Your Secondary Burn Times

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Dec 5, 2007
145
South Coast, MA
I've read a lot on this site about how to achieve a good secondary burn, but I haven't seen a lot relating to how long the secondary burn lasts. I've read some posts where they get the secondary burn for 15-20 seconds at a time as the fire jumps up to ignite it also read people getting 1-2 hr secondary burns. I'm new to burning and stoves in general and the best I can seem to do is get a good 30-40 minute secondary burn, with lots of flames both on the wood and above it coming out the burn tubes. Air control closed half way... close it any more and I lose the flames on the wood, open it anymore and too much air gets in and kills the secondary burn. After that 40 mins or so the wood is starting to get pretty chared and maybe it stops gasification (I'm guessing that is why.)

If people do achieve secondary burns for 1-2 hours how is that done? Bigger splits?

So lets hear what your average secondary burn times are...

Thanks
 
On my Dutchwest, bigger splits do help getting longer secondary burns, I make em phone book sized and can get 2 into the box and get up to 3 good solid hours on secondary burn as long as I get a good char on the wood before shutting down the air control to around 25% or less.. Also red/white oak gives a lot more time vice pine or ash..

T
 
When I load the box full, at least 2-3 hours
 
If you close down that air more do the secondaies stop too or only on the logs??, If the secondaires keep rolling with no action on the logs I would keep it further closed. I get 2-3 Hours on a real full box, 1-2 hours on a half full box. Also depends how I stack it in there. If I go narrow and high I seem to get better secondaries then when I spread the wood out more. Of couse thats only when I put like 3 splits in instead of 6
 
To answer wxman's question, when i turn the air control down a bit more than usual, I still get flames from the tubes, but the flames on the wood diminish. I haven't left it like that for too long, though because I thought having flames on both the wood and tubes would be better. But to get those longer burn times maybe I'll try letting the wood flames die out as long as the tubes keep going...
 
Cear,

Hey lay down and relax in front of that insert just dont singe your eyebrows!. I time it from when I damper down after char until there is no active secondaries at the baffle. I'm not counting the small blue flames on the coaling pile.
 
Clydesdale,

As long as those secondaries keep going and no smoke coming out of the stack you should be good to go and see longer burn times.
 
I personally get a couple hours but, it took me a 6 months to get the system down. You may be lowering the fire too late, you should be at your 1/3rd setting within around 30 minutes.

But, something I learned is that when you turn the air down you shock the fire and it will temporarily die and you lose secondary burn. But, give it about 10 minutes it'll recover and secondary burn will come back and, can last a couple hours. Depends on what kind of wood you burn, if you burn red maple which seems to last only several hours your secondary burn time is not going to be very long. If you burn Hickory which will burn for around 10 hours in the clydesdale you should have many hours of it.
 
As I sit here and watch the secondary burn baffles light up, I was wondering is it OK to add a split to the fire during a secondary burn? I ask because I noticed having a split or two near the baffles helps keep the secondary burn going, but my wood just shifted and the top split fell down. Its still going good, but it is so tempting to add a split to get keep that secondary firing.

Thanks
 
Rhonemas said:
But, something I learned is that when you turn the air down you shock the fire and it will temporarily die and you lose secondary burn. But, give it about 10 minutes it'll recover and secondary burn will come back and, can last a couple hours. Depends on what kind of wood you burn, if you burn red maple which seems to last only several hours your secondary burn time is not going to be very long. If you burn Hickory which will burn for around 10 hours in the clydesdale you should have many hours of it.

I have noticed the same thing... and learned it accidentally one evening when I loaded for a night burn. I did notice that, as I would expect, she smokes a lot during that 10 minute period, but once the secondary comes online, the smoke burns up.
Generally, after a fresh full load, I aim to have the air at 1/3 to 1/4 within 30 minutes, less if possible. I am not sure which method I like better, the first method, where you stare it for air and let it recover on its own, or a regular, staged air reduction.

Thoughts?

To answer the instant question, I get about 3 hours of secondary before she burns down to short flames on the splits.

-- Mike
 
Update on secondary burn time:

I'm going on 1 1/2 hours of constant secondary burn. Difference - I used more wood as someone had mentioned on my initial reload. I put 3 large splits and 1 small in the firebox, that just about filled it up. Left the door open for 5 mins to get the splits charred then shut the door. Left air control open for 10 minutes to continue getting the wood going, then dampered down 50%... waited 10 minutes, dampered down all the way. So now 1 1/2 hrs later I got the air control shut all the way down. The flames on the wood are small, but the secondary is going, not out of control, but its going. My stove top temp is steady at 360 degrees and the best part... I still have a firebox that is 75% full of wood. Looks like I might get the longest burn yet tonight.

Thanks for the tips everyone.

And as an added bonus... the history channel's Modern Marvels is featuring the art of brewing beer!
 
Mike Wilson said:
I am not sure which method I like better, the first method, where you starve it for air and let it recover on its own, or a regular, staged air reduction. Thoughts?

I get smoke during the starvation before it recovers. If I stage the air reduction it stays clean.
 
If I load her up and get her to level off at 700 to 750, I got secondary the last 2 nights for about 4 hours. As the temp lowers, at about 500 to 550 the secondary finally dies out. But, at that time the splits are firey orange and I am thinking the volatiles have burned off. At 700 its a massive secondary jetstream show. Ain't no mistaking that. The jets shoot down and burn holes and tunnels into the top pcs of wood ;)
 
My stove is an insert so 350-400 degrees is the surface temp on the cook top which does not have direct contact with the firebox, so I can't get direct stove temps or flue temps for that matter... I'd love to see your stove's baffles burning holes in the wood. That is amazing. I can see the fire shooting out the baffles but its not quite a constant stream of fire.

Happy Burning
 
ClydesdaleBurner said:
My stove is an insert so 350-400 degrees is the surface temp on the cook top which does not have direct contact with the firebox, so I can't get direct stove temps or flue temps for that matter... I'd love to see your stove's baffles burning holes in the wood. That is amazing. I can see the fire shooting out the baffles but its not quite a constant stream of fire.

Happy Burning

I am not sure if you can, but I have my thermometer on the front, actually 2 thermometers, both on front face of insert above each corner of the door. You can try it there on the face for a more realistic reading. I'll have to get the camera out one night. When I ever finish unpacking, I'll get the vid camera and make a video.
 
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