what he said, we built 3 and i have to say seamless is the way to go. i can get about 14-16 hrs on a load of coal. It is a bit of a hassle getting the grates in and out but thanks to a tip from a fellow brethren member and competitor we now just use 18" grates on top of our 22 and have no problems loading and unloading. Good luck and happy smokes.
Sean B., Rub This! BBQ -- Jumbo Joe, UDS (3), Stoker