Rookie creosote question with pictures

[ce208b]

This is my second year burning using a model 74 Buck. This is the driest wood I have used yet. It is hardwood slabs split in April, no bark. The attached pictures show my creosote problem on the flue cap. The stove was letting a little smoke back into the room when I opened the door, so I went up to the cap to check for any obstruction. The cap was 70-80% blocked with creosote. When the stove is running during the day, it burns so cleanly that I don't see any smoke coming out the flue, just heat. At night, I load it up and choke it back to make it last, so I assume this is when I am accumulating creosote.

So, what is the trick to still have coals in the morning, but avoid the heavy creosote buildup? The stove doesn't use a cat but it has the secondary burning tubes that allow it to burn so clean. It only has an intake air control with no damper control.

Thanks for a great website.

John

 

[BrotherBart]

Get over choking it back to make it last. Make sure that there is a fire burning in that firebox. And I don't care what it is last April ain't making for good dry wood.

 

[begreen]

Does look like the wood is not quite ready to burn if it's gunking up the flue badly. Tell us a bit about the entire flue system from stove to cap. Maybe it's cooling down the flue gas too much? Do you have a thermometer on the stove or flue and if so, what temps are you running?

 

[burntime]

Definitely the wood is not ready... If the chimney is external it definitely needs to be insulated as well. That allows to choke it back more and still maintain temps...

 

[ce208b]

It is an uninsulated stainless liner on an internal wall brick chimney; with about ten feet sticking out above the roof. I have a magnetic thermometer on the side of the insert, not the flue, that stays at about 500-600 degrees all the time while burning.

 

[trailrated]

My cap looked like that today. I too was getting a little bit of smoke puffing back upon opening the stove's door. So I planned brushing the chimney today. Went out and looked for a poly brush.....none to be found, only steel. So I climbed up on the roof to have a look, sure enough cap was partially plugged. I cleaned it and checked the chimney. Gonna have to wait til I get a poly brush. Anyhow, my chimney and cap haven't been touched until today. Been burning since last winter, with last years wood being marginal. Only the last few feet could use a brushing. I have 10 feet of single wall pipe followed by 8 foot of SS insulated pipe. Its probably your wood causing your issue. Choking down your stove will build the creosote up quickly, if you want to continue doing it, just check your chimney more frequently.

 

[begreen]

That sounds like a good temp for the stove to be running at. Could be the wood, but it would be good to see if there are compounding factors. Is the flue collar tightly sealed to the liner start collar? How tall is the flue liner?

If it's not too difficult to get up there maybe check the temp of the flue top when the stove is running?

 

[bogydave]

When I had issues like in the pictures,
it was the wood.
Now I' burning some 2 yr old well seasoned wood, problem went away.

May have to burn hotter so the temps of the flu gasses stay vapor until out the top of the stack.
(but clean it before burning hotter, chimney fires are no fun) Watch it when burning, you may notice lots of steam
coming out the stack. Very hard to not have it condense & create creosote on the cap though.
Insulated chimney helps too, but if it's wet wood, you'll have to brush the pipe frequently, even if it is insulated.
(smokes drifts away for quit a long distance, steam dissipates in to the air with in a 100 ft or so)
A good burn, no smoke or steam. Looking at the chimney, can't tell I have a fire.

See if you can find some real dry wood & compare a burn cycle of each (the real dry vs what you've been burning)

 

[Todd]

You say you load her up and choke her back. How soon before you choke her back, do you let the load get rippin first? Might be cutting the air too soon, got to keep those secondaries going.

 

[Backwoods Savage]

Now remember to check that chimney and cap monthly! You might get along just fine by cleaning the cap once in a while but cleaning the chimney a bit less often. Still, check it. If it needs cleaning, do not put that off.

 

[jtb51b]

Do you have a blockoff plate top and bottom of that brick flue?

Jason

 

[Adios Pantalones]

Get it ripping well. Close air a little. Let the fire catch up (5-10 mins). Close a bit more, and so on. When it's darn near closed- you should still have secondary flames. If you don't- then it was either not hot enough or you have wet wood that you should roast a little longer with primary air before shutting down.

 

[Wood Heat Stoves]

very common for screened caps
every chimney is different, you might be using the stove perfectly( looks like dry flakes soot, not glazed)
is the chimney clean?

 

[Highbeam]

Looks pretty normal for this time of year, middle of the burning season. The real question, as has been asked, is what the rest of the flue looks like. If the rest of the flue only has a thin layer of powdery brown stuff on it then you are doing fine, clean the screen and keep going. If the rest of the flue is gooped up with a thick layer of black chunky or shiny accumulation then you need to sweep the chimney make a change. Thick layer is above 1/4"

You don't need to insulate the liner unless the original brick chimney is no longer up to code.

 

[Battenkiller]

This is the driest wood I have used yet. It is hardwood slabs split in April, no bark.

Wait... Debarked hardwood slabs you got from the mill? Like 3/4 -1" thick slab wood, cut and stacked way back in April? That stuff should be drier than Aunt Irma's a$$ by now, even oak.

I'm on board with letting it get more air, though. Slabs are not the thing to be choking the air down on, too much surface area making too much smoke for the amount of air you're feeding her. Next year try a mix of woods and gets some big splits for the overnight. They'll burn both slower and cleaner, so they'll make less smoke for a given unit of time. You'll also have the coals you are now missing in the AM. Big, dense wood is always the answer to that, not choking her down.

Even though I don't have a cap on my chimney, that looks like what I'd expect to see half way though the season burning that slab wood that way. Smoke goes up and hits that cold metal sitting out there in the open air, don't matter how hot it was when it left the top of the stack, some of it's got to condense onto the cap I would think.

 

[wood-fan-atic]

This is the driest wood I have used yet. It is hardwood slabs split in April, no bark.

Wait... Debarked hardwood slabs you got from the mill? Like 3/4 -1" thick slab wood, cut and stacked way back in April? That stuff should be drier than Aunt Irma's a$$ by now, even oak.

.......now THAT sounds pretty dry to me

 

[ce208b]

Thanks for all the responses, this website is great.

It is about 15 feet of liner that is not tightly sealed, just screwed together.

I probably am cutting the air too soon. I am going to try choking it back slowly and maintaining my secondaries. I'll try the idea of larger pieces at night.

I haven't checked inside the pipe, just the top. I'll run the brush down it and see what I get.

I don't have a blockoff plate at the bottom, just fiberglass insulation stuffed in the top of the chimney with a stainless cap/cover.

The wood is sawmill slab hardwood but it is about 4" square, so it may need more drying.

 

[littlesmokey]

How did you stack your wood. If you did not "sticker" it, you basically are drying at the ends only. %Think of it as one thick split, no air , no dry. I'd check the moisture readings on a few middle stack splits. If you don't have a meter, take a few boards to the lumber yard and ask if they'd give them a quick check.

The soot and ash look dry, so that is a plus, and if it has taken all season to build to this state, that's good too. Like other have said, check farther down the line, if you have a cleanout tee, pull it and see what's there.

Let us know what's up from here.