doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com Nitre bluing salts

I use the Brownells salts for parts too big to fit into my old electric lead bullet melting pot., trigger guards, ect. Seems to work OK

But for a handfull of screws to blue or drawing back springs I still use the lead pot.
Heats up quickly, easy to maintain the needed temp w/the simple control knob and using my elderly but still accurate high temp thermometer.
Wire up the part(s) and keep them in the lead for a few minutes for the blue to appear. Don't let the part touch the sides or bottom of the lead pot.

It'll want to float in the lead so it takes a little rigging & bending of the wire attached to a vise grip lying next to the pot to allow it to sit submerged by itself for the needed time. You can hand hold each one of course just as easily but that gets tedious for me w/a number of small parts to do..
Shake off excess lead when they come out.

Some lead will stick on occasion especially where it's attached to the wire but that peels right off when cooled & taken apart.
Same thing when doing springs.

Thanks Kutter.

Mike,
How are you hardening screws before nitre bluing?

Interesting article Garro, i might try that.

The clock and watch screw article is really good but it is I feel aimed at clock people Like my self who make clocks. So I would like to fill in the little but important things that have been left out. Firstly clock and watch screws are made from high carbon steel like drill rod, this of course takes to heat bluing perfectly. Now a top class maker polishes the screws then coats the screws with a mix of water and Fullers earth before heating to cherry red and quenching, this clay stops the steel surface from oxidising and loosing its fine polish. Then the screws are re polished then heated again to obtain that clockmakers blue. But the article did not say that the blue colour is a type of oxide and the slower you bring the steel up to the blue colour the thicker this layer becomes and the finer the blue colour is.
If you are using basic steel screws and want that clock blue colour the standard method is to case harden the screws first by using a product like Kasenit then polish then flame blue.

Hope this is of further help.