13NC Secondary Burns

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delp

Member
Jan 6, 2009
186
pittsburgh, pa
What does it take to get the first two tubes to engage the gases and do the secondary burn?

I tend to load the stove with more splits toward the rear of the firebox so as to avoid logs rolling onto the glass. Is this why I've never seen the first tube take off?

Or...?
 
what temps are you getting it up too. What should happen is if you get the stove top to say 550 and the stove pipe about 12 inches up to about 400 you then start to reduce the air intake and the wood will start backing down but the top of the stove is hot and will ignite the smoke produced from the wood at the bottom of the stove that is not burning as hot but producing more smoke to burn. THe stove from backing the air down will get hottter as it becomes more of a smoke gas burner rather than a wood coal burner. Also if you dont back it down you might not see as much secondary burn as if the bottom is burning pretty hot its already burning up the smoke before it gets to the tubes. The idea is to some what smolder the logs once the temps are up in the stove so you can burn the gases coming off the smoldering logs but its finding tha thappy medium that gets the stove working just right.

If you start your fires top down filling the bottom of the stove with a couple layers of wood to build a platform in which to lay your kindling and fire started so its up close to those secondary tubes you will get the top of the stove going good quicker to secondary burn temps. Plus the wood stack up closer to the secondary tubes reduces the area up there and its easy to build heat in a smaller area up there by the tubes.

If starting from coals rake your coals to the front but dont block the dog house air in the front, stack wood in but leave the front of the box open for small kindling to burn hot and rapid to get the stove temps up fast so you dont burn all of your big splits in the back to get temps up.

One other thing is if your burning wood that has too much moisture then it kills your secondary burn as your using the extra heat to boil water out of your logs and that moisture kills the temps in the top of the stove so it hard to get secondary burn. You can get a moisture reader for wood at lowes.
 
Thanks, HD1

I'm not a 24/7 burner, so the first fire/load starts with a fast and hot starter to get coals - two small splits NS, a CD btwn them and kindling on top; I'll throw a small split on top of that and when i have good coals i'll load it up, which is anywhere from 3-5 splits EW. Like I said, I'll usually put 3 splits at the back and 1-2 up front. I'll get that going and cut the draft about 1/4, and down in 1/4 over about 1/2hr +/- until stove top get close to 500, by then i'm usually closed down all the way, less a tap for good measure.

I get good secondaries but only in the rear tube (the 13 has three tubes).

So, I'm just curious as to why I've never seen secondaries in the front tube, and only rarely in the middle tube....

My wood is good and dry, s/s for two years, MM reading in 10-14% on a fresh split face.
 
It depends on how you build the fire. If the bulk of the wood is in the back of the firebox then the rear secondaries will fire the most. The smoke gasses flow from back to front so if they're not burnt yet from the rear tubes they get burnt at the front tubes. If they get totally burnt by the rear tubes then there's nothing left for the front tubes to burn. If the fire and smoke is near the front of the firebox then you'll get secondary burn on the front tubes and little/none on the rear tubes.
 
It does depend on where the fire is placed. I learned not to worry about the secondaries to much and go for a good burn and stove temps. I got longer burn times by doing this.
 
Thanks, BA and FA

Next burn I'll load the stove more evenly and watch for secondaries along the first and second tube.
 
You aren't really engaging the tubes. It might look a little like the flames are coming from the tubes like little gas jets, but that isn't really the case.

The tubes are designed to inject the air into the top of the firebox. The specific angles of the holes in the tubes inject the air in a way that creates some turbulance in the top of the stove that helps burn the smoke.

If all of the smoke is burning off in the back of the stove, there won't be much activity up front. As long as you aren't puffing smoke from the chimney,you are doing fine, and the stove is working properly.

-SF
 
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