The dolly i had it sitting on, while one of the biggest i have, was a little top-heavy and with the riser on the whole thing was gonna be too tall. So i bricked it in, then built a low-riding cart for it to sit in...2" off the floor, 32" wide so it will fit between the trim board on a 34" wide door.
I spent quite alot of time finishing the top of the cold-air intake. I decided the Peterburg plate (the plate that channels fresh air down to the top of the burn tunnel) might eventually burn out so i made it removable. It slides down into two metal slots and the curled lower edge is just 3/8" below the burn tunnel roof.
Matt said his RMH 'Really took off' when he pushed red-hot clay tiles up under the heat riser, so i made a 1/4" plate that sits just above the bottom of the burn tunnel under the heat riser, figuring it will get really hot and help the convection process. It is angled up to round off the back bottom corner to ease the flow of hot gases up into the vertical heat riser. Also shown is my output port. It interfaces with the bottom of the drum and keeps vermiculite from sifting out the side of the brick wall.
To cap off the rear of the brick box and keep the loose vermiculite where it belongs, and because my burn tunnel didn't quite come up to the top of the bricks, i used 1/4" plate under the drum.
Bottom finished ready for a bit more vermiculite, some mortar, and then the top.
Completed. I tack welded the riser down to the 1/4" plate so it didn't shift. Wet vermiculite/ clay mix was poured in a disk shape between the plate and riser. That ring is because i made the riser a little tall. The drum will sit 1" down inside the ring on 6 tabs, that will place the flat top of the drum 2" above the top of the 6" center of the heat riser. The shiny tubes sticking up off the heat riser will temporarily support the barbecue grill experiment, before the whole thing is transported out to my friend's house for installation as a furnace.
Wood burning merrily in the feed chamber. I was soo relieved it worked as planned.
Barbecue grill attachment sits down around the heat riser, with (3) 2"x4" holes on the bottom of that 55 gallon drum section to allow it to breathe...and to allow it to fit closely down around the heat riser while still allowing the 3 spacer tubes to fit up into the grill to support it. Two pieces of expanded steel mesh hold lava rock between the top of the heat riser and the food.
I grilled some chuck steak last night. A little drier than usual but still juicy and sooo delicious. It's very nice to be able to use sticks and non-treated lumber instead of store-bought charcoal or propane. My retired Marine friend Ron was by this evening, and was Very surprised that when the RMH is going there is only clear hot gas escaping the top of the heat riser, no visible smoke. We barbecued some chicken (I've never barbecued chicken before in my life) and the magnetic thermostat on top the old Weber grill lid usually read 300-350°F. I left it on too long and dried it out too much. The meat inside was really tender though. Wednesday night i'll do 20 thighs, and use a different recipe.
Yay!! Success!!
Darrell "Jake" Jacob, Oddmar on all the forums, KC9PZN to all you amateurs.