Which blue formula?

[longcruise]

I'm in the process of cleaning up and reconditioning my GPR. The metal has previously been finished with birchwood casey plum brown but I'm going to a cold blue finish this time around (not looking for browning suggestions).

What, in your collective experience is the better cold blue formula?

 

[Col. Batguano]

The Brownell's Oxpho-Blu one seems to stick better than the Birchwood Casey. Those are the only two I have experience with.

I would like to try doing real hot bluing / salt bluing some day, but there aren't that many historical ML'er guns that did it that I am interested in building.

 

[dave_person]

Hi,
Are you looking for a cold rust bluing or an instant blue? Cold rust bluing is the same as browning except you boil the barrel after carding to turn the brown to a dark blue. For that purpose I prefer Laurel Mtn Forge's and Wahkon Bay's bluing solutions.

dave

 

[Zonie]

If someone wants to use a cold blue, I think Birchwood Casey offers the best product.

The Birchwood Casey Perma Blue is made for low carbon steel like most muzzle loading guns are made from. This is what I would suggest for a Lyman GPR or GPH.

The Birchwood Casey Super Blue is made for alloy steel like most modern cartridge guns use. It does not work on the low carbon steels as well and often will leave an uneven appearance.

If the barrel was previously browned with BC Plum Brown, sanding off all of the old finish is about the only way to get rid of it so the new cold bluing can take effect.

 

[longcruise]

I've got it pretty well sanded out. Just a bit more to get it perfect. The barrel is actually a GM that I modified to fit way back. So how does that fall into the alloy picture?

 

[dave_person]

Hi,
Green Mountain barrels are made of 1137 steel, which is a manganese steel alloy. It will brown and blue very nicely.

dave

 

[longcruise]

I rummaged through my plunder and came up with a perma blue bottle and did a test on the underside of the barrel. Three applications per the instructions.

I didn't like it! I m going to polish the barrel out to a final finish then do the same to the tang, butt plate and TG leaving it "in the white".

Thanks to all for the information.

 

[Pete G]

Try painting with a solution of phosphoric acid. That will yield a somewhat mottled antique gray finish.