All of a sudden, I'm getting smoke pouring out my chaff cleanout door. I think the chimney is clear, but I will confirm tonight. The only I did was run it really hot for 20 minutes to burn off some organics in the drum. Maybe I burned out the coffee resin around the door that was keeping it sealed!

When I close the door, I can fit a knife blade in between the door and the collector body around the hinge area. And ideas to seal it? I suppose I can take the door off and hammer it into shape, but the collector is in an inconvenient spot and I don't do tight spaces on the floor as well as I used to!

Maybe https://www.amazon.com/Lavalock-Nomex-g ... 2244&psc=1

That's the stuff I was going to recommend. The surface has to be impeccably clean however. The same kits are used to close up the gaps and air leaks on smokers like the larger Weber Smokey Mountain, which otherwise burns thru a ton of charcoal per cook. Sealing up the air leaks helps stabilize the otherwise runaway temps, but there's countless stories of the nomex failing because it didn't adhere and cure properly.

Thanks, Tom. I think I'll put it on the door. Easy enough to remove and do the work on the bench.