Sooty stack

[MarkL]

Hi all,

We've done three boils so far this season, and my chimney is already full of soot and having trouble getting a good draw. I actually pulled the wood out of the firebox last night near the end of the boil because I was concerned about all the smoke that was leaking out of the stack at the seams. The stack in the shack is regular galvy. It goes out the wall through an insulated pipe, and the rest of the stack outside is insulated.

I'm going to scrub it out tonight, but I wonder why this is happening so early? Is it that I am burning softwood only?

I'm firing a half-pint and I have a damper installed in the first section of pipe out the back of the arch so I can try to keep the heat under the pan. I usually damper it about 1/3 after the wood is really burning hot. I burn with the front damper fully open.

Any thoughts or suggestions?

MarkL

[ericjeeper]

You are not burning it hot enough, or dry enough wood.

[Waynehere]

When I ran my HP, I didn't use a damper in the flu pipe, but controlled the draft from the front of the arch. There is just no way to keep the heat in the arch and make it boil hard. I usually had to open the door a crack to get a better draft. The slower you burn the wood, the more soot you are going to produce. Hotter is better.... You will use more wood though...

[bowhunter]

I wouldn't use a damper in the stack for a half pint. You need all the draft you can get. Control the air flow through the front. Also make sure you don't have a big gap in front of the grate for the air to bypass the grate. I closed this up with a couple of 1/2 brick and a piece of flat iron earlier in the season and it made a big difference. This will also give you a little better mixing in the grate and that should translate into faster and more complete combustion. As short as the pan is on the half pint you don't get very good heat transfer and most of the heat energy just goes out the stack. I have a half pint and have done 14 boils this year. I've resigned myself to burning a lot of wood if I want to maximize the boil rate. Good luck.

[MarkL]

Thanks for the feedback. I don't have any problems getting a ripping boil as long as the sap isn't too deep in the pan. The wood's nearly all dry, and burns pretty well.

I'll try closing the gap and using the arch damper only next time to see what happens. And I'll start saving $$ for the Smoky Lake drop flue pan I just read about...maybe next season!

[packrat]

Even wood heating stoves dont work good with a bend in the stove pipe. You need a straight up stack to get them to work right. Harold

[PerryW]

Even wood heating stoves dont work good with a bend in the stove pipe. You need a straight up stack to get them to work right. Harold

That could be the answer. I've been using my current stack for 20 years and have never cleaned it. No damper and straight up through the roof.

[MarkL]

Yep, that could be it too but changing that is not in the cards for this season, if at all...

[bowhunter]

If you could add a 2-3 feet section of stack to the vertical part, it will help overcome the elbow if you continue to have problems.

[maple flats]

You need to burn hotter. Split your wood fine and fuel more often, but don't fuel above about 8" from the pan. You will not get any smoke after the initial lighting gets going fully. The extra stack will also help. No damper and give it as much air as you can. Before I had high pressure air over and under the fire, I ran with my 6"x18" draft door full open (on a 3'x8' arch) No smoke, no soot, no creasote. My stack has never been cleaned and it looks clean inside after several years of operation.

[MarkL]

Definitely going to add a section to the stack. Thanks for the advice.