Hot Bluing

[stockerphil]

Howe wrote a very compehensive book on gunsmithing including the bluing processes. You might try looking there. I believe he made his own formulations but I'd start with commercial chemicals. You might find him in the library or get a copy through amazon.com

Brownells.com sells all the equipment and chemicals needed. If you check their website you should also find a tech data sheet that details the process.
GunTech : Dicropan IM One Tank Bluing Kit - World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools
is the start of it. I can't get the whole process sheet to show up but have always found that emailing them and asking for help to see it gets a direct link sent to me.

[tbonesmith]

I've got the book and find it very interesting and informative, but as it was written in 194o-something many of the formulas are for swab applied rust bluing and other methods, I will probably give some of these a run as well as the method described by Roy Dunlap in his book, but what I'd really like to get my head around is modern, tank, hot bluing. The sort that your gunsmith does.

[jmoore]

Rust blue techniques are also used on fine doubles, as the hot salt bath will separate the solder joints holding the barrels together.

Its not an either/or situation. You can do both. Rust bluing is just quicker to set up and requires less expensive equipment. Downside is the time and labor required.

ETA- Ach, missed your last post! Sorry.

[jmoore]

BTW, my "rifle" gunsmith does Parkerizing. He sends out the bluing jobs to a fellow who only does rust bluing. My pistolsmith (who only gets the tedious stuff I don't want to do...) sends his work to another fellow. I know ONE good local hot blue-er. The other "gunsmith" hot tank users, well, mostly, ummm,

[tbonesmith]

Yeah, before I got too much further I'll do a rifle using a rust bluing method detailed in Howe or Dunlaps book. I've just bought a few fixer upper's/parts No1 mk111*s and they will be the guinea pigs. Tried and of the methods specifically?
I'll have a shot a parkerizing while I'm at it, there's a few real easy looking techniques/formulas in Dunlaps book. I'll post the procedure.

[bigduke6]

Yeah, before I got too much further I'll do a rifle using a rust bluing method detailed in Howe or Dunlaps book. I've just bought a few fixer upper's/parts No1 mk111*s and they will be the guinea pigs. Tried and of the methods specifically?
I'll have a shot a parkerizing while I'm at it, there's a few real easy looking techniques/formulas in Dunlaps book. I'll post the procedure.

I,ve had good results with rust bluing, using salt (industrial stuff,sal ammoniac) be carefull with the solution you make, and try on scrap first, very basic, clean item, apply solution (i use a paper towel), leave to rust, place in boiling distilled water approx 20 mins, remove from water and remove the black rust (carding) using soft wire brush or wire wool etc. repeat process untill desired finish. i prefare to boil once a light coating of rust appears, you have a bit more control , but will need to repeat the process up to 5 times.

[Chuckindenver]

hot salts blue.. or Black oxide coating as it pertains to guns..

sodium hydroxide 5 parts.
amonium nitrate 2.5 parts.
10 pounds to one gallon of pure water.
heated to 270 to 300 degrees

since you cant get amoinum nitrate anymore, sodium nitrate can be used in its place.
thats just the basics, and not the exact formula i use..but will work and give you a nice dark black finish.
remember that disposing of depleted salts is tough to do, you should nutralize the sodiumm hydroxide, Brownells sells a product that does this.
remember to start small, and be safe, keep aluminum away from this..you wont like the results.

[Buntlineguy]

Look at the Caswell, inc. site. They have all the stuff. After you see the prices, you will probably want to find someone locally that does bluing. I did buy the outfit and it works great. I have done several rifles and pistols and all came out like new. The 1911 I did for the owner of the local gun shop put the one I did next to one out of the case and the re-blued one looked better. Remember 95% of your time is in prep. The better it looks going in, the better it is when done.

[bigduke6]

Buntlineguy,
your kit from caswell, was it a "cold black oxide" kit ? i got one last year have used for a few jobs, only probs i have had is with walther barrels, finish is good but they rusted, even when drenched with oil, after a clean and another dip come out perfect.

[Pattern14]

its a big mess with a large learning curv..
i dont receommend anyone thats doesnt know how it works do it at home.
not only is it very dangerous, it can be a heath hazard as well.
the salts run at almost 300 once they splash you, its too late, your burnt,
and youll never forget a small splash of hot sodium hydroxide in the corner of your eyes under you safety glasses.
somethings are better sent to someone that does it for a living.

...Not to mention the environmental issues. My brother the gunsmith went into this a few years ago and had to build an outdoor area away from the rest of his shop to provide the service and was visited by the ATF and EPA on several occasions to ensure that the disposal of used chemicals and other environmental issues met with Government regulations- and they were very through.