I bought this smoker in Northwest Illinois. It was built by a retired welder using bent steel from a specialty shop in Rockford, IL. I believe it is 1/4 inch. It is a brick S*#$house!!!! It is equipped with propane(which I use only to burn crap off the rack) and I have modified the bottom with a metal tube with holes to direct the heat evenly. I am in discussion with a welder presently to have a 1/4 inch shelf built on the bottom to get a reverse flow and have more even heating. It works well now but I know when I get that sheet in there conducting heat evenly it will make it even easier for me. I believe I will have brackets welded in and then set the steel sheet over the brackets. It needs to be removable so I can clean the bottom. I will get more pics later as I won't be able to show the inside as I have meat on.
The turkey breast is around 7 lbs and I have great luck in the past with them. Pull the skin back and apply garlic salt and pepper liberally. Cook until about 165-170. That puppy will be a perfect pinkish color on the inside and is great with sandwiches. I have had cookouts where I make ribs, pulled pork and turkey and everyone raves about the turkey. Maybe that says something about my ribs and pulled pork!