Summer corrosion, humid air brought in via vent

I honestly believe coal stoves would become very unpopular to many is the process you practice was needed! There has to be a solution sans such extreme measures.

With my age, dodgy shoulder and even worse right knee, my days of performing Swan Lake are over too. No two situations are alike and as it is in the basement I can afford not to be pretty. Powervent remove - 5 minutes including plywood cover. Saran wrap two minutes. Removing combustion blower and rolling road apparatus 10-15 minutes. Moving stove to other side of room ( it's now quite light) 30 seconds. Installing Mr beer kegs and making summer beer in the hole left - 14 hours a day, three months of hard labor and possible liver damage. Peace of mind - priceless.Next time you replace the SS lining on your chimney please give me a breakdown.

coalnewbie wrote:

I honestly believe coal stoves would become very unpopular to many is the process you practice was needed! There has to be a solution sans such extreme measures.

With my age, dodgy shoulder and even worse right knee, my days of performing Swan Lake are over too. No two situations are alike and as it is in the basement I can afford not to be pretty. Powervent remove - 5 minutes including plywood cover. Saran wrap two minutes. Removing combustion blower and rolling road apparatus 10-15 minutes. Moving stove to other side of room ( it's now quite light) 30 seconds. Installing Mr beer kegs and making summer beer in the hole left - 14 hours a day, three months of hard labor and possible liver damage. Peace of mind - priceless.Next time you replace the SS lining on your chimney please give me a breakdown.

I hope to be long gone from these parts before that happens. Lisa

Hmm, long gone - yes? The SW has a water crisis of unsolvable proportions. Florida - please take Florida. North of you and we freeze our asses off. Coal is about to make a giant comeback. The fly over states - you have to be kidding. Mittleburg, on of the most beautiful horse towns in the nation. Exactly where is this paradise you are escaping too?

lowfog01 wrote:My issue with corrosion is on the exterior of the SS chimney. Apparently, the flayash is carried by the draft and deposited on the outside of the chimney near the top. The chimney cap prevents the rain from removing that flyash. That accumulation is causing the corrosion I'm seeing there. I am going to try to remove as much of the corrosion that I can with steel wool and baking soda before I treat the SS with a rust preventative product. I hope that will slow down the corrosion but we'll see. I'm open for suggestions if anyone has one. Take care, Lisa

Just a thought, we may have very different conditions and different coal so this may not apply to your situation.

I get essentially zero fly ash to the my chimney upper sections. Something in my setup isn't providing enough draft to carry fly ash through the 2' horizontal run, up 1 1/2 stories plus roof clearance. I do have two 30 degree elbows such that the chimney can hug the house (2" clearance per fire code) and then angle out to clear the roof edge.

Just possibilities to consider:

- is your barometric damper set correctly to avoid excess draft?

- do you reasonably frequently clean out fly ash using the chimney's clean out tee?

SMITTY wrote:If there's any kind of humidity in the basement, you need to get that pipe out of there & into a dry environment. My basement is on the extreme end of this spectrum, but I learned my lesson .... even with stainless!

This is 304 stainless steel connector pipe. I though because it was stainless, I could slack off & leave it in the basement attached. Boy was I wrong! Look at the pinholes everywhere. They've gotten worse since this pic was taken .... which reminds me ... I need to get down there tomorrow & clean it out!

I just checked, my chimney is DuraTech using Stainless Steel - Grade 430. 430 is specifically formulated for good corrosion resistance in mildly corrosive environments and good resistance to oxidation at elevated temperatures. 304 is not.

"***EDIT/CORRECTION "304 is not." seems to depend upon the reference and how the material was formed, polished and other factors. An interesting topic! Dura Tech appears to be using highly polished 430 due to it's forming characteristics and acceptable performance. It is marketed for "appliances fueled by wood, oil, coal, or gas".

Guess this correction opens the flood gates as to what grade and how it is prepared affects corrosion. Perhaps just how humid things get and if condensate actually forms.

So far, In three years, I have no visible pitting on the interior or exterior of the polished 430. Even in the section directly coupled to the black pipe destroyed in 2 months last summer. It was a horizontal section through the wall. Fly ash blown out when I cleaned the chimney. However I didn't wash or treat it with any chemicals.

coalnewbie wrote:Hmm, long gone - yes? The SW has a water crisis of unsolvable proportions. Florida - please take Florida. North of you and we freeze our asses off. Coal is about to make a giant comeback. The fly over states - you have to be kidding. Mittleburg, on of the most beautiful horse towns in the nation. Exactly where is this paradise you are escaping too?

We are looking to buy some where in the middle Shenadoah Valley, around Stauton, VA. I will be designing a coal burning boiler system to heat the house and provide DHW year round. And believe me it will have a tile chimney. I'm hoping to devise a way for it to do the dishes, too. Lisa

gerry_g wrote:

lowfog01 wrote:My issue with corrosion is on the exterior of the SS chimney. Apparently, the flayash is carried by the draft and deposited on the outside of the chimney near the top. The chimney cap prevents the rain from removing that flyash. That accumulation is causing the corrosion I'm seeing there. I am going to try to remove as much of the corrosion that I can with steel wool and baking soda before I treat the SS with a rust preventative product. I hope that will slow down the corrosion but we'll see. I'm open for suggestions if anyone has one. Take care, Lisa

Just a thought, we may have very different conditions and different coal so this may not apply to your situation.

I get essentially zero fly ash to the my chimney upper sections. Something in my setup isn't providing enough draft to carry fly ash through the 2' horizontal run, up 1 1/2 stories plus roof clearance. I do have two 30 degree elbows such that the chimney can hug the house (2" clearance per fire code) and then angle out to clear the roof edge.

Just possibilities to consider:

- is your barometric damper set correctly to avoid excess draft?

- do you reasonably frequently clean out fly ash using the chimney's clean out tee?

You may be on to something. My chimney is only one story plus high. I always have a good draft as measured by the manometer. And I do get a large build up of flyash in my horizontail run of black pipe. I clean that out often. I woner what it would do if I was to run the barro a little more open. I'm going to make a note to myself to remember to think about this next fall. Thanks, Lisa

SMITTY wrote:

gerry_g wrote:Thus NOT JUST humidity. You did state "Nope - just humidity - which will result in condensate." although, to be fair you then added + fly ash in the next sentence.

Just, curious, your photos show deep pitting without holes on the outside of the pipe. How did fly ash get there?

Holes that begin on the inside will inevitably make there way to the outside of the pipe. I was just trying to help. You seem to have this all figured out on your own. Have a good one.

I understood you were trying to help and appreciate it.

However, your first photo shows evidence of standing water/condensate and most holes on the upper surface of the pipe and what looks like some external pits sans holes.

I would have expected the highest acid concentration and damage on the underside of the pipe where condensate and fly ash accumulates to have the most severe damage.

Of course, one photo can't describe the entire situation. We all know "stainless" really means "corrosion resistant to some extent". Putting a hand print on a DeLorean and not cleaning it quickly will leave a permanently etch the surface.

cheers

gerry

lowfog01 wrote:

gerry_g wrote:

lowfog01 wrote:My issue with corrosion is on the exterior of the SS chimney. Apparently, the flayash is carried by the draft and deposited on the outside of the chimney near the top. The chimney cap prevents the rain from removing that flyash. That accumulation is causing the corrosion I'm seeing there. I am going to try to remove as much of the corrosion that I can with steel wool and baking soda before I treat the SS with a rust preventative product. I hope that will slow down the corrosion but we'll see. I'm open for suggestions if anyone has one. Take care, Lisa

Just a thought, we may have very different conditions and different coal so this may not apply to your situation.

I get essentially zero fly ash to the my chimney upper sections. Something in my setup isn't providing enough draft to carry fly ash through the 2' horizontal run, up 1 1/2 stories plus roof clearance. I do have two 30 degree elbows such that the chimney can hug the house (2" clearance per fire code) and then angle out to clear the roof edge.

Just possibilities to consider:

- is your barometric damper set correctly to avoid excess draft?

- do you reasonably frequently clean out fly ash using the chimney's clean out tee?

You may be on to something. My chimney is only one story plus high. I always have a good draft as measured by the manometer. And I do get a large build up of flyash in my horizontail run of black pipe. I clean that out often. I woner what it would do if I was to run the barro a little more open. I'm going to make a note to myself to remember to think about this next fall. Thanks, Lisa

The lower section of my clean out tee fills up before my horizontal section starts accumulating much. I "cheat" and set my thermostat to get a very low feed rate and open the clean out cap outside to empty the tee without needing to relight the stove.

gerry