Fire Blued Lock

[dave_person]

Nice Blue David. Do you use a pile of charcoal ash on a hot plate. I,like you use Dry Lime powder.. O.D.

Hi Greenswlde,
I am lucky to have a heat treating oven that I use for casting, heat treating, case hardening, and charcoal bluing. It allows me a controlled heat for hours if needed. I use a steel box with lid, pack it with bone and wood charcoal, and heat it in my oven. I used to use pretty high heat (about 450 C, 800-850 F) but I learned from a master finisher to lower the heat to about 370 C (700 F). The lower temperature did not change the color at all but what it does do is lower any risk of making metallurgical changes in the steel or iron. I use linseed oil and rottenstone rather than lime. I am going to try your method of dry polish with lime. The oil and rottenstone works very well but it does change the color a little. It deepens and darkens the blue a bit, sometimes maybe more than I desire. Plus, I have to degrease the parts each time in the heating cycle after using the linseed oil. Thanks for mentioning the lime.

I am going to be doing a lot of charcoal bluing this next year. I have another late flint English rifle to build plus 3 cased pairs of dueling pistols. Two Wogdon pairs and a pair of early Twiggs. Hopefully, I'll be getting the lock castings for them from Kevin Blackley in a few months.
dave

 

[andy52]

If memory serves me correctly the old royal blue colt used at one time was a bone meal covering, similar to the ash mentioned.

 

[GREENSWLDE]

Hi Greenswlde,
I am lucky to have a heat treating oven that I use for casting, heat treating, case hardening, and charcoal bluing. It allows me a controlled heat for hours if needed. I use a steel box with lid, pack it with bone and wood charcoal, and heat it in my oven. I used to use pretty high heat (about 450 C, 800-850 F) but I learned from a master finisher to lower the heat to about 370 C (700 F). The lower temperature did not change the color at all but what it does do is lower any risk of making metallurgical changes in the steel or iron. I use linseed oil and rottenstone rather than lime. I am going to try your method of dry polish with lime. The oil and rottenstone works very well but it does change the color a little. It deepens and darkens the blue a bit, sometimes maybe more than I desire. Plus, I have to degrease the parts each time in the heating cycle after using the linseed oil. Thanks for mentioning the lime.

I am going to be doing a lot of charcoal bluing this next year. I have another late flint English rifle to build plus 3 cased pairs of dueling pistols. Two Wogdon pairs and a pair of early Twiggs. Hopefully, I'll be getting the lock castings for them from Kevin Blackley in a few months.
dave

HI David,
My method came from a mentor in the "Old Brum" trade. (He also taught me his methods of Colour hardening).He used an old Marble wash stand top with a gas ring under and a large pile of ash to cover the item. He rubbed with Tow & dry lime after de-greasing in TRYC(no longer legal here).He rubbed as soon as the item started get hot and kept going untill he had the the sort of blue you can't see the bottom of.You may see the finish on an old post of my Metford. Go well,Stay well and don't burn your fingers.. OLD DOG..

 

[GREENSWLDE]

HI David,
My method came from a mentor in the "Old Brum" trade. (He also taught me his methods of Colour hardening).He used an old Marble wash stand top with a gas ring under and a large pile of ash to cover the item. He rubbed with Tow & dry lime after de-greasing in TRYC(no longer legal here).He rubbed as soon as the item started get hot and kept going untill he had the the sort of blue you can't see the bottom of.You may see the finish on an old post of my Metford. Go well,Stay well and don't burn your fingers.. OLD DOG..

PM me & I'll tell you how he obtained the Deep Blue marbled case hardened finish prefered by BOSS.O.D.