Quote Originally Posted by anthonyget View Post
I see all of this as an experiment in many ways . . .
If that is your approach - have a look at Rick Sparbers furnace, when laid horizontally. To operate it horizontally, Rick would have to fill the groves holding the heating elements with refractory cement, of course, otherwise it would just fall out at temperature, producing a dangerous short. But that would give him also the opportunity to cut the heating element into three, and controlling it with three separate controllers via three separate control thermocouples.
If all three controllers are set for the same temperature, the front and rear controller would pump more energy into the furnace than the centre one, producing a more uniform temperature distribution in the furnace . . .

And once the heating element grooves are filled and electrically isolated from the furnace interior, you can safely put a thick stainless steel plate into the central, "uniform" temperature zone to make it even more uniform. And that is where the MEASURING thermocouple belongs, the couple telling you what temperature the furnace has and at which your knives are heat treated. And don't confuse the MEASURING thermocouple with the CONTROL couples! The control couples belong as close as possible to the heating elements, since they control the temperature of the furnace (zones). The measuring couples (plural, if you are as picky about the real world as I am, in contrast to the stories most people try to sell as true) tell you essentially how long you still have to wait until your knife is within the temperature range where you want it to be.

Welcome to the world of continuous improvements !