Cold Blueing

[Don357]

I was talking to a friend about refinishing guns and the subject of "cold bluing" came up. I have heard of using it to touch up scratches and repair jobs, but how durable would it be to refinish the outside of a gun such as the barrel and/or reciever? What kind of appearance would it have? I am considering either "cold blueing" or "duracoat". Opinions Please!!!

 

[Bad Flynch]

Cold bluing, as the term is used nowadays, is a second-rate, maybe third-rate finish. It uses selenium compounds to produce a blue with a characteristic selenium -salt odor. It is a very fragile finish.

You should try Rust Bluing. It was the standard for the commercial firearms industry all through the 19th century and was used by Remington well into the 20th century. Variations in processes are known, and some of the solutions are toxic, but it is an otherwise excellent process and can produce a beautiful blue that is durable and unlike hot-tank bluing.

 

[Jim K]

Rust bluing is great and produces wonderful results. It is also tedious, messy and takes a lot of time to do it right. And if you are doing a long gun you need a hot tank big enough to take the barrel/barreled action. So it is not that easy. I recommend lots of practice with scrap metal before pitching into a good gun with rust blue.

Jim

 

[ShunZu]

Duracoat. I've used cold-blue on several pieces (not very valuable, just old single-shot shotguns when I pick them up cheap and just want another for the gun safe) without very satisfactory results. Nearly impossible to get a good "looks factory" finish on it. It will be slightly better than letting the piece rust, imho.

 

[alucard0822]

Ive had decent results with Blue wonder, but surface prep is everything. But like bad flynch said, it is a very fragile, easily scratched finish that offers absolutely 0 rust protection, and is best left for touchups. Rust bluing looks good, but is a messy pain, and is best used if you are planning on doing a few guns at a time. Durakote is easy, fairly durable, and offers great rust protection, but may not be the look you are after. You can also try a phosphate parkerizing kit, they are not terribly expensive, are fairly easy to use, and give decent and durable results.

 

[DiN_BLiX]

Brownells alumahyde work well also.

 

[Onmilo]

Brownell Oxpho-Blue is the only cold bluing product I use.
It can be used to refinish a whole firearm but the quality of the finish can vary considerably from gun to gun due to variences in the metals used in each particular firearm.

For applying a protective surface finish to bare metal, a cold blue refinish can be effective.
For refinishing a firearm in the hope of increasing its value for resale I cannot recommend cold bluing of any sort.

I hate paint of any kind on the metal surfaces of a firearm.

 

[sweetkicker]

I have had mixed feelings about cold bluing. I am not an expert or a metallurgists, but I have found that cold blue works best on straight steel. if you try to use it on any kind of alloy you will just turn a moderately cheep gun in to a ghetto ditch gun. I have had nice results with a very tedious process.

I use a wire wheel on a bench grinder, and then I scrub with industrial strength degrease, straight purple juice "don't add water". then I rinse with hot water until I can no longer feel a slip when I touch it. hang to dry "be sure all standing water is removed" and put gloves on. then I brush the blue on with a good sponge brush. I let it dry at room temp until it gets a yellow "sulfur" look. then I rinse it off in cold water while buffing it with the finest of fine steel wool. now I inspect it for a go or no go are all surfaces uniform and clean? if it is a go I have the wife put water, and 2 bags of ice in the tub while I heat up the part to about 150%. I then brush again with cold blue and clean gloves. I toss it into the ice bath right after. then I pull it out, soak it in oil.

I don't care what anyone says. you can get good results with a cold blue. prep is everything. would you like to see someone "not" prep your car before it was painted?
I did look at the brownell line of products and i opted only to use that kind of finish if I had a pitted barrel or an alloy.

lol,,,, I am not a brownell spokesman.

 

[brickeyee]

Use a hot air gun and cold blue for a little better finish.
Still not as tough as hot blue.

 

[Ceemack]

I did a rifle with Brownell's Oxpho-Blue cream, inside and out. It looks a lot better that one might expect, but an awful lot of work went into it.

Oxpho-Blue doesn't produce a very good color with the metal at room temperature. It works much better if it's heated up with a hair dryer or heat gun until the piece is almost too hot to hold.

Uniformity is hard to achieve. To do the barreled action, I built a cradle that was longer than the barreled action. I took a quarter-inch aluminum rod and built it up with masking tape until it was a tight fit inside the barrel, then rotated the barreled action in the cradle like barbecue on a spit as I rubbed the bluing cream onto the action, and kept rubbing until the color was uniformly dark.

Preparation is critical. I used copious quantities of Castrol degreaser to remove any oil or grease (it was an old service rifle, with lots of nooks and crannies to hold the cosmoline), naval jelly to strip off the old blue, and then a final wash with Dawn dishwashing liquid and a hot-water rinse to get the prep chemicals off. A wire brush on a rotary tool took care of any old bluing the naval jelly didn't get.

Note that steel wool will leave oil behind, so if you're using that for prep you have to degrease again before you apply the bluing.

I'm not sure of the point of a cold-water rinse after bluing--I wouldn't do that myself. Just wipe off the last of the bluing cream, being thorough but gentle, then coat VERY liberally with gun oil (no motor oil or 3-in-1 oil) and let the finish cure for a good, long time. Two weeks is a good target, although longer isn't a bad idea. Wipe off the oil and you should be good to go.

I have to confess that when it came to the smaller parts, there were several cases where the original results looked terrible. In these cases I stripped the cold blue back off and started over.

Duracoat will last a lot longer and provide better corrosion resistance. Only you can tell whether or not it will give the appearance you want. It's a fairly permament solution, though, so be real sure it's what you want.

You may also want to think about having a gunsmith do a nice hot blue on it. With the amount of material I went through, I doubt I saved more than 50% over the cost of a hot blue.

 

[chris allen]

cold blue

cold blueing is like trying to pee on a forest fire --just doesn't work well.

If you have access to a gunsmith, in your area, who hot blues they will generally give you a reasonable price if you have the gun stripped and polished. He/she only has to run it thru the blueing tanks.

chris

 

[sweetkicker]

the idea of hot and then cold is to expand the metal and then shrink it with blue intact. like I said before I am no expert, but this worked well for me at a reasonable price. and everything I have done this way has taken the test of salty hands, rain, and rough handling with a good result.

 

[brickeyee]

"the idea of hot and then cold is to expand the metal and then shrink it with blue intact."

The heat in hot blue is to dissolve the salts in the water and then speed up the reaction so it will occur in a reasonable time.
"expand the metal and then shrink it" has nothing to due with the chemical process you are trying to use.

 

[Sunray]

Cold bluing is definitely for touch ups, not whole firearms. However, as Ceemack says not all cold bluing products are created equal. And the prep work and the time it's left on before oiling is important. The gels seem to work better for large areas than the liquids do as well.