If you want rust browned barrels, then you don't boil them. The boiling turns the rust orange/brown to black.
I usually boil after the second rusting, boil, then card, then dip in the etchant for 5 seconds, repeat until the desired color of the barrels. That could be 5 rusting or 10 rustings.
I thought English guns were browned not blackened/blue, but if blackened, then 5 minutes would do in the boiling water.
I have used Radio Shack's circuit board etching solution. I mixed it 15% etchant to 85% distilled water to bring out the Damascus pattern. Not sure if that is available to you there.
The logwood dye is used to enhance the blackened barrels and from what I have read, the amount of solution to use is when you cannot see through the water.
Last edited by JDW; 09/06/10 12:38 PM.