He then hammers the tough, low-carbon steel, which he has shaped so it will make a snug fit into the ... insulating mixture of clay and charcoal powder onto the blade's upper sides and dull ...

Learn how to easily make your own homemade charcoal ... In a small bowl, combine the calcium carbonate powder, baking soda, xylitol, and activated charcoal. Stir well until the mixture is uniform.