There have been a few threads lately that dealt with rust blueing questions, specifically a formula to mix the solution. This is the formula that the late Dr. Oscar Gaddy gave in a two part article that he wrote for the 1997 summer and autumn issues of the Double Gun Journal. It is a concentrated formula that he diluted with deionized water at various rates based on humidity and temperature. This formula is a modification of the C-26 formula in Angiers's book on blueing and browning. Gaddy was well respected for his blueing and browning, but best known for refinishing damascus. He used this formula for fluid steel as well as black and brown damascus finishing.
These chemicals are hazardous, so use care and good ventilation. Use at your own risk. These amounts make one liter of concentrated formula.
Mercuric Chloride 50 grams
Ferric Chloride Solution 40 milliliters
Nitric Acid (concentrated) 9 milliliters
Ethyl Alcohol 24 milliliters
Add deionized water to make 1 liter total volume
He diluted this formula by a factor of 2 several time with distilled water, keeping a supply of X2 to X16 on hand. The more concentrated X2 was used for the first rusting and each stage used a weaker dilution. He often didn't go past X8. This solution will create a brown ferric oxide rust that is suitable for finishing early damascus barrels. Boiling the rusted parts in distilled water for a few minutes converts the brown ferric oxide to the black ferro-ferric oxide that gives a white/black finish found on later damascus barrels and a black finish on fluid steel.
Here are a few tips related to general finishing that are mentioned in the articles. Nobody had mentioned damascus finishing in previous posts, but if you're interested in that I'll add some of Gaddy's information related to it.
Use a commercial blue remover to remove old finish. Polish to a 300 or 400 grit finish.
To degrease boil in a mild solution of potassium hydroxide. This removes oils and grease from all surfaces and crevises. This is followed by scrubbing with a paste of mildly abrasive house hold cleanser such as Bon Ami or Comet. Rinse thoroughly.
Start with the X2 solution for the first rusting. Use a 1 inch wide foam paint brush with the exess liquid squeezed out before application to prevent streaking.
After the application of the solution Gaddy let the barrels sit for 24 hours to rust before boiling.
Wet carding was done with fine steel wool and running water.
After final rusting the parts are immersed in a bath containing a mild potassium hydroxide solution at room temperature for 1 hour. This completely neutralizes any traces of acids from the rusting solution that might remain on the surfaces or pores of the metal. When removed the parts are thoroughly rinsed, dried, and oiled.
I'm not a blueing expert, I just thought I would pass this along. Hopefully the experienced guys on this site will add their methods and tips. This might be just enough information to get some guys in trouble. If you want to start blueing you might want to go to the Double Gun Journal website and see if back issues containing these articles are available, and pick up Angier's book.
These chemicals are hazardous, so use care and good ventilation. Use at your own risk. These amounts make one liter of concentrated formula.
Mercuric Chloride 50 grams
Ferric Chloride Solution 40 milliliters
Nitric Acid (concentrated) 9 milliliters
Ethyl Alcohol 24 milliliters
Add deionized water to make 1 liter total volume
He diluted this formula by a factor of 2 several time with distilled water, keeping a supply of X2 to X16 on hand. The more concentrated X2 was used for the first rusting and each stage used a weaker dilution. He often didn't go past X8. This solution will create a brown ferric oxide rust that is suitable for finishing early damascus barrels. Boiling the rusted parts in distilled water for a few minutes converts the brown ferric oxide to the black ferro-ferric oxide that gives a white/black finish found on later damascus barrels and a black finish on fluid steel.
Here are a few tips related to general finishing that are mentioned in the articles. Nobody had mentioned damascus finishing in previous posts, but if you're interested in that I'll add some of Gaddy's information related to it.
Use a commercial blue remover to remove old finish. Polish to a 300 or 400 grit finish.
To degrease boil in a mild solution of potassium hydroxide. This removes oils and grease from all surfaces and crevises. This is followed by scrubbing with a paste of mildly abrasive house hold cleanser such as Bon Ami or Comet. Rinse thoroughly.
Start with the X2 solution for the first rusting. Use a 1 inch wide foam paint brush with the exess liquid squeezed out before application to prevent streaking.
After the application of the solution Gaddy let the barrels sit for 24 hours to rust before boiling.
Wet carding was done with fine steel wool and running water.
After final rusting the parts are immersed in a bath containing a mild potassium hydroxide solution at room temperature for 1 hour. This completely neutralizes any traces of acids from the rusting solution that might remain on the surfaces or pores of the metal. When removed the parts are thoroughly rinsed, dried, and oiled.
I'm not a blueing expert, I just thought I would pass this along. Hopefully the experienced guys on this site will add their methods and tips. This might be just enough information to get some guys in trouble. If you want to start blueing you might want to go to the Double Gun Journal website and see if back issues containing these articles are available, and pick up Angier's book.
