For whatever reason, cyanide colors vastly outlast pack hardening colors, IMO. Decades ago I knew a local fellow who did cyanide hardening and had him do some parts including a test piece. I left that test piece un-coated, un-oiled in the western Oregon very humid atmosphere for several years with no sign of rusting or fading. Last I remember it was still in great condition, at least a two decades later, un-coated. I'll see if I can find it in the parts drawers sometime...
Guessing doesn't answer 'why' questions.
Last edited by SDH-MT; 05/03/18 02:25 PM. Reason: edit
