Talk to me about bluing

J

Jason Fry

Knifemaker / Craftsman / Service Provider
Joined
Jun 5, 2008
Messages
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I'd like to blue a few mild steel fittings. Talk to me about my options.

I'd assume that I could heat color them, but that this process wouldn't leave a very durable finish?

I'd assume I could use cold blue solutions. Would these work better if the metal was hot?

I really don't want to go all in with caustic salts and bluing tanks. Is there an intermediate option?
 
Might be worth seeing if a local gunsmith would be willing to drop them in his bluing tank next time he blues a gun for someone.
Nothing really works like a proper hot blue, but it's not a process that's particularly enjoyable (or safe)

Mine will do it for $10 provided I'm willing to wait until someone gets a gun blued
 
Bluing is a surface oxide. It will rub off the surface eventually. Any sanding or polishing will also remove it.

Hot bluing is a bit more robust that a cold blue, but it still isn't permanent.
Parkerizing is another surface treatment that wears fairly well.

Make sure every task is done on any parts you have blued, as any further work will damage the finish.
 
What's the important part? You want a deep blued color on a polished surface? Hot bluing is the only good answer, and like Bill said, not terribly durable.

Cold bluing can be attractive but is never going to give a consistent deep blue.

If protecting the piece is more important then parkerizing is a good answer. It's easy and inexpensive to do, and is far more durable. I would never blue a blade that was meant to be used without that being understood by the customer, as just regular use would destroy the finish, nice for a presentation piece or fittings, but not a blade. But I parkerize a lot of blades and it holds up surprisingly well. The color will be gray to black however, depending on the alloy and the solution you use. Zinc trends gray/green and Manganese charcoal/black.

But nothing gives that satisfying deep blue like hot bluing.

I used cold blue on this blade. It's more mottled than a clean ground blade would be because I etched the hamon first. It's the only example I have a photo of right now.

GGSndV4.jpg
 
Ive had luck with cold bluing i researched alot and tried a few different brands but the nu blue works great for me. The trick is multiple coats and heating it up the metal. I have done axe heads knives guns etc. Wear gloves and clean the metal with alcohol.
 
This will be a presentation piece for sure. I've done plum brown a half dozen times, so I have the basic process down with regard to surface finish, 100% shaped and polished before assembly, etc.

Doesn't have to be a beautiful peacock blue, just needs to be dark and bluish to contrast with some light spalted wood and silver spacers. I think multiple methods would get me where I need to be for this particular piece, but I'm always looking for new ideas. I was leaning toward using heated metal and cold blue initially. If I can't find a gunsmith, I will likely just stick with that.
 
Although more time consuming, old-fashioned rust-bluing is another option. Brown the piece (through various methods) and boil to turn it black.
 
12345678910 said:
Karl B Anders-n has done it
Click to expand...
Yes, it would be accurate to say I've done it.
I've been hot-bluing on a regular basis for 15 years.
I often get just a tiny irritated when I hear someone suggest that it's not durable.
Look at it this way, I have a Model 70 Winchester in .22 Hornet and a Model 12 Winchester in 12 gauge.
Both made in 1946. That makes them 73 years old.
Carried afield by my Father for decades, and now I carry them
They are still 95% blued.
I blue many fittings and nearly all of my Damascus. And I will continue to do so.
Anything can be abused.



 
Karl,
Please don't be offended by my comment.
But, for a working knife blade, bluing is not particularly durable.
For guns, bluing is a better option.
You do beautiful bluing work, BTW.
 
Bill DeShivs said:
Karl,
Please don't be offended by my comment.
But, for a working knife blade, bluing is not particularly durable.
For guns, bluing is a better option.
You do beautiful bluing work, BTW.
Click to expand...

Same here, I was simply stating that it won't hold up to any real wear like buffing, sharpening, scratching, etc.
It is also NOT a procedure for untrained people to attempt with minimal equipment
 
You may want to look into Nitre bluing. The salts are pretty cheap and the equip. needed is minimal (heat source & SS pot). Its basically heat bluing but the salts give more control. You can do several different colors by using different temps. Should be plenty durable for fittings, especially on a presentation piece.
 
I have had mixed results with cold bluing, but if you are talking about mild steel fittings then I think you are in luck.
I used Oxpho-Blue on some mild steel parts for some of my daggers and found it to work very well.
On 3V it didn't work at all. On A2 it worked slowly. On mild steel it worked very well in seconds.
I suggest trying it on some scrap steel and if you like the result then you save time and money over sending parts out.
 
Darrin Sanders said:
You may want to look into Nitre bluing. The salts are pretty cheap and the equip. needed is minimal (heat source & SS pot). Its basically heat bluing but the salts give more control. You can do several different colors by using different temps. Should be plenty durable for fittings, especially on a presentation piece.
Click to expand...
You can rub off nitre bluing with your thumb. I tried that early on and found it to be worthless. It is true that you can get some cool coloring characteristics but those colors will rub off simply by looking at it too hard
 
Regarding cold bluing, this is one of the most thorough 'tests' I've seen comparing various brands on how they look and hold up to wear.

http://ronkulas.proboards.com/thread/267/evaluation-cold-bluing-products-pics

The only downside that I can see to the testing done in the link above, is that he states at the beginning, that to be fair he applies each of them exactly as the instructions read. The overall winner of the testing was the only brand that actually has written instructions to preheat the part before applying the bluing solution, which I believe is pretty much always a must for best results. So take that for what it's worth.

~Paul
My YT Channel Lsubslimed
... (It's been a few years since my last upload)
 
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Cold bluing is formulated for touch ups only- regardless what it says on the bottle.
It stinks, most of it promotes rust, and it really isn't bluing.
There are no secrets on how to use it, and no secrets on making it work/look better and last.
Cold bluing pretty much sucks.
 
It definitely can promote rust. I've seen several guns reblued with it become coated with rust after weeks.
It'll stop after a few rub downs with OOOO steel wool and gun oil, but what's left at that point is more patina than bluing
 
Jason you know you won't be happy until you give it a whirl. Call Brownell's tell them you want 40 lbs.
of oxynate #7. 290 degrees later beautiful blued parts. The salts come with great instructions.
Ken.
 
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