Rust bluing

[Mauser lover]

Okay, a while back, I had a thread on slow rust bluing. I did okay with that one ("fantastic" would be the word that I would use to describe my attitude toward how it turned out, not that it looked perfect, I was just ecstatic about how it turned out).

Here is a link to it, if you want. https://www.thehighroad.org/index.php?threads/slow-rust-bluing.657572/

Okay, for this time....
If a slow rust process is used to basically make a barrel rust evenly and then convert the red oxide to black (blue, whatever), couldn't you use anything that would make the barrel rust?

Wouldn't even vinegar work? Just an acid of any sort? Or, even just leaving it in a humid room... although that might be far too slow.

Thoughts? Experience? Thanks

 

[LoonWulf]

Ive quick rust blued stuff with peroxide, came out ok, but for small parts ive found hot bluing easier. Big stuff i dont know if id try it.

 

[LoneGoose]

I use vinegar to take rust off of old files and to chemically sharpen new files. I don't see how it could create rust for bluing.

 

[boom boom]

You can find different formulas for rust blues from old gunsmithing manuals--Howe for example. Many of these manuals have been scanned and you can get them for free assuming internet access. Kindle version might also be a low cost option.

 

[boom boom]

Clyde Baker's Modern Gunsmithing also has a lot about bluing with formulas including rust bluing. Just pulled it out. If you can find the Traister update version of Baker, it is even better.

 

[entropy]

I like brine rusting for BP guns, gives a nice built-in patina.

 

[Mauser lover]

Brine rusting? Please expound.

I have a commercial compound handy, plus a bunch of recipies. I was just looking to see what someone who had no access to special chemical compounds might use. As in... What did they use two hundred years ago... Or whenever they started bluing?

 

[4v50 Gary]

Get a bottle of express blue from Brownells and follow the instructions.

 

[entropy]

Bluing uses a solution with selenium in it; that's what supplies the blue color. Before that was used, (I don't know dates on that) guns were either left in the white and (hopefully) kept oiled, or browned. The least technical way of doing this was to soak the parts in a brine solution and allow rust to form on the surface. Then it was removed, and the surface oiled, leaving a brown, often mottled finish that protected the metal underneath. I did a BP pistol this way and loved the finish I got better than the finish I've seen from B/C Plum Brown.

 

[morcey2]

Selenium solutions are used in cold blue, not rust blue. Most modern rust bluing solutions are a combination of hydrochloric acid, nitric acid, and/or ferric chloride. I have used one from brownells, but I can't think of the name of it right now. I did a rifle with it and I didn't have a proper tank to boil to convert the red oxide to black oxide. I used steam from a tea kettle for the conversion and it probably wasn't quite hot enough. The rifle looks more like it was browned than blued. I'm going to be getting a tank in the next month or so and probably redoing that rifle. I also did a couple of small parts as part of an experiment with vinegar as the rusting agent and it worked really well. I diluted it quite a bit so it wouldn't strip the finish.

Most of the cold blues won't hold oil the way that rust or hot salt bluing will and are more prone to corrosion, not to mention that selenium is quite toxic and relatively easily absorbed through the skin.

Lots of the really old rust bluing solutions contain really toxic stuff like mercury. I read through some old gunsmithing books and some of those solutions were downright scary.

Matt

 

[Mauser lover]

Okay, so theoretically, one could brine the part, then boil it to convert to black oxide? It might be worth a shot just for fun...

4v50, I am not looking for a recommendation for commercial compounds. So far, I've had pretty good success with Laurel Mountain browning and degreasing compound.

Old handbooks are always fun. You go down the list...
1. ...nope, that one is deadly...
2. ...nope, that one is regulated..., although only mildly toxic
3. ....nope, that one emits deadly fumes when used hot...
4. ...repeat the first three In varying order until enough ingredients are listed!

 

[boom boom]

Mauser lover,

Your current solution, Laurel Mountain is probably the better way to go unless you are having problems or perhaps Pilkington's (if any is available anymore) if they work for you. My suspicion is that the prep work wasn't quite right if Laurel Mtn. did not work for you--overpolishing surfaces to be rust blued can cause problems as well as imperfect cleaning etc.

I took a look at the old formulas in Baker or Howe manuals but many include mercury based compounds which I am not sure that you could even buy or that would be safe to use without a hazmat suit. Lock Stock and Barrel gunsmithing book also has the real old timey formulas for browning muzzleloaders and the like if I remember correctly.
Good luck.