Smoke rolls out load door - any advice?

I'm going to try to replace all the 6" pipe like Greg suggests, and leave the 6" collar for now. I have not measured the draft, but can do that anytime. I know from "feel" that it must be OK, but I guess I should live and die by the numbers. When I get to it, I'll post back. Guess I should do it before I change the pipe. But like Berlin says, I may have a good draft reading, just not enough volume.

My chimney is actually probably on the short side. If I make it taller, it will be very difficult to clean, as my roof pitch is 6/12. Right now, I think I can stand on the roof and sweep it. I might still be able to clean it if I add another 30" or 36" section (which I have laying around). As it is now, it's probably 10' long, but the top is about 18' off the ground.

And yes - codes and inspections are pretty lax in WY. But I'm comfortable with the old triple-wall pipe in my garage. The price was right.

Steinke

Just an update - I removed the 2' section of 6" pipe and installed all 8". The only thing left of the 6" is the stove collar. It now seems to work great. No smoke out the door at all. I forgot to check the draft before I made the change, but from my trained "ear" and the way the wood fires rumbled, I'm sure I had good draft then. I hooked a manometer up after the change, and I can achieve 0.08" of draft with a roaring wood fire. Even with no fire and a cold stove in the morning, the draft meter read 0.01" (it also read 0 when I unhooked it, so it was calibrated). Not sure how things will change when burning coal, but my chimney appears to be capable of good draft.

I added the tee for a possible future barometric damper, though I'm not sure I can use one with a bit. handfed. I'd sure like one, as I know I sent major heat up the stack even with a 6" chimney. If not, the tee will still be good for inspecting the soot buildup though.

So once again, Berlin had it right all along. A post of his above from about 2 years ago pretty much said I needed an 8" chimney in the house. I couldn't manage that in the house, but once I installed the stoker in the house, and moved the handfed to the garage with all 8", all smoke problems have ceased.

Anxious to try some coal in it, but all I have is stoker coal right now. Thanks for all the replies. Remember - go 8" pipe for a bituminous handfed.