Rust Blueing?

[twhidd]

Has anyone here ever tried rust bluing their own gun? If so, how did it turn out? If anyone has any pics of one they did, I would like to see your results.

[Unclenick]

I've never done a whole gun, but have done a number of my hand made parts that way. It works very well, leaving a very slightly satin surface rather than high gloss, but smooth enough. I used the Pilkington solution Brownells sells and degreased steel wool for carding.

The only issue I ran into was water. At the time I was doing that I lived in a town whose wells were all in limestone. The Culligan man said they considered anything over ten grains a gallon dissolved minerals to be very hard. Ours was 35 grains per gallon. In that water the red rust to magnetite conversion just would not take place. So I used to go visit the Culligan distributor with a 5 gallon carboy and they would run some water through about a half dozen tanks in series to give me some high megohm deionized water. That stuff worked great.

You don't need to go to that extreme, but you will benefit from at least using distilled water. You don't want water spots to form on the work when you pull it from the boiling tank and it flash dries because of the heat.

[kraigwy]

I thought "rust bluing" was nothing more then Hot tank bluing. That is a rusting procedure after all.

Yes I have bluing tanks. 4, first degeaser, then a cold water bath, then to he bluing salts, back to the fresh water bath, then to the grease tank (water solibable oils.

Dont know if this is what you are talking about. Biggest problem is cleaning and temp of the salts, about 295, too hot it turns readish rust color, too cold and it turns green.

Best procedure is to set up the tanks, polish a rifle and PRACTICE.

[twhidd]

Maybe I'm mistaken, but it's my understanding that rust bluing is the process that was used before someone developed the hot salt tank process. Maybe someone who is more familiar with the process can give more incite.

[Slopemeno]

Rust bluing is a different process than hot tank bluing. For instance, double barreled shotguns that are soft-soldered together can't be hot blued- they would be rust blued...or else.

Rust bluing is a process where the parts are polished and degreased, then immeresed in bioling water. The parts are removed from the boiling water, and the rust blue solution is swabbed on the parts. They are then immersed in boiling water. The second time they are removed from the water, they are "carded", or rubbed with 0000 steel wool to remove the scale. Your best bet is to degrease the steel wool before use, by the way. The whole "dip, swab, dip, card" is repeated until you're satisfied with the results.

The upside is it seemed to me to be a bit tougher than hot tank bluing. The down side- labor intensive. The potential for scratching your work and having to start all over again due to all the handling required should be perched right on your shoulder when doing this, by the way.

[Unclenick]

I didn't realize rust bluing would be unfamiliar to most. It needs a little clarification from the last description. The idea is to cause very fine surface rust to form on the steel, then the rusted steel is put in boiling water which converts it from red to black iron oxide (magnetite). The fact this blue starts out as rust is why it is called "rust bluing".

Like rust, some of the black oxide is well-adhered and some is loose, so you then use a find wire wheel or fine degreased steel wool to "card" the steel, meaning that you rub all the loose black oxide off. That's why its a tough bluing. It has all survived carding and anything more easily removed is gone.

On the first pass the carded steel looks like someone sprinkled pepper on it. You repeat, and each time the dark areas spread and it becomes apparent that they are really more blue than black. I find it takes about six cycles to reach full blue coverage.

The traditional means of inducing rust is a steam box. Howe's, The Modern Gunsmith has an illustration of the setup. You would suspend the barrel (or whatever you were bluing) in the box by wood plugs in its ends. A watch glass was put in the box with a few drops of nitric acid in it. The box was closed and a steam kettle that exhausted into the bottom of the box was set to boiling. After a number of hours the steam and acid fumes create the very fine surface rust for boiling.

The modern method avoids the steam box by using special fine rusting solutions. The Pilkington solution I mentioned is one. You just swab it lightly over the metal in the evening and the rust has formed by the next day. There are a couple of other brands of solution out there. Mark Lee's, for one, and it's less expensive than the Pilkington these days, but I've forgotten the other names. I've only used the Pilkington so far, and it's worked very well, even in fairly dry air.

As I mentioned in the last post, you need good boiling tank water quality for good results. Distilled water and deionized water both work. I would imagine that water from a reverse osmosis filter would work, too, but haven't tried it.

The result is a rich slightly satin blue. It is not a black blue like S&W blue, but is closer to the old Colt blue. The rich appearance is how it came to be favored on hand made shotguns after they ceased using Damascus pattern steels in the late 1800's.

If you want to create a plum brown finish instead of the bluing, you simply skip the boiling step. The rest is the same. The brown will usually absorb a bit of oil at the end, and both need to be oiled, of course.

[mapsjanhere]

If you want to create a plum brown finish instead of the bluing, you simply skip the boiling step.

Thanks for that tip, I tried the browning solutions on some test pieces but was never happy with the results. Looks like I need to try it with the carding in between.

[HiBC]

I have one brownell's bluing tank .I use boiling water and Brownell's Mark Lee #2 Browning solution.Boil,swab,card.The finish is deep,and a black coffee color.It looks good on old type guns.
Try it on some clunkers to get the hang of it.

I mix turpentine and beeswax to a sludge,and rub that in hot as a sealer.

[Scorch]

I once tried rust bluing a shotgun by degreasing with ammonia and spraying it with distilled water and closing it in a cabinet, then boiling and carding it (the results were less than perfect, but it worked). There are many ways of inducing the surface rust: fuming sulfuric or concentrated nitric acid (as mentioned by Unclenick), ammonia, copper sulfate (many of the commercial rust bluing sloutions are copper sulfate), and silver cyanate all cause the fine surface rust that can be boiled then carded off and leave the black surface oxide. The rust/boil/card process has to be done several times before the bluing is even enough to be called finished.

You can also use Brownells' Dicropan to "rust blue" metal. You use it the same way, but in addition to the rusting process, you get some of the staining from the cold blue that can even out the finish.

[Unclenick]

Interesting idea about the Dicropan. I've still got most of a bottle somewhere that I quit using because I wasn't satisfied with the color evenness when following the directions. Indeed, I did a test with cold blues on steel wire one time, leaving the finished parts (well-rinsed in acid neutralizing detergent and hot water, but un-oiled) sitting in room air conditions for several weeks. All got after-rust except the phosphoric acid-based blues: Van's and Brownells Oxpho-blue. Some of the rust was too coarse for rust bluing, but some was not. It seems to me the old hydrochloric acid-based Outer's formula was worst in that regard. The nitric acid based 44-40 blue may have been the best? It certainly had the best color depth independent of any other consideration.