unburnt chunks

[dave7965]

I hope someone can help me. I'm burning some oak which was split in April and seasoned through the summer. It fires up right away on hot coals and secrets no moisture and by all accounts appears dry and good to burn. My "problem" is that the wood breaks up into red hot chunks as it burns and eventually it piles up so high that I can barely fit any additional wood into the stove. This causes the stove to not burn as hot as I would like, so every few days I shovel out large amounts of black chunks which is extremely inefficient. Last night I kept the stove's airflow all the way open to see how far down this heap of coals would go down. The result is that it did burn down quite a bit but the house is cold now. Other wood I've burnt goes right down to gray ash. What's up here ?

 

[LLigetfa]

I say your wood is not as dry as you think.

 

[SolarAndWood]

The burn down trick works better if there isn't a whole lot of fuel in there to begin with and you do it before every reload. Once it piles up, you need something like pine to throw on top to get it to both burn down and produce heat.

 

[Battenkiller]

Folks often refer to woods like oak, hickory and locust as "coaling" woods because they exhibit that property. I like to mix my wood to avoid that. I burn lots of cherry, and since that doesn't form big coals, it is a good one to toss on top of a big coal bed. In general, the denser the wood is, the slower it burns and the more coaling tendency there is. But there lots of BTUs in those woods, so getting the right mix is the secret to getting good heat out of your stove. Throwing split after split of oak on top of a coal bed, eventually the box has nothing but coals in it. Air can't get through it, so it just sits there and doesn't give any heat. If your stove was a forge, you'd just force more air in, but a stove relies on draft to suck air in, so as the flames die, the flue cools and less air comes in, which further cools the flue.... you get the picture.


Wood has a greater tendency to form coals the less seasoned it is, so I agree that your wood is probably not as dry inside as you think. Oak needs lots of conditioning time to become a prime firewood. It's not just dryness that make a wood burn well. Constant exposure to the elements will leave it deeply cracked, which helps it burn faster. Even fully dried wood seems to burn much better after it has had been abused by a few seasonal swings. I buy my wood in the fall, but I don't burn it all then. I pull out the all the denser stuff and stack it separately. I leave it in a sunny location to season for the next year, and it stays uncovered until the next fall. Getting wet and dry over and over all summer long really helps to condition dense woods like oak for the stove. At least that is my experience.

Also, make sure that it is all coals in there. Ash can easily build up unnoticed under a coal bed that is too big and hot to deal with. I've been surprised to find massive amounts of dense ash under not as many coals as it looked like.

 

[Valhalla]

Keep those chunks aka coals! Reburn them
for more btus. Remove only the ash.
My ashes go in the garden and on the compost
pile. Everything is used.

 

[Todd]

What kind of stove and chimney setup? Could be a draft problem as well?

 

[basswidow]

When you start noticing the chunks - open up your air flow and get them glowing orange. Let it ride like this until they reduce to ash. They'll burn down. There's still btu's in those chunks.

 

[fire_man]

Folks often refer to woods like oak, hickory and locust as "coaling" woods because they exhibit that property. I like to mix my wood to avoid that. I burn lots of cherry, and since that doesn't form big coals, it is a good one to toss on top of a big coal bed. In general, the denser the wood is, the slower it burns and the more coaling tendency there is. But there lots of BTUs in those woods, so getting the right mix is the secret to getting good heat out of your stove. Throwing split after split of oak on top of a coal bed, eventually the box has nothing but coals in it. Air can't get through it, so it just sits there and doesn't give any heat. If your stove was a forge, you'd just force more air in, but a stove relies on draft to suck air in, so as the flames die, the flue cools and less air comes in, which further cools the flue.... you get the picture.


Wood has a greater tendency to form coals the less seasoned it is, so I agree that your wood is probably not as dry inside as you think. Oak needs lots of conditioning time to become a prime firewood. It's not just dryness that make a wood burn well. Constant exposure to the elements will leave it deeply cracked, which helps it burn faster. Even fully dried wood seems to burn much better after it has had been abused by a few seasonal swings. I buy my wood in the fall, but I don't burn it all then. I pull out the all the denser stuff and stack it separately. I leave it in a sunny location to season for the next year, and it stays uncovered until the next fall. Getting wet and dry over and over all summer long really helps to condition dense woods like oak for the stove. At least that is my experience.

Also, make sure that it is all coals in there. Ash can easily build up unnoticed under a coal bed that is too big and hot to deal with. I've been surprised to find massive amounts of dense ash under not as many coals as it looked like.

These were three great points, Battenkiller. I split and stacked some oak in July of 2008 and tested it today (re-splits) and it PEGGED my moisture meter at 34%! You could smell that it was not seasoned. I re-split it smaller and am hoping for dryer wood next year. This was an awful drying season in the east.

 

[dave7965]

just dont have room in my yard to season wood for 2 years..wish I did..and I refuse to pay $200 for a seasoned cord...cheap green that I can season myself. I like the idea of burning pine on top while chunks burn down
So is it safe to say that burning pine in a stove is not a bad thing ?

 

[fire_man]

I was brought up on the east coast to believe burning pine was the worst thing you could do. But from what I've read on this site the Western boys burn it all the time cause that's all those poor guys have (mostly). And from what I can tell they are still around to talk about it. I want to give some pine a try!

 

[Battenkiller]

I split and stacked some oak in July of 2008 and tested it today (re-splits) and it PEGGED my moisture meter at 34%! You could smell that it was not seasoned. I re-split it smaller and am hoping for dryer wood next year. This was an awful drying season in the east.

Terrible drying season. Thankfully, we have all this frigid weather now, so at least it will freeze-dry to 20% in a couple days. ;-P

 

[Valhalla]

Trying to burn any improperly seasoned fuel will
result in reduced heat output and higher than normal
moisture condensation in the flue, in the form
of creosote. This is why we continually work
to season our wood fuel.

 

[DBoon]

Trying to burn pine is not bad, but burning unseasoned wet pine is not good. Try cutting up some pallets to use to burn down your coals.