I did'nt know that nitre bluing was so easy! Check this out!

[O.S.O.K.]

http://www.youtube.com/watch?v=-vF3zKiUIkY&feature=g-vrec&context=G2e87b56RVAAAAAAAACQ

[Krupski]

-video-

The molten salts are at 650 degrees F... wonder what that would do to a heat treated part?

[O.S.O.K.]

I wondered that too but I think it's below the trouble point - I think you have to get up over 1,000 degrees before you have trouble?

Pretty sure.

[circuits]

If you held at 650F for more than a minute or two, you'd be drawing down the hardness. Dip and swirl only as long as you must to achieve the correct color.

[O.S.O.K.]

Ah... thanks. Larry should have mentioned that! Those are all hardened parts...

[Krupski]

I wondered that too but I think it's below the trouble point - I think you have to get up over 1,000 degrees before you have trouble?

Pretty sure.

Well when the guy in the video said the metal was getting a "straw color" it made me think of what steel does when you heat it a second time after hardening to "draw it out" to the right hardness.

I have a nice old pistol that is almost in the white from age and wear and that nitre blue looks pretty nice... but I don't want to ruin a heat treated part... :eek:

[Krupski]

If you held at 650F for more than a minute or two, you'd be drawing down the hardness. Dip and swirl only as long as you must to achieve the correct color.

Thanks.

[deth502]

not what i was thinking....

[deth502]

this is what i was thinking of, most likely because of the use of nitric acid.

http://www.assra.com/cgi-bin/yabb/YaBB.pl?num=1282132883/0