What is the best way to chemically blacken the couplers?
I use Carrs Metal Black for Nickel Silver, and I normally blacken the coupler components after soldering and folding-up but before assembling the components. Carrs Metal Black for Nickel Silver is available from many model shops and mail order outlets or indeed, directly from its manufacturer C+L Products, who advertise regularly in the model railway press. Remove any excess solder from the components with files and a glass fibre pencil, then shake the components in washing-up liquid in hot water for a few minutes to degrease. Then, immerse the components a few at a time in the blackening solution. Agitate or brush the components so that bubbles do not cling to either the upper or lower surfaces of the components. If you do not remove the bubbles, you will have unblackened spots on your couplers. Remove the components from the blackening solution when they are dark-brown to black and drop them in clean water to remove excess blackening solution and stop the chemical reaction. If blacke
