Air wash, operator or draft?

[Andy S.]

I'm using dry Pine and am still a bit frustrated by darkened glass in the bottom corners on my HI200. Procedure is it light it off with the door closed but unlatched until it catches, then lightly engage the latch for a few minutes until the fire recovers, then fully close the latch until the fire recovers again then turn down the air in two steps. The whole thing takes 30 minutes or so.

I'm getting a "smiley face" of dark glass. I'm thinking I have an air wash problem but am also wondering if it is because it is relatively warm (40's) and the draft isn't strong enough.

 

[DAKSY]

How dry is "DRY?" Did you check the moisture content with a meter?

 

[Andy S.]

How dry is "DRY?" Did you check the moisture content with a meter?

Yes... 18% or less.

 

[Jags]

What kind of temps are you letting the stove get too? Do you have a way to measure the temps (insert)?

 

[Andy S.]

I have reference spots in the center and on either side of the door. My IR pins at 610* on the center and reads @450* on either end when it is closed down. Secondaries start right away when I lightly engage the latch, recede a bit and then recover. It is tough with my insert to get a "stove top" reference.

 

[Jags]

It is tough with my insert to get a "stove top" reference.

Understood.

Does the glass clear up after a good long, hot run? Have you done the dollar bill test in the areas of darkening?

 

[Andy S.]

Does the glass clear up after a good long, hot run? Have you done the dollar bill test in the areas of darkening?

The glass clears some but not completely. I've done the dollar bill test but not specifically for this problem. I'll repeat it - thanks. In that regard, am I correct in thinking that ANY resistance passes the test? I have always had varying degrees of pull.

Thanks for all the speedy replies.

 

[Jags]

Yeah, it doesn't need to clamp like a vise, but it should be a bit snug, not just slip out.

 

[Grisu]

I have the same problem when burning my dry pine. I assume the wood is outgassing the stuff more quickly than hardwood and overwhelms a bit the secondaries. Leaving more room between the wood and the glass helps somewhat as does leaving the air open a bit to keep the air-wash going. Still, I could not yet completely avoid some black spots.

 

[begreen]

Yes... 18% or less.

I have dry fir and it almost ignites itself. Was the wood tested on a freshly exposed face of a resplit piece of wood? Where are you setting the air control lever during the fire starting procedure? Is it wide open?

 

[Andy S.]

Was the wood tested on a freshly exposed face of a resplit piece of wood?

Yes. I say 18% or less because some of the stuff measures in the 13% range and I doubt those readings.

Where are you setting the air control lever during the fire starting procedure? Is it wide open?

Wide open. It is a good question, though. I've caught the wife forgetting a few times to open it up.

 

[Andy S.]

I have the same problem when burning my dry pine. I assume the wood is outgassing the stuff more quickly than hardwood and overwhelms a bit the secondaries. Leaving more room between the wood and the glass helps somewhat as does leaving the air open a bit to keep the air-wash going. Still, I could not yet completely avoid some black spots.

Not happy to hear you have the same problem but it IS good to know that it could possibly related to the Pine. My problem with leaving it away from the glass is that I have a tiny (1.4) fire box as it is.

 

[begreen]

What are the outside temps when you were starting the fire? Can you describe the flue setup from stove to chimney cap?

 

[Andy S.]

What are the outside temps when you were starting the fire? Can you describe the flue setup from stove to chimney cap?

Mid-40's or so last evening. Inside temp had just dropped to 70 and the wife likes it no lower than that. I have about 25' of insulated 5.5" liner exiting out the top of the insert straight to the cap. No block-off plate. It sure seems as though it is pulling hard because the roar I get in that firebox prior to starting the shut-down procedure is plenty easy to hear from a room away.

 

[begreen]

Yes, that should draft well. If the fire is hot and the wood is dry, the glass should stay pretty clean. If not the either the fire is turned down too much, the wood is not fully dry, there is an air leak in the door gasket, wood is too close to the glass, or the stove has a poor airwash design.

 

[Sprinter]

At what point in the burn do you notice the darkening? At this point in the season I'm burning quite dry softwood (Noble and Grand Fir mostly - similar to pine) as welI. I still get some darkening on my lower corners now and then. But it only seems to occur after the main burn cycle and mostly coals are left. I've noticed that if I turn the air back up at this stage, I don't get the darkening. I've also noticed that this wood seems to require more air for good burning than my alder did and the operating temps are lower. Don't know if this will help you or not.

 

[Andy S.]

Passed the dollar bill test. Tried slowing down my startup process and making sure it was hot at every stage. Also made sure to stay away from glass. Same result. The wood is dry - I know it. Will try tomorrow with some dry Maple. After that I'm left with outside temps being too warm. That can be eliminated later this week. I don't want to blame the insert's air wash because that means I'm stuck.

 

[ckitch]

My stove is doing the same thing with pine, but not so much with my ash. I find that if I leave the air cracked just a 1/4 inch open it doesn't happen. I think with the secondaries going it kind of traps the smoke in the bottom, but if its open just a bit some flames on the wood help keep the glass cleaner

 

[Sprinter]

Just how bad is it? That is, is it really heavy out or just a little colored, or what? All I can suggest beyond what you've tried is keeping the air up a little higher.

You may also try to get a hold of some dry hardwood, like maybe some store bought wood of known quality and try that. A few days worth should tell you something.

 

[Andy S.]

Here is a pic with a load of 18% Ash in the coal stage. Here it is left side only. This color is about typical.

 

[Grisu]

Here is a pic with a load of 18% Ash in the coal stage. Here it is left side only. This color is about typical.

You have logs rolling against the glass; of course it will be getting black in those spots. That has nothing to do with the air wash or the wood you are burning.

 

[Andy S.]

Nothing against the glass.

 

[Sprinter]

Well, maybe I'm not looking at it right, but I don't see much there to be concerned with or that is abnormal. If you want to see a properly dark window, talk to the Blaze King folks! Although that's a different animal altogether. Just by the pic, you're window looks fine to me.

 

[Sconnie Burner]

Are your air controls on the right side? If they are that means you have cool air traveling along that side of the stove before it enters the firebox. This will tend to keep that side of the box and glass cooler causing the soot deposits. I see this on my quad glass from time to time. one load will burn clean and the next will make it dirty. It just happens sometimes.

 

[Sprinter]

Well, maybe I'm not looking at it right, but I don't see much there to be concerned with or that is abnormal. If you want to see a properly dark window, talk to the Blaze King folks! Although that's a different animal altogether. Just by the pic, you're window looks fine to me.

Okay, I can see what you mean now after another look. If you are getting that on each burn, then it could be improved upon, but it could be a lot worse.