Total creosote clog and CHIMNEY FIRE: THREE WEEKS after brand-new install?!

[Lumber-Jack]

Thats the point. Just because you can't see it working doesn't mean that it is not working.

Perhaps that is your initial point, but my point is what is the definition of "working"?
If all the tubes are doing is allowing additional fresh air in to the chimney exhaust then by emission control standards you may be reducing the particulate count per given volume of emission (out the top of the chimney), but you are doing nothing to reduce the total particulate count per volume of wood burned, or burn of any un-burned fuel, which really should be our goal.
Pumping air into the exhaust to satisfy emission standards is an old automotive industry trick.
If you define working as simply meeting EPA emission standards, then perhaps the tubes are "working" effectively (without visible flames), but if working means effectively burning off some of the escaping un-burned fuel, then flames are a requirement.

 

[Jags]

but if working means effectively burning off some of the escaping un-burned fuel, then flames are a requirement.

I disagree. Consuming particulate matter doesn't have to require visible flame. If enough is present - sure you will have flames and ghost flames and a rolling river at the top of the box, but just because you don't see those types of reactions doesn't mean that the tubes aren't picking off those particulates. Its the whole smoke/no smoke discussion.

 

[Dune]

You said "seasoned" pine. I just wondering with this being a new install, how long have you prepared for the stove by seasoning wood. Or did u get the pine from someone who said it was "seasoned". My guess is the pine is green, that coupled with an unnecessary damper in the stove pipe caused a serious problem (to say the least). Pine has a bad rep. around here because if you burn it to green your going to have trouble eventually. Burning hardwoods green is bad, but pine is way worse; and can lead to a big pile of ashes where your house use to be.

Nope, green oak produces way more creosote than green pine.
The OP made clear that in spite of thinking he wasn't smouldering, he was, with the stove control and the chimney damper set at minimum.

 

[Dune]

i find it amusing that the op hasn't responded yet and you guys keep theorizing i am curious to see what they have to say

Not really, the OP provided more than enough info.

 

[Plow Boy]

Nope, green oak produces way more creosote than green pine

sappy pine burns alot hotter than green hardwood and will start a cresote fire in your chimney. My grandpa burned green pine slabs and we had us a big fire one evening

 

[Dune]

Perhaps that is your initial point, but my point is what is the definition of "working"?
If all the tubes are doing is allowing additional fresh air in to the chimney exhaust then by emission control standards you may be reducing the particulate count per given volume of emission (out the top of the chimney), but you are doing nothing to reduce the total particulate count per volume of wood burned, or burn of any un-burned fuel, which really should be our goal.
Pumping air into the exhaust to satisfy emission standards is an old automotive industry trick.
If you define working as simply meeting EPA emission standards, then perhaps the tubes are "working" effectively (without visible flames), but if working means effectively burning off some of the escaping un-burned fuel, then flames are a requirement.

If the fire is hot enough, then excess outgassed volatiles will burn due to the input of air. If it is simply diluting the output then the fire wasn't hot enough.

 

[Dune]

sappy pine burns alot hotter than green hardwood and will start a cresote fire in your chimney. My grandpa burned green pine slabs and we had us a big fire one evening

Yes, the volatiles are burning, pine burns hotter than Oak regardless.
Your Grandpa's stove wasn't an a Quadra fire, or he couldn't have burned green wood.

Your statement is an encapsulation of the pine myth.

 

[Lumber-Jack]

If the fire is hot enough, then excess outgassed volatiles will burn due to the input of air. If it is simply diluting the output then the fire wasn't hot enough.

True, and that is why when the stove is cool at the beginning of the burn cycle we don't see secondary combustion flames, but as the stove get hotter is when we generally start to see them, and then when the stove cools down again the secondary combustion begins to extinguish and we no longer see any visible secondary combustion.

 

[Jags]

Randy - your secondaries visually die out long before all the particulates are burned up. If the tubes are still at the required temps, they are still working to pick off the stuff floating by them. It just isn't doing it with a big light show to prove it.

Anyhow - we are getting side tracked and I would like to keep this one on its tracks. The OP needs help.

 

[DougA]

I would like to keep this one on its tracks. The OP needs help.

Yup. Good topic for another thread though.

 

[branchburner]

sappy pine burns alot hotter than green hardwood and will start a cresote fire in your chimney.

Perhaps unknowingly, you are perpetuating the pine myth. Yes, sappy pine burns hotter than green hardwood and will START a creosote fire. So the very hot fire, regardless of wood species, will START the fire by lighting off the pre-existing buildup. But where did the creosote buildup come from? By previously burning green wood, regardless of wood species, at cooler flue temps.

So by your own analysis, if green pine burns hotter, then green oak must burn cooler. If green oak burns cooler, then IT is the more likely cause of the prior excess buildup. WHATEVER wood you burn, it is the smoky, smoldering fire that causes the creosote, and the hotter fire that lights it off. People blame the hot-burning pine because it is the match that lights the chimney, but the fuel that is already IN the chimney comes from whatever was cool-burned before the pine (which may or may not itself be pine). By blaming the igniting pine, people are shooting the messenger.

 

[Toba Guy]

Hello Folks,

So tried another test-burn, with the poplar this time. The results just have me confused.

Didn't use any scrap, just bark and newspaper as kindling, normal sized splits as the fuel. Lit the paper, noticed the extreme lack of draw, remembered that the window wasn't open, opened it, draw improved but only somewhat.

Got a lazer-thermometer, measured the upper-left corner of the griddle.

Even at 125 F no black smoke coming from the flue, just some grey.

Took 25 minutes for the stove to get up to 400 F, during which time the flames got smaller and smaller.

No smoke, only "heat-mirage" off the flue at this temp.

Turned off the ignition-air (pulled back out all the way).

Stove temp only got up to 460 / 490 F, flames diminished further and draw poor (window next to the stove wide open throughout, primary air all the way to the left throughout).

So where does this leave us now?

Black smoke from the pine but not the poplar means there is something off with the pine?

Why did the draw get so awful with the poplar? (It is snowing with heavy-low clouds today, is it an atmospheric pressure issue exacerbating something else?)

Insights? Thoughts?

 

[Toba Guy]

Your scrap is untreated wood, right?

For sure.

I've got gardens all around the house, no way I'd be burning pressure-treated.

 

[Toba Guy]

Sometimes light grey smoke can appear black depending upon the sky conditions you are viewing it against. I agree, if it was indeed black, that is troubling.

Seems like it was actually black yesterday with the pine. Similar sky today (overcast and grey), and smoke didn't appear at all the same when burning the poplar.

 

[jatoxico]

Did you put the MM on the poplar? Sounds like not fully seasoned poplar but that's more like what is supposed to be like. It's encouraging that you were able to run w/o smoke and those temps seem more appropriate and show you have some control over the stove. If you have more, a mix of pine and poplar may give a you what you want.

 

[begreen]

Draft is weak. Can you describe the flue system from stove to the chimney cap? How tall, any bends? All metal or??

I'm not surprised about the poplar, it has low btu content. Good for shoulder season burning though.

 

[Plow Boy]

Perhaps unknowingly, you are perpetuating the pine myth. Yes, sappy pine burns hotter than green hardwood and will START a creosote fire. So the very hot fire, regardless of wood species, will START the fire by lighting off the pre-existing buildup. But where did the creosote buildup come from? By previously burning green wood, regardless of wood species, at cooler flue temps.

So by your own analysis, if green pine burns hotter, then green oak must burn cooler. If green oak burns cooler, then IT is the more likely cause of the prior excess buildup. WHATEVER wood you burn, it is the smoky, smoldering fire that causes the creosote, and the hotter fire that lights it off. People blame the hot-burning pine because it is the match that lights the chimney, but the fuel that is already IN the chimney comes from whatever was cool-burned before the pine (which may or may not itself be pine). By blaming the igniting pine, people are shooting the messenger.

I agree, I burn pine to this day(seasoned a year). and yes the issue is burning green wood and then burning something that got the fire hot enough to light the cresote.

 

[jatoxico]

I'm taking the weak draft with a grain of salt at the moment. Just because the load of poplar didn't take off like a load of super dry kindling pine doesn't mean the draft is weak. Are you getting smoke in the house?

 

[Jags]

Hmmmm...
No black smoke = good. Not being able to get above 490F = bad. You may find that stove temps will INCREASE as you shut the primary down on an established fire. It allows heat to be retained in the stove instead of getting flushed up the stove pipe. Heavy, wet air can affect draft.

With your description of flames getting smaller and smaller it suggests that you may have another fuel issue. It sounds like the dry exterior was burning off exposing the wetter interior wood. As suggested above, maybe a combo of the fuel is the ticket.

The issue of draft is tricky. With the scraps it was raging. With the cordwood it appears slow. Wondering out loud if this is actually a "draft" issue or a fuel issue.

 

[Jacyte]

This entire issue sounds very similar to the behavior of my stove when burning 3-4 year split but stacked too tight red oak. The wood was very dry and nice at the top of the stacks and the ends but as I reached the middle it smoldered and created a ton of creosote. It would flame up nice early then die down to barely burning within 30 mins. It would struggle to get the cats to active range and even a long burn would fail to evaporate enough water to dry it before the bulk of the wood was gone. I now have even wetter wood but the cores are dry while the exterior is wet. This wood takes a few minutes to light but once it flames it does well.

 

[Jags]

I would try the test one more time. I would try it with 25% of the scrap material and 75% of cord wood. Load the scraps on the bottom and stack cord wood on top. Light from bottom.
At 450F shut down the primary to 2/3rds closed and monitor. If you see stove temps starting to rise (this can take an additional 10-15 min), close primary air down accordingly, BUT allow for stove top to rise to ~600F. If this is successful check your stack for smoke (I'll bet you a shiny nickle there won't be any). If it DOESN'T rise we have a draft/fuel issue for sure.

 

[saskwoodburner]

I'm taking the weak draft with a grain of salt at the moment. Just because the load of poplar didn't take off like a load of super dry kindling pine doesn't mean the draft is weak. Are you getting smoke in the house?

I'm thinking the poplar he's tried isn't quite there, moisture wise. I've made all my mistakes (maybe more to come yet!) since October and while I'm no expert on poplar, if it was dry enough, he should have nailed the temp out of the park. I'm a happy peasant burning poplar, and while you never get a long burn time, you sure can generate some heat. And with poplar that's not quite there, it seems to need a lot more air to keep going, and never hits the nice high temps.

 

[branchburner]

As suggested above, maybe a combo of the fuel is the ticket.

Agree, it's hard to figure out what's going on just on the basis of one poplar load. I burn a fair amount of poplar, and depending on source if it's not borderline green it often ends up being borderline punky with lower heat output... sometimes it burns really great for me, but sometimes not.

Maybe try a few loads where both species AND sizes are mixed. No need to avoid a healthy amount of kindling or smaller stuff on startup, just don't make that the entire load (and don't use much if any on reload).

A lot of my loads end of being a combo of pine, poplar and various hardwoods, with a little 1-3" branch wood underneath the bigger splits to help them along. A few very big splits on top of just paper and bark wouldn't generally cut it in my stove for a nice hot fire, especially if there is no underlying coal bed.

 

[branchburner]

And with poplar that's not quite there, it seems to need a lot more air to keep going, and never hits the nice high temps.

That's how I started this season, so I've left those stacks for next year. Last year I had some standing dead poplar that was a little too far gone, dry though starting to get punky. But two years ago I had perfect poplar, burnt easy, hot and quick, and coaled up very nicely (unlike my white pine).

Most people I know around here tend to treat poplar like pine, not enough BTU per volume to bother with. More free tree left for me.

 

[saskwoodburner]

Most people I know around here tend to treat poplar like pine, not enough BTU per volume to bother with. More free tree left for me.

I feel the same way about free wood. Neighbor has a 80 acre chunk of land, about 1/3 is still trees, and he knows I like poplar. He tells me, take all you like. So I said deadfall or live.....he says take whatever you want, with a smile.

Well I hope the OP gets to the bottom of this problem.