Cleaning a catalytic combustor with vinegar bath

[georgepds]

You could always use vinegar as the bath in the ultrasonic cleaner

 

[Woody Stover]

Maybe you can extend that life if your not burning low and slow all the time and keep a little flame going that would keep the cat from doing all the work?

keeping it low reduces the chances that you'll get the cat white-hot and sinter the wash coat.

Yeah, I figure it's easier on the cat if I don't glow it real brightly, like bright orange or yellow. So I'll either run a bit of flame in the box, or if I want no flame I'll cut the air to where the cat isn't glowing real bright. I don't run it at the point right under where the flame goes out and the cat is bright.

 

[georgepds]

from woodstock

(broken link removed to https://www.woodstove.com/images/editorial_support/209%20PDFs/209%20Catalytic%20Combustor%20171011.pdf)



"VINEGAR & WATER CLEANING HOW TO:

The vinegar & distilled water cleaning is recommended 1-2 times during the heating season. The vinegar is just acidic enough to remove any ash within the cells that may be masking the catalytic coating. Materials needed: (1) work gloves and safety glasses; (2) spray bottle; (3) white vinegar; (4) distilled water.

1. Be sure the fire is out and the stove is cold. Remove the top stones from the stove. Lift the cast iron cook top and stand it up in the rear channel.

2. Slide the combustor forward and out from under the cast iron surround. Place the combustor onto 21 newspaper or an old towel. In the spray bottle prepare a 50/50 white vinegar & distilled water mixture.

3. Spray the 50/50 mixture through one side of the combustor and allow it to drain onto the newspaper. Flip the combustor over and spray through the other side and allow it to drain.

4. Rinse the combustor with 100% distilled water to remove any remaining vinegar, allow the combustor to dry before returning the combustor to the stove.

5. Return the combustor to the stove. Be sure that it is seated properly to the gasket behind.

6. Close the top lid."

 

[heavy hammer]

Highbeam I ended up replacing my cat while cleaning out my stoves and chimney's today. Your pic's helped out a lot. I'll post some in a bit, thanks for posts.

 

[heavy hammer]

Removing the old cat was more difficult than putting the new one. I used scotch tape to hold the gasket together and on the corners for a smooth slide in. The dogs supervised since the stove room is their hangout. Three years and not bad, the old cat looks worse than it was from pulling on it with needle nose and regular pliers. Appreciate the old pics Highbeam!

 

[Kevin Weis]

Okay, what about the metal cats?

 

[jetsam]

Okay, what about the metal cats?

Same deal, can be handled less gingerly. Thermal shock isn't an issue if you're boiling it.

 

[kennyp2339]

Quick question, I’m boiling off the cat now in distilled vinegar, how long does it stay in this bath? 30min an hour? Just wondering

 

[kennyp2339]

So I’m answering my own question, I let the cat sit in the vinegar bath for 2hrs, multiple times I brought the vinegar to a boil, then let cool off to just steam when I opened the lid, I gently dunk the cat all throughout the process, rinsed it off with distilled water twice and then put it in my kitchen oven in a disposable backing pan at 300 for 30 min to dry off.
I re-installed the cat with a new gasket and made a fire, 20min in I closed the bypass, the needle climbed to 1pm, cat is glowing happily T stat is set at 2:30 position, just have ghost flames above the wood.. let’s see if this holds

 

[sacountry]

Anyone tried compressed air to clean their cat? Ive read this thread about vinegar which makes sense but I opted to go with compressed air to clean the cat for faster turnaround time during burn season.

 

[begreen]

Anyone tried compressed air to clean their cat? Ive read this thread about vinegar which makes sense but I opted to go with compressed air to clean the cat for faster turnaround time during burn season.

Yes, that's ok for clearing out ash from the cells as long as the pressure is low.

 

[sacountry]

Yes, that's ok for clearing out ash from the cells as long as the pressure is low.

Have a hot burn going now to see if I can get the cat to glow, even on wide open. Wondering if that's an indicator of a failing cat (after 2 consecutive years of Sept-May burning) despite no signs of collapsing / worn cells. Maybe I have burned off the coating???? Or maybe the compressed air didn't uncoat the ash from the cat enough. Wish there was a better way to know......I've seen BK40 cats for $400 on Amazon which is not cheap.

 

[begreen]

An average catalytic has a lifespan of about 10,000 to 12,000 hrs. That can be 2yrs. of 24/7 burning for 8 months of the year. Check MidWest Hearth's website for a replacement cat.

 

[sacountry]

So would a lack of glow to the cat be an indicator of failing ?

 

[kennyp2339]

Get your stove up to temp, engage cat and wait 15min, then go outside and look at your stack, see smoke or not?
Another way is to burn on high for 20min, then lower to 1/2 air setting, if the cat probe needle falls to just above the engagement line on the probe then it’s time to change the cat.
Compressed air can blow off the wash coating on the cat itself, burning the stove to high (with draft out of spec) can at nearly 1,700 deg f start flattening out that wash coating making the cat less effective/ efficient.
Same with burning wet wood or wood with snow / ice on it, thermal shock can collapse cat cells in ceramic cats.
On my princess I’ve notice towards the end of the cats life, poorer heat coming from the stove, more of an orange / blonde fly ash building near the cat shield, a dirtier chimney cap since my cap has a mesh screen.

 

[sacountry]

Get your stove up to temp, engage cat and wait 15min, then go outside and look at your stack, see smoke or not?
Another way is to burn on high for 20min, then lower to 1/2 air setting, if the cat probe needle falls to just above the engagement line on the probe then it’s time to change the cat.
Compressed air can blow off the wash coating on the cat itself, burning the stove to high (with draft out of spec) can at nearly 1,700 deg f start flattening out that wash coating making the cat less effective/ efficient.
Same with burning wet wood or wood with snow / ice on it, thermal shock can collapse cat cells in ceramic cats.
On my princess I’ve notice towards the end of the cats life, poorer heat coming from the stove, more of an orange / blonde fly ash building near the cat shield, a dirtier chimney cap since my cap has a mesh screen.

That is all SUPER helpful. I have noticed more smoke with the cat engaged which lead me to think the cat wasn't clogged (although it was partially) but rather probably coated with ash. I never really considered that the metal coating could be blown away by compressed air towards end of life. I saw some dude on YouTube running a pipe cleaner through each cell and several other using a shop vac taped to the stove. Didn't see anyone doing a vinegar bath....but I have learned a ton from this website so thank you. I do have a sneaking suspicion now that 2 solid winters of burn have killed the cat. Anyone have a favorite online dealer that isn't charging $400 for a steel cat?

 

[kennyp2339]

Midwest hearth

 

[begreen]

So would a lack of glow to the cat be an indicator of failing ?

No, not necessarily. Smoke coming out of the chimney is a better indicator.

 

[sacountry]

An average catalytic has a lifespan of about 10,000 to 12,000 hrs. That can be 2yrs. of 24/7 burning for 8 months of the year. Check MidWest Hearth's website for a replacement cat.

I've been doing some research. I can't find any other options that SteelCat and Midwest Hearth for my BK40 ceramic OEM combustor. I'm intrigued by Midwest Hearths warranty. If I'm only going to get 2 years (current combustor age) on 24x7 burning 7-8 months a year then their 40% off warranty is super compelling ....and probably worth the price.

Curious to see if anyone has leveraged the warranty and how smooth was it?

 

[Highbeam]

I've been doing some research. I can't find any other options that SteelCat and Midwest Hearth for my BK40 ceramic OEM combustor. I'm intrigued by Midwest Hearths warranty. If I'm only going to get 2 years (current combustor age) on 24x7 burning 7-8 months a year then their 40% off warranty is super compelling ....and probably worth the price.

Curious to see if anyone has leveraged the warranty and how smooth was it?

I recommend you not get a steel cat. I would pay more for ceramic.

 

[NHWS]

I recommend you not get a steel cat. I would pay more for ceramic.

Why?

 

[Highbeam]

Why?

Lots of reasons but the most important are that the steel doesn't last as long, clogs easier, and reduces draft. I believe that they are primarily on the market because they are harder to physically damage. There is no tangible performance difference between steel and ceramic. To further push my preference away from steel we have been seeing shrinkage of the steel honeycomb from the can, some sort of material failure.

A new steel outperforms a dead ceramic every day which is why you see people so happy with their new steel cat.

 

[sacountry]

Lots of reasons but the most important are that the steel doesn't last as long, clogs easier, and reduces draft. I believe that they are primarily on the market because they are harder to physically damage. There is no tangible performance difference between steel and ceramic. To further push my preference away from steel we have been seeing shrinkage of the steel honeycomb from the can, some sort of material failure.

A new steel outperforms a dead ceramic every day which is why you see people so happy with their new steel cat.

Very interesting

 

[sacountry]

Lots of reasons but the most important are that the steel doesn't last as long, clogs easier, and reduces draft. I believe that they are primarily on the market because they are harder to physically damage. There is no tangible performance difference between steel and ceramic. To further push my preference away from steel we have been seeing shrinkage of the steel honeycomb from the can, some sort of material failure.

A new steel outperforms a dead ceramic every day which is why you see people so happy with their new steel cat.

Very interesting

 

[Highbeam]

Very interesting

To be clear, either cat substrate material works well enough. You can't go terribly wrong with either. But you have to choose and the choice is clear to me after using both.