Secondary Burn: Dark and then flare cycle

[tdhd]

I have moved into a home with a Hearthstone Mansfield 8011 and am getting to know it. I replaced the baffle, as the one that was in it was broken and misplaced. Suspect that most fires for the last little while were going straight up the chimney. I put a blanket on it too. Reoriented the baffle support on the manifold as I think it should be from browsing posts to these forums. Cleaned things as well as I know how. Tried blowing some air through the secondary intake vents and they dont seem to be blocked.

Let me start by saying: my wood isn't great but its all we've got and could possibly get for now. Most was cut in Feb/March, split about a month ago, stacked in sun and wind, top covered in rain. Some older than that ... I'm working at finding and using those.

I'm able to get what seems like a secondary burn going. But something is happening that I've never really seen before. The fire goes completely dark, like I thought it was snuffed out the first time I saw it. Then it flares up powerfully about every 10 seconds. Is this normal? Does it indicate anything?

I'm really working at trouble shooting this stove, my technique, etc. Learning!

 

[Kevin Weis]

That's the off gassing or back puffing. Your draft is too weak to pull the off gasses through and out the stove. Open it up the primary some more. Also likely your wood is a little on the wet side. What is your moisture reading on a fresh split? Should less than 25%.

 

[begreen]

Sounds like the wood is not fully seasoned. It doesn't really start drying until it's split and stacked.

 

[kborndale]

Wood split a month ago is your problem. Can you get some construction lumber or some broken up pallets (not the green tinged ones) to mix in with the wet wood? Your recently split wood won't really be ready until next winter.

 

[tdhd]

Sigh. Sigh. Yes, I am beginning to accept that I have green wet wood. Not much I can do about that.

 

[Ctwoodtick]

Like you said, wood not great. Split for one month=Very wet wood. That is what is causing the fire to go out. Gasses build up and then ignite periodically. I know it’s frustrating, we’ve all “ been there. If you think wood burning is going to be a trend for you, get wood put up ASAP. Reference the “3 year plan” on the search bar on this forum for some more guidance.

 

[xman23]

Normal event from time to time. I get it when the secondary burn starts and stops. When the fire box is hot enough and the fire is burning stronger, it stops.

 

[begreen]

Sigh. Sigh. Yes, I am beginning to accept that I have green wet wood. Not much I can do about that.

Bring it indoors for a few weeks in a tote or boxes. That will accelerate drying. Mix it with 2x4 cutoffs. And clean the chimney frequently, at least once a month.

 

[ratsrepus]

Sigh. Sigh. Yes, I am beginning to accept that I have green wet wood. Not much I can do about that.

Get a supply of compressed saw dust blocks, Tractor supply and the likes have them. they work great. just make sure they are the right ones and can burn in your stove. i use them in the shoulder season in my blaze kings

 

[RickJocko]

I second the sawdust blocks from Tractor Supply or Rural King. I was in the same situation last year with the recently split wood. Here's what worked for me last winter.

Small splits, like 2-3 inches. I had to resplit most of the wood smaller than I bought it. If you can cross-stack them in the firebox, do that. Mix in a couple sawdust blocks. This kept my stove burning hot enough to get the secondaries going and keep the creosote to a minimum. I burned like that almost every day over the winter and when I had my flue cleaned over the summer the guy said it was "very clean and looks like I'm burning nice hot fires with dry wood." I kinda laughed to myself a little when he said that, but was very relieved.