Gun bluing

[Potashminer]

I do not remember the articles, but about that time I had bought the four volumes of the Gunsmith Kinks books - I've since passed them on to another guy - that is likely where I had read about the Oxpho Blue being so good. I am simply not seeing anything about it (or any other "Cold Blue"), 8 or 10 years after applying it. I do still use the stuff - mostly on m1917 or P-14 action screw heads that I peen out and polish to fix the screw slots, since I am not finding a good source, any more, for NOS replacements.

 

[SIGP2101]

Caustic hot bluing will give you absolutely best and most durable finish but it is pain to execute it properly. Preparation, pickling, temp control, neutralizing are just some of the steps required. There are books and books written on this topic.
Rust bluing is most time consuming and bit easier to do but it is not for all guns, mostly for historical significant pieces that someone wants to bring to former glory. Best looking indeed.
For the cold bluing I would go with some of the possibilities offered by www.caswellcanada.ca/black-oxide but you still need to do your homework on the topic in order to execute it properly. They offer many solutions for metal finishing and rust protection.

 

[M1-Garand]

When ammonium nitrate was still widely available I rebluid a few hand guns, with the proper preparation they turned out beautiful.
But I always did it outside on the camp stove and in a ceramic bowl that was ruined for anything else.
From what I have read potassium nitrate works

 

[Jonnyofalltrades]

Caustic hot bluing will give you absolutely best and most durable finish but it is pain to execute it properly. Preparation, pickling, temp control, neutralizing are just some of the steps required. There are books and books written on this topic.
Rust bluing is most time consuming and bit easier to do but it is not for all guns, mostly for historical significant pieces that someone wants to bring to former glory. Best looking indeed.
For the cold bluing I would go with some of the possibilities offered by www.caswellcanada.ca/black-oxide but you still need to do your homework on the topic in order to execute it properly. They offer many solutions for metal finishing and rust protection.

I would have to disagree about hot caustic bluing being the best, or even most durable. Slow rust bluing beats it out fairly thoroughly.
The one area where hot caustic bluing rules is with highly polished, "mirror" finishes. Rust bluing can't do that.

 

[HuskyDude]

The last several barrels I've done, has been with a mixture of these two.

With the consistency of paint applied with an acid brush.
Removing all oils is paramount for a consistent finish.
For best results heat the barrel 110-120°F.
Use a heat gun not a torch as one of the byproducts of your touch is H₂O.
Once it cools, hit with some steel wool, seal with some oil...and your good to go!

 

[Potashminer]

The last several barrels I've done, has been with a mixture of these two.

...

With the consistency of paint applied with an acid brush.
Removing all oils is paramount for a consistent finish.
For best results heat the barrel 110-120°F.
Use a heat gun not a torch as one of the byproducts of your touch is H₂O.
Once it cools, hit with some steel wool, seal with some oil...and your good to go!

...

Yep! Sure looks good - when picture was taken - take a look after 5 or 8 years and see what you have - was the part about "cold blue" that I do not read much mention about.

In my attempts here, after time, it fades away to nothing - can only see the metal work that you might have done - no colour left at all. There are rifles here made in late 1800's - so like 130 years old or so - I do not think they used "cold blue".

 

[tiriaq]

Here is a M94 (4 million serial number) which I rebuilt perhaps 30 years ago. The matte finished parts were Oxphoblued right out of the blast cabinet. Hard to get steel any cleaner than freshly blasted. The barrel was polished on the lathe, spinning it against increasingly finer grades of abrasive. Thoroughly degreased, then Oxphoblued. No fading in decades. The butt and long forend were Winchester surplus. I whittled the nosecap out of a piece of 2" diameter steel round stock. I cannot explain why the cold blue worked so well on this rifle. Excellent colour, no fading.

 

[bearhunter]

Absolute cleanliness is a must, whether cold bluing or hot tank bluing.

That's very likely why your Mod 94 came out so well. The matte finish, instead of high polish on the receiver helps as well.

I really like Oxpho Blue. I've tried a few others, like Black Magic etc but none are as consistently successful as the Brownelle's offering.

I make sure the parts are degreased, then just to make things go faster and smoother, I will boil small parts in a pot before applying the Oxpho Blue.

The combination heat and being very clean makes the metal take on the "blue" oxidation solution very quickly and dries quickly. I usually repeat the boiling between coats and if necessary carding.

When I do a barrel separately, I chuck up the tenon in a lathe and put a live center into the tail stock, then turn on the lathe and polish with different grit cloths and sometimes jeweler's rouge if I have to match a polished receiver, then I use a propane torch to heat the barrel while it's spinning to the point it's hot to the touch, then apply the Oxpho Blue as often as needed to match the color of the receiver.

 

[Jonnyofalltrades]

I cannot explain why the cold blue worked so well on this rifle.

Clean living?