Faking an "original" Colt finsh on an Italian reporodcution?

[ExMachina]

Can anyone point me to a discussion or a technique that might get the "blue" finish on my Uberti looking more like an original Colt from back in the day (ie, I'm not trying to "antique" or distress this gun)

One technique I found was this guy and his results look quite nice. However, I don't think that rust bluing was ever preformed at the Colt factory and I would like a finish that was not so dull in the end.

Any ideas would be greatly appreciated

 

[ExMachina]

I should add that I'm considering attempting just a simple cold blue but would be willing to try a hot blue as the parts are not too large (i would not blue the case hardened parts)

 

[BCRider]

As I understand it cold blue and hot liquid salts bluing are going to give you a finish that mimics the texture and sheen of the metal surface. If you want a dullish satin look you need to start with that.

Rust bluing, on the other hand, involves at least some of the metal of the surface being corroded to rust then converted. So a mirror like rust blue doesn't seem possible. But if you start with a near mirror like look then the final finish will retain more of that than not.

There's an inbetween option too. In one of his excellent videos Larry Potterfield uses a "Belgian Blue" product which is wiped on and then boiled with steel wool carding between treatments. It appeared to produce a rather nice dark and rich blue rather than the near black finish of some cold blue options.

https://www.youtube.com/watch?v=KrdESVrBA_Y

 

[Jim K]

Colt, "way back in the day", used a carbon deposit finish, sometimes called a charcoal finish that, used in conjunction with a high polish, gave a "hard" black finish that looks almost like that of a black painted automobile. None of the finishes that are commonly available today will duplicate it.

Cold blue, no matter how good it might look when first put on, won't last. I know some folks claim they have some kind of magic touch, but if they subject that finish to any significant wear, the cold blue finish will come off. Rust blue or Belgian blue is very durable, but the finish is a "soft" blue (if you have seen original WWI era Lugers, you have seen rust blue) not like the Colt black.

There are some restorers who claim to be able to duplicate the original Colt blue; I have seen some that come very close. FWIW, Colt was not the only company that used that "charcoal" blue; Remington, Starr and others used it also. It and rust blue were the only kind available at the time; caustic salt blue was not available until the mid-1930's.

Jim

 

[Ephraim Kibbey]

Jim Watson posted this on TFL in 2002:

From Haven and Belden "A History of the Colt Revolver" reprints "A Century of Achievement"

"Frames, cylinders, barrels, slides, receivers and parts come to the bluing room direct from the polishing department. Side plates and cranes are removed. Everything is first given a bath in hot gasoline… gasoline heated to 150 deg F. This removes all dirt particles, dust, or grease that may have gathered on the way down from the polishing room. Hot air is then forced over them to eliminate all presence of moisture – the arch enemy.

After washing and drying is completed, the side plates (revolvers) are put back on. But they are put on with work screws that hide beneath the surface so that the entire surface can be completely exposed for cleaning and bluing. When finished, blued screws will replace the work screws.

All surfaces to be blued are then wiped with a solution of alcohol and whiting – a polishing compound of very fine texture. Wiped with a clean dry cloth, they are now chemically clean. From this point on until the bluing process is complete, not a human hand touches a surface to be blued.

“These are bluing racks,” interrupted Mr. Carmody. “They are built to hold a maximum number of pieces, yet allow ample room for air circulation with no chance for parts touching each other. This one is for barrels. We have racks for frames, cylinders, hammers, triggers, extractors, latches, grip safety, etc. All our screws and pins, however, are blued in bulk in those small part furnaces that you see over there.” Matched parts, such as a slide and receiver, are alternately fastened in place in the bluing rack. Racks are stored under uniform heat in closed compartments to keep them sterile and dry.

All this is preparatory to the actual bluing process itself.

Let’s take a look at the bluing room. What do we see? Twin rows of revolving drums – thirty large furnaces and eight small part furnaces.

A bluing run starts the first thing in the morning. A secret mixture of charred bone and primer is put into the furnace. Furnaces are heated up to 500 deg or more to evaporate all moisture. The racks are loaded into the bluing furnaces, the doors bolted. The furnaces slowly revolve. Pyrometers control the heat in all furnaces. Readings are taken every 15 minutes during the five hours it takes to complete the bluing process. Top heat is 650 deg.

The furnace itself is gas fired. Four burners supply the heat and it is interesting to note that the forward burner is larger to compensate for any heat loss through the doors.

The charge used in the bluing process is ground animal bone charred to chemical purity in a bone pot placed into a white hot furnace at 1400 deg hot. Two hundred pounds of bone are charred at a time, burning away all foreign matter.

The primer is bone, soaked in pure petroleum oil. Even the oil is boiled to remove moisture and foreign matter. It must be chemically pure. The primer is what gives off the smoke that keeps free oxygen away from the pieces being blued in the revolving drums. The primer and charred bone are mixed and put into the furnace before the work goes in.

What is the chemistry of bluing, anyway? How does this bluing process impart this handsome and lasting blued steel finish so famous on Colt firearms? Bluing is a combination of carbonizing and oxidizing that by heat, brings the inherent carbon of the steel through the opened pores to the surface. All the coloring is done by heat, no particle of bone ever touches the parts being blued. The smoke given off by the primer expels free oxygen from the drum leaving only sufficient to allow combustion. The primer and the charge control the composition of gas in the furnace, the heavy carbon dioxide shielding the parts from contact with oxygen. All this calls for expert knowledge and experience in mixing the proper proportions of the primer and charge not only to obtain the proper color but to create a smoke that shall be free from moisture. Otherwise, though blued, the pieces would be spotted.”

He then suggests that you send your gun to Doug Turnbull!!!

This is an interesting DIY article:

http://www.americanhunter.org/blogs/home-charcoal-bluing-test

 

[ExMachina]

Thanks for the quality posts guys!

Jim, I'm interested in your source for likening the early Colts' carbon finish to that of a black car?--if accurate then it seems like the Italian replica Colts might actually be pretty close! (though not the Uberti "charcoal blue" which IMHO looks slightly weird)

 

[Old Fuff]

See post #5

The bluing process described therein is not "Charcoal Blue" (a term Colt never used), but rather a finish called "Gas Oven Blue," that was used starting in the early 1920's and discontinued about 1940 or '41 when the factory was retooled for wartime production and a Parkerizing setup was installed.

I haven't personally seen a Gas Oven blued SAA. They may exist, but I suspect because of slow sales during the 1920's and 30's the blued parts were earlier produced and had the older charcoal finish. For the record, Colt called it their "Trade (best commercial) Finish". The same process, but lesser polishing was used on most government orders and called the "Army Finish."

 

[Panzerschwein]

I would just leave the finish as is.

You won't get the "real" original looking finish on these guns.

 

[Old Fuff]

You won't get the "real" original looking finish on these guns.

Absolutely true. Some say they can, but exactly, no. Close or amost, maybe. And doing that will be very expensive.

 

[ExMachina]

What are best examples of what the original finish looked like?

Sometimes the original finish look blue/black



And sometimes it just looks black



What evidence is there that Colt used just one process or that the process was in any way consistent?

EDIT: and I'm not trying to replicate the exact finish on the original guns. I'm just trying to get closer than the strange industrial black that some Italian guns come with

 

[Jim K]

Most large Colts were "charcoal blued" like the barrels of those in the pictures. So were most of the other makes of the time. I have a Starr that is the same color. Some Colt pocket models have what looks very much like rust bluing, and it appears to be original, not a refinish. So I would tend to agree that Colt was not always consistent, though they seem to have been consistent within a model and period.

The process described by Haven and Belden is called Carbonia blue; it was a trade secret of the American Gas Furnace Co. and was used by both Colt and S&W in the 1920's and 1930's. It did not exist in the mid-19th century.

Here is the story:

The carbonia finish which was developed by the American Gas Furnace Co. is a method of coloring iron and steel surfaces with any of the temper colors that are obtained by the drawing of the temper of steel.

Furnace Used for Carbonia Finish
This operation is carried out in a rotary furnace as made by the company.
The work to be finished is placed in the retort and before charging the "carbonia mixture" the work should be oxidized way beyond the blue, almost to a black (between 625 and 700 deg. F.). This oxidation is accomplished by putting a certain amount of granulated charred bone (only) into the retort with the work; this will take about an hour, more or less, according to whether the articles to be treated are heavy or light. This oxidation forms a sort of foundation for the deep black of the "carbonia finish," and the time required for the latter may be considerably reduced if the preliminary oxidation is thorough.
After the articles have been thoroughly oxidized the work and the bone are left in the retort and more bone, which has been thoroughly mixed with about one pint of the carbonia mixture, is added to the charge. The carbonia mixture consists of a special oil which is compounded by the American Gas Furnace Co., and it is of great importance that this oil mixture be thoroughly mixed with the bone; to facilitate this they should both be warmed before mixing. If this precaution is not taken the work is liable to become spotted. The work must be exposed to the action of this mixture for from 1 ½ to 3 hours for each charge for a black finish. When the time necessary for producing the desired finish has been reached a sample is taken from the retort and dipped into sperm oil and then rubbed with a cloth. The surface of the work will be a dull gray when it is taken from the retort so that its condition cannot be judged until it has been polished, and if this shows the desired finish the gas is turned off and the furnace opened up and allowed to partly cool. When discharging the retort, sift the bone from the work and dump the latter (if small parts that will not injure each other by striking together) into a wire basket submerged in sperm oil. It might be objectionable to dump certain articles in sperm oil, due to their shape; should they have grooves, folds, etc., they might retain some of it, and it might ooze out later; therefore, tumbling of such work in oily cork is recommended. After the work is sufficiently cool raise the basket to allow the oil to drip off, and finish drying in sawdust or ground cork. This gives the articles a lustrous finish.
In cases where the very finest finish is required the work should not be removed from the retort until the heat has been allowed to decrease sufficiently to prevent oxidation of the carbonia finish when it comes into contact with the air.
In the case of such articles as gun barrels, receivers, sewing machine parts and similar work which cannot be tumbled, special fixtures must be provided upon which these articles are held in the retort while the oxidation and the production of the carbonia finish are being carried on.

Jim

 

[Panzerschwein]

OP, I've asked others about refinishing Colt SAA and 1851 Navies to look like they originally did, but learned that it is either impossible or terribly expensive to do. Same thing with the wood grips... it's pretty much can't get done without spending a mint. I would just accept the finish as is, we are lucky the Italians are making these things at all!

 

[ExMachina]

Most large Colts were "charcoal blued" like the barrels of those in the pictures. So were most of the other makes of the time. I have a Starr that is the same color. Some Colt pocket models have what looks very much like rust bluing, and it appears to be original, not a refinish. So I would tend to agree that Colt was not always consistent, though they seem to have been consistent within a model and period.

That's what I'm beginning to believe as well. There was no "one" original finish but a variety of finishes that were all roughly similar. I'm guessing that a Turnbull charcoal blue is as close as anyone can get these days and likely would have met Colt's standards way back when. Anyway, at least I now have a reference to go off of.

 

[elhombreconnonombre]

Deleted

 

[Old Fuff]

They're is a basic misunderstanding concerning finishes used by the Colt Company (and others) over the years.

Regarding bluing, they used only one process during a particular era - except for one instance I'll get to later. However the basic process could make substantial differences in color and texture, depending on the degree of polishing. This observation still holds today.

During the period when the 1st generation SAA revolvers were made (1873 to 1940), and to be more focused, between 1873 and prior to the early 1920's, a so-called Charcoal Blue was used to produce two finishes with substantially different appearances. The first was what Colt called their Trade Finish, that was a highly polished deep blue-black. The second was their Army Finish," that was used almost exclusively on model 1873 Single Action revolvers ordered by the government, that had a flatter, more blue color and was less expensive.

Now about the exception I previously mentioned. Charcoal Blue worked well on major parts (frames - if not color case hardened - cylinders, barrels, back straps, trigger guards, ejector tubes, etc.) but not screws, triggers, and other small parts. These were Nitre Blued where batches were submerged in tanks containing melted Potassium Nitrate (or similar) that produced an iridescent blue-blue color. It is the only bluing process used by Colt (and again many others) during the 19th century that can be exactly duplicated today.