Jekyll and Hyde draft

[DTrain]

So it's still not full on cold here yet but I've been playing with different loading, adjusting air and what not. I've been getting ok results on cold start from doing a small loads ( two small splits of really dry pine, and three small splits of oak). I can run the stove up to 350/400 fairly quick and add my medium size oak splits (3 or 4) get air shut down and get to 525/550, never really any higher. With my flue temps dropping as I turn down the air. . I have an 8x10 tile flue. Next season hopefully I will have a liner in. So my draft isn't what it probably could be. I have nice over night burns of 6-8 hour burns with good coal bed and stove is still to hot to touch in morning.

I've tried some large splits and filled it up good on a nice coal bed (low flue temps showing) and get the thing rocking up to say 500/525, and it never gets much above that, but as I shut the air down my flue temps don't drop they stay up near the red zone on the dial, and the stove is sucking hard (audible) my secondaries are going wild, seems the big loads die out much quicker than anticipated and I don't get much more heat out of a load like that.

What's up with that?

 

[BrotherBart]

If you are spreading the coal bed and loading the big ones on top of a hot coal bed they all off gas at once. That off gassing is a third of your heat value in the wood with the fiber burning stage another third or so and the coal burn the other third of the heat in the wood. And most of your heat it going up the pipe in the off gassing stage with the loading on top of hot coals.

Dragging the coals to the front and letting it burn back through the load will get some what the results you are getting from the cold start loads, or better. Longer more even burns.

 

[DTrain]

Ok so I have an abundance of gases burning all at once and this is causing the stove to kinda run away, or as much as a stove can run away with the air shut all the way down? Is that right?

I am spreading the coals and making the tunnel. Next time I'll try getting the coals to the front.

My stove never seems to get above 575. I hear folks speaking of much higher temps. My guess is I am not reaching such temps perhaps because of the lack of a liner, combined with only 20 month seasoned oak. I read 36 month is best.

 

[Nick Mystic]

Where are you recording your stove temperatures on your Oslo? On my F 600 the manual calls for readings on one the corners on the top. When I hit various spots on the stove with my IR thermometer I see that readings on the top corners can be as much as 200 F lower than a reading on the center of the top. So, where are your temps coming from so we can interpret your data accurately?

 

[DTrain]

Front right corner on top plate. As directed in manual.

 

[DTrain]

Just checked things out. Of the two large splits and 2 medium splits I have 1 intact split burning and a third of another. Everything else fell apart when tapped. Started on a bed of coals, stove read 300ish. This would have been around 7:45pm and it is now 10:20. Stove went up to 550 and is now at 425 with flue reading midway thru safe burn temp zone on dial. Not what I was hoping for!

 

[DTrain]

Ok, and I just moved my dial to center of top plate and literally watched the dial run up over 500. Now I'm confused. Where should I be measuring?

 

[firefighterjake]

Ok, and I just moved my dial to center of top plate and literally watched the dial run up over 500. Now I'm confused. Where should I be measuring?

According to my manual . . . any one of the four corners on the top. Not the center plate . . . that will consistently show hotter temps.

 

[DTrain]

If you are spreading the coal bed and loading the big ones on top of a hot coal bed they all off gas at once. That off gassing is a third of your heat value in the wood with the fiber burning stage another third or so and the coal burn the other third of the heat in the wood. And most of your heat it going up the pipe in the off gassing stage with the loading on top of hot coals.

Dragging the coals to the front and letting it burn back through the load will get some what the results you are getting from the cold start loads, or better. Longer more even burns.

Yep, pushing the coals to the front and piling the wood behind that has worked for me in fires since. Bigger stuff to the back and some smaller stuff on the coals to get it going quick.

How about reloads when there are quite a lot of coals still there. Any tips?

 

[BrotherBart]

Coals to the front and a small split on top with the air 1/2 or full open. The flaming split keeps the stove temp up while burning the coals down under it.