I'm getting ready for a RMH build in my cabin here in southern Ohio. I've been shopping for used firebrick and stove pipe. I'm planning on doing an 8 inch J-tube with a cob bench. I've considered a batch box but like the simplicity of the J-tube. I've used a RMH before when I lived in Oregon. I built a really nice Rocket oven 6 years ago and it has been awesome and is still doing good... The RMH will have a firebrick core with an insulated riser and 55 gallon barrel. I'm leaning toward running about 20 feet of stove pipe through a cob bench but I'm also thinking about a half barrel stratification chamber covered with cob.....Here's a few questions I have..... I can get a stainless steel barrel for $100 which is really cheap. I love the immediate heat from the riser barrel but I'm wondering if the stainless steel barrel will radiate less heat than a typical carbon steel barrel? I know it will last longer but I'm thinking that more heat will go into the bench with stainless steel....One other question....Typical 22 gauge 8 inch stove pipe is .030 - .032 inches or .762mm - .81mm thick. The 18 gauge half barrel that I will use is .039 - .047 inches or 1mm - 1.2mm thick. The half barrel is a little thicker than the stove pipe. Will that make much of a difference? Will the thinner stove pipe transfer more heat to the cob bench and transfer it faster? It seems to me that the thinner stove pipe would be a little more efficient transferring the heat.
