Disregarding the bad experience with the sulphur, the trial with the plastic refractory substantiated my feelings that density as well as alumina content is necessary for the resistance of sodium vapors in salt kilns. An arch like this would be high in alumina and density, light weight, and I think as permanent as can be at this point in time. There are other brands of refractories available as well as other types of refractories. This hasn't been an ad for A. P. Green, these are simply the materials I've been using and am familiar with. My concern is that people starting out might avoid the problems that some of us have experienced.
Special refractories are expensive, as is down-time for repairing kilns and sore backs.
Tom Turner teaches at Clemson University and operates a pottery in Liberty, North Carolina. As a professional potter the first thing that comes to my mind in planning a salt kiln is what the costs will be to build, maintain, and fuel the kiln. I was able to find a free source of hard firebrick for my present salt kiln, but I didn't know how they would react in salt. I had seen a salt kiln which incorporated refractory castables in its design, so I decided to do the same. I constructed a 50 cu.