From Rust to Salt Blue...

[Hugh]

Heinz & Viggo,

<img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" /> I don't know why I have a perverse desire to get into the middle of this, but this information may be of help to those interested.

Quoted from INTRODUCTION TO MODERN GUNSMITHING by Harold E. Macfarland, pages 235 & 236, discussing rust bluing:

"The object of any bluing process is to oxidize the surface of the steel with a minimum of the common red or brown oxide known as ferric oxide, or rust, and with a preponderance of the desired black ferrosic oxide. This is a black magnetic sesquioxide. It occurs in nature as "black sand" and is commonly found in connection with placer gold. Ferrosic oxide is impervious to rust. Surfaces so blued will subsequently rust only because the film is non-continuous, "porous". Hence a high degree of polishing on the steel surface is indicated, since it helps prevent rust by making the film continuous.

Essentially, the desired ferrosic oxide is formed by nitrogen compounds. Sodium nitrate is commonly used. Potassium nitrate is more desirable for several reasons, but more expensive. Ammonium nitrate is sometimes recommended but should be avoided, since it is highly volatile; loss from the tank is great, in the form of ammonia fumes. Sodium or potassium nitrate will promote the oxidation when used within a critical heat range. Sodium hydroxide (lye) is added, partly to raise the boiling point of the solution to that critical heat range and partly to promote the chemical cleanliness on parts, permitting uniform oxidation. Sodium nitrite is the first product of the decomposition of sodium nitrate. Oxidation is slow until some nitrite has been formed. Hence we age the bath and promote oxidation by the addition of a small amount of sodium nitrite.

For the benefit of experimenters, other oxidizing chemicals are potassium dichromate and potassium permanganate. Manganese dioxide or manganese acetate will act as a catalyst, to speed the reaction, while also serving to hold the unwanted red ferric oxide in solution. I find that the addition of a small, non-critical amount of tri-sodium phosphate will hasten the bluing, while giving a deeper color."

<img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" />

[policeluger]

Great information, the only thing here I would again suggest, is the use of Brownells materials and again, call the tech section if you have questions, yes John I do know what thay will say, this fine group of very knowledgable folks will assist you in all means available too them and will even refer you too others in the business if thay can't answer your questions. What I wasn't going too say but will, last year, at the ripe old age of 56, I replaced for the first time in my life a new water pump in one of my trucks. Now if this seems small and unimportant chore too you, too me auto work of any kind was a mystery....but I asked a few question, and since beening retired, I had more time than money...dug right in and repaired it!! now too me this was a biggie, may seen small too you, but then you may think blueing a gun is black magic voodo...its not...just a matter of reaching out and trying. Now put the K date navy away, start small, and ask any gun shop for an old discarded barrel, or something thay are tossing away, too experment on.....have fun.

[Heinz]

Thanks Viggo.

Hugh, Viggo and I thought Angiers hard to read. With those instructions for dip bluing it is no wonder you turned to chrome, err, nickle.

This forum is a great place.

[Edward Tinker]

Hey Heinz! Don't go pickin' on chrome, uh, I mean Nickled Guns!

Ed

[Hugh]

Heinz,

Those were the instructions for RUST bluing, I ain't got the ones for "dip bluing" yet!!!

[Tony S.]

After reading some of these posts and looking at Mr. Green's wonderful work, I decided to re-finish and old 1910 that was deep blued long time ago. Since this gun was already blued (w/incorrect finish) and was relatively inexpensive, I thought that I give it another shot. Well, I am pretty happy. It is not as great as the ones finish by Mr Green, but for being my second attempt I think that it is not that bad. Okay, The Coast Guard is keeping me pretty busy therefore I will leave this stuff to the professionals.
Thanks, Tony

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[chuck17]

Tony,

That looks pretty darn good! Is that a rust blue with a commonly available formula?

Thanks,
Chuck

[policeluger]

I told you before Tony, don't sell yourself short, that is a beautiful job and your first if I'm correct...looks like you got a job waiting for you after the CG, and the straw is just wonderful....where ever did you learn that!

[Tony S.]

Well, thanks for the complement. This one took me about four days to do. It is rust blue and I got it from Brownells. You have to go slow with it and be very careful. As far as the straw, well there are some wonderful people out there that do not mind sharing their secrets. I appreciate them for keeping the eager, like myself, and the â??mythsâ?� alive.
Thanks, Tony