Gun bluing

T

treebutcher

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Hi
I'm trying to bet setup to blue small parts. I have used cold blue in the past with varying degrees of success. I would like to be able to achieve a more uniform finish. Anyone know where I can source gun bluing salts? I am considering using potassium nitrate but I don't want to buy something that is not pure enough.
 
Why not consider slow rust bluing. It is a fine traditional finish that doesn't require a significant outlay in equipment and chemicals and any of the commercial browning or bluing solutions can be used. The only difference is the hot water or steam bath for bluing.
 
I had good results with a basic mixture of potassium nitrate and sodium hydroxide.

Not sure if my source of the nitrate is still available, but I was getting it from a garden center and they were only allowed to sell it to me already mixed with water. Kind of a pain, but it worked.

Overall, I like that I was able to do my own, as I had a few projects to work on and it was nice to not have to send parts away and wait on someone else's schedule. But in the end, hot bluing is a bit of a pain in the ass for 1 gun at a time.

JLoaug0.jpg
 
ssapach said:
I had good results with a basic mixture of potassium nitrate and sodium hydroxide.

Not sure if my source of the nitrate is still available, but I was getting it from a garden center and they were only allowed to sell it to me already mixed with water. Kind of a pain, but it worked.

Overall, I like that I was able to do my own, as I had a few projects to work on and it was nice to not have to send parts away and wait on someone else's schedule. But in the end, hot bluing is a bit of a pain in the ass for 1 gun at a time.

JLoaug0.jpg
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that is nice work
 
I have tried most all methods of bluing, and can't recommend enough that you stay away from hot salts bluing. The only exception I would make is if you are going to do LOTS of it. Then giv'er.
My vote for the DIYer is Art's Belgian Blue. Not sure if Brownell's can ship that anymore. But if not that, then slow rust bluing. Better results than hot dip, with very low startup cost. The only downside is the elbow grease required.
 
Done with the stump remover and lye from Home Hardware. Bit spendy compared to other sources but both were pure.
Used a hotplate and it gave me issues as the thermostat kept kicking off. A simmerstat equipped model or gas stove would work a lot better to keep the heat steady.
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Yep..look like it. Good job !

Doing small parts is relatively easy. Doing a gun - action and barrel to get a good deep blue (black) - no streak look is not for everyone.
 
Jonnyofalltrades said:
I have tried most all methods of bluing, and can't recommend enough that you stay away from hot salts bluing. The only exception I would make is if you are going to do LOTS of it. Then giv'er.
My vote for the DIYer is Art's Belgian Blue. Not sure if Brownell's can ship that anymore. But if not that, then slow rust bluing. Better results than hot dip, with very low startup cost. The only downside is the elbow grease required.
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Good advice. Hot caustic bluing solution is miserable stuff to deal with. A serious setup for regular volume use is one thing. For occasional home shop use quite another.
Hot water bluing works very well and is far less hazardous. Prepare, boil, apply, card, boil, apply, card, boil, etc., until desired colour is there. Time consuming, but the results are worth it. A professional quality finish in a home shop. For professional results, proper metal preparation is essential. That does not include heavy use of a buffer to round all edges, dish all holes, etc. Proper polishing takes time, care and thught.
Parkerizing is also excellent for a small shop, and also safer than hot blue. Blast, simmer, rinse, oil. Excellent results if the parked finish is appropriate. Really easy.
The best cold blues I have used are Oxphoblue and 44-40. With careful preparation, the results can be quite acceptable.
 
Du lite is a good source for bluing/blacking gun metal , they ship anywhere in the world , their smallest amounti think is fourth pounds , it works flawlessly ever time
Or Brownells sell oxynate # 7 again fourth pound pail
 
related question:
i'm debating a couple of different options for my pistol.
1. high polish blue, how do I do it?
or
2. bead blasted blue. bead blast then blue or blue and then bead blast?
 
Preparing a first class high polished surface is a skill. Lots of guns have been ruined by someone getting carried away with a buffer. Rounded edges, smeared markings, dished holes. Any of the classic gunsmithing texts will describe how to do it properly. Brownells also has instructions available.
Blast and blue, blast and Park produce good matte finishes. Rather than using glass beads, I prefer fine aluminum oxide and moderate air pressure.
Blast and cold blue works quite well. The clean blasted surface really allows the chemical to bite.
Blasting after bluing will take you back to bare matte steel.
 
tiriaq said:
Good advice. Hot caustic bluing solution is miserable stuff to deal with. A serious setup for regular volume use is one thing. For occasional home shop use quite another.
Hot water bluing works very well and is far less hazardous. Prepare, boil, apply, card, boil, apply, card, boil, etc., until desired colour is there. Time consuming, but the results are worth it. A professional quality finish in a home shop. For professional results, proper metal preparation is essential. That does not include heavy use of a buffer to round all edges, dish all holes, etc. Proper polishing takes time, care and thught.
Parkerizing is also excellent for a small shop, and also safer than hot blue. Blast, simmer, rinse, oil. Excellent results if the parked finish is appropriate. Really easy.
The best cold blues I have used are Oxphoblue and 44-40. With careful preparation, the results can be quite acceptable.
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Is no doubt that I did something wrong. Some years ago, I got some Oxpho Blue from Brownells - had read, then, that it was the "best" - I worked over my Dad's M1917 sporter - it actually looked really good, at the time. Circa 5 or 8 years later, mostly sitting in cabinet storage, that cold blue has faded, so is as if I had done nothing to it, except smooth it out, back then. I do not know how Oxpho "bluing" works, but is possible it might need a periodic "touch up" or "re-do"?

Maybe 5 years ago or so, I received a Schultz and Larson rifle that someone had soldered on a front sight ramp. I removed that, and removed the remnants of solder - which left a "bare" area on that barrel. I coloured that up with Birchwood Casey "Super Blue", and I am getting that same fading effect, on that area, over the years.
 
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All cold blues I have ever researched use copper(and/or nickel) sulfate to give a quick copper (and/or nickel) plating. They also contain selenium dioxide, along with other things like phosphoric acid, to turn the copper and nickel black.
They fade over time, don't provide much protection, go on blotchy, all good reasons to restrict them to things like screw heads or such.
I got very excited recently about Caswell's cold blue, because it is called "Black Oxide". Digging into it, it turned out to be just like all the others. Application appears easier, but still just copper plating.
"Real" bluing is black iron oxide, or ferric oxide.
 
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