It's in a shipping-container workshop and tool storage area, but yeah, I'll move it outside.
Cleaning a catalytic combustor with vinegar bath
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I did it for the first time this weekend. A vinegar bath, that is.
Cat has about 9000 hrs.
I do think it's getting a little "tired"; I think I have to dial down a bit slower, after a slightly longer charring phase.
Is that really the case, or some trick my brain plays on me because I am cognizant that it's getting closer to the magical (or merely fantastical, as in not having any basis in reality...) 12,000 hrs, or I'm just getting more impatient... - I don't know.
I don't see a difference after the vinegar bath.
Cat still works but it didn't fire up earlier, it didn't allow to dial down quicker.
It's a nice glow, not bright white but just nice, uneven over the face of the cat though (likely due to an uneven burn/gas flow from a mix of pine and oak), while there has been zero flame for 2 hrs.
Tstat is at 3.15 or so, cat gauge 3/4 of the active range.
(32 outside and storming, 70 upstairs for the next many hours due to the Tstat working properly.)
So for me, based on this one data point, it's anecdotally not worth the gasket of taking it out...
Cat has about 9000 hrs.
I do think it's getting a little "tired"; I think I have to dial down a bit slower, after a slightly longer charring phase.
Is that really the case, or some trick my brain plays on me because I am cognizant that it's getting closer to the magical (or merely fantastical, as in not having any basis in reality...) 12,000 hrs, or I'm just getting more impatient... - I don't know.
I don't see a difference after the vinegar bath.
Cat still works but it didn't fire up earlier, it didn't allow to dial down quicker.
It's a nice glow, not bright white but just nice, uneven over the face of the cat though (likely due to an uneven burn/gas flow from a mix of pine and oak), while there has been zero flame for 2 hrs.
Tstat is at 3.15 or so, cat gauge 3/4 of the active range.
(32 outside and storming, 70 upstairs for the next many hours due to the Tstat working properly.)
So for me, based on this one data point, it's anecdotally not worth the gasket of taking it out...
To clarify for those that are following. Your test was performed on your original "steel cat".
I would agree that Steel Cats have not responded well for me either. I won't waste a minute on a steel cat.
A ceramic from Midwest is worth consideration when you are ready for a replacement. Then you will have something worth cleaning.
Correct.
I have a replacement on the shelf already.
I am satisfied with the steel cat, it's light off speed, it not clogging as it does for some. So at this point I am not getting another type.
I have a replacement on the shelf already.
I am satisfied with the steel cat, it's light off speed, it not clogging as it does for some. So at this point I am not getting another type.
I just lit the stove last night again after a relatively warmer spell when I use my minisplits.
But before the cleaning I did not see any smoke, say, 95% of the time of a 18 hr burn or so. Sometimes a few whisps (have to look carefully to note them when working outside) for 15 minutes and then nothing.
Of course I have a job (though at home) so I'm not constantly watching the flue.
That is all consistent with it not being dead.
But it was my understanding that the vinegar bath doesn't make a Lazarus out of a dead one, it instead adds a bit of oomph to one that's not as youthful anymore as it once was.
That I'm not seeing.
I just went to have a look
.
Inside the 85% full load of red oak (shorties) and 3 pine splits is about 60% consumed 12 hours after starting it. I think there have been no flames since dialing it down.
The cat gauge is at 1/4 of the active range. The (double wall) flue probe is at 300 F.
Outside there's zero smoke (no opacity) to be seen. No steam either but it's only 30 F here now.
Maybe I was too early. Though Midwest Hearth says to do it every 2 years.
Or maybe it's consistent with what @moresnow experiences.
I didn't try this because something is wrong, but because the discussion above triggered my interest, and because I do think it's slowly decreasing in performance. That's gradual, hard to quantify or prove to be the case without taking detailed data 3 years ago...
But before the cleaning I did not see any smoke, say, 95% of the time of a 18 hr burn or so. Sometimes a few whisps (have to look carefully to note them when working outside) for 15 minutes and then nothing.
Of course I have a job (though at home) so I'm not constantly watching the flue.
That is all consistent with it not being dead.
But it was my understanding that the vinegar bath doesn't make a Lazarus out of a dead one, it instead adds a bit of oomph to one that's not as youthful anymore as it once was.
That I'm not seeing.
I just went to have a look
.
Inside the 85% full load of red oak (shorties) and 3 pine splits is about 60% consumed 12 hours after starting it. I think there have been no flames since dialing it down.
The cat gauge is at 1/4 of the active range. The (double wall) flue probe is at 300 F.
Outside there's zero smoke (no opacity) to be seen. No steam either but it's only 30 F here now.
Maybe I was too early. Though Midwest Hearth says to do it every 2 years.
Or maybe it's consistent with what @moresnow experiences.
I didn't try this because something is wrong, but because the discussion above triggered my interest, and because I do think it's slowly decreasing in performance. That's gradual, hard to quantify or prove to be the case without taking detailed data 3 years ago...
You are possibly experiencing a tapering off of Cat effectiveness. You will eventually gnash your teeth over it enough, while dealing with increasing primary air settings etc. and low Cat temp outputs that your replacement must go in!
Eureka!
Until then. If it's providing adequate performance. Milk it.
Great. There is no question efficacy decreases over time. But going outside and seeing smoke (on a regular, often basis) is a sign of time to either deep clean or replace.
As I have posted before, cats, like tires, wear with time. Some drivers can "feel" the loss of traction and handling, others not so much, more a visual, "hey, I have less tread" sort of deal. With combustors, I know there are wood stove geeks that can feel the change over time.
BKVP
As I have posted before, cats, like tires, wear with time. Some drivers can "feel" the loss of traction and handling, others not so much, more a visual, "hey, I have less tread" sort of deal. With combustors, I know there are wood stove geeks that can feel the change over time.
BKVP
If I'm above 800 or so (on the Condar cat thermometer) I don't see any smoke. But when I shut it down for an overnight burn and it hovers around 600, I do. Would you call that failing, or not ?
OK, then the cat therm reading isn't influenced by the fan air...thanks for doing the experiment.
BKVP
Yeah man, the fumes from boiling vinegar are pretty stout.
Well, no experiment, really, since I have no fans to turn on or off.
But what do you think of my cat's condition, based on what I reported (in post #110 above) ? After all these years, I'm still not really sure what to expect.
I would certainly say it's failing. Those overnight smoke sessions can gunk up your flue until the tar drips onto your roof. The low end dies out first in my experience.
Smoke is wasted fuel.
Dang, I wonder what happened ? It's about two years old (got it halfway thru 2023-24 season, Midwest Hearth steel). Hard to say how many hours that is, but I'd say maybe 1000 hrs per year. Guess I'll try the vinegar next time we have a couple warm days.
600 isn't stalled but it's to close. What happens if you crack the thermostat a tiny bit? Even 800 isn't very hot, so it may need replacement.
BKVP
I've posted this before, but online sellers do not and are not required to provide the same matrix of precious metals coatings. Call Midwest to see if they will warranty the combustor.
BKVP
@RustyShackleford
I would try to dial down a bit later and in smaller steps.
That's what I think (...) I have to do with mine.
Sometimes I go a bit too fast (i.e. as fast as I could initially), and I see the cat gauge not increasing but slightly decreasing. If I look then I can sometimes see some smoke out of the flue. Dial up to get some robust flame for a couple of minutes (the cat generally starts glowing then - presumably because of the heat from the firebox/flame), and then dialing down in smaller increments works for me; the cat gauge goes up even when the flame does down (as it should). And the smoke is then gone.
This is my current state. Black box when the light is on but some glowing when it is dark. Cat glows nicely though (not as bright as it seems in the dark; just a nice warm orange).
This is 2 hrs and 15 mins of a load of about half red oak and half pitch pine.
I would try to dial down a bit later and in smaller steps.
That's what I think (...) I have to do with mine.
Sometimes I go a bit too fast (i.e. as fast as I could initially), and I see the cat gauge not increasing but slightly decreasing. If I look then I can sometimes see some smoke out of the flue. Dial up to get some robust flame for a couple of minutes (the cat generally starts glowing then - presumably because of the heat from the firebox/flame), and then dialing down in smaller increments works for me; the cat gauge goes up even when the flame does down (as it should). And the smoke is then gone.
This is my current state. Black box when the light is on but some glowing when it is dark. Cat glows nicely though (not as bright as it seems in the dark; just a nice warm orange).
This is 2 hrs and 15 mins of a load of about half red oak and half pitch pine.
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I'm a little confused. I thought you'd recommended Midwest Hearth before. But they are an online seller. Are you saying best to go thru authorized BK dealer ?
I can get another photo tomorrow, if needed... but Hearthstone 8024. 1.5(ish) years of burning, have never cleaned the cat.
What are your thoughts on the cleanliness of this cat? does it need to be cleaned?
- I generally burn doug fir and larch. Sometimes a white pine gets thrown in here or there but it's 90-95% doug fir/larch
And if it needs to be cleaned, is it "clean it now while you don't freeze during cold spells" or "clean it whenever you next get a chance. If you're not seeing drastic reduction in burn times/heat output, there's no worry"
What are your thoughts on the cleanliness of this cat? does it need to be cleaned?
- I generally burn doug fir and larch. Sometimes a white pine gets thrown in here or there but it's 90-95% doug fir/larch
And if it needs to be cleaned, is it "clean it now while you don't freeze during cold spells" or "clean it whenever you next get a chance. If you're not seeing drastic reduction in burn times/heat output, there's no worry"
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