Cleaning a catalytic combustor

SCOTT S.

Burning Hunk
Mar 22, 2014
242
Waupaca WI
Great thanks for the great thread I’m going to give it a shot.
 

Highbeam

Minister of Fire
Dec 28, 2006
16,222
Mt. Rainier Foothills, WA
Great thanks for the great thread I’m going to give it a shot.
It’s fun and made a noticeable difference but it only bought me a few more months. In my case, the cat was just past the rated service life. If your cat is still young but coated with “stuff” then you may get more bang for your vinegar buck.
 

SCOTT S.

Burning Hunk
Mar 22, 2014
242
Waupaca WI
95DDD2FA-A452-4116-866F-46769840053D.jpeg
My cat was 80% plugged. Did the acid bath last night. I did the distilled water rinse four times before it was clean. I think my cat probably won’t last much longer as we burn starting in September until early June and this is its third year. I wish I would have taken pictures, I never seem to think of it in the middle of a project. I haven’t seen this much glow in a while.
 

Highbeam

Minister of Fire
Dec 28, 2006
16,222
Mt. Rainier Foothills, WA
View attachment 225687
My cat was 80% plugged. Did the acid bath last night. I did the distilled water rinse four times before it was clean. I think my cat probably won’t last much longer as we burn starting in September until early June and this is its third year. I wish I would have taken pictures, I never seem to think of it in the middle of a project. I haven’t seen this much glow in a while.
After the vinegar bath process my worn out cat was rejuvenated significantly but it did not last. Got a few good months out of it before the cats age again became apparent. Really, it wasn’t worth the time, cost, and effort to do an acid wash when a new cat is so cheap.
 

SCOTT S.

Burning Hunk
Mar 22, 2014
242
Waupaca WI
After the vinegar bath process my worn out cat was rejuvenated significantly but it did not last. Got a few good months out of it before the cats age again became apparent. Really, it wasn’t worth the time, cost, and effort to do an acid wash when a new cat is so cheap.
Did you buy your new cat from firecat?
 

SCOTT S.

Burning Hunk
Mar 22, 2014
242
Waupaca WI
Yes! Through their amazon store mid mountain or whatever. 186$ shipped! It's running at 1400 right now.
Ok , I looked at them on amazon the ceramic one for the princess is the same size as the steel one for the Ashford is there any reason I can’t use the ceramic in my Ashford?
 

Highbeam

Minister of Fire
Dec 28, 2006
16,222
Mt. Rainier Foothills, WA
Ok , I looked at them on amazon the ceramic one for the princess is the same size as the steel one for the Ashford is there any reason I can’t use the ceramic in my Ashford?
Oooh, excellent question. I can use either on my princess but I am unsure about the newer ashford that was only ever manufactured ant tested with the more expensive steel.

That’s a great question for bk. I’m sure their official answer is steel only but would the ceramic work? After having gone back and forth I’m perfectly happy with the ceramic.
 

Todd

Minister of Fire
Nov 19, 2005
9,244
NW Wisconsin
Soaking my Keystone cat now in a 50/50 solution, no boil, I'll just let it soak for a couple hours then rise with distilled water. Ive gone 3.5 years with this steel cat and i wanted to replace but Woodstock is having problems with their supplier so they've been out of stock for quite some time and cant give me a date on new ones coming in. I'm hoping to get it will rejuvenate and give me another month or two.
 

Highbeam

Minister of Fire
Dec 28, 2006
16,222
Mt. Rainier Foothills, WA
Soaking my Keystone cat now in a 50/50 solution, no boil, I'll just let it soak for a couple hours then rise with distilled water. Ive gone 3.5 years with this steel cat and i wanted to replace but Woodstock is having problems with their supplier so they've been out of stock for quite some time and cant give me a date on new ones coming in. I'm hoping to get it will rejuvenate and give me another month or two.
Sorry about the supply chain problems. Deep down I think all of us cat stove guys worry about that.

I didn’t reread the whole thread but I recall easily getting a month or two of excellent cat activity after the full cat boil. The Woodstock guys have been known to use a spray bottle of vinegar and then a spray bottle of distilled water for rinse it so I’m thinking the boiling may not be required.
 

Todd

Minister of Fire
Nov 19, 2005
9,244
NW Wisconsin
Yeah, I usually do the spray bottle thing once a year, hoping a longer soak will help. Woodstock told me they are waiting on some equipment then they will start making their own cats so they never have this problem again.
 
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Todd

Minister of Fire
Nov 19, 2005
9,244
NW Wisconsin
Looks like I have some new cat life this morning, how long is yet to be determined. I was having problems getting the stove temp up to 500 with a full load of Black Locust before the soak now she's cruising along nicely at 600+. I soaked the cat for 3 hours occasionally lifting it out to flush out the loose deposits and it came out looking brand new. It left lots of junk in the bottom of the soaking tub, a lot more than I thought there would be.
 
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Rockey

Minister of Fire
Dec 18, 2007
791
SW Ohio
Anyone ever tried an ultrasonic cleaner? I bought one for my business about 5 years ago and does a great job cleaning circuit boards. The unit we have is controllable on duty cycle and frequency. I could try a low setting and hope the substrate integrity is not compromised. May have tot ry it at the end of the season this year and see what happens.
 

jetsam

Minister of Fire
Dec 12, 2015
4,225
Long Island, NY
youtu.be
Anyone ever tried an ultrasonic cleaner? I bought one for my business about 5 years ago and does a great job cleaning circuit boards. The unit we have is controllable on duty cycle and frequency. I could try a low setting and hope the substrate integrity is not compromised. May have tot ry it at the end of the season this year and see what happens.
I think you should try it. I understand there are 3 layers- substrate (ceramic or steel), then a high surface area wash coat (aluminum oxide), and then some catalyst (palladium?).

I don't know anything about how the catalyst is made to adhere to the wash coat, so no speculation as to whether the ultrasonic cleaner will be harmful. I do suspect that if the cat has ever been overheated, you will lose a lot of substrate in the cleaner.

Ultrasonic cleaners are good at decalcification, which is basically the goal of the vinegar bath, so maybe it will be awesome!
 
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Woody Stover

Minister of Fire
Dec 25, 2010
10,638
Southern IN
I soaked the cat for 3 hours occasionally lifting it out to flush out the loose deposits and it came out looking brand new. It left lots of junk in the bottom of the soaking tub, a lot more than I thought there would be.
Was the catalyst peeling or coming loose, that you could see by looking through it? I guess not if " it came out looking brand new."
 

Todd

Minister of Fire
Nov 19, 2005
9,244
NW Wisconsin
Was the catalyst peeling or coming loose, that you could see by looking through it? I guess not if " it came out looking brand new."
No peeling I could see just some hard light colored deposits mostly on the cat face that wouldnt come loose with a paint brush.

My take on these new steel cats is they need a little more maintenance than the ceramics since the holes are much smaller. I tend to brush mine about every two weeks or so. Also need to brush that scoop as well. Im tempted to go back to ceramic for a little better flow as well as a little more heat. I always had a hotter stove with may ceramic cats but I'm not sure they last as long as the steelies?
 

jetsam

Minister of Fire
Dec 12, 2015
4,225
Long Island, NY
youtu.be
No peeling I could see just some hard light colored deposits mostly on the cat face that wouldnt come loose with a paint brush.

My take on these new steel cats is they need a little more maintenance than the ceramics since the holes are much smaller. I tend to brush mine about every two weeks or so. Also need to brush that scoop as well. Im tempted to go back to ceramic for a little better flow as well as a little more heat. I always had a hotter stove with may ceramic cats but I'm not sure they last as long as the steelies?
If you take care of a ceramic, the service life is the same. End of life happens when not enough catalyst is exposed- through washcoat collapse, washcoat delamination, or masking. Could be other stuff I've never heard of.

BKVP says he's been burned one cat 24/7 for 10 years, and it didn't get any special treatment.. I got 2.5 out of my first one. I expect the user's definition of 'dead' plays into that heavily.
 

Woody Stover

Minister of Fire
Dec 25, 2010
10,638
Southern IN
My take on these new steel cats is they need a little more maintenance than the ceramics since the holes are much smaller. I tend to brush mine about every two weeks or so. Also need to brush that scoop as well. Im tempted to go back to ceramic for a little better flow as well as a little more heat. I always had a hotter stove with may ceramic cats but I'm not sure they last as long as the steelies?
Yeah, I need to brush the cat and screen and clean the glass as well but it's too cold to let the stove go out right now.
I'm not sure about how long the cats last. I think I had the first steelie (diesel-foil) for about three years before I bought this one. I also have the original ceramic that came with the stove, which still works OK. Hard for me to say how many hours I have on anything; I was switching cats back and forth, and switching the Fireview and Dutchwest in and out since 2010.
 

heavy hammer

Minister of Fire
Jul 18, 2015
1,447
Kirtland Ohio
What is the average life of a cat? The ones who have done he acid bath is it worth the time or would you just purchase a new cat? How long after the acid bath would you say the cat lasted?
 

Highbeam

Minister of Fire
Dec 28, 2006
16,222
Mt. Rainier Foothills, WA
What is the average life of a cat? The ones who have done he acid bath is it worth the time or would you just purchase a new cat? How long after the acid bath would you say the cat lasted?
Pretty consistent across all brands and forum members on this and the other forum to get 10-12000 hours before a significant decline in function. Just as the cat manufacturer rates them.

It is ridiculous to use “years” as a time frame in this application because a cat can last for 1000 years if the stove never gets used.

I tried to summarize in the thread but since I only got a few more months and since a new cat is under 200$ I will not be doing another vinegar bath unless I run into an emergency where a new cat is not available for some reason.
 
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Todd

Minister of Fire
Nov 19, 2005
9,244
NW Wisconsin
What is the average life of a cat? The ones who have done he acid bath is it worth the time or would you just purchase a new cat? How long after the acid bath would you say the cat lasted?
Average life of a cat is 12,000 hrs give or take and that number probably has a lot of variables with it. 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?
 
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jetsam

Minister of Fire
Dec 12, 2015
4,225
Long Island, NY
youtu.be
Burning low and slow makes the cat do more work over the course of the load, not less. A catalyst (by definition) isn't consumed by the reaction that it encourages, so that doesn't matter. On the other hand, keeping it low reduces the chances that you'll get the cat white-hot and sinter the wash coat.


On the cat bath thing, I am kind of using this as scratch paper to do my thought process...

Consensus seems to be that we get 2-3 months out of a cat bath. Say that's 1/3 of a 5000 hour burning season for a full time burner, or 1666 hours.

A cat costs $200 and lasts 12000 hours, or $0.017/hr, so a bath gets us $28 worth of cat lifespan back, less $10 for the gasket and vinegar.

If masking is the primary issue, I should be able to keep one cat going indefinitely for $30 a year (3x gasket + 3 gal vinegar).
If substrate sintering is the issue, performance should not be impacted by the bath and the cat will function in a degraded capacity.
If substrate delamination is the primary issue, time for a new cat.


Still curious to hear how the ultrasonic cleaner does. That would be neat if it works well. (I am basically looking for an excuse to buy a new gadget here. Found one that fits my cat for $130 on Amazon. :) )