I still haven't had time to finish but here's another picture.
The riser is made of 18 or 20 guage steel with a slight taper to friction fit the trash can.
All the rest just follows the standard Phil Thien separator plans.
Due to poor cutting, there's a gap where the baffle should meet the inside of the riser that will have to be taped. (Or, I'll cut that part again and try to do better.) After that, caulking the seams should finish it.