Stack Fire #4

[kennyp2339]

I have got to learn to read better lol

 

[BigFir]

I have got to learn to read better lol

Haha, no sweat.

Be sure when you clean it, that any glaze comes off, if not I would replace the pipes.(easier than getting the **** off). Then burn hot baby!

 

[velvetfoot]

I've been burning the stove at the lower range of 'safe' at about 450f (or less) on the top and 300f (or less) 18" above the stove on the flue pipe.

That doesn't seem too high to me. Plus, the lower section is single wall, so that 300 is....300.

 

[ddahlgren]

How big are the splits? The larger they are the longer to season. If you have a bunch of rounds that were not split because small they take forever in my experience.

 

[begreen]

I just got a moisture meter today from Amazon and my boiler-room dried spruce tests at 14%. Other seasoned wood in my workshop close to my Earthstove tests at 15%

Just to verify, was the wood resplit first so that the test could be done on the freshly split face of wood?

 

[kodpvd]

Ok, an update...

First, I feel a little like "The Boy Who Cried Wolf"... The stack fire that I may have had, may not have been... After talking a little time off for the holidays and waiting for better weather, I was able to brush out the chimney/stack. I didn't get very much material out of stove, which was a little surprising. Feeling somewhat confident that I was in the clear, I built another fire in the stove on Monday. Interesting enough, I had another 'stack fire' in the upper level of the stack, nearly the same place as before... I can put my hand on the double-wall stack below and above the location, but at that level, it's HOT!!

With all this evidence in hand, my theory is that I'm getting secondary combustion at this particular location inside the stack. That sounds totally absurd, but it seems plausible... I'm still not getting good secondary combustion in the burn chamber. I still need to get the fire hotter and keep the secondaries going.

I am burning VERY dry wood. I measured 11% from split splits that have been sitting in the boiler room for the last few weeks.

Am I crazy, or is this possible?

 

[Poindexter]

Ok, an update...

First, I feel a little like "The Boy Who Cried Wolf"... The stack fire that I may have had, may not have been... After talking a little time off for the holidays and waiting for better weather, I was able to brush out the chimney/stack. I didn't get very much material out of stove, which was a little surprising.

What color and fine-ness of powder did you get out? I am running all spruce up here, I am accustomed to grey-brown cornmeal sized pieces with a few flecks of hard shiny black.

After my chimney cap caught on fire I got out some flat grey like talcum powder sized, with no shiny black bits in it.

Feeling somewhat confident that I was in the clear, I built another fire in the stove on Monday. Interesting enough, I had another 'stack fire' in the upper level of the stack, nearly the same place as before... I can put my hand on the double-wall stack below and above the location, but at that level, it's HOT!!

All good. Begreen has signed off on your observed temps, no need to second guess him. You have an infrared thermometer. How wide is the hot section, and how hot is HOT!!?

With all this evidence in hand, my theory is that I'm getting secondary combustion at this particular location inside the stack. That sounds totally absurd, but it seems plausible... I'm still not getting good secondary combustion in the burn chamber. I still need to get the fire hotter and keep the secondaries going.

I anticipate you might be getting secondary combustion somewhere between the burning wood and the hottest part of the pipe. For a good secondary burn in a not catalytic stove you need and oxygen rich environment, high heat and significant turbulence so the excess oxygen and unburnt smoke can clang together in a hot collision. Need more data.

I am burning VERY dry wood. I measured 11% from split splits that have been sitting in the boiler room for the last few weeks.

Am I crazy, or is this possible?

It's possible, but I think unlikely, that your spruce, on Kodiak, in one summer, is down to 11% all the way through. Try splitting a couple splits open to measure the MC in the "middle" of a few of your current splits. One of the foresters in Fairbanks did a stint in Kodiak before he came up here. I have never heard him speak about firewood in public without talking about how easy we have it in the interior compared to trying to get cord wood dry on Kodiak. Your air is essentially blowing salt water with some oxygen molecules in it to hear him tell it.

One thing you might try that I haven't seen suggested here yet is to burn half loads of wood at wide open throttle. That might be a solution that both keeps your flue clean and doesn't roast your wife out. Just a half load in the AM and a half load in the PM for a couple days...

Best wishes.

 

[Easy Livin’ 3000]

View attachment 191102 View attachment 191103
Here's a couple photos of the install...

Beautiful place you have there. Man, you are living the dream, getting a woman to move up there to Kodiak with you. Also, sounds like you have a very well insulated house as warm as you are getting it, I'm jealous of that. Now if you can just not burn the place down! Good luck to you figuring this out, it would be a shame not to be able to heat with your local resource. I don't have anything to add, many of the resident sages have already weighed in, just admiring your sitiation. Any chance you could post some additional pictures of your place and views around your place?

 

[bholler]

With all this evidence in hand, my theory is that I'm getting secondary combustion at this particular location inside the stack. That sounds totally absurd, but it seems plausible...

I honestly dont know that that would be possible without some air being introduced at that point. But regardless it would still be considered a chimney fire because you would at that point have flames in the chimney. It would still be dangerous and could easily result in over heating of the pipe at that point. And as far as not having much material in the pipe after your fire that is pretty common.

 

[kodpvd]

Bholler, I think you were spot on! After several days of busy-ness, I was able to light another fire tonight. After it was lit and the burn chamber was full of flames, I went up to the loft to check the stack. When I did, I also looked down the single-wall stack and saw flames between some joints. I immediately got the caulking gun with the high temp mortar and sealed the joints. I think air was infiltrating in the seams and causing the secondary combustion up higher. I'd like to change the title of the thread from "Stack Fire #4" to "Secondary Burn MIA".


Sent from my iPhone using Tapatalk

 

[jetsam]

Your flue is hot enough for secondary combustion to happen halfway up, which means the flue is at least 1100°F in the middle?

So much unburned material is being released from the stove that this is occurring?

I would not burn that stove.

 

[osagebow]

As an aside, don't be shy about showing your wife the posts on how to properly run the stove at hotter temps. Mine was terrified of stoves in general (even pellets) and operating temps before I showed her I had done my due diligence with the experts here. She now enthusiastically gets the stove up to temp so we can use our catalyst.
For some reason, she believes experts on certain subjects more than me.

 

[Elciteeve]

Nice place, and great looking stove! Is it just me or does that door open really close to what seems to be carpet?

 

[bholler]

I'd like to change the title of the thread from "Stack Fire #4" to "Secondary Burn MIA".

It would still be a chimney fire regardless. And if your stack temps are high enough to facilitate secondary combustion you have problems anyway.

 

[enigmablaze]

As a slightly hesitant wife myself of a guy wanting to take the stove plunge, this thread is a little terrifying. I was under the impression chimney fires were super rare. Kodpvd, have you tried burning it again since your last post?

 

[bholler]

I was under the impression chimney fires were super rare.

Nope not rare at all. But if you burn good wood correctly and have a good setup the risk of a chimney fire is pretty low and the risk of that chimney fire causing a house fire is very very low..

 

[kennyp2339]

I've been burning for 5 years, never had an issue, dry wood seasoned for 2 yrs minimum coupled with 2 chimney cleanings a year keep my mind at ease.
I'm also a fire fighter so I take care to be very fire conscious and safe, you treat it with respect you won't have anything to worry about

 

[rwhite]

What is the length of your total chimney? Looks like 23' or so interior, how much is exterior? I didn't read back through all the posts but do you have a damper? Could the possibilty exist that you have a huge vacuum sitting on top of your stove?

Edit: I see you estimated 14' interior. I count what looks like 5 sections of 4' and 1@3'. Even if they were 3ft'rs and a two it would seem you have at least 18' interior.

 

[kodpvd]

rwhite,
The chimney is 2 - 2' sections of single wall, a drip-less adapter w/ 1' showing, 4 - 3' sections of Metalbestos double-wall, 1 Metalbestos Roof-Jack (2'), 1- 3' section of Metalbestos (exterior) for a total of 4' + 1' + 12' + 2' + 3' = 22'.

enigmablaze,
Yes, I've burned it a little this week and this weekend its going steady as the temps are down in the 20's.

Elciteeve,
Yes, I don't have much of a hearth in front of the stove. We're really careful when loading. It was better with the old BlazeKing Princess, where the door would come down in front of the stove.

Thanks all for responding!