blueing.   I would also like to hear the answer to that question.   

[bob in the woods]

Gary Brumfield had a rifle with a charcoal blued barrel , [ see his website], and it seems to have come out alright.
He does mention that he had to lap the bore after the job was done. Whoever did that job may shed some light on the process ?  Some day I'd like to try it, but I'll start with a pistol barrel .

[Tmas]

Peter Alexander, in his book "The Gunsmith 0f Greyville Co." chapter 35, discusses charcoal bluing.  He describes a steel box for the process and gives a discussion on the subject.  He seems to say that the usual way to finish a gun in the early day was to deliver it in the white, but that early guns were often charcoaled blue and this finish was better looking and longer lasting then other methods.  If I remember correctly browning wasn't introduced until early 1800.  I concluded that charcoal bluing  provided the preferred finish for Iron, however the process requires more skill, equipment, and a fire then any other method of finishing a barrel we have today.  Time (years) will add rust to a blued barrel giving a mixed finish.  So 200 + years will make it
hard to tell what the original finish was.

I would really recommend Peters' book if you don't have one.  Lots of good stuff.

[jerrywh]

 Bluing barrel was done for hundreds of years, It was first done by the sword makers and it was reportedly done in hot sand. Then later they started doing it on guns. In England and probably Europe it was done by professional bluers probably in a guild, Manton and some others mentioned sending guns to the bluers.
 Bluing then was almost if not always a heat type blue. Some of it was probably done over a charcoal fire and was called charcoal bluing. There in comes the confusion. Since many of the original gun smiths in colonial America came from there it is very logical that they brought that method with them since they brought everything else. Every European gun I ever have seen has the heat blue type on them.
 It would not be abnormal for a cast butt plate to show some heavy blue oxide from being red hot when cast or forged.  I have successfully done both types of bluing more than a few times but never in a fire pit. The high temp blue requires a red hot heat. By the time I reached that level of blue the temp was about 1200° or a low red heat in a low light. Jack Brooks describes a good way to do it and he doesn't bury the barrel according to his description. He just lays it on the coals.
   Where are those guys who were worrying about warping a barrel at 430° the other day?
 That pit idea is a good way to warp one. at least now and then. By the way- if doing this required lapping the bore as said before then the barrel was scaled. That's not good a tall.
   Some of those Jaegers were very high end and it would be equivalent now days to putting a $310000.00 barrel in a bonfire.  The only other type of clean heat then would have been a baffle furnace. 18th century French and Belgian  shotgun barrels were brazed in a baffle furnace.

[hortonstn]

I think mike Miller has done charcoal blueing

[Joey R]

Yes for Mike Miller. I have 2 rifles charcoal blued by Mike. Tom Snyder does nice blueing also.

[bob in the woods]

I really like the look of "heat blueing" , and used that method on my last Chambers build..an Officer's fusil in 20 bore.  I got a very pretty, deep blue with a touch of purple.  I just polished the barrel, and then heated it over a charcoal /brazier fire . It was with a touch of anxiety, but by starting at the breach area, and then working along the length of the barrel to the muzzle, I just "followed the blue " as the temp came up.
The comment re scale with regard to "charcoal blueing " i.e. packing the bore with charcoal, and then using the fire pit , is from what I've seen. a pretty accurate description.   I always thought it was supposed to look like that. It is an unmistakable finish when you see it. I liked the one I saw.

[bob in the woods]

It just occurred to me that Brad Emig  [ Cabin Creek } might have something to add. I believe he's done charcoal blueing.

[Tmas]

Alexander, in his book, uses a 6in x 6in x 5 ft long iron box.  This gets filled 2/3 full with real charcoal,  The box is mounted above a wood fire on bricks.  The charcoal is not burning.  He heats it to 700 F using pine "pencils" to indicate the charcoal temp.  When the pine chars he buries the barrel in the charcoal an leaves it about 15 min, then checks the color.  I believe this produces an Iron cyanide sometimes called Prussian Blue.

I would defer to a real chemist on this one.

04/11/16   I did some reading in Wikipedia and find that my chemistry was indeed wrong.  The blue on steel is black iron oxide, magnetite and not iron cyanide, Prussian blue, which is a pigment.  People have been using this process since the early days of blacksmithing.

[Tony Clark]

I've used the pit method of charcoal bluing with perfect success many times. Only once did I have a failure with a warped barrel and that was because I pulled it out of the pit while it was still hot. I was able to straighten it out though and the gun was a great shooter. Some things I have learned are to use good dry hardwood which is reduced to small pieces and let it burn down so it is all uniformly burning charcoal. Use enough so that the barrel will be buried and have at least 6" of charcoal around it on all sides. I fill the bore with powdered charcoal so that it is an oxygen free environment. I do this in the evening when it is dark so that I can be certain the barrel is just at a black heat and no more or less. Once I place the barrel in the charcoal and see it has reached a black heat I cover the pit to stop the fire from getting any hotter, and let it cook for 1-2 hours, and very importantly simply leave the fire go out on it's own and the barrel cool by itself in the charcoal. Once I take it out I oil it using neatsfoot oil and scrub it with a piece of wool. You'll get some variation in the colors, but I like the look of that much better then a uniform blue. It's important to have the charcoal burning evenly if you don't want variations in the coloring.

[Tmas]

Tony, thanks for the nice pictures.

[jerrywh]

 Tony
  That is a pretty good looking job as far as I can see and I think it is likely the kind of blue most of the blued long rifles had. That's just my educated opinion.  
 However, That is not the same blue some people are talking about. The color some are thinking about is achieved at real high temperatures, around 1350°, A regular red heat. The color you have is what some people call temper blue. Thanks for showing and contributing.

[Ed Wenger]

I spoke with Wallace a little while ago about this subject, and he felt most "blued" barrels were done as Bob described, a heat blue.  This was based on existing color on the underside of barrels.  It wasn't necessarily a durable treatment, but it presented a "finished" piece.  This was in keeping with the 18th century mentality of "finishing" a product, such as hemming a cloth edge.  Most of the "charcoal blued" barrels I've seen (contemporary) had a mottled finish to one degree or another.  I personally like the look.  What Tony posted is very well done.  This is a good discussion and I look forward to what you continue to come up with, Jerry.


             Ed

[T*O*F]

This may jog someone's memory.  In discussions predating this site, there was a period reference describing the charcoal pit method of bluing.  I read it back then but didn't save it or its source.  The one thing that I remember is that the barrel was removed during the process several times and rubbed down with lime before being placed back in the coals.

[Long John]

Didn't Acer blue the barrel of that Jaeger rifle he was building a few years back?  Acer, how did you blue the barrel?  I see to remember you mentioning charcoal bluing but cautioned that the color was not as durable as rust bluing.  Or am I misremembering again?

John Cholin

[Curtis]

Here is one I did by placing it in a pipe filled with granulated charcoal, then putting the whole thing in a fire pit (trench).  It has a mottled look Like Ed referred to.  I will be doing another one in the neare future and am curious to see how it turns out.





Curtis

[jerrywh]

Curtis.
  Thanks for showing your work.  I have done tests on this type of bluing and am developing a method to do it with charcoal that prevents the spotting.  In 18th century European high art guns charcoal bluing did not show any spotting.  I have already done two rifle barrels that were perfectly free of any spots and one double shotgun along with two pistols, None of which were done in charcoal but by heat alone.
`I think I have the process figured out but am going to run a test later this week with charcoal. I ran a half dozen tests last week on the high temp blue. I ran two tests with charcoal this month and they both came out similar to yours Your photos have helped to verify my tests.
   There are a few companies that do this type and the process is kept secret.  I don't understand why because it is too costly for ordinary gun makers to set up for. 
  Your process is excellent for doing an American long rifle and I believe it is correct but I do not think it was the only method used in the colonies to blue barrels. Just my opinion but there are some small clues.

[T*O*F]

Perhaps the rubbing of the barrel with lime during the process had something to do with evening out the mottling effect by polishing the thin film of scale formed during the process.  I can only believe that's what accounts for the mottling.

[eddillon]

Didn't Acer blue the barrel of that Jaeger rifle he was building a few years back?  Acer, how did you blue the barrel?  I see to remember you mentioning charcoal bluing but cautioned that the color was not as durable as rust bluing.  Or am I misremembering again?

John Cholin

I remember that, also.  Hopefully Tom C. will chime in and drag the link to those photod.  It was a magnificent looking Jaeger as I cecall.

[bob in the woods]

I just ordered a new DVD release from American Pioneer video  .  Charcoal Blueing a Gun Barrel, with Tom Snyder.   I'm hoping the secret will be revealed !

[Tony Clark]

Tony
  That is a pretty good looking job as far as I can see and I think it is likely the kind of blue most of the blued long rifles had. That's just my educated opinion.  
 However, That is not the same blue some people are talking about. The color some are thinking about is achieved at real high temperatures, around 1350°, A regular red heat. The color you have is what some people call temper blue. Thanks for showing and contributing.

From the "Journal of Historical Armsmaking Technology" Volume V article entitled " Charcoal Bluing of Rifle Barrels" by James Anderson which describes the physical evidence, written documentation and processes re-developed by Williamsburg gunsmiths to duplicate the charcoal bluing found on original longrifles:

"On a dark winter afternoon, they discovered that the temperaturre needed to produce the nice blue like that found on rifle barrels was a "black red." That is the heat that causes the metal to begin to glow red in a dark room or at night."

"With that temperature range in mind , experiments focused on ways to control the amount of oxygen reaching the barrel. They tried sealing a barrel in an air tight tube. They packed the barrels in lime, charcoal, wood ashes and sand. They heated the sealed tube in a forge, but the color and texture of the resulting scale (emphasis added) was to varied to be considered a viable shop practice. Not all these experiments were failures. In 1972, the barrel of a silver mounted pistol, made by Wallace gusler, developed a pleasing blue/gray finish and it became the first product to leave the shop with a fire blued barrel."

"A copper trough had been formed for boiling rifle barrels that were being rust blued. The smiths decided to put the barrel in charcoal, in the trough, and heat it up to the "black red" heat known to produce the right color and thickness of oxidation." (emphasis added)

"The temperature needed, i.e., the "black red" heat, could be observed by raking back the charcoal and observing the color changes as the barrel passed through the range of draw colors" (emphasis added)

"The gunshop had no scientific way to measure the thickness of oxide on old and new barrels, but trial and error lead them to conclude that once the barrel got up to the right temperature (black heat) , it needed an hour, or at most, two, to build up a coating of oxide (emphasis added)

So you see Jerry in their experiments, which I duplicated in part, much more than a temper or draw blue was being achieved at a black red heat. It was an actual oxidized finish , much more durable then a fragile temper or draw blue. I wouldn't want to take a barrel much past a black heat for fear the finish would flake off. You don't need to take it to 1350 degrees or any more than a black heat to achieve an oxidized finish.