Don't confuse Cyanide processing with Charcoal pack processing.
I'd love it if someone would just make a PE showing .5 in thick pieces case hardened, representative samples sliced and polished, and then re-cased at an agreed apon temperature for the purpose of coloring. Finishing with slice and polish, and measuring of the case after round 2. Just think how boring the vintage machinery and gun sites would then be.
That would tell us more than we wanted to know.
I read an additional article from way back about japanning the pieces to shield them when re-coloring. A paint on protectant might be much easier than Cu plating for round 2.
Latest guys to get poisoned around here were stripping stolen X-ray film in a garage. Some others were rendering the gold from recycled computer parts.
