Recommendations on Cold Bluing Products

[tippit]

I'm more interested in trying some cold bluing of knife blades that I forge...tippit

[D. Taylor Sapergia]

Any product that gives a rust brown will also give you cold (rust) blue, if you boil the browned steel in distilled water for about 15 minutes.  You'll want to card off the black oxide after boiling too, yielding a wonderful burnished blue.  I use Brownell's carding wheel and 0000 steel wool.

[phatton]

I like Bronnells Oxpho Blue liquid.  It's pretty easy to apply, is super tough, and does not after rust.  Birchwood Casey super blue is also good

[wmrike]

I second Oxpho-Blue for durability.  I've not found it to be not quite as bright as other of the cold blue solutions, but it is tough.  Part of that is due to the phosphate component in the solution which contributes to rust resistance.

[greybeard]

In my humble opinion there there is no place on a hi end firearm for cold copper smelling stinky blue!!

[Jerry]

I have used 44/40 with great results for years. I sometimes buy the gel. Jerry

[deepcreekdale]

You might also play around with the brass tarnishing solutions that Jim Kibler sells. I gives a very nice, pleasing bluish grey color which is surprisingly durable and rust resistant. It is not a rust blue finish as far as depth and durability goes, but it might fit your needs.

[heinz]

Tippit, follow Taylor's advice.  The chemicals in cold bluing solutions are not acceptable for use around food.  Cold blue is essentially a selenium activated copper plating turned dark. Food acids will remove it. Selenium is extremely toxic.  And I am in Graybeard's camp.

[Eric Smith]

I too am interested in the idea of cold blueing some knives made from 5160 steel.  My knives are large Bowies that I want to display.

[Daryl]

I would suggest the Birchwood Casey's Gun Blue Paste.  Rub it in, several fresh applications over and over then wash in cold water, wipe dry and oil
with your choice. I use WD40 after the washing & wiping & rub that in well, too. Beautiful even dark finish, but of course, it smells like cold blue.

[Scota4570]

I buy oxphoblue and dichophan by the quart.  Do not over polish with either.  #320 is plenty.  I like a light sandblast that just takes the shine off. 

Apply oxpho blue with scotchbrite.  You will see when it bites evenly, let it soak a bit then.  You will get black flock.  Rub that off with cloth and oil. 

Dichophan is an express blue that you boil after.  I use it like BC plum bown, apply to hot steel.  I apply it with degreased steel wool until it evens up.  Then boil or steam. 

Both make a durable blue black.  Not everyone can do real rust bluing at home. These are viable options. 

I bet a real gunsmith would "blue" your knife blades with a hot caustic process for a minimal fee if you did the polish.