Karl Meisenbach : In One Word, YES ! You just need to re-figure the Cross Sectional Area, The C.S.A., Everything will be a little smaller and you will use less of every thing except
Cob ! Don't get to far ahead of your self, have you a firm grasp on how you are going to burn out your barrel removing the paint on
the exterior at the same time ?
With using a 6'' pipe your C.S.A.s Will change, your
Feed Tube opening
should be 6''by 5'', with a C.S.A. of 30 sq. inches. The interior walls of your burn tunnel
will be 5''x6'' for a C.S.A. of 30 sq. inches, to transition to the full sized 6'' diameter Heat Riser with a C.S.A. of 28 sq. inches you will want a 5''x6'' exit with a C.S.A.again of 30 sq. inches, The very top of the Heat Riser should end 1.5'' to 2'' below the Inside of the top of the barrel, The outside wall of the Heat riser should end before touching the inside walls of the 55gal barrel leaving you a gap no smaller than 1.5'' all the way around !
The transitional area where the hot exhaust gases leave the bottom of the barrel should be very generous opening into a 10'' cavity above a generous
ash pit,
here the gases take a wide sweeping 90 degree turn Flowing past walls as smooth as sheetrock, and funneling down into the 6'' horizontal pipe receiver of the
Thermal Mass.
