Hey I made this out of just a wine barrel and a couple of screws and it pretty cool
What you will need
Wine barrel, angle grinder, jig saw, orbital sander, sand paper 80-360, file/rasp
How to do this project
Create shape of your seat.
Mark, drill clearance hole, drill countersink hole and screw in to keep the barrels shape
Angle grind the rings that you haven’t screwed in and jig saw your shape
Sand and your done !!!