Rust blueing

[Otley]

I am restoring an old BSA and have been trying to find a good method of recreating a rust blue. When I was a lad and you could walk into a chemist and just buy small amounts of any chemicals; I used a mixture from Dunlap’s Gunsmithing book that included mercuric chloride, for which I remember having to sign the poison book!

Times have moved on and I have no idea where I could now buy a small amount of mercuric chloride, potassium chlorate, spirits of nitre and potassium nitrate. Having seen the results of Birchwood Casey’s Plum Brown on Ed Bear’s various restorations, I thought I’d try it in place of my mercuric chloride formula. The key to producing a blue, rather than brown, is to boil the parts in water after swabbing the solution on and then rubbing with fine wire wool. Then back in the boiling water for a few minutes before swabbing on the next coat.

Well, I’ve just tried it and it seems to work – it even has the same mildly acrid smell when it’s swabbed on.

The photos show a couple of mild steel tommy bars that I just blued – one is straight from the boiling water tank, the other has been rubbed with 3 in 1 oil, which completes the process. They have had five applications and there is no trace of the brown patina that you get without the boiling.

These rust blues give a very durable finish – parts that have been polished bright will be etched to a satin finish that seems to hold oil and resist rust better than the modern caustic blues. They also will not attack soft solder as caustic soda does. The downside is that the process is labour intensive and messy. All that swabbing, boiling and carding.

http://s23.photobucket.com/albums/b391/Otley/Blueing/

Kind regards, Otley

[spartan]

i used to do a lot of browning and rust bluing on shotgun barrels and old guns using similar chemicals, as you say its much more durable than modern chemical blacking and gives a blue tinge instead of pure black, i stopped doing it, as the fumes where to say the least toxic,especially when the bluing formular hit the hot metal. i doubt i would have seen forty if i continued doing it, you cant buy the chemicals now anyway, unless you are a registered buisness, i dont think spirits of nitre or nitrous ether as its now known, can be bought, i could never get any anyway, you will be hard pushed to find any chemical company now who even knows what it is. i made my own by distilling , dont know if it was exactly right, but it seemed to work ok.

[Morningstar]

I`ve been exerimenting this last few months with different solutions with varying results but have found 2 solutions that work quite well. One that works well is Swiss Black. based on Methalated spirts ( denatured alcohol ) Ferric Chloride ( PCB etch ) ferric sulphate and copper sulphate. This formular ( Swiss Black) does not require any neutalising with an alkaline soltion because it is salt based the formular came from a book called `Firearm Blueing and Browning by R. H. Angier.
Another good basic recipe is Hydrochloric acid and Nitric acid and iron filings or wire wool and diluted with water after the reaction ends and added Ferric Chlorided but be warned this is nasty stuff to make !!! and after final boiling the gun parts have to be neutralised with an alkaline solution. I have a few litres of this stuff enough to do hundreds of guns 50cc will do several guns. They come out a black satin finish which requires little in the way of oiling apart a wipe over every few months or so.
The hardest part in the long drawn out proccess is finding a boiling tank long enough! I finally found a stainless steel fish poacher is long enough to do barrel breaks but underlevers and side levers are a bit more difficult due to the length.

ATB Graham.

[spartan]

I`ve been exerimenting this last few months with different solutions with varying results but have found 2 solutions that work quite well. One that works well is Swiss Black. based on Methalated spirts ( denatured alcohol ) Ferric Chloride ( PCB etch ) ferric sulphate and copper sulphate. This formular ( Swiss Black) does not require any neutalising with an alkaline soltion because it is salt based the formular came from a book called `Firearm Blueing and Browning by R. H. Angier.
Another good basic recipe is Hydrochloric acid and Nitric acid and iron filings or wire wool and diluted with water after the reaction ends and added Ferric Chlorided but be warned this is nasty stuff to make !!! and after final boiling the gun parts have to be neutralised with an alkaline solution. I have a few litres of this stuff enough to do hundreds of guns 50cc will do several guns. They come out a black satin finish which requires little in the way of oiling apart a wipe over every few months or so.
The hardest part in the long drawn out proccess is finding a boiling tank long enough! I finally found a stainless steel fish poacher is long enough to do barrel breaks but underlevers and side levers are a bit more difficult due to the length.

ATB Graham.

as you say trying to find a suitable tank, and a good pipe burner is the hard part, i found the metal needed to be as hot as water could possible make it, the water needed to be rolling boiling, not just simmering, it cost me quite a bit to set everything up with a proper pipe burner, tanks and stands, but i was earning my living from it so i did not matter.

you mentioned you got a satin finish, i found this due to, to much nitric acid, which acts as a etchant and gives steel a frosted apperance hence the satin finish, i left it out of my formula, and i gave a shiner finish, which was preferred on modern shotgun barrels, but used nitric if i was doing a old english guns or muzzle loaders ect, where a satin finish was preferred.

just be careful when doing this type of hot bluing as its extremly dangerous, most of what your using are very toxic and poisonous chemicals, when nitric acid hits hot metal it gives off a noxious gas which name i have since forgot, but you will be seeing fairies if you breath to much in, make sure your in a well ventilated place, most off the formulas in r h angiers book are probably over 100 years old, and no longer used today by most gunsmiths, as there are much safer alternatives available, although probably not as good as the old methods.

my advice would be, if you only have one gun to do get it done professionaly, as the cost of the burners, tanks ect are not cheap, also getting the chemicals is difficult, but that said, if your like me you probably like experimenting and i still do, trying to find better and better metal finishes, trying to find a hot brown finish for modern steel at the moment, not that birchwood casey plum brown stuff thats about as good as cold blue, but finding it difficult, will have to keep persevering

[Morningstar]

Hi Shaun, I`ve done a little experimenting with hot blueing and was accidentaly give some sodium nitrite instead of Sodium Nitrate. using the same formular as Nitrate the Nitrite gave a brown finish on my gun parts. Got both my Nitrate and a little nitrite from a friendly butcher , Just thinking it maybe worth a little experiment by you to try Nitrite to achieve a brown finish. Also the Butchers are less twitchy selling Nitrite to the general public
ATB Graham

[deebee]

I have just been informed by a 'gobby ' English guy (ie don't believe a word he says without proof cos he has ALL the answers!) at my range, that if you degrease a part & then rub it with the sap from an oak branch, it blues it Anybody heard this one before?
If not, I'll let you know when I've tried it!!
db

[spartan]

I have just been informed by a 'gobby ' English guy (ie don't believe a word he says without proof cos he has ALL the answers!) at my range, that if you degrease a part & then rub it with the sap from an oak branch, it blues it Anybody heard this one before?
If not, I'll let you know when I've tried it!!
db

i know oak contains a tannin that rusts metal, but i have never heard of it being used as a bluing formula, but saying that, all bluing is, is a controlled form of rust, so you never know someone may have made it work.

[T 20]

I have just been informed by a 'gobby ' English guy (ie don't believe a word he says without proof cos he has ALL the answers!) at my range, that if you degrease a part & then rub it with the sap from an oak branch, it blues it Anybody heard this one before?
If not, I'll let you know when I've tried it!!
db

Hi Dave

This isn't so daft as it sounds.

I've noticed when log splitting Oak the sap turns the blade black/blue.



All the best Mick

[johnbaz]

Hi


I've just re-blued this pre war Webley mk1 today with Birchwood casey blueing gel...

It's a rubbish finish but then everytime i've tried the cold blue creams, the finish is always bad (it rubs off easy too )

Pic 1

Pic 2

It's not put back together properly, just a sort of dry fit to see how bad it was

I'll be stripping it off again to have it done properly


John

[deebee]

Hi Dave

This isn't so daft as it sounds.

I've noticed when log splitting Oak the sap turns the blade black/blue.



All the best Mick

Thinking about it, I have seen this. Also you shouldn't use steel screws on oak as they corrode very quickly. Perhaps 'Mr Gobby' was actually onto something.
He did mention he used it for something to do with boats.
When I have the time I'll give it a go on a 6" nail or something
Dave

[ChrisH00]

Yes t's the tannin (tannic acid) in Oak that will rust steel - turmeric also contains it, as do many other spices. I made the mistake of making some pistol grips from Oak many years ago and the result was rusted grip screws! Similarly, wood tool chests are never made from Oak as anything left in them will rust.