Congrats, Ben, on another job!
I have not used the half barrels myself, but it is a tried and true system.
How many barrels in a row were you thinking?
Matt told me that with an 8", you could have up to five.
As far as how much cob on top, 4" at the high point might be more than you want, 4" at the top means 6"+ on the low points.
I would start with 2"+ on the high point and see what your heat transfer is like.
If you were up north and this needed to burn longer, a 4" cob layer would be perfect.
When you cut your barrels, leave an inch or so on the ends to maintain the barrel curve.
13 acres in extreme rural Montana 100% off grid since 1983. Solar and micro hydro. Summer time piggy farmer. Restoring 2000-04 Subaru outbacks wagons for fun and a little profit. Not quite old enough to retire YET but closing on it fast... until then I must occasionally leave Paradise "home" and run large construction cranes on union job sites across the inland northwest. I make (Well try) A-2 A-2 cheese, I love cooking with my wood smoker for everything! Would not live anywhere else but rural Montana ! My wife Liz runs "Rocks by liz" a successful Etsy store and we have a summer booth at the Missoula peoples market. We currently breed and raise persian cats but are about to retire all the girls and let them be happy kittys for the remainder of their days.Oh and my biggest thing is... I LOVE MY RMH !
