Is this considered secondary burn?

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d.sebens

Member
Oct 26, 2021
89
White Heath Illinois
Is the main fire in this picture primary or secondary combustion? I would assume this is mainly primary. What I would consider secondary is the turbulent flaming jets that come out of my secondaries. I hear of people talking about turning down until the secondaries are “lazy”. I don’t really ever see lazy secondaries. Sometimes I will see pretty flame fronts propagate through the box when turned down though.

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hard to say for your pic (w/o video to see if they're "connected" to the wood or not).

I (can) have secondary flames (if tuned to the parameters that allow this) - but no secondary air. Those are always "lazy" (and often bluish-purple).

So it depends on the stove configuration. I don't think there is a "standard" here (even if the ubiquitous tube stove folks set expectations of secondary flames).

I'd not aim for secondary flames per se, I'd aim for 1. the right amount of heat WITH 2. no smoke outside. However the latter happens does not matter, THAT it happens means you're golden (and efficient).
 
That’s really what I do. I’m getting used to how this operates. I was just curious what people are calling secondary flames. That picture in real life to me looked like primary combustion but it was really lazy flowing flames.
 
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Hard to say from that pic.

Here are some pics of secondary combustion being used to light a fresh reload from the top down. Same unit as yours.

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Hard to say feom that pic.

Here are some pics of secondary combustion being used to light a fresh reload from the top down. Same unit as yours.

View attachment 293227 View attachment 293228
Do you feel your secondaries look like torch flames when the fire is really going? That’s the majority of secondary action I see on mine. That may also be because I usually stack all the way up to touching the tubes.
 
To be honest, the flames on your pic look like either wet wood or the air being pulled back by increments that are too dramatic. The flames don't look like what I typically see on a "clean burn" and I see the glass is a little blacker than I might expect.
 
Do you feel your secondaries look like torch flames when the fire is really going? That’s the majority of secondary action I see on mine. That may also be because I usually stack all the way up to touching the tubes.
Yes, at times it looks torch-like. Usually only for a while when the most smoke is being produced for secondary combustion.
 
That picture was before it was fully up to temp. The wood is a about 22%, I fully expect next seasons woods (already split) to operate different.

The soot at the bottom seems to happen when I start the insert on a full load when cold. It is probably tied to moisture still, but what I experience is as it warms up it starts outgassing faster than it can consume since the fire isn’t large enough. This doesn’t seem to happen when I do a hot reload.
 
That picture was before it was fully up to temp. The wood is a about 22%, I fully expect next seasons woods (already split) to operate different.

The soot at the bottom seems to happen when I start the insert on a full load when cold. It is probably tied to moisture still, but what I experience is as it warms up it starts outgassing faster than it can consume since the fire isn’t large enough. This doesn’t seem to happen when I do a hot reload.
That makes sense based on the MC. You will notice a big difference using wood at 18% MC vs 22%. Yes the first year is tough. I went through the same thing. Now I'm about 3 years ahead on splitting with a goal of getting to 5 years.

On a cold start try cross stacking the wood to allow more air flow. That may help some. Also use some smaller kindling on a top down fire. You may already be doing this.
 
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I usually do a top down. This time I started. Smaller fire on the bottom with some sawdust bricks and then loaded on top of that. The only reason I tried this is because when cold and fully loaded the insert takes sooo long to turn the fan on. It starts getting really hot on the top without the air flow. It’s probably normal but a cold full load takes like 1.25 hours to turn the fan on when doing top down.
 
Just chiming in. I still use the good ol' TeePee method. I have no luck with top down, I mean none.
 
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Just chiming in. I still use the good ol' TeePee method. I have no luck with top down, I mean none.
Try again, but this time take a picture before lighting. And then again, 5 minutes later. We may be able to spot the issue. Also, have you watched this video?
 
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Here is are 2 examples of secondary flames.




bigealta has the secondary burn happening for sure, check out my avatar those are secondaries with very dry wood and pushing a little harder; that rolling flame at the top.
 
Here is are 2 examples of secondary flames.




My 'secondaries' only look like that on start up not during shutdown operation. That just looks like flames forced through the baffle. My real secondaries look awesome and shoot down about 6-8 inches. They're bluish and like a torch. They don't ignite until they're about 1-2 inches out of the baffle. They're awesome.
 
people talking about turning down until the secondaries are “lazy”. I don’t really ever see lazy secondaries. Sometimes I will see pretty flame fronts propagate through the box when turned down though.
I've most often heard "lazy" used in reference to the flames coming off the wood. When those are lazy, the secondary flame can be blasting!
Yep, I love those gentle flashovers that ripple through the box sometimes...gorgeous!
I still use the good ol' TeePee method.
Toilet Paper? ;)
 
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My 'secondaries' only look like that on start up not during shutdown operation. That just looks like flames forced through the baffle. My real secondaries look awesome and shoot down about 6-8 inches. They're bluish and like a torch. They don't ignite until they're about 1-2 inches out of the baffle. They're awesome.
Yeah this is how the secondary flames burn in my jotul f400. I sometimes get some bluish flames mixed in, but nothing like the blue bbq gas burner like flames i've seen on some other stoves.
 
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Yeah this is how the secondary flames burn in my jotul f400. I sometimes get some bluish flames mixed in, but nothing like the blue bbq gas burner like flames i've seen on some other stoves.
With the right fuel the F400 can give blue flames. I would see them when burning locust and also with NIELs sometimes.
 
With the right fuel the F400 can give blue flames. I would see them when burning locust and also with NIELs sometimes.

Yup very similar here, when i get the blue flames they are usually lightish blue and partially mixed with yellow flames. I've seen a few youtube burns that show secondaries that are dark blue just like my nat. gas burner.
 
Yup very similar here, when i get the blue flames they are usually lightish blue and partially mixed with yellow flames. I've seen a few youtube burns that show secondaries that are dark blue just like my nat. gas burner.
Yes, I only get those off of the wood when the initial bloom has burned down and the wraith-like bursts of flame are blue. It has to do with the ratio of oxygen in the burn I think.
 
Try again, but this time take a picture before lighting. And then again, 5 minutes later. We may be able to spot the issue. Also, have you watched this video?

This is a great video tutorial.
Also, some of the comments are priceless,lol.
 
And here is another secondary flame video with some ghost flames towards the end.

 
This is a great video tutorial.
Also, some of the comments are priceless,lol.
First off, that video was amazing. I’m a better person for having watched it. Secondly, I actually learned a lot.