03 April 2015, 02:02
Bob NisbetWhat Bluing Technique was used by Colt in the 1920s
I just acquired a 32 Pocket Auto. Pictures where reasonable (not great), but didn't show the brown patina in a few dominant areas. The seller had said it's only got blue wear on the backstrap and some edges.
I'm Ok with it, but have a preference that my weapons have a nice bluing to prevent moisture degredation.
Since it's a shooter and not a collector's item, I am not opposed to rebluing.
Does anyone know what bluing technique Colt used back in the 1920s. (Was it simply a rust blue, or was it a proprietary hot dip?
What should I expect to pay to have it reblued?
03 April 2015, 02:33
farbedoI believe that they used a carbona blueing process at that time. Basically, the parts were heated in a furnace to oxidize them in a controlled manner.
Turnbull Restoration does that type. No idea of the cost, though.
I could be wrong, but I think that Colt used that blueing technique up past WW2 for some arms.
Jeremy
03 April 2015, 02:50
speerchucker30x378quote:
farbedo
farbedo is right on for the early Colts. It was a form of carbone bluing smiler to what S&W used. It was sort of top-secret-double-probation with a decoder ring type of process that they never got to open with but it was pretty tough stuff. Not as tough as the S&W system but it was a lot harder than regular bluing. It was more sort of blue in color than black and I'm still amazed when I see how well the finish on those old 1885 pistols have held up after 100 years of being packed around and abused. Like a lot of other "good things" I think it was rather labor intensive which is probably what led to its demise.
03 April 2015, 23:51
2152hqColt used a charcoal blue system till about 1912. It was the real, place the individual parts into charcoal and pull them, burnish them one at a time as they color at the 800/850F temp of the charcoal. Very labor intensive, but labor was the cheap part of the factory expense then. A few of the very early 1911's were done by this method.
Then the American Gas Furnace mechanized process took over the gun bluing industry (and the hardware and others). It' the so called Carbonia (Oil) or Carbona Blue system using the rotating drum and gas furnace for heat. Making production much quicker and a bit more predictable.
Hot salt blue was known in the 20's especially in Europe but didn't come intocommon use till the 30's. Mid 30's in Europe is some Military applications. Winchester switched over to hot-salt blue ( Dulite) around '38 or '39. Until then they had used the Carbona Blue /American Gas Furnace system also for their M12, M42, M21, ect.
SxS bbls and single bbl w/soft soldered on ribs were and continued to be rust blued.
Nitre blue can be run at the 800 to 850F temp and will also give the deep blue/black color of charcoal and Carbona blue. A lot depends on steel type and polish for the look of the final finish. Playing with a vat of sodium or potassium nitrate at 800+F is dangerous stuff if you're doing large scale work.
Charcoal blue can be done on a small scale w/ good results. One of the tricks is to keep the charcoal burning w/o any draft of outside air current.
That drafting will increase the temp of the charcoal pit and take it above the magic temp needed for the color. Then you are quickly into scale forming and the finish is ruined.
Carbona Blue got it's name from the proprietary CArbona oil used in the process. But the factorys soon found that other oils could be used with OK results for less critical parts. Simple linseed oil was used by Winchester on bulk parts like screws, pins,washers, ect.
The hardware industry used the system to blue their goods (remember when all the wood screws, washers, metal fasteners, hinges, bolts, ect were that nice blue?)
They often used linseed or other inexpensive oils in the process. One trick is to heat the oil before use to drive any moisture from it and the char (usually bone charcoal) mix.
With these and any metal finishing processes, the parts must be clean,clean,clean before you start.
04 April 2015, 00:03
AtkinsonThat about covers the whole ball of wax..
04 April 2015, 04:51
Bobsterquote:
Originally posted by 2152hq:
Colt used a charcoal blue system till about 1912. It was the real, place the individual parts into charcoal and pull them, burnish them one at a time as they color at the 800/850F temp of the charcoal. Very labor intensive, but labor was the cheap part of the factory expense then. A few of the very early 1911's were done by this method.
Then the American Gas Furnace mechanized process took over the gun bluing industry (and the hardware and others). It' the so called Carbonia (Oil) or Carbona Blue system using the rotating drum and gas furnace for heat. Making production much quicker and a bit more predictable.
Hot salt blue was known in the 20's especially in Europe but didn't come intocommon use till the 30's. Mid 30's in Europe is some Military applications. Winchester switched over to hot-salt blue ( Dulite) around '38 or '39. Until then they had used the Carbona Blue /American Gas Furnace system also for their M12, M42, M21, ect.
SxS bbls and single bbl w/soft soldered on ribs were and continued to be rust blued.
Nitre blue can be run at the 800 to 850F temp and will also give the deep blue/black color of charcoal and Carbona blue. A lot depends on steel type and polish for the look of the final finish. Playing with a vat of sodium or potassium nitrate at 800+F is dangerous stuff if you're doing large scale work.
Charcoal blue can be done on a small scale w/ good results. One of the tricks is to keep the charcoal burning w/o any draft of outside air current.
That drafting will increase the temp of the charcoal pit and take it above the magic temp needed for the color. Then you are quickly into scale forming and the finish is ruined.
Carbona Blue got it's name from the proprietary CArbona oil used in the process. But the factorys soon found that other oils could be used with OK results for less critical parts. Simple linseed oil was used by Winchester on bulk parts like screws, pins,washers, ect.
The hardware industry used the system to blue their goods (remember when all the wood screws, washers, metal fasteners, hinges, bolts, ect were that nice blue?)
They often used linseed or other inexpensive oils in the process. One trick is to heat the oil before use to drive any moisture from it and the char (usually bone charcoal) mix.
With these and any metal finishing processes, the parts must be clean,clean,clean before you start.
I read on other forums that the key to control is to cap the work in an enclosed iron vessel packed in small diameter charcoal. Pure wood or bone charcoal not contaminated with fillers like clay and binders. Namely, place the parts in an iron pipe and pack glowing charcoal around it. Then cap the pipe on both ends and cover in a bed of coals for 2-3 hrs. This completely seals out oxygen and keeps the charcoal hot inside.