Flux or vitreous enamel


So, a few years ago I won the CKCA Cutlery Challenge aka Fisk Cutlery Challenge. I have won a lot of awards with my knives but this was special.  CKCA is the Custom Knife Collectors Association and they have twice now hosted the contest. The prize allowed me to have the time and pay for materials to create the process for adhering flux or vitreous enamel to both a knife handle and a sheath.

The knife pictured won the award. I had seen a photo of a Celtic shield that had bronze attached to portions of the wood shield. The library photo described the bronze as having glass enamel on the bronze. Basically, it turned out that this appeared to be flux similar to what bladesmiths today think of flux used in welding like borax.  It is highly unlikely that this was borax. I have a hypothesis that early Celts probably had bonfires where broken shields with bronze parts or even bronze swords came in contact under high heat with sand with the right silica content to allow the molten silica/glass to fuse to the metal. Of course today we have vitreous enamel or flux on all sorts of metal surfaces. There are signs, sinks, cookware, and jewelry being made to day with this vitreous enamel. It’s hard, protects the metal underneath, scratch and chip resistant, and impervious to low to moderate heat or acid.  So, why not try it.

First I had to figure out how to taper a metal tube and shape it so it looks like a knife handle. This ultimately led to learning about metal spinning on a large lathe. Then I had to experiment with vitreous enamel. I found that I had excellent control in my forge if I heated the forge to around 1800 F and then shut down the blower and propane. The walls of the forge radiated heat and I could spin slowly the metal handle watching the flux or vitreous enamel powder (glued to the handle) until it began to melt at about 1500 F. It took a lot of experimentation but I feel I can teach anyone to do it in a forge.

So, here is a technical tip. I use G16 which is a ground coat or flux. It fuses into the metal surface at a little higher temperature providing a base coat that makes it pretty easy to add coats of more vitreous enamel of all kinds of colors.  I have done it with copper, stainless, ultra low carbon steel with no problems. The base coat of G16 has some cobalt in it and really sticks to a lot of metals. I can create a host of patterns on handles, knife fittings, guards, buttcaps (see photos). I have even dropped a handle on concrete without chipping or scratching. The vitreous enamel is as strong as the metal underneath. Wedded together the metal handle with vitreous enamel on it is stronger than without it. A benefit is that it also has this no slip feel to it. I suppose a coat of oil on the handle would change that but not water or sweat.  The artistic options are unlimited.