Now I have never tried to colour case harden though I have used commercial case hardening products. Given that I have collected snippets of information on colour case hardening mixtures over the years especially the little additions to the basic bone and wood charcoal mix. Some of you folks who colour case harden may like to try some of these extra additions. As far as I know they are all forms of carbon but with various trace elements and should not cause any strange effects other than improving the final colours of the finished article.
1 Carbonised Blood Fish and Bone garden fertilizer. Made by roasting in a tin keeping the air out with just a small hole to let the fumes escape, keep heating until totally converted to carbon.
2 Carbonised leather made by treating as Blood Fish and Bone. Traditionally a small amount of Ivory turnings where also added. But we all know that Ivory looks far far nicer on elephants so that is a no no, though there was a substitute recommended which was crushed sheep’s teeth.
3 And to improve the surface hardness it is recommended that a small quantity of Potassium Ferricyanide is added to the final colour case hardening mixture before use.
***** Even though the name is similar to its extremely poisonous big brother Potassium cyanide, it has a low toxicity but can be an irritant. *****
Keep the Air blowing through the quenching tank all the time. This causes uneven cooling effecting the final colour pattern, and Potassium Nitrate I have already mentioned.
Colour case hardening is “all steam muck and magic” improved by lots of practice.
Last edited by damascus; 12/09/16 05:05 PM. Reason: Oooops!!
