black oxide finishes

surveyor · October 24, 2015, 06:54 PM

I'm needing to have a refinish job done, and am more a tradionalist,.
I prefer durable ( read non sprayed on paint type) finishes, blued, parked, etc.
The smith doing the machine work on the slide mentioned something about black oxide.

I have seen several processes of this, a higher heat one, a mid level heat one, and a room temp one.

I have also seen that it needs a after finish to increase the corrosion resistance.

So would I be better off with this or a parkerizing?
I'm looking for something that wears about equally to blueing.

I'm not worried about any collector value on this one, its just for me.

If black oxide will meet the goals, it is fine with me.

Dfariswheel · October 24, 2015, 07:45 PM

Actually, black oxide is not much more than unpolished gun bluing.

Parkerizing would be more durable then oxide or tradition bluing.
The durability and rust proofing of parkerizing is due to the rough, porous surface that absorbs a lubricant and the lubricant prevents rust.
As long as you maintain some lube in the parked coating the gun won't rust easily.
The greater durability is why the military changed from bluing to parkerizing during WWI and still uses it today.

If you want a black color, parkerizing can be done in a black color by either a pre-dip chemical or by using a black parkerizing phosphate process either of which gives a flat charcoal black finish.

jcj54 · October 24, 2015, 07:47 PM

is black oxide. The majority of modern gun makers use this process or parkerizing, with a few using one form or another of paint.
Cold dip bluing is nowhere near as durable as the hot salt dip method.
Hot salt bluing is much thinner than rust bluing and thus less durable, but is much faster and far less labor intensive.

Dixie Gunsmithing · October 24, 2015, 07:51 PM

The only good blue-black finishes are either hot caustic bluing, which is performed at most all gun factories, and hot water bluing. Parkerizing is a different process, and you don't get a black-blue finish. Any bluing that is put on at room temperature (chemical cold bluing) is not very good, and does not wear well. They use this on sprockets, gears, and other machined parts, to give them a better protection than being left unfinished, but it will wear pretty easy. They also use this for touch-up on guns.

My preference is hot caustic bluing, which is the factory finish. On doubles, I use a hot water blue on the barrel set, though some can be successfully caustic blued. Polishing is what will determine how good they look, and if the smith leaves pitting, rounds off corners, etc., then the bluing job will look pitiful.

On aluminum, the better finish is anodizing, which is a plated and dyed finish. They are using a lot of paint for this, these days, but I prefer anodizing.

surveyor · October 24, 2015, 07:57 PM

Thanks for the reply, told me just what I needed to know.
I'll have him parkerize it.

He has hot blued, as well as hot water blued some for me before.
Both have turned out well.

Going for something a little different on this one though.
(Norinco)

Dfariswheel · October 25, 2015, 06:51 PM

If you want the park finish to be black, Brownell's sell a pre-dip chemical that makes it come out black.

T. O'Heir · October 26, 2015, 12:53 PM

"...black oxide is not much more than unpolished gun bluing..." Um, no it isn't. Black oxide is done with the same process as Parkerizing(that being the commercial name.) using different chemicals. Black oxide is the finish that what was put on FAL's and most current so-called 'tactical', flat black finished rifles and shotguns. Finish is called Lube-Rite, commercially. Comes out flat black.
Had my .243 done years ago. No wear, at all, in roughly 35 years. Makes no difference if the inside gets done either. Normally, you put an empty case in the chamber and lightly tap a cast bullet in the muzzle. Didn't have the bullet. Hasn't made any difference whatsoever.
Black Parkerizing is done with manganese as the chemical. Grey uses zinc. Zinc Parkerizing comes out in shades of grey depending on the steel it goes on. There is no such thing as green Parkerizing.
Hot bluing isn't much better than cold for protecting the steel.
Anodizing is electro-plating. Works on SS as well as Al.

**Unclenick** · October 27, 2015, 08:03 PM

Quote:

Black oxide is done with the same process as Parkerizing.

Um, no it isn't. The black oxide process is basically a form of hot bluing with molten hydrated salts that leave the oxide blacker than blue. It forms a magnetite (black iron oxide) finish that is much thinner than the phosphating (Parkerizing) baths produce. Here's a description by the largest commercial black oxide finishing company in the country.

Manganese phosphating is something I do in my home garage when one of my Parkerized guns needs it. I like it better than zinc phosphating both because of the darker color and better scuff resistance. The finish I get from the Brownells solution (made by the Parker company) is a dark gray, but still gray. Shooter's Solutions and others make a blacker version by adding other compounds to it. There is also the blackening pre-dip mentioned earlier, but it makes a zinc phosphate turn black by altering the crystal structure. Quite different looking.

Jim Watson · October 27, 2015, 09:13 PM

If you want it really black, go from Parkerizing to the bluing tank.
That gives a dead flat black.

Dixie Gunsmithing · October 30, 2015, 01:11 PM

Unclenick is correct. Hot caustic bluing is just that, caustic chemical bluing, as it is about all sodium hydroxide (lye) and water, with a few other small amounts of chemicals thrown in. It is mixed, so the solution will not come to a boil until around 290 to 295 degrees, as the salts raise the boiling point of water from 212 F. You control the boiling point by adding salt, if it boils below 290, and adding water if it starts boiling after 295 degrees. Some steels (nickel steel) require a higher temperature, around 305-310 F. Cast Irons, such as older receivers on single and double barrel shotguns, require an additive to be added to the solution, such as Oxynate S, or they will turn a reddish purple.

Brownells, Bluing The Traditional, Hot Salts Way:

http://www.brownells.com/GunTech/Blu....htm?lid=11044

Parkerizing is a different alligator.

October 24, 2015, 06:54 PM	#1
surveyor Senior Member Join Date: April 13, 2007 Posts: 773	black oxide finishes I'm needing to have a refinish job done, and am more a tradionalist,. I prefer durable ( read non sprayed on paint type) finishes, blued, parked, etc. The smith doing the machine work on the slide mentioned something about black oxide. I have seen several processes of this, a higher heat one, a mid level heat one, and a room temp one. I have also seen that it needs a after finish to increase the corrosion resistance. So would I be better off with this or a parkerizing? I'm looking for something that wears about equally to blueing. I'm not worried about any collector value on this one, its just for me. If black oxide will meet the goals, it is fine with me.

October 24, 2015, 07:47 PM	#3
jcj54 Senior Member Join Date: February 28, 2011 Posts: 226	hot salt bluing is black oxide. The majority of modern gun makers use this process or parkerizing, with a few using one form or another of paint. Cold dip bluing is nowhere near as durable as the hot salt dip method. Hot salt bluing is much thinner than rust bluing and thus less durable, but is much faster and far less labor intensive.

October 24, 2015, 07:45 PM	#2
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,484	Actually, black oxide is not much more than unpolished gun bluing. Parkerizing would be more durable then oxide or tradition bluing. The durability and rust proofing of parkerizing is due to the rough, porous surface that absorbs a lubricant and the lubricant prevents rust. As long as you maintain some lube in the parked coating the gun won't rust easily. The greater durability is why the military changed from bluing to parkerizing during WWI and still uses it today. If you want a black color, parkerizing can be done in a black color by either a pre-dip chemical or by using a black parkerizing phosphate process either of which gives a flat charcoal black finish.

October 24, 2015, 07:51 PM	#4
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	The only good blue-black finishes are either hot caustic bluing, which is performed at most all gun factories, and hot water bluing. Parkerizing is a different process, and you don't get a black-blue finish. Any bluing that is put on at room temperature (chemical cold bluing) is not very good, and does not wear well. They use this on sprockets, gears, and other machined parts, to give them a better protection than being left unfinished, but it will wear pretty easy. They also use this for touch-up on guns. My preference is hot caustic bluing, which is the factory finish. On doubles, I use a hot water blue on the barrel set, though some can be successfully caustic blued. Polishing is what will determine how good they look, and if the smith leaves pitting, rounds off corners, etc., then the bluing job will look pitiful. On aluminum, the better finish is anodizing, which is a plated and dyed finish. They are using a lot of paint for this, these days, but I prefer anodizing.

October 24, 2015, 07:57 PM	#5
surveyor Senior Member Join Date: April 13, 2007 Posts: 773	Thanks for the reply, told me just what I needed to know. I'll have him parkerize it. He has hot blued, as well as hot water blued some for me before. Both have turned out well. Going for something a little different on this one though. (Norinco)

October 25, 2015, 06:51 PM	#6
Dfariswheel Senior Member Join Date: May 4, 2001 Posts: 7,484	If you want the park finish to be black, Brownell's sell a pre-dip chemical that makes it come out black.

October 26, 2015, 12:53 PM	#7
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...black oxide is not much more than unpolished gun bluing..." Um, no it isn't. Black oxide is done with the same process as Parkerizing(that being the commercial name.) using different chemicals. Black oxide is the finish that what was put on FAL's and most current so-called 'tactical', flat black finished rifles and shotguns. Finish is called Lube-Rite, commercially. Comes out flat black. Had my .243 done years ago. No wear, at all, in roughly 35 years. Makes no difference if the inside gets done either. Normally, you put an empty case in the chamber and lightly tap a cast bullet in the muzzle. Didn't have the bullet. Hasn't made any difference whatsoever. Black Parkerizing is done with manganese as the chemical. Grey uses zinc. Zinc Parkerizing comes out in shades of grey depending on the steel it goes on. There is no such thing as green Parkerizing. Hot bluing isn't much better than cold for protecting the steel. Anodizing is electro-plating. Works on SS as well as Al.

October 27, 2015, 09:13 PM	#9
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,625	If you want it really black, go from Parkerizing to the bluing tank. That gives a dead flat black.

October 30, 2015, 01:11 PM	#10
Dixie Gunsmithing Moderator Emeritus Join Date: April 27, 2013 Location: Ohio Posts: 1,923	Unclenick is correct. Hot caustic bluing is just that, caustic chemical bluing, as it is about all sodium hydroxide (lye) and water, with a few other small amounts of chemicals thrown in. It is mixed, so the solution will not come to a boil until around 290 to 295 degrees, as the salts raise the boiling point of water from 212 F. You control the boiling point by adding salt, if it boils below 290, and adding water if it starts boiling after 295 degrees. Some steels (nickel steel) require a higher temperature, around 305-310 F. Cast Irons, such as older receivers on single and double barrel shotguns, require an additive to be added to the solution, such as Oxynate S, or they will turn a reddish purple. Brownells, Bluing The Traditional, Hot Salts Way: http://www.brownells.com/GunTech/Blu....htm?lid=11044 Parkerizing is a different alligator.