[orionjib]

Actually I did talk with Harbison-Walker, but folks I talked with were not very knowledgeable about pizza ovens. They recommended the Greenlite 45L because of weight and strength, but as you say, there does need to be something on the inside with reflective properties. The original oven was a cast unit made from a heavier, more dense, smooth castable with the lightweight material packed in around it with a ceramic blanket over the top of everything.