White powder inside wood stove?

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Isaac Carlson

Minister of Fire
Nov 19, 2012
1,131
NW Wisconsin
There is white powder that is coating the inside of our firebox. I don't know what it is. Does anyone else have this? We are burning oak, maple, and elm. Nice hot burns.
 
fly ash? Can you post a pic?
 
It looks like a fire extinguisher went off in there. It's on every surface. It rubs off and is a dusting thick. Like a thin coat of white flocking. It rubs off the lid when we reload, so I snapped this picture. I can't get close enough to the hole to get a good picture of inside right now.

20210214_173859.jpg
 
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Hm. If you burned nothing but proper cordwood, then I do think it has to be flyash. It is fine powder for if it has not been touched, though.

The only other thing I can think of is whether there are ceramic (nonmetal) parts/boards in there? If so, do they still look normal?
 
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What do I know, but I get a small amount of white deposit on the top of my oil boiler cladding. I attribute it, without research, as the heat doing something to the galvanized smoke pipe.
 
Are you using any chimney creosote remover in the stove?
 
I was also thinking that if you had some creosote in your firebox, and then had a hot fire, is this burned creosote?
 
Not sure how helpful this is, but I sometimes get whitish powder in my pellet stove firebox.
 
I was also thinking that if you had some creosote in your firebox, and then had a hot fire, is this burned creosote?
That looks quite different and will still be black.
 
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That looks quite different and will still be black.

We should have a database of pics like that... I saw @bholler identify a burnt clump of creosote (from a chimney) from a pic. All those types of things we can see would make a useful thing if collected and identified?

At least I could learn a lot...
 
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I’ve had that before after a very hot fire. I was told it resembled fly ash. When I looked up inside my liner the inside of it was coated with it. Can’t say I’ve seen it since tho.
 
We don't use creosote remover, so we can rule that out. My wife said she had a pretty hot fire this morning that pegged the thermometer, but the white stuff was there before that. I have no idea what the actual fire temps are, but if I crack open the lid during the burn, there are swirling blue/purple/white flames quite often. The top runs about 700* Up to about 900*. This is not a secondary stove and no cat. The flue thermometer reads about 300-350 and we reload around 250.
 
Talk about money going up the chimney...
 
Wipe a little on your gums and report back.