PA Guns & Ammo
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Anyone have any personal experience with firearms that have a nitre bluing? Thinking down the road of having one of my revolvers done. Anything I should know about?
Thanks, James
Thanks, James
Nitre bluing?
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Pig Hunter
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Because of the heat necessary to melt the salts, usually only screws or accent pieces are done
These guys are probably the best place to go...
Turnbull Mfg. Co. for firearm restoration of antique guns - antique revolvers, antique pistols - including 1886 Winchester rifles, Marlin rifles, Parker shotguns, Colt revolvers, and more
Turnbull Mfg. Co. for firearm restoration of antique guns - antique revolvers, antique pistols - including 1886 Winchester rifles, Marlin rifles, Parker shotguns, Colt revolvers, and more
Nitre Blue is a quick way to blue parts. It doesn't give a coating that is particularly resistant to abrasion. In fact it's probably one of the most fragile of the 'blue' finishes.
It's applied by placing the polished part into the molten salt, usually potassium nitrate,,though sodium nitrate will work as well.
We used ammonium nitrate once in a pinch and got good results too.
The idea is to keep the oxygen in the atmosphere away from the surface of the parts while they heat to
the required temp.
The temp has to be just right to bring out the correct blue color. The type of steel comes into play as well.
Temps are in the 600F and up range. It's a method that's used (or was used) to temper springs after hardening. Thus the term 'spring temper blue', the bright blue color of many older flat springs.
Thats the correct temp of the salts that was required to draw the temper on the hardened spring. It just happens to leave a nice bright blue.
The same temp can be used to provide a decorative blue color to screws,pins, hammers and even bbls and larger parts sometimes. The temp can be run up in small increments to vary the blue all the way to around 850F where a deep blue/black results. There it mimics charcoal blueing quite well. Well enough that some 'smiths use the process and lable the results as charcoal blueing.
Charcoal bluing and it's more modern, less labor intensive Carbonia/machine bluing both run at that 800/850F mark.
You can see from the temps involved that you have to be selective in what parts you blue with these methods. You have to respect the heat treat levels in the parts and what may be annealing temps applied to them in the process.
Those shops doing these processes will pick and choose their work based on their experience and rightly reject anything they are not sure of.
The only recent production handgun that comes to mind that had a Nitre blue finish were some of the Cimmaron import SAA revolvers.
A bright, nitre blue on the cylinder, bbl, ejector housing, trigger guard and backstrap. The frame was casecolored. Beautiful to look at but the nitre blue wore quickly as expected.
Charcoal type blue is a more resistant finish and was the industry standard for a general bright bluing for a century. Rust bluing was usually used on shotgun and rifle bbls, though occasionally bbls were charcoal blued too. The Henry rifle bbl was charcoal blued IIRC.
I can add RGS Restorations (Ron's Gun Shop) to those doing both Nitre and Charcoal/Carbonia bluing. Lots of info on his website.
Ron?s Gun Shop. Antique Gun Restoration, Gun Bluing and Custom Gun Blueing Services
Good luck with your project.
It's applied by placing the polished part into the molten salt, usually potassium nitrate,,though sodium nitrate will work as well.
We used ammonium nitrate once in a pinch and got good results too.
The idea is to keep the oxygen in the atmosphere away from the surface of the parts while they heat to
the required temp.
The temp has to be just right to bring out the correct blue color. The type of steel comes into play as well.
Temps are in the 600F and up range. It's a method that's used (or was used) to temper springs after hardening. Thus the term 'spring temper blue', the bright blue color of many older flat springs.
Thats the correct temp of the salts that was required to draw the temper on the hardened spring. It just happens to leave a nice bright blue.
The same temp can be used to provide a decorative blue color to screws,pins, hammers and even bbls and larger parts sometimes. The temp can be run up in small increments to vary the blue all the way to around 850F where a deep blue/black results. There it mimics charcoal blueing quite well. Well enough that some 'smiths use the process and lable the results as charcoal blueing.
Charcoal bluing and it's more modern, less labor intensive Carbonia/machine bluing both run at that 800/850F mark.
You can see from the temps involved that you have to be selective in what parts you blue with these methods. You have to respect the heat treat levels in the parts and what may be annealing temps applied to them in the process.
Those shops doing these processes will pick and choose their work based on their experience and rightly reject anything they are not sure of.
The only recent production handgun that comes to mind that had a Nitre blue finish were some of the Cimmaron import SAA revolvers.
A bright, nitre blue on the cylinder, bbl, ejector housing, trigger guard and backstrap. The frame was casecolored. Beautiful to look at but the nitre blue wore quickly as expected.
Charcoal type blue is a more resistant finish and was the industry standard for a general bright bluing for a century. Rust bluing was usually used on shotgun and rifle bbls, though occasionally bbls were charcoal blued too. The Henry rifle bbl was charcoal blued IIRC.
I can add RGS Restorations (Ron's Gun Shop) to those doing both Nitre and Charcoal/Carbonia bluing. Lots of info on his website.
Ron?s Gun Shop. Antique Gun Restoration, Gun Bluing and Custom Gun Blueing Services
Good luck with your project.
DWalt
Member
Any particular reason you want Nitre bluing? Virtually all bluing done by all firearms manufacturers (and many gunsmiths) today use a hot bath oxide bluing process as it is simple and fast. The actual bluing process used is not nearly as important to the final appearance as the quality of the polishing of the metal prior to bluing.
OP
PA Guns & Ammo
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