After scouring the internet for design ideas I ran across this forum. I found alot of useful information but I still have a couple of questions that I was hoping someone would be willing to help with. I am planning on using a food grade 55 gallon drum as the frame of my cooking chamber. At this stage of design my two biggest questions revolve around metal thickness. If using a reverse flow design how thick should the metal be for the deflector? Is a tight seal necessary for this to be effective or would a decent fit and the weight of the steel be sufficient to redirect the heat. Secondly I am having a difficult time with material thickness for the firebox. I have read everything from sheetmetal to 3/8" plate. Would I be incorrect in assuming I can use a sheet metal, say 14ga, for the box as long as I have it insulated? what is the typical insulation used? I am a blacksmith and there are several insulations used in our forges, but I believe that they would be overkill for this application. There will certainly be more questions as the design nears completion, but thank you for the information I have already learned from the forum and I hope to learn more.