catalyst replacement... condar vs firecat?

[clemsonfor]

Anyone have any thoughts. Prices are about the same. Doesn't look like the "steel cat" version of the condar brand is availible from what I see.

I have a high valley.It takes 3 x 7 x 2thick. One of the sites I think condar its like a c 351 part #.

Just really looking for opinions on those who have either or had both.

 

[Woody Stover]

I haven't tried both in the 91 but I got the Firecat (Applied Ceramics) for it last year. The catalyst spray looked a little spotty to me, but maybe all brands are that way? The pic of the Condar looks about the same. The catalyst metal is expensive so I guess they try to go as light as possible.
Why don't you get the Condar and we can compare notes.
Cat seems to be working OK, but you have to get the cat probe up to about 1100* before it really starts burning up all the smoke. Maybe that's just the nature of the 91....
To me, it would be worth an extra hundred bucks to have 'em put the catalyst on heavier if it would be easier to light off....

https://www.hearth.com/talk/threads/new-combustor-maybe-its-not-as-bad-as-it-looks.106688/

 

[clemsonfor]

Yea I remember reading your thread now. The 91 is similar in look and design to the HV 2500. I may do that. Also from the manufacturthere about the same price. I'll see what they catty and why.

 

[Todd]

I haven't tried both in the 91 but I got the Firecat (Applied Ceramics) for it last year. The catalyst spray looked a little spotty to me, but maybe all brands are that way? The pic of the Condar looks about the same. The catalyst metal is expensive so I guess they try to go as light as possible.
Why don't you get the Condar and we can compare notes.
Cat seems to be working OK, but you have to get the cat probe up to about 1100* before it really starts burning up all the smoke. Maybe that's just the nature of the 91....
To me, it would be worth an extra hundred bucks to have 'em put the catalyst on heavier if it would be easier to light off....

https://www.hearth.com/talk/threads/new-combustor-maybe-its-not-as-bad-as-it-looks.106688/

I haven't tried both in the 91 but I got the Firecat (Applied Ceramics) for it last year. The catalyst spray looked a little spotty to me, but maybe all brands are that way? The pic of the Condar looks about the same. The catalyst metal is expensive so I guess they try to go as light as possible.
Why don't you get the Condar and we can compare notes.
Cat seems to be working OK, but you have to get the cat probe up to about 1100* before it really starts burning up all the smoke. Maybe that's just the nature of the 91....
To me, it would be worth an extra hundred bucks to have 'em put the catalyst on heavier if it would be easier to light off....

https://www.hearth.com/talk/threads/new-combustor-maybe-its-not-as-bad-as-it-looks.106688/

Did you ever send those pictures to Applied Ceramic? Maybe they could give you more info? I've talked to them in the past and they were very helpful.

 

[clemsonfor]

Called Stohl (who owns High valley now) and they said they have always used Applied ceramics and that is the OE one. So i think i will go with them. He was honest and told me to order directly from them it would be better. That way i have a warrenty through them (AC). If i order from them its up to them to warrenty the product. ANd if i order from them it would be cheaper for me to drive up to the shop to get it which is an hour both ways (they have $20 shipping), and then i would have to pay $15 tax on the sale and they are $15 more per cat and i need 2 So ordering from AC i will save $45 plus the time and fuel to drive an hour! Firecat has free shipping!

 

[Ashful]

Cat seems to be working OK, but you have to get the cat probe up to about 1100* before it really starts burning up all the smoke.

At 1100F, the smoke will burn without a catalyst, thus the entire operating principle of a non-cat reburn stove. With the catalyst, you should get complete action at any temperature above 500F.

That said, I've noticed that my Condar SteelCat's burn the smoke completely at 450F when brandy new, 500 - 700F for a few weeks / months after that, and it climbs from there. A year in, and they don't seem to burn completely until above 700F.

I think these SteelCat's (all brands, not just Condar) are apt to go into over-temperature (>1500F) when new, as they are highly-reactive out of the box. At temperatures above 1500F, the catalyst starts to delaminate from the substrate (stainless or ceramic), thus severely shortening the life and effectiveness of the cat. It seems it just takes a few almost-unavoidable forays into this range, before the combuster becomes much less effective at lower temperatures.

Coming back to your case, Woody, if your cat is not consuming the smoke until you hit 1100F, you don't have any catalyst left on your combustor. It's operating as a non-cat.

 

[Woody Stover]

At 1100F, the smoke will burn without a catalyst, thus the entire operating principle of a non-cat reburn stove. With the catalyst, you should get complete action at any temperature above 500F.

That said, I've noticed that my Condar SteelCat's burn the smoke completely at 450F when brandy new, 500 - 700F for a few weeks / months after that, and it climbs from there. A year in, and they don't seem to burn completely until above 700F.

I think these SteelCat's (all brands, not just Condar) are apt to go into over-temperature (>1500F) when new, as they are highly-reactive out of the box. At temperatures above 1500F, the catalyst starts to delaminate from the substrate (stainless or ceramic), thus severely shortening the life and effectiveness of the cat. It seems it just takes a few almost-unavoidable forays into this range, before the combuster becomes much less effective at lower temperatures.

Coming back to your case, Woody, if your cat is not consuming the smoke until you hit 1100F, you don't have any catalyst left on your combustor. It's operating as a non-cat.

The way I understood the manual, you are OK if you avoid extended periods over 1800. But who knows....this is starting to sound like rocket science, which I'm definitely not qualified to do. But once the combustor lights, it will burn at much lower temps. After I cut the air to almost nothing and the stove is smoIdering, I can come back hours later and the cat temp will still be around 800, even though the stove is nowhere near that temp, so the cat is definitely working. If I don't get a fairly high temp at the beginning, I can still see some smoke out of the stack, which I don't like. It's not a lot, but still.... Others shut the 91 down at 500 and I think that eventually the cat will burn more and more of the smoke as the cat temp rises. I never played with this approach much, as I like to burn clean as quickly as possible, especially since my MIL has a lot of neighbors close by. Even new out of the box, the ceramic cat never took off fast from low temps in the 91 like the cats in the Woodstocks (and maybe the Firelight) will.

Did you ever send those pictures to Applied Ceramic? Maybe they could give you more info?

No I didn't but that's a good idea....

 

[Woody Stover]

With the catalyst, you should get complete action at any temperature above 500F.

I've seen that number, too. The 91 manual says engage at 700-900 on the probe thermo, however....

 

[clemsonfor]

I think my manual says around 500 mininmum but i tend to see the best result when i engage around 700?

 

[Ashful]

Yeah, same here. If I engage under 700'ish, the cat seems to stall for a very long time before taking off, if at all. Often, if I engage below 700, it will never take off, and will just gradually fall down below 500 over the course of an hour.

However, my point was two-fold:

1. Woody Stover should see complete combustion at temps below 1100F. If not, I assume he has no catalyst action, and is simply seeing the same reburn activity you would have in a non-cat.

2. Both of my new steel cats used to take off like a bat out of hell, when engaged at 500F. Now it's 700F, and sometimes even fails then. Next year, will it be 900F? For full disclosure, my wood supply was variable last year, as I was burning a mix of stuff, some CSS'd less than a full year. Maybe I'll see more consistent lower-temperature light-offs this year, with dryer wood.

Then again... the way it's raining (another 5 inches last night), maybe I won't have dry wood. I have never seen such a combination of constant summer rain and humidity in my life.

 

[Woody Stover]

Woody Stover should see complete combustion at temps below 1100F. If not, I assume he has no catalyst action, and is simply seeing the same reburn activity you would have in a non-cat.

I think what I'm seeing, instead of "no catalyst action," is partial cat burning until the stove temp gets sufficiently high. As I said, there isn't a ton of smoke coming out, just enough to piss me off. The cat is working since the stove can be burning with no smoke and the cat glowing red with probe readings of only 600 with the air cut. I just think that all the steel mass in the stove must have something to do with the cat being slower to light off completely at the beginning of the burn.

For full disclosure, my wood supply was variable last year, as I was burning a mix of stuff, some CSS'd less than a full year. Maybe I'll see more consistent lower-temperature light-offs this year, with dryer wood.

Moisture in the wood will definitely affect how quickly you can light the cat and get a clean burn, that's for certain.

the way it's raining (another 5 inches last night), maybe I won't have dry wood. I have never seen such a combination of constant summer rain and humidity in my life.

Although I'm not new to burning, I'm new to getting my wood dry. I haven't tested any of my quick-dry soft Maple yet to see how much slower it is going than last year with the hot, dry weather we had but I can tell it is definitely slower. I hope it's not setting my drying schedule back too much....

 

[mellow]

I notice after really hot days my piles need to be realigned, that is how I know something is changing. I don't have to do it after rains.

 

[clemsonfor]

I had piles need to be fixed after rain! We had 12 inches in june alone, the ground was super soft and it sank in.

 

[clemsonfor]

Took the cats out. When I got the stove used 2 .5 yrs ago dealer said he replace the cats.
How brittle are these things they fell apart as I prayed it out. No I did not use the hammer I thought o would pry but it did not work.

Could I have worn them out in that time of 24/7 burning from late Nov to early march 24/7 and part time before n after that? I burn 9 month to 2 year seasoned wood
I know longer is better but its what I had and the manufacturer says 1 yr wood anyway.Rally from the begenninof the season I always saw some smoke even though the vat was in the active range, but after cleaning the chimney I do believe that it was not working right most of the season!

 

[BrotherBart]

A little industry birdie just whispered in my ear that Applied Ceramics makes the substrates for Condar.

 

[Ashful]

Thats pretty bad for 2 years. My last cat was 19 years old (intermittent use), and had no fracturing or cratering.

Looks like classic steam impingement damage. Basic theory, cat is hot when you throw in a fresh load. Steam hits cat causing very rapid cooling, and fracture.

Three possible solutions:

1. Use wood at or below 20% MC.
2. Delay cat engagement.
3. SteelCat.

 

[clemsonfor]

I think they didn't replace them honestly. And they don't make a strelcat for my stove

 

[Woody Stover]

A little industry birdie just whispered in my ear that Applied Ceramics makes the substrates for Condar.

And then Condar sprays on the catalyst at their facility, so there could be a difference between the two brands?

I've read that besides thermal shock, flame impingement (roaring fire causing flame to hit the face of the combustor) can also cause cracking. I'm not sure what causes the cupping or scooping of the flat surface of the combustor face....

 

[Ashful]

Jotul has a nice write up on this in the Firelight 12 manual, available on line. My memory is not good, but IIRC, Flame impingement is supposed to blow little chunks of ceramic out of the face upon which the flames are incident, where as cracking thru is usually blamed on steam. Check me on that...

 

[jharkin]

That said, I've noticed that my Condar SteelCat's burn the smoke completely at 450F when brandy new, 500 - 700F for a few weeks / months after that, and it climbs from there. A year in, and they don't seem to burn completely until above 700F.

I think these SteelCat's (all brands, not just Condar) are apt to go into over-temperature (>1500F) when new, as they are highly-reactive out of the box. At temperatures above 1500F, the catalyst starts to delaminate from the substrate (stainless or ceramic), thus severely shortening the life and effectiveness of the cat. It seems it just takes a few almost-unavoidable forays into this range, before the combuster becomes much less effective at lower temperatures.

Same experience I have had. Condar rates these things as OK up to 1700F, but I have found that after only 4 seasons mine seems to have seriously degraded performance (visible smoke up to 1000F and lot of creosote even though I get good light offs), in spite of the fact Ive only been over 1700 on 3 occasions and typically cruise at 1100-1300.

Im considering sending mine back for a warranty replacement. I'll only get like 25% off the new one at this point but its better than nothing.

 

[clemsonfor]

Yep firecat shows about 8 different pics of cats and what causes them, did not look at the cupping, but steam is what causes cracking.

My cats sit in a metal trough on the front of the stove, in bypass the hole is in the back and the flames go up it, but not i am thinking i have engaged with a roaring reload a few times...maybe i got impingement. I could see the flames being sucked in at the ends of the trough and into the cat chamber but to hit the cats is a streach but maybe, will have to change my burn style with new ones.

But as far as normal flames, they just lick the metal chamber that they sit in, you cant physically see my cats putting your head in the stove unless your a little nomb and can crawl up in there and look East west inthe stove into the trough they sit in. Its not like some of those high dollar fragile stoves where they just sit there up top.

 

[mellow]

Sadly with everything else these days it sounds like the quality of cats is declining, in my Sierra cat stove the cat was wide open to flame impingement and other abuse and it kept on rolling, was working when I sold that stove.

The applied ceramics cats on my app seem to be doing OK, I have damaged some of the cells with trying to get my thermocouples working right but they still glow and the chimney was very clean for the last season, of course they only have 1.25 seasons on them so they should be still working good.

 

[Woody Stover]

Jotul has a nice write up on this in the Firelight 12 manual, available on line. My memory is not good, but IIRC, Flame impingement is supposed to blow little chunks of ceramic out of the face upon which the flames are incident, where as cracking thru is usually blamed on steam. Check me on that...

Your memory ain't that bad. The Woodstock manual has a good description, too, about half way down the page:

(broken link removed to http://www.woodstove.com/pages/pdffiles/Catalytic%20Combustor%20Tips.pdf)

i am thinking i have engaged with a roaring reload a few times...maybe i got impingement. I could see the flames being sucked in at the ends of the trough and into the cat chamber but to hit the cats is a streach but maybe, will have to change my burn style with new ones.

I cut the air back in stages as I approach the temp I want to engage at, so the fire is pretty tame at that point.

But as far as normal flames, they just lick the metal chamber that they sit in, you cant physically see my cats putting your head in the stove unless your a little nomb and can crawl up in there

I'm not normally known as a gnome so I'm looking forward to putting the Keystone back in this fall; Then I'll be able to see the cat from the couch. On the Buck, I can look in through the hole for the bypass rod and see the cat glowing. In the fire box, it is obscure by the impingement shield. the flames have to go around the side of the shield and back to the middle to get to the cat. You have to drop the shield to remove the cat.

 

[Ashful]

Sadly with everything else these days it sounds like the quality of cats is declining...

I'm not sure I'd say that. Materials science and engineering is one area where, in general, we are vastly improved over the past. Remember cars that rusted out in 3 - 4 years? Plastics that fell apart if left out in the sun a year or two? Today's catalytic combusters almost certainly have endurance and performance characteristics beyond their predecessors, but perhaps our expectations, or the way they're being used in individual stove designs has changed over the years.

 

[clemsonfor]

i have a cat on my 1990 ranger with close to 300k miles on it to my knowledge works fine, the thing burns oil too and almost no smoke unless im dogging it over 4k rpms that ones got some age on it