That perfect primary/secondary air ratio setting!

[Dexter]

If we are really careful -- I mean borderline anal -- about adjusting the primary air on our stove as the fire matures, we get a different looking, and most efficient fire:

If the primary is open too far, the fire burns bright yellow and is consumed relatively quickly.

Shut a hot fire down abruptly, and you get the most spectacular -- but short lived -- result: You know...the spectoral blue wispy flames at the top. 'The "gas stove" appearance at the secondary burn tubes. This fire produces longer useful heat than when burning "wide open", but the wood is not well consumed.

Take a fully involved, well packed fire over 475 degrees (stove top), and close it ALMOST all the way, but play with the setting until it's just right, and something neat happens: The secondary tubes get so hot that they glow pretty brightly. The flames up top build downwards from the top, filling half the box. They are partly blue, but are mostly dim yellowish orange. The secondary is so involved that nothing reaches the tubes unignited, so there is no "gas stove" effect. But the tubes and firebricks stay so hot that they continue to radiate the wood with intense I.R. There's not enough oxygen at the wood for flame, but it is REALLY baked, and continues to "distill" in the hot gasses, releasing (wood alchohol?)and aeromatics, gradually, until it is powder. 'Built a large fire at 8:40pm and refueled at 6:00am and it lit-off easily -- all with lodgepole pine. (firelight 600 cb)

Regards!

 

[pen]

This cries for a picture! I want to see!

pen

 

[EddyKilowatt]

That sounds pretty neat. I've only ever gotten secondary flames while the "easy" volatiles are cooking out of the wood, for about the first one-third of the burn. Never got hot enough to pyrolize the charcoal (is that what you are describing?) and burn it all the way to powder.

I agree, pictures are a must.

Eddy

 

[fishinpa]

I think it cries for about a dozen!

 

[Dexter]

Pyrolize?... I don't know. I don't think it burns this way for more than a couple of hours or so. As the fire subsides, I assumed the secondary ceases and the "baked" wood gets enough air at the reduced setting for the coals to "glow" to ash.

Uh...I don't know how to post photos, but we do have a digital camera, so I'll read the blurb on this site and try to figure it out.

Regards,

Dexter

 

[kd460]

Dexter, if I may, that is an excellent discription! Thanks for posting it. KD

 

[captainjim04]

Hey, you really need to write a book...put me in for 1 copy please great post ...oh by the way...what happened next?

 

[WOODBUTCHER]

Yes, my Oslo rips perfectly with my draft control 75% closed.
I put up a streaming video link...check it out. Fully packed with hickory.... front draft control 75% closed.....stove top temp@600

(broken link removed)


WB

 

[begreen]

That's nice! I could feel the warmth coming from my monitor.

 

[SlyFerret]

Pretty cool, eh! It does have a different look to it. The texture of the flame almost makes it look like a blanket at times.

-SF

(Yeah, apparently, I'm one of the anal ones... hehe)

 

[tutu_sue]

That's a GREAT one for You Tube WB!

 

[Dexter]

woodbutcher:

Yes, that's very similar to my firelight's burn characteristics, with most of the burn at the top, but with just enough air to keep it from looking as blue. My best heat versus LOB looks like your video. (Cool video!)

Dexter

 

[Pagey]

I can mess around with the primary on my Endeavor and get this really intense secondary where I have flames pouring out the holes in the burn tubes (like the video), but additionally I get this huge secondary "wave" of flame that rolls across the top of the wood from the back of the stove to the front and washes up the glass from the bottom of the door to the top. It's a very wild looking fire, almost scary in a way to think you've got all that heat right there in your house. But it's amazing to watch! I've tried to capture it will my little rinky dink Kodak camera, but it's video quality simply can't capture it well at all.