Hi ya'll, Some of you may have seen my buildup thread in the Smoker Builds section of this here forum, but if not I will inform you of what I am dealing with. Below is s picture of my smoker. This is not the most recent picture of it, but it will allow for me to explain my problem. The fire goes in the far right door and the smoke comes through the two left doors. I need some ideas of how to insulate the fire side of the smoker. This tank is about one eighth inch thick. Does anyone have any ideas of how to insulate this that won't cost me a fortune to do and won't take too terribly long to do. I have a couple ideas but I want some fresh ideas. The front wall of the wood box on the back is getting hot (hot enough to cook the sap out of the planks) and the wood on the other side of the tank is actually burning. So I need to insulate it. Not to mention that if it is hot to be around when it's cold outside, I can only imagine what it will be like in the 110*F summer humid Tennessee heat. Here are my concerns/questions: It must be something that doesn't cost a fortune Insulated enough that the outside of the tank is less than 200*F Is there a spray on insulation? Will firebrick/refractory withstand vibration from traveling? Should I insulate the inside or outside?