Creosote/oxidized paint stains form wood burning fireplace

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Has anyone seen something like this before?

  • creosote

    Votes: 1 25.0%
  • oxidation

    Votes: 3 75.0%

  • Total voters
    4
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Maysa

New Member
Jun 18, 2014
8
Jordan, MN
Has anyone got a clue as to what is causing this stain on my chase? It's not rust and seems to be a change in color of the paint on the metal. Any feedback would be greatly appreciated. Jeff
 

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Certainly looks like rust. Why can it not be rust?

Does the appliance hooked to this stove burn wood only? Coal? Pellets? Other?

Are you certain that metal crown had paint on it to start?
 
Certainly looks like rust. Why can it not be rust?

Does the appliance hooked to this stove burn wood only? Coal? Pellets? Other?

Are you certain that metal crown had paint on it to start?
It's not rust when you get up close and look. Galvanized metal is intact and not rusting. This appliance burns only wood. Yes, I have confirmed the metal crown was painted. Thanks.
IMG_0345-2.jpg
 
Sure looks like iron oxide. I'd consider replacing the cap with one made of stainless steel.
 
Sure looks like rust/oxidation.
Just for giggles why not clean it off and paint it just to see.
 
That just looks like a galvanized cover to me. I see no paint.
Creosote is very corrosive! I see this rust/creosote mess on galvanized covers pretty often. Replace it with stainless and it should go away.
Also, how seasoned is the wood you are burning? Pre fab Fireplaces don't typically produce much creosote. Any chance you have an insert in it? Either way, you might need to consider letting the wood season longer.
 
Can the discoloration be cleaned off with a solvent (like kitchen counter stuff)? Is the stuff on the top plate gooey or tacky in any way?
The pics sure do make it look like rust.
 
Thats rust!!
 
Thats rust!!

Ok, so thanks everyone for their input. It's been very helpful.

So I then went back on the roof to research further and found some additional problems. I pulled the rain cap off and while doing so I realized it is the item that is rusting which then appears to be dripping down and staining everything(paint, etc.). See new pics, this was a new install 3-4 years ago. I went back to the dealer and so far they are pushing back and saying it's not covered under warranty. I'm trying get them to change their mind. Stay tuned.

IMG_4904.JPG IMG_4906.JPG
 
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Can you answer a few questions?
Is this just an open fireplace? Is there an Insert in there by chance?
That's a lot of sticky creosote for just an open burner! How long has the wood been split and stacked before you burned it?

I also suspect that cap has been on fire. The only time I see rust like that in a cap is if the galvanizing has been burned off of it.
 
I'd also have to say that I would not expect a cap fire to show there, right at a seam and outer edge where condensation would build up and corrode. Thoughts?
 
Yeah that rust is because the galvy gave up from the heat and left the building and rain took over. Not the wood. I ain't buying any "cap fire". They start a lot farther down than there.
 
Yeah that rust is because the galvy gave up from the heat and left the building and rain took over. Not the wood. I ain't buying any "cap fire". They start a lot farther down than there.

Also, with that cap having such tight (too tight for my taste) mesh on it; I'd be very surprised if there would be a build-up issue without the operator knowing it was going on, since that sucker would be clogged tight..

@Maysa , how much accumulation are you getting out of that chimney when you sweep? Any draft issues from that cap clogging up? Smoke in the house from stove not wanting to draft well? If everything is normal and without incident, I'm guessing that cap was just a lemon. Know the brand? Try contacting them directly?
 
Also, with that cap having such tight (too tight for my taste) mesh on it; I'd be very surprised if there would be a build-up issue without the operator knowing it was going on, since that sucker would be clogged tight..

@Maysa , how much accumulation are you getting out of that chimney when you sweep? Any draft issues from that cap clogging up? Smoke in the house from stove not wanting to draft well? If everything is normal and without incident, I'm guessing that cap was just a lemon. Know the brand? Try contacting them directly?

There is accumulation(say 1/4") each year but I do clean it every season. It really doesn't clog up but by the end of the season there is some restriction. No smoke in the house, it's got a locked door for the combustion just like a stove. I am trying to get a response from the manufacturer through the dealer. No word back just yet other than the dealer saying the generic "I've never seen this before". I'm saying now you have. :)
 
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If it had been stainless or aluminum that would not happen. Even my psi ted cheap steel terracotta cap has not done anywhere close to that in 3 yrs.

How tall is your chimney? Seems like your getting a lot of consensus.g moisture on your cap as it may be cool from a long run. And are you sure your not burning wood with a MC 25% or higher say closer to 30%?
 
If it had been stainless or aluminum that would not happen. Even my psi ted cheap steel terracotta cap has not done anywhere close to that in 3 yrs.

How tall is your chimney? Seems like your getting a lot of consensus.g moisture on your cap as it may be cool from a long run. And are you sure your not burning wood with a MC 25% or higher say closer to 30%?

Chimney is 27'-30' tall. I really don't know the moisture content but it is dried 1-2 years and some of it has been dead(elm) 2-3 years more before it is split, stacked, and burned. How can I measure the moisture content?
 
Moisture content can be measured by a moisture meter.
 
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Yeah that rust is because the galvy gave up from the heat and left the building and rain took over. Not the wood. I ain't buying any "cap fire". They start a lot farther down than there.
Cap fires are pretty common. They can have a small fire in them without the flue catching fire. It's not uncommon at all, and the result is burned off galvanizing. Just like the one picture.
 
This one would benefit from a good cap fire.


chimney cap plugged.jpg
 
I've seen a few like that this season! The ones i see that have been on fire in the top are usually stoves with a bypass. Sparks, burning paper, and flames from a ripping fire can make their way to the top. Often the flue isn't even very dirty, but the cap and the last few feet of pipe are. It can burn out without the operator even knowing it.
 
Has anyone got a clue as to what is causing this stain on my chase? It's not rust and seems to be a change in color of the paint on the metal. Any feedback would be greatly appreciated. Jeff

This looks identical to mine, and you are right, it's not rust. I believe this is caused by creosote collecting on the cap and then the rain dissolves it and it drips down staining everything in its path. My fireplace has cat combuster also.
 
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