This seems to be the toughest step for DIY'ers trying to make a compost tumbler. Where can you find large plastic 55 gal. drums? My advice is to keep your eyes open when you're out and about. We've all seen them at some point, but never pay attention as to where or when. LOOK... you will find them. I planned on cutting the bottom off of one to make a door, but thought of a better idea so I could make two tumblers.