Another Dirty Glass Question

[Mastoo]

I'm new to advanced wood burning but I've been reading this forum for the last month and everyone here is great. I now know what a secondary burn is. hehe. So anyway, I have a new Lennox Montecito and I get brown deposits on the glass covering maybe 4 - 5" at the left side. Hopefully my attached photo shows this, or you can see it in my signature picture. I've used a variety of woods, all seem dry to me. I only see smoke during the startup. The brown stuff cleans off with a rag dipped in ash (thanks to this forum). I've tried leaving the air all the way open and closing it to 1/2 but it didn't make much difference on the glass. From various threads here, I'd guess either my fire isn't hot enough, I have a leak on the left side, or I'm being too picky expecting perfectly clear glass. Can I get your thoughts on this please? Oh and this thing is amazing how much heat it puts out.

 

[webbie]

It could be just the nature of the stove - which would fall under the too picky label, but you could check some things.....
It could be that the gasket near that area is leaking a bit and letting air flow in in that corner....this could be either the door gasket or the glass gasket and chances are it would be at the top of where the mark is......where it was loose or not contacting.

Still, if it stays that clean and the brown ash wipes right off - you are probably in the "good to go" mode....

 

[Mastoo]

Thanks for the reply. I eye-balled the gasket and went all around it with a dollar bill - it seems to pass.

Last week I was determined to watch for when the glass gets dirty. Either the fireplace waited until I got bored or a watched-fireplace-never-smokes, but I missed it and the results are attached. Wow.

I'll watch longer after my reloads next time. I wonder if the reload smolders before getting a good flame, and messes my pretty fireplace. I just have to wait for the weather to turn a little colder so my wife will let me use the fireplace...

 

[argus66]

your being to picky i have seasoned 2 yr + oak and black locust. i still get dirty glass now and then after a good over night burn. looks like your gasket is in good shape. burn a good hot fire gets rid of most of it or let cool down wet towel with ash glass will look like new. or try some other wood as well.

 

[LLigetfa]

your being to picky...

Really? I'd be pretty disgusted with myself if I fouled up my glass like that. It looks to me like the stove isn't burning hot enough or the wood is less than ideal.

 

[fishingpol]

If the pattern looks the same after every burn, I would suspect a leak in the gasket. Did you check the glass gasket? Maybe the clips loosened during shipping. I had a similar problem, but not as bad.

 

[xman23]

Don't worry about it most stoves will blacken the glass when they aren't brought up real hot before having the air closed down. Blackening the glass is much worse in the shoulder season most of us are still in. Somethings to do that can help, burn hotter for short burns. Keep the but ends and the splits away from the glass. Here's what I do after I find blackened glass. I don't clean it just fully load the stove up, after a few reloads with it ripping hot close down the air which creates a wash of the glass with the flames. In about an hour the glass is clean.

 

[LLigetfa]

If the pattern looks the same after every burn, I would suspect a leak in the gasket. Did you check the glass gasket? Maybe the clips loosened during shipping. I had a similar problem, but not as bad.

In your case it was the gasket but in the OP's case, the pattern looks like it's coming from the air wash screen.

 

[fishingpol]

It does have a pretty distinctive pattern there.

 

[daleeper]

Don't worry about it most stoves will blacken the glass when they aren't brought up real hot before having the air closed down. Blackening the glass is much worse in the shoulder season most of us are still in. Somethings to do that can help, burn hotter for short burns. Keep the but ends and the splits away from the glass. Here's what I do after I find blackened glass. I don't clean it just fully load the stove up, after a few reloads with it ripping hot close down the air which creates a wash of the glass with the flames. In about an hour the glass is clean.

I don't have that particular stove, but I have a similar pattern, and have heard this advice, but I just can't let the stove burn hot enough long enough to burn that stuff off, because I don't want to overfire the stove. How do you guys do this without running the stove too hot? If I let the stove run open for more than 30 minutes both the cat and stovepipe thermometer is pegged, and none of the black is burned off the glass.

 

[Huntindog1]

As for cleaning the glass, I found some cheap stuff at one of the dollar stores awesome orange that seems to melt the stuff off the glass better than anything and its cheap.

 

[LLigetfa]

As for cleaning the glass, I found some cheap stuff at one of the dollar stores awesome orange that seems to melt the stuff off the glass better than anything and its cheap.

Most of those orange cleaners have pumice in them which works almost the same as wet paper towel dipped into some ashes.

 

[LLigetfa]

...and none of the black is burned off the glass.

I think the problem is letting it get black in the first place.

 

[oldspark]

your being to picky...

Really? I'd be pretty disgusted with myself if I fouled up my glass like that. It looks to me like the stove isn't burning hot enough or the wood is less than ideal.

+1, would not like that at all.

 

[Wade A.]

I'm thinking you have a gap between your glass and your gasket, not between the door and your stove. I just fixed a similar problem on my Jotul. Check and make sure the glass clips are snugged down all the way all around the edges of the glass. My Jotul has allen screws. If the screw clips are as tight as they will go, you're going to have to adjust one of more of the clips, paying particular attention to the clips near where the glass is getting dirty.

Loosen and take out the screw and take the clip off. it will probably be a Z shaped clip. With a pair of pliers, or a crescent wrench with the jaws almost closed, bend the top leg of the clip ever so slightly down. This will give it less height and a tighter clamp on your glass.

 

[Mastoo]

Sorry to take so long with a follow-up. My wife told me no more fires until it was colder outside. I went around the door with a dollar bill and it all seems snug. I did smoke around it and the window while burning and there was no appreciable leak. I poked a moisture meter in my wood and it generally reads 15% (I didn't do this on fresh splits though).

Finally it dipped below 20 today so I started a fire and set up surveillance on the couch with a bottle of Johnnie Walker Green. First burn went well with hardly any smoke, and glass was clear. I reloaded while I still had a good load of red embers, and it smoked quite a bit for the first 15 minutes and the left side of the window turned brown (though not nearly as bad as the picture above).

I've read this entire web site but I could still use some suggestions. Should I be adding kindling with the reload? I reload with 4 splits that fill maybe 3/4 of the height of the box, is that too much at once? This smoke can't be avoided? It has to be my wood isn't seasoned enough? Hmmm, back to the couch.

 

[rdust]

15% on a face that hasn't been freshly split means nothing, split a piece and take a reading.

Walk us through your reload procedure, when you turn the air down, stove temps ect...

 

[fishingpol]

Do you open the air on reloads until the new splits catch? If the firebox is hot, it only takes a few minutes. When the wood is burned down to coals, and the temperature drops, I open my primary air for a few minutes to liven the coals and add splits(credit to BeGreen for this advice). Once going nicely, close down 1/2 and then full.

 

[HotCoals]

I might be nuts..but I swear on reloads after I dial down is when I get what he has.
It almost seems the air wash is blowing the smoke to my glass some...from the top down but mostly the lower corners.

 

[RORY12553]

your being to picky...

Really? I'd be pretty disgusted with myself if I fouled up my glass like that. It looks to me like the stove isn't burning hot enough or the wood is less than ideal.

I think it's an issue with the wood. Had the same problem and it was due to the wood being less than ideal. I did some test on the wood and swithched the wood up to more seasoned wood. Also a hot fire should be able to burn that off. I am new to this and asked the same question about a month ago.

 

[Mastoo]

My reload is: open the door, open the air all the way and with the boost open, put in the 3 splits (2 on bottom 1 on top pyramid), wait a couple minutes til the the first flames appear, close the door. And I've tried leaving the air and boost open for the next hour, and this time I closed the boost after 20 minutes but left the air open, and in either case it smokes enough during that first 20-30 minutes that both sides of the glass are dirty. My wood is from the basement so it isn't cold from outside. And, help me out here but there aren't any temperatures to measure on this setup? I leave the blower set low on the off chance it cools the box too much. My IR thermometer doesn't work through the glass. I've tried loading it up to burn the residue off - it puts out a bunch of heat but doesn't clear the glass. I've used wood from 3 different suppliers, each telling me the wood had been seasoned thinking at least one of the three would be reliable but maybe not.

And HotCoals, you would have liked the previous burn that led to my post and picture. The smoke provides a nice visualization of the air wash. You could see smoke come off the wood, rise towards the front, the wash then looks like a blower pushing smoke down the glass. But this last time I didn't have nearly the smoke but apparently enough to still get things dirty.

So this weekend maybe I'll pick split some wood and measure it. I was also thinking I'd try some of those $6 "kiln dried" bundles as an experiment.

Thanks everyone for the replies.

 

[Retreadsme]

I agree with LLigetfa all the way on not hot enough and less than desired wood. I was given a couple of those $6 "kiln dried" bundles last year by a kind person and my assessment was, they may have passed by a kiln on their way out the gate on the delivery truck. In my insert the glass will blacken if the air is cut way back, it's an all-night burn, and the wood starts smoldering. If the air is opened to full once the wood gets to the coals stage then the glass remains clean. With that said, it applies when the wood is dry. I'm burning 3 yr (split & stacked) red oak, hackberry, and cherry. For me in W TN anything less than 3 yrs produces ...... black glass.

If you have not tried it, you may consider burning a load N-S instead of E-W. That makes a difference in mine also, strange as it may seem.

Where in MO are you? I favor Dent and Texas Counties.

 

[Wood Duck]

It sounds like your wood isn't dry enough. Try reloading with some small splits or kindling in the front to get more flame more quickly and maybe you can avoid the smoky start-up after the reload.

 

[HotCoals]

My reload is: open the door, open the air all the way and with the boost open, put in the 3 splits (2 on bottom 1 on top pyramid), wait a couple minutes til the the first flames appear, close the door. And I've tried leaving the air and boost open for the next hour, and this time I closed the boost after 20 minutes but left the air open, and in either case it smokes enough during that first 20-30 minutes that both sides of the glass are dirty. My wood is from the basement so it isn't cold from outside. And, help me out here but there aren't any temperatures to measure on this setup? I leave the blower set low on the off chance it cools the box too much. My IR thermometer doesn't work through the glass. I've tried loading it up to burn the residue off - it puts out a bunch of heat but doesn't clear the glass. I've used wood from 3 different suppliers, each telling me the wood had been seasoned thinking at least one of the three would be reliable but maybe not.

And HotCoals, you would have liked the previous burn that led to my post and picture. The smoke provides a nice visualization of the air wash. You could see smoke come off the wood, rise towards the front, the wash then looks like a blower pushing smoke down the glass. But this last time I didn't have nearly the smoke but apparently enough to still get things dirty.

So this weekend maybe I'll pick split some wood and measure it. I was also thinking I'd try some of those $6 "kiln dried" bundles as an experiment.

Thanks everyone for the replies.

Ah!
You seen it!
But I concur..it seems to happen with mine.

 

[gyrfalcon]

My reload is: open the door, open the air all the way and with the boost open, put in the 3 splits (2 on bottom 1 on top pyramid), wait a couple minutes til the the first flames appear, close the door. And I've tried leaving the air and boost open for the next hour, and this time I closed the boost after 20 minutes but left the air open, and in either case it smokes enough during that first 20-30 minutes that both sides of the glass are dirty. My wood is from the basement so it isn't cold from outside. And, help me out here but there aren't any temperatures to measure on this setup? I leave the blower set low on the off chance it cools the box too much. My IR thermometer doesn't work through the glass. I've tried loading it up to burn the residue off - it puts out a bunch of heat but doesn't clear the glass. I've used wood from 3 different suppliers, each telling me the wood had been seasoned thinking at least one of the three would be reliable but maybe not.

And HotCoals, you would have liked the previous burn that led to my post and picture. The smoke provides a nice visualization of the air wash. You could see smoke come off the wood, rise towards the front, the wash then looks like a blower pushing smoke down the glass. But this last time I didn't have nearly the smoke but apparently enough to still get things dirty.

So this weekend maybe I'll pick split some wood and measure it. I was also thinking I'd try some of those $6 "kiln dried" bundles as an experiment.

Thanks everyone for the replies.

Try reloading sooner, when there's still a bit of the shape of the wood in the hot coals instead of waiting until it's all collapsed down into a bed. If you have a thermometer, you want to catch it to reload when the temp is just starting to move down from your cruising temperature. I have superb dry wood, but even a couple of small splits of good dry maple take a while to catch on a small coal bed with the stove temp has fallen down to around 300. If I reload closer to 400 (cruising range on my stove is 450-500), even big fat splits of oak are flaming by the time I get the door closed again.

That said, some stoves have a better airwash than others. I've never had more than a slight film or a couple spots of dark crap even when I was first starting with less than seasoned wood and had no idea what I was doing and made a lot of smoky fires while I was getting the hang of if.

Last, before you resort to a commercial cleaner or even ashes to clean the glass, try a plain damp paper towel. That's all I've ever needed.