Weber got it right for the WSM. However, if I’m using a 22.5 grill lid, it is a different story. On the WSM, the lid fits inside an outer lip on the center barrel section causing the grease to run on the inside as Hoss mentioned. On the grill, the outer lip is on the lid which sits outside of the drum diameter. This causes the grease to run down the outside of the drum.
Hoss is on to something though. Has anybody fabricated an outer lip on the drum? I can’t think of an easy way to do it. Grease gutter?
White Sox UDS, Black UDS, Weber OTG and Performer, Orange Thermapen