Observation about Ash Buildup

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I

illini81

Feeling the Heat
Apr 7, 2017
376
Southeastern CT
This is my second year heating with a wood stove. I cleaned out the stove about once every two weeks during the first year. The stove would fill up with ash nearly to the top of the doghouse over about a two week period.

I read on hearth.com that some people can go a month or more without cleaning out the ash. I figured they simply had a larger "basin" to hold the ash.

Recently I have gotten lazier. On Saturday, I cleaned out the stove after a full four weeks. I noticed that over time, the ash seems to compress into these "bricks" of ash, which reduces their volume. The volume taken up by the ash seems to stabilize at about the height of the doghouse or a little below that point at two weeks. Another two weeks later, and it was at about the same point, presumably because the ash was continually getting compressed.

Anyways, I thought this was interesting. If you have never experimented with the duration of time between ash cleanouts, give it a try!
 
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Guessing your wood quality is getting better as you go also(drier). Makes a difference for my ash buildup.
 
a week and a half is typically my max before I start getting really fed up with the amount of ash in the stove. I do get those compressed chunks but at some point you have to just get rid of it. My manual states not to load wood above the firebrick, why I do not know (maybe to avoid more damage to the baffle?) but if that were the case of how I actually burned then I'd have to clean every few days.
 
illini81 said:
I noticed that over time, the ash seems to compress into these "bricks" of ash, which reduces their volume.
Click to expand...
Sounds like you are talking about "clinkers." I'm not sure what those are..
 
Clinkers result from burning coal. I get those in the coal stove which I only run about four times a Winter on the coldest days. Today may be one of those days here. Stuck at 9 with 25 mph winds.
 
Woody Stover said:
Sounds like you are talking about "clinkers." I'm not sure what those are..
Click to expand...

Yes, and they aren't made from just the ash getting deeper & compressing itself. It is a byproduct of combustion. Differing types of wood play a part.

If ones wood is dry, and burned as completely as possible, there is only so much (so little?) ash it will make. So any apparent difference in how much ash is left in the firebox or ash pit, with everything else in the burn being equal, is most likely to due to a change in how much is going up & out the flu. If the pit fills up, that might create a change in airflow through the stove, as well as take away a place for it to settle out of the airflow (the pit) - therefore more gets sucked up the flu.
 
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The type of wood can also be a variable in the amount of ash produces. Some wood simply is more “ashy” than others.
 
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I'm with Jags, the species of wood is the biggest factor in how much ash is left over. I burn mostly Oak, which leaves little ash. Other woods like Maple, Cherry & Black Walnut leave loads of ash, especially the latter two. You could always scoop the front bit of ash out with each reload or every other reload or so, that would also get rid of the clinkers also. The just spread the remaining coals & ash across the firebox floor prior to reload..
 
Hogwildz said:
You could always scoop the front bit of ash out with each reload or every other reload or so, that would also get rid of the clinkers
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I've got some in the box now. I kinda like some of them up near the glass; I just pull a few coals up there, too, and it seems like a lot of air can blow through the clinkers to help start the kindling. I guess at some point I'll have to take some out. Seems like maybe the Black Locust makes more of them, I don't know..
 
My boiler cranks out fine ash with no coals as its a bottom grate design. I have a fairly large ash pit in the unit but when I am burning heavy I need to empty it out on occasion. I transfer it to 5 gallon galvanized can with a metal lid. It goes in the can quite fluffy but if the boiler is running I can use my shovel to compact the volume of the ash quite a bit in the can so I can stuff more into it. I probably can double the capacity by compressing it in layers. I do notice that I can get more solid ash bricks directly under my grate where the ash is exposed to high radiant heat. The trade off is with compressing it in the can is I need a stick to get it to come out when I dump it.

There is definitely higher levels of ash in bark, than in hearthwood. Strip the bark and the ash generated definitely reduces.
 
Woody Stover said:
I've got some in the box now. I kinda like some of them up near the glass; I just pull a few coals up there, too, and it seems like a lot of air can blow through the clinkers to help start the kindling. I guess at some point I'll have to take some out. Seems like maybe the Black Locust makes more of them, I don't know..
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I scoop em out more frequently, cause I have had them melt into the bottom bricks, and getting them off took part of the brick with them. That's just my routine though, and everyone has their own.
 
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Hogwildz said:
I scoop em out more frequently, cause I have had them melt into the bottom bricks, and getting them off took part of the brick with them. That's just my routine though, and everyone has their own.
Click to expand...

Same, have had that happen as well. Might be replacing another one at the end of the season.

All ash is is the incombustible content of the wood, which generally includes minerals and other compounds. Each species is somewhat different in its chemical makeup, hence the variability in ash content between species.

Also, ash doesn't really go up the flue, at least in any quantity that would change how much is in your stove.
 
Hogwildz said:
I scoop em out more frequently, cause I have had them melt into the bottom bricks, and getting them off took part of the brick with them.
Click to expand...
That wouldn't be good if it happened to my soapstone! :oops:
 
Different wood. I could go months without removing ash if I only burned fir. When I burn a lot of alder I have to clean the ash out every few days.
I'm burning more maple this year than ever before and I'm getting clinkers like never before.
 
yooper08 said:
Same, have had that happen as well. Might be replacing another one at the end of the season.

All ash is is the incombustible content of the wood, which generally includes minerals and other compounds. Each species is somewhat different in its chemical makeup, hence the variability in ash content between species.

Also, ash doesn't really go up the flue, at least in any quantity that would change how much is in your stove.
Click to expand...
Bark can contain up to 5 times the amount of ash. Also, lots of coals can linger for a long time semi buried in the ash, making startups easier. Emptying ash pans can make cleaning easier, ash built up can make startups easier.
 
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