Hi All I just got a 50 gal NG water heater. I intend to strip the sheet metal and use the tank to build a smoker. My questions are, should I insulate the cook chamber? Not sure of the tank gauge yet(I am guessing 12-14 is about average) I am thinking of using old propane tanks to make the firebox, should I insulate that as well? Does it matter what gauge metal use for firebox to cook chamber or for the chimney? I have used the pit calc and got my basic dimensions, but was hoping to draw on the experience of the other builders here. This pit will be my learning curve for my REALLY BIG pit later, I wanna build a whole hog cooker, maybe trailer mounted, ambitious I know, but I am too Cheap, er frugal to buy one of the thing especially when I can build it myself. All help is appreciated!!