Is there a good place to find the brake-down of the materials that go into the mortar for the dome?? Also is the a air temperature restraint? Should I not use it if it is going to get below freezing?? I was originally using a refractory mortar call "Demon" that is put out by a company called "Plibritco" but it is getting to expensive and I can not use it when the air temperatures get below freezing.