Fire Blue

[rebel727]

How do you get that fire blue color I've seen on some of the pics?

 

[Brasilikilt]

You'll need a propane torch. Whatever you intend to blue usually smaller parts such as screws etc just heat it up red hot and let it cool. I did this last weekend for some staples I was making for my powder horns out of old nails, worked really well
I don't remember if I let it air cool or if I dunked it in water.

I'm sure someone else will know more about this than me........good luck

IMH

 

[dlemaster]

I thnik if you dump it in water you will pop the dark scale off the metal.
Bring the part up to a dull red, let cool slowly, and then oil it.

Regards, Dave

 

[Roy]

You can lay it on an electric eye for and even heat or use a torch, I've even heated up a flat piece of steel in the forge and layed the piece on this. This is just a superficial blue, is not a protective finish. Slowly heat the piece up untill you see the color change, from straw, purple, blue and quench to stop the heating process. If you heat the part up red then let cool its more of a gray color, If you heat it up red and quench it in oil it will turn out a blackish color. If you don't like the color, polish and start over.
Warning: do not do this to a hardened piece it will lose its temper. :thumbsup:

 

[rebel727]

Thanks. :thumbsup:

 

[44-henry]

The color you will get from the above posts will probably not give you what your looking for. Heating to a red heat and quenching, or letting it cool, will give more of a dull grey color. The deep blue you are seeking is done at lower temperatures. Check out Gunsmithing Tips and Projects for an article by Bivins where he describes the use of Potassium Nitrate to obtain this effect, there are also other methods, but they all rely on creating a stable enviornment where the heat can be evenly distributed to the work piece without highs or lows. I think the appropriate temperature is closer to the 600-700 range.

 

[dlemaster]

Potassium Nitrate will give a blue to parts that are heated in the melted chemical, but this is not fire blue or charcoal blue. It is referred to as niter blue and was common in the late 19th century and later. This is the method of blue used on 1896 Broomhandle Mauser pistols.
Heating parts slowly and watching the color range from the heat gives a very nice blue referred to as a temper blue but it is not very durable. The scale blue brought on by heating to a dull red heat and slowly cooled is a little more durable. True charcoal bluing is probably even more durable than the scale blue but is more labor intensive. This does not include rust blueing.
I did the scale blue on two large Siler locks that came out a blue/gray color but more toward the blue. They are both over 20 years old and do show wear but for the most part have held their color.
That is just my experience, others may vary.

Regards, Dave