# Steel Blackening



## redvan22 (Feb 22, 2020)

Hi,
I was watching a video on YT about a guy named Tony creating a shoulder strap for his sons BB gun and when it came time to finish it up, he blackened the fitting he made in a pail of selenium dioxide (at least that's what he flashed on the screen while doing it) so, I did a Google search and found that there are many, many products out there to use. 

Now, rather than go through endless trials and errors; what would you all recommend for blackening steel, or bluing as I've also heard it called?

Mike


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## MontanaLon (Feb 22, 2020)

Brownells oxphoblue.


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## gjmontll (Feb 22, 2020)

I had used Brownell's cold bluing. But it, and many other chemicals, are now banned in California and some other states. 
Instead, I heat the part with a propane torch and drop it into my used motor collecting can.


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## redvan22 (Feb 22, 2020)

gjmontil,
But did you get good results with Brownell's?


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## benmychree (Feb 22, 2020)

The best and most protective bluing/blackening is done with molten nitrate salts; I posted an article on this forum in the past.


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## redvan22 (Feb 22, 2020)

MontanaLon said:


> Brownells oxphoblue.


I'm guessing you got good results?


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## benmychree (Feb 22, 2020)

I have used cold blue products in the past, including Brownell's, and rate them much less than satisfactory' basically, they copper plate the part with copper sulfate with a mild acid, then blacken the surface with the selenium dioxide,  It does not wear well or provide much corrosion protection.


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## redvan22 (Feb 22, 2020)

benmychree said:


> The best and most protective bluing/blackening is done with molten nitrate salts; I posted an article on this forum in the past.


Yeah, that may be the best but the wife blows a fit when I weld in my shop. She's not going to sit still with molten anything in the shop.
Thanks anyway.


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## redvan22 (Feb 22, 2020)

benmychree said:


> I have used cold blue products in the past, including Brownell's, and rate them much less than satisfactory' basically, they copper plate the part with copper sulfate with a mild acid, then blacken the surface with the selenium dioxide,  It does not wear well or provide much corrosion protection.


Thank you for the honest answer.


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## RJSakowski (Feb 22, 2020)

I have used a torch for bluing/blackening of steel followed by a protective coat of automotive clear coat for the antique dorr hardware in our home.  It holds up well even with daily use.  Clickspring does some amazing decorative bluing of his work.

I have not had good results with the various commercial cold bluing products.

Another source of information on bluing/browning/blackening is "The Modern Gunsmith" by James V. Howe, Chapter 16.  It is available on line.


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## SLK001 (Feb 22, 2020)

Here's what I use.  You can get all the chemicals from dudadiesel.com.  It's a fairly easy process and relatively safe.  Just mind the safety precautions - not only will everything be hot, but 100% lye will dissolve your hand.  DO NOT put anything with zinc in it, as it will kill the solution and you will have to make it up again.  I made myself some wire baskets that I put my parts in.


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## gjmontll (Feb 22, 2020)

redvan22 said:


> gjmontil,
> But did you get good results with Brownell's?


This was generally for use in my garage workshop (in generally low-humidity Southern California) where it did prevent rust, but scratches rather easily. Under rougher, more humid conditions, probably not the best choice. But then, the flame-and-oil treatement would also be questionable.


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## cathead (Feb 22, 2020)

Horse urine works really well if the horse will cooperate and he doesn't have rhabdomyolysis. .....................


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## darkzero (Feb 23, 2020)

gjmontll said:


> I had used Brownell's cold bluing. But it, and many other chemicals, are now banned in California and some other states.



When did this happen? I'm aware of various chemicals & solvents being banned in CA but never heard anything about cold blue.


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## gjmontll (Feb 23, 2020)

I started my home machinine shop hobby about 11 years ago and bought the Brownell's bluing at a sporting goods store. It was perhaps 2013 or so when I went back to refresh my supply. I didn't see it on their shelf and was told, "We don't carry it anymore." No further explanation was offered. So I went to my local Big Five sporting goods store. Again, not on the shelf, but there they told me it was banned because of its toxicity. (Likely the selenium content.)
Another useful chemical that has also disappeared from CA retail stores is non-detergent motor oil. I used this for lubricating my lathe (excluding the ways) and my air compressor. Like the blueing situation, the local auto parts stores stopped carrying ND oil. I did pick up a quart when I was in New England four years ago.


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## darkzero (Feb 23, 2020)

As far as I know cold blue is not banned anywhere in the US. Non detergent motor is not banned or anything like that either. Auto parts stores most likely stopped carrying it due to supply & demand. Modern automobiles don't use ND motor oil. Can still buy ND oil & cold blue online. Only time I have purchased cold blue locally was from gun shows.


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## redvan22 (Feb 23, 2020)

Amazon is sending me a 4oz bottle of Brownells oxphoblue as we speak. No special shipping or requirements.


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## Video_man (Feb 23, 2020)

Couple of non-molten techniques have been discussed here.  One simple one:  Clean part to bare metal so you can see the oxides form.  Heat until the oxides pass thru purple to grey, immediately dunk in Canola (rapeseed) oil (from the grocer's).  Imparts a blue-black coating rather like nitre-blue, fairly durable and attractive.  Like the motor-oil version of the process, it produces a coating rather than a real oxide black. 

You can do a real rust-blue with hydrogen peroxide and salt (quick version of the 18th century rustblue process).  Completely degrease metal, drop in boiling water, when hot, drop in the peroxide solution until rust forms. Leave until cool.  It will look awful.  Gently remove any flakey rust, leaving a nice attached smooth coat of rust.  Drop it back into the boiling water, where the rust will turn black.  Repeat the process 3 to 6 times (depends on the alloy, I think).  When the process produces no more effect, you're done.  Dry and apply a thin protective oil.  This is a real oxide blue but a lot safer than molten sodium nitrite.

In my humble experience the cold blue solutions are only good for minor touch-up.  They are very hard to apply evenly to a large surface and are only a chemical colorant, they haven't provided any substantial protection that I have seen.  Brownell's products are about as good as you can get, if you want them....


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## DavidR8 (Feb 23, 2020)

@Video_man thanks for the hydrogen peroxide and salt option. 
Any sense of the proportions for each ingredient?


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## MrWhoopee (Feb 23, 2020)

DavidR8 said:


> @Video_man thanks for the hydrogen peroxide and salt option.
> Any sense of the proportions for each ingredient?



This provides a fairly detailed description.




__





						Quick rust bluing--- Back in black!
					

The black finish left by the Birchwood-Casey Super-blue just wasn't doing it for me this day.      The photo misleads, making them look a b...




					mypeculiarnature.blogspot.com
				




I found that the peroxide was exhausted pretty quickly and ran out before I could finish. Trying fume bluing/blackening using acid now.

No one mentioned the characteristic smell of the selenium treated parts, smells like pocket change (pennies?).


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## Video_man (Feb 23, 2020)

MrWhoopee has posted the link to where I got the info.  One thing I disagree with in the info is heating the peroxide as this will drive off the extra oxygen molecule that does the magic, leaving just water behind.  I just used the peroxide/salt mix cold (and it's not critical on amounts, just a glug of salt in a glug of peroxide, you know...) but you need the heat of the boiling water before and after the peroxide to make this work.


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## derfatdutchman (Feb 23, 2020)

My results with cold blue have never been satisfactory. It does make a good base coat if your doing a French gray finish. Little things I usually temper blue (heat and dunk in oil). Big things I brown or slow rust blue with Laurel Mt. Forges browning solution.


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## Chewy (Feb 23, 2020)

Here is a video showing the salt & hydrogen peroxide blueing.  Located at "The Cogwheel". It was on this forum a couple of months ago. He uses vinegar as an etch before brushing on the solution.  



I intend to try this in the next week or so.  I have collected all the ingredients.


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## FanMan (Feb 23, 2020)

I've used cold blueing (I think it was a  Hoppe's product, IIRC it was selenious acid) and it worked pretty well.  Used it on some gun parts as well as a hillbilly surface plate (a 12x12 piece of precision ground steel somebody gave me).  

The  toolmakers at work sometimes to black oxide which is also easy, I forget the chemicals involved.


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## john.oliver35 (Feb 24, 2020)

And then, Clickspring can show us to do this to perfection if one has crazy skills and lots of time:


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## darkzero (Feb 24, 2020)

I mainly use Brownell's Formula 44/40 for touch ups. Works well for me but a bit on the expensive side. I'm running low so I ordered more along with Oxpho Blue. Have heard good things about it & have been wanting to try some for a while. No ban in CA, my orders shipped out no problem. I've used Brownell's Dicropan T-4 & rarely get a satisfactory result with it.

I use Caswell Black Oxide for blueing parts that are completely bare. It's not a true black oxide process, still cold, it's just their name for the product. Comes in a concetrate, even the smallest size they sell will make 1.25 gallons so it's actually pretty inexpensive IMO compared to other cold blues.

I posted about it in the following thread in post 15 & 17.








						Bluing or black oxiding your custom made tools?
					

I have been told the hot processes are far better (deeper penetration) Parkerizing is different as the surface contains phosphorous unlike bluing.     Sent from my iPhone using Tapatalk




					www.hobby-machinist.com
				




Since then I have found that sometimes I get a browning result overtime when using their recommended penetrating sealer. I just lightly buffed them with scotchbrite or steel wool, reapplied the Caswell stuff & used oil to coat them instead of the sealer. Haven't got browning again since.

I haven't tried heating the parts before applying yet to see if I get a better result. They also sell an activator for use on hardened steel or when it doesn't take the blue well (grey result). I plan on buying some of the activator the next time I need to purchase from Caswell.

The middle wrench below that I use for my QCTP was done with the Caswell Black Oxide. As I mentioned in the thread linked above it's more of a flat finish than glossy. Bottom wrench is what it originally looked like. Top wrench is true black oxide. Good enough for me.


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## DavidR8 (Feb 24, 2020)

Thanks Will, that middle wrench looks great. I’d be plenty happy with that result. 


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## darkzero (Feb 24, 2020)

DavidR8 said:


> Thanks Will, that middle wrench looks great. I’d be plenty happy with that result.
> 
> 
> Sent from my iPhone using Tapatalk



Caswell has a distributor in Canada also. 



			Contact Us - Caswell Canada


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## DavidR8 (Feb 24, 2020)

darkzero said:


> Caswell has a distributor in Canada also.
> 
> 
> Contact Us - Caswell Canada


Looks like I just found the product I'll be using


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## darkzero (Feb 24, 2020)

DavidR8 said:


> Looks like I just found the product I'll be using



See, I can even help you spend your money on things that are not machining tools related.


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## DavidR8 (Feb 24, 2020)

darkzero said:


> See, I can even help you spend your money on things that are not machining tools related.


You are absolutely part of the Collective!


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## darkzero (Feb 24, 2020)

DavidR8 said:


> You are absolutely part of the Collective!







Oh, if you do buy it, IMO don't bother buying the kit. The kit comes with concetrate, 2 cans of sealer of your choice, & a bucket. No need for all that sealer IMO or the bucket which may just add to the shipping cost.

I bought just the concetrate & 1 can of sealer individually, cheaper. I don't always use the sealer anymore. There's 2 types of sealers, penetrating type which leaves an oily finish & "dry". The dry sealer just sounds like some kind of clear coat to me (I didn't look up the MSDS though). Again I have just been applying oil & works fine for me so I may not ever buy anymore sealer when I run out.

Oh and just mix up what you think you might need. I mixed up 10oz the first time & had it sitting in a sealed container for like 6 months. Next time I went to use the mix it didn't work anymore. Not sure if it was related to how I stored it or the container I used. I read that the mix should last a while & can be "reactivated" by adding more concetrate but I never tried. I just make a new small batch everytime.


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## darkzero (Feb 24, 2020)

redvan22 said:


> I was watching a video on YT about a guy named Tony creating a shoulder strap for his sons BB gun and when it came time to finish it up, he blackened the fitting he made in a pail of selenium dioxide



On a semi related note.... I just watched his new video that released today. In it he made a wrench & blued/blackened it.

What I thought was funny was what he jokingly called his "bending jig".





Well I have that very same "bending jig"! Except mine is holding up my DRO display.   It's the display mount that came with the SINO DRO that I used to have & he does have a SINO DRO on his lathe.


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