Buck 91 Help me understand my first burns

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Kvic

New Member
Sep 12, 2021
93
Middle Tn
I have been reading through the forum trying to answer some of my questions/concerns, without starting another thread, but can't find an answer to everything.

From what I've gleaned so far, may be due to new cat being overactive and needing a few weeks of burning to settle down. But still concerned about some of the other. Sorry for the length.

First 3 burns done (almost) per manual to cure paint. 2-3 small splits, top down start, bypass open, air controls open, door open 1-2 inches for 1.5 to 2.5 minutes, shut door, after 3-4 minutes shut bypass completely .

First burn didn't open up the air controls all the way (didn't read the manual closely) and shut the bypass after 3-4 minutes. Lots of smoke opened bypass and then realized the air controls were closed. Got some flame and shut bypass, started smoking again so opened bypass a little to reignite flame and then closed. After a few minutes shut down air controls. Didn't pay enough attention to cat probe thermometer (Condar), but I think it hung out around 900.
Second fire opened air controls but still shut the bypass at 3-4 minutes still a lot of smoke. Opened bypass and got some flames and shut again, then shut the air controls down. Again cat probe got up to around 900.
Before third fire watched some videos of model 91 reviews. Started third fire the same as second, but left the bypass open longer until good flame going then closed. Let it burn a little then closed the bypass. Cat probe got up to 1200.

First big burn. Re-watched videos. Once again didn't pay attention to the manual. Thinking the start with 2-3 small splits was just for break in, I packed the stove, did top down start and following the videos, started to wait until the cat probe got up 500 before shutting bypass and air controls, but after a raging fire began to unnerve me, shut the bypass and just left the air controls open. Cat started to move a little, but fire was still raging. Shut down the air controls and fire subsided and cat started to climb. Got up around 900 and nerves calmed. Looked back at the stove after a few minutes and the probe was up to 1400 and started getting a little nervous. No fire but glowing embers and within a another couple of minutes, the probe temp started approaching the end of the safe zone (1500). Remembered reading somewhere, possibly this forum, that turning the blower on full speed would help to lower the temp so did that and began to scour the net for direction. One thing said open the bypass for a few seconds so did that and probed dropped a little but then went back close to 1500. Didn't have a stovetop thermometer, but didn't feel that hot when I put my hand close to it. Kept watching the probe and opened the bypass when it got close to 1500. Within about 30 minutes it settled at the 1400 mark and then later dropped to 1000. Felt safe to go to bed then. Hot bed of coals in the morning.

Second big burn. Bought an IR gun before any more fires. Started fire per manual with 3 small splits. Gradually closed the bypass until I saw the cat probe start to move a little then shut all the way. Left air controls open waiting for good burn and cat probe to get up to 500 before loading the stove. Seemed to have good fire and embers started before 500 so loaded the stove and kept air controls all the way open, and then about half way. At 500 shut air controls and cat started to climb. With the probe reading at 1000 went out and took the first picture. Thought there would have been less smoke at that point. Went back in and sat down for a minute and then looked over at the probe. It was right at 1500, so went out and took the second picture and no smoke. By the time stamp on the pictures it was just 3 minutes. Having read that new cats can be overactive wasn't too concerned until the temp started getting to close to 1600. Turned the fan on high and once again opened up the bypass for a few seconds. The probe hung out around 1600, and any time I saw it start to go up I opened the bypass. Did that a few times and then it started to settle down. Highest reading from the IR gun was close to 400 on the front between the bypass handle and probe. Stovetop was low 300's as well as the rest of the front where I measured it. Third picture shows how it was burning at that time. I remember noting that the picture actually made it look brighter than it was. Cat temp dropped to 1200 after a while and I felt much better. About 3 hours later the probe temp dropped some more and I decided to add more wood to burn through the night. Turned off fan, opened bypass and added 3 splits. Closed bypass opened the air controls per manual to make sure the new wood was burning and shut the air controls. That's when it got really interesting, and couldn't find answers for. After a few minutes I started seeing the ghost flames (I think that's what I remember them being called). No worries, read and viewed videos about them. Settled back in the chair and then panic ensued. I looked at the stove the cat was glowing, and it looked like fire was consuming the catalyst. Didn't know what to do so opened the bypass and it settled down. Closed bypass cat still glowing but no flames. Big whoosh of what looked like ghost flame and started again. Probe shot back up between the 1500 to 1600 mark. Checked stove top temp and still just under 400, front at same spot was 480s. Flames would burn for a while then after a burst of flame would die down. Some more ghost flames and the fire started back up. Kept opening the bypass to keep it down and eventually it settled down to just glowing cat. Calmed down but worried about damage to the catalyst. The pictures are screenshots from a video I took. Not real clear, but the first 2 show flame around the cat, and the second 2 a burst of flame that made all the flame disappear for a few seconds and then the flame would start back up around the cat. Flame periodically would increase and decrease and then the occasional big flame. The pdf is side view of the stove with the area where I saw flame highlighted. The closer I look at the video, it does seem to appear that the flames are around the cat, but not actually under it as it appeared at first, but I still have no idea if this is detrimental or not to the cat/stove.

Don't have a flue thermometer yet, and only have about 12" to work with, part of which is elbow, once I have block off plate installed. Right now only rock wool insulation.
Mix of hardwoods and not sure of all of them, but some ash, cherry and maple. All tested under 20% on fresh split after sitting inside.

So please let me know what I did wrong through the burns, and what other things I might need to be doing or not doing. Getting cold again tomorrow and hope to burn again.

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Kvic

New Member
Sep 12, 2021
93
Middle Tn
I have been reading through the forum trying to answer some of my questions/concerns, without starting another thread, but can't find an answer to everything.

From what I've gleaned so far, may be due to new cat being overactive and needing a few weeks of burning to settle down. But still concerned about some of the other. Sorry for the length.

First 3 burns done (almost) per manual to cure paint. 2-3 small splits, top down start, bypass open, air controls open, door open 1-2 inches for 1.5 to 2.5 minutes, shut door, after 3-4 minutes shut bypass completely .

First burn didn't open up the air controls all the way (didn't read the manual closely) and shut the bypass after 3-4 minutes. Lots of smoke opened bypass and then realized the air controls were closed. Got some flame and shut bypass, started smoking again so opened bypass a little to reignite flame and then closed. After a few minutes shut down air controls. Didn't pay enough attention to cat probe thermometer (Condar), but I think it hung out around 900.
Second fire opened air controls but still shut the bypass at 3-4 minutes still a lot of smoke. Opened bypass and got some flames and shut again, then shut the air controls down. Again cat probe got up to around 900.
Before third fire watched some videos of model 91 reviews. Started third fire the same as second, but left the bypass open longer until good flame going then closed. Let it burn a little then closed the bypass. Cat probe got up to 1200.

First big burn. Re-watched videos. Once again didn't pay attention to the manual. Thinking the start with 2-3 small splits was just for break in, I packed the stove, did top down start and following the videos, started to wait until the cat probe got up 500 before shutting bypass and air controls, but after a raging fire began to unnerve me, shut the bypass and just left the air controls open. Cat started to move a little, but fire was still raging. Shut down the air controls and fire subsided and cat started to climb. Got up around 900 and nerves calmed. Looked back at the stove after a few minutes and the probe was up to 1400 and started getting a little nervous. No fire but glowing embers and within a another couple of minutes, the probe temp started approaching the end of the safe zone (1500). Remembered reading somewhere, possibly this forum, that turning the blower on full speed would help to lower the temp so did that and began to scour the net for direction. One thing said open the bypass for a few seconds so did that and probed dropped a little but then went back close to 1500. Didn't have a stovetop thermometer, but didn't feel that hot when I put my hand close to it. Kept watching the probe and opened the bypass when it got close to 1500. Within about 30 minutes it settled at the 1400 mark and then later dropped to 1000. Felt safe to go to bed then. Hot bed of coals in the morning.

Second big burn. Bought an IR gun before any more fires. Started fire per manual with 3 small splits. Gradually closed the bypass until I saw the cat probe start to move a little then shut all the way. Left air controls open waiting for good burn and cat probe to get up to 500 before loading the stove. Seemed to have good fire and embers started before 500 so loaded the stove and kept air controls all the way open, and then about half way. At 500 shut air controls and cat started to climb. With the probe reading at 1000 went out and took the first picture. Thought there would have been less smoke at that point. Went back in and sat down for a minute and then looked over at the probe. It was right at 1500, so went out and took the second picture and no smoke. By the time stamp on the pictures it was just 3 minutes. Having read that new cats can be overactive wasn't too concerned until the temp started getting to close to 1600. Turned the fan on high and once again opened up the bypass for a few seconds. The probe hung out around 1600, and any time I saw it start to go up I opened the bypass. Did that a few times and then it started to settle down. Highest reading from the IR gun was close to 400 on the front between the bypass handle and probe. Stovetop was low 300's as well as the rest of the front where I measured it. Third picture shows how it was burning at that time. I remember noting that the picture actually made it look brighter than it was. Cat temp dropped to 1200 after a while and I felt much better. About 3 hours later the probe temp dropped some more and I decided to add more wood to burn through the night. Turned off fan, opened bypass and added 3 splits. Closed bypass opened the air controls per manual to make sure the new wood was burning and shut the air controls. That's when it got really interesting, and couldn't find answers for. After a few minutes I started seeing the ghost flames (I think that's what I remember them being called). No worries, read and viewed videos about them. Settled back in the chair and then panic ensued. I looked at the stove the cat was glowing, and it looked like fire was consuming the catalyst. Didn't know what to do so opened the bypass and it settled down. Closed bypass cat still glowing but no flames. Big whoosh of what looked like ghost flame and started again. Probe shot back up between the 1500 to 1600 mark. Checked stove top temp and still just under 400, front at same spot was 480s. Flames would burn for a while then after a burst of flame would die down. Some more ghost flames and the fire started back up. Kept opening the bypass to keep it down and eventually it settled down to just glowing cat. Calmed down but worried about damage to the catalyst. The pictures are screenshots from a video I took. Not real clear, but the first 2 show flame around the cat, and the second 2 a burst of flame that made all the flame disappear for a few seconds and then the flame would start back up around the cat. Flame periodically would increase and decrease and then the occasional big flame. The pdf is side view of the stove with the area where I saw flame highlighted. The closer I look at the video, it does seem to appear that the flames are around the cat, but not actually under it as it appeared at first, but I still have no idea if this is detrimental or not to the cat/stove.

Don't have a flue thermometer yet, and only have about 12" to work with, part of which is elbow, once I have block off plate installed. Right now only rock wool insulation.
Mix of hardwoods and not sure of all of them, but some ash, cherry and maple. All tested under 20% on fresh split after sitting inside.

So please let me know what I did wrong through the burns, and what other things I might need to be doing or not doing. Getting cold again tomorrow and hope to burn again.

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Not sure how Buck 91 made it in the heading. It was meant to say "Please help me understand my first burns".

Might have been more aptly titled "Help, dumb *** doesn't know how to operate a cat stove"

Also attached picture of pdf, didn't realize it would be a download.

IMG_3583.jpg
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
I added Buck 91 to the title to attract more attention from Buck owners and to make future searches specific to this stove model easier.
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,545
07462
I can say this much, your being conservative with your burns just by looking at your door glass, one of buck's biggest marketing q's are large viewing glass with air wash for viewing pleasure, your glass after a couple burns is dirty and that suggests to me that your strictly going by temps off the cat, like you said the cat for the first few weeks of burning will be hyper active, stove top temp should be near 500 - 675deg f for good burning anything over 800deg should cause concern. I totally understand that this stove was a big investment but its built to run, in other words cut the cord and burn, clean glass at medium / high setting is the standard for this stove with its air-wash tech.
FYI I own a BK princess, I replaced my cat at the beginning of last season, my cat probe still goes to 4 o'clock now and will hold that position for hours with no flames in the firebox, if I look up I have a bright burning orange glow from the cat, no issues 10 hour burn times at 3-4 o'clock then after 20hrs its around 10 o'clock with 8 o'clock being the line of an active cat.
 
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Highbeam

Minister of Fire
Dec 28, 2006
19,773
Mt. Rainier Foothills, WA
I have a condar cat meter in my princess and even well seasoned cats like my current one at about 50% worn out will usually hang out at the upper end of the "normal" range which tops out at 1500 when everything is right. When new, it can go higher. Lots of new owners of new stoves with new cats get justifiably worried when they see this. A well designed cat stove is designed to handle the overactiveness of a fresh cat. Just be sure the door gasket seal is tight and the draft strength of the chimney is in spec.

I don't understand why anybody would close the bypass after 3-4 minutes. The stove temperatures as indicated by that cat meter need to be in the active region above 500 before you engage the cat whether that takes 10 minutes or an hour.

Don't open the bypass to cool the cat. That exposes the bypass opening to excessive temperatures and it can be damaged. Definitely on the BK.

Turning on the fan to cool the cat doesn't work. All that does is cool the condar meter's bimetallic coil on the back which makes the needle move colder but the cat isn't really any colder.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
I added the Buck 91 to the title to attract more attention from Buck owners.
Got it. I had originally thought about adding it, so it threw me off. I knew I had forgotten the "please" but was really starting to wonder if I had added the buck 91 and forgot.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
I can say this much, your being conservative with your burns just by looking at your door glass, one of buck's biggest marketing q's are large viewing glass with air wash for viewing pleasure, your glass after a couple burns is dirty and that suggests to me that your strictly going by temps off the cat, like you said the cat for the first few weeks of burning will be hyper active, stove top temp should be near 500 - 675deg f for good burning anything over 800deg should cause concern. I totally understand that this stove was a big investment but its built to run, in other words cut the cord and burn, clean glass at medium / high setting is the standard for this stove with its air-wash tech.
FYI I own a BK princess, I replaced my cat at the beginning of last season, my cat probe still goes to 4 o'clock now and will hold that position for hours with no flames in the firebox, if I look up I have a bright burning orange glow from the cat, no issues 10 hour burn times at 3-4 o'clock then after 20hrs its around 10 o'clock with 8 o'clock being the line of an active cat.
Thanks, this helps me understand a little more.
The glass was actually clean at the beginning of that burn. All the burns have darkened the glass, I assume that is because I closed it all the way down too soon?
Was wondering about stove top temps from reading other threads and folks getting to 500+ deg. On that burn even with the flames around the cat the stove top never broke 400 deg. Both big burns put out some heat and the rheostat was still active the next afternoon on this burn, but not enough to keep the heat pump from kicking on.
Was considering a BK Princess insert, but no local dealers.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
I have a condar cat meter in my princess and even well seasoned cats like my current one at about 50% worn out will usually hang out at the upper end of the "normal" range which tops out at 1500 when everything is right. When new, it can go higher. Lots of new owners of new stoves with new cats get justifiably worried when they see this. A well designed cat stove is designed to handle the overactiveness of a fresh cat. Just be sure the door gasket seal is tight and the draft strength of the chimney is in spec.

I don't understand why anybody would close the bypass after 3-4 minutes. The stove temperatures as indicated by that cat meter need to be in the active region above 500 before you engage the cat whether that takes 10 minutes or an hour.

Don't open the bypass to cool the cat. That exposes the bypass opening to excessive temperatures and it can be damaged. Definitely on the BK.

Turning on the fan to cool the cat doesn't work. All that does is cool the condar meter's bimetallic coil on the back which makes the needle move colder but the cat isn't really any colder.
Thanks for the reply, more helpful information.

I know how to check the door gasket, which I haven't done, but how would I know the draft strength is in spec? I know the installers didn't do anything other than the one on the roof saying that it had good draft due to him feeling the air flowing through.

The 3-4 minutes is from the manual, but now I know to let the cat get up to temp before shutting the bypass. There is no mention of cat temps except for after reloading.

Ok, no more opening the bypass damper unless opening the door to reload, and fan stays on low unless needing more heat. Not sure where I read about opening the bypass, but don't think it was on here.
 

Rickb

Minister of Fire
Oct 24, 2012
1,199
St.Louis
If you turn your air control down and the flames die down then most likely your door gaskets are fine.

Cat stoves cat temps go up when you turn them down but the firebox temps and activity go down.

Try this. Use 3 or 4 very small splits to start the stove till the cat is almost up to temp. Then add 1 or 2 bigger splits and let it rock wide open for 5 - 10 minutes. Then shut the bypass and close the air down till the firebox flames are lazy and almost dark. On my BK with a 20' chimney thats all the way down.

At that point my flames go to almost nothing but my cat raises. When new the cat went almost off the scale now its about 1/2 way up. Then 7 or so hours later I open it all up and add another 2-3 big splits and let them burn for 10 minutes and shut it all back down down.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
If you turn your air control down and the flames die down then most likely your door gaskets are fine.

Cat stoves cat temps go up when you turn them down but the firebox temps and activity go down.

Try this. Use 3 or 4 very small splits to start the stove till the cat is almost up to temp. Then add 1 or 2 bigger splits and let it rock wide open for 5 - 10 minutes. Then shut the bypass and close the air down till the firebox flames are lazy and almost dark. On my BK with a 20' chimney thats all the way down.

At that point my flames go to almost nothing but my cat raises. When new the cat went almost off the scale now its about 1/2 way up. Then 7 or so hours later I open it all up and add another 2-3 big splits and let them burn for 10 minutes and shut it all back down down.
Flames definitely die down when I close the air controls.

Thanks, I'll give those burn directions a try.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
Fire over the weekend started good with the above recommendations. Started with 2 splits instead of 3 for some reason, and let it get hot and burn down before adding 3 more splits. Glass still clean and cat in 1600 range for about 30 minutes then settled down to about 1400. Let that burn down and loaded the stove for the night. Shut down for slow burn and had one wispy flame coming from the end of a split in the center for a while and then just down to glowing, no flame for a while. Cat was glowing and suddenly started to have flames like before dancing above the heat shield around the cat, but not quite as bad, and some wispy bursts of flame filling the stove. Looked at the probe and cat was just over 1800. A bit unnerving, but what else I could do, so rode it out and about 30 minutes later it dropped down to 1600. Hot bed of coals in the morning and still warm air blowing.

Fast forward to tonight and probe was around 1600 after letting the initial loads burn down, and then loaded it not quite full. Let the flames get going and shut it down for low burn. Looked at the probe and it was maxed out at 2000. One wispy flame coming from the end of a split on the right side and just glowing other places. Stovetop was 360 at the hottest spot. and front of the stove by the probe 550. Now about 30 minutes later the probe is slowly dropping, and now at 1900.

Feeling a bit more comfortable after the replies, though the 2000 tonight was a bit unnerving. But trying to do as kennyp said, cut the cord and let her burn.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
After the last post added a few more splits for the night. I noticed while loading the stove that I could see flame between the flue collar and stove top. Once I closed the bypass, I couldn't see it anymore. Took the top surround trim panel off and it looks like they didn't tighten the left side of the collar and you can actually see the fastening bolt in the gap. There is a gasket on the collar, but it's not doing any good at the moment. Contacted the installer, and they are coming tomorrow. So no fire tonight, and of course the temps will be in the 20's.

Also had more flames above the lower heat shield again after about 30 minutes of reloading. Looked closely again and it looks like the flames are being generated by the cat. I know the heat shield is there to protect the cat from direct flame, so I'm confused as to why this would be happening. Could the loose collar have anything to do with it?
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
Not sure what is happening now. Realized there was a gap between the collar and stove and the company came out and fixed it last Wednesday. Prior to this cat probe temps were getting up to 2000 range a few times, but was attributing that to overactive cat, but now not sure.

Since the fix, I've had fires that maxed out the cat probe thermometer. First was on Friday morning after a cold start. Once the fire was going good I left both air controls set at low burn to get some good heat started and walked away. About 30 minutes later I checked and the probe was pegged out and had strong flame (secondary flame?) as shown in the first and second pictures below. Shut air controls all the way and then checked the stove temperature. Top was 400 in the middle and dipped down on both sides. Front of the stove highest temp was 663 with slightly lower temps farther out from center. This lasted about 30 minutes then the probe started to drop and eventually got into the normal range.

Second time was after a big reload later for that night. Once the new wood had a good char I shut down the air supply and flames died down with just one small flame that went for about 20-30 minutes then no flame and just glowing wood. At that point the probe was in the 1800 range. Fell asleep in the chair and woke up to strong flames similar to the picture, but top third of the glass was clear, and the rest was completely dark (both lower corners of the glass had some build up already). The probe was again pegged out. This again lasted for about 30 minutes and then slowly began to settle down and eventually get back into the normal range. Stove temps were similar.

Did it again the next night after a big reload. Once again let the wood get a good char and then shut the air controls all the way. A little flame for a while and then just glowing wood. After 30 minutes or so the secondary flames start suddenly and the probe got into the 1800 range and then a little while longer it was pegged out again. Once again this lasted for about 30 minutes and then it started to settle down.

Am I still getting too much air somehow even with the supplies shut all the way, or shutting down too soon? Hopefully haven't done too much damage to the cat.

On another note, I'm suddenly finding more older threads on the 91 that for some reason didn't come up in the way I searched before. Or maybe didn't look back far enough. Just put in 91 instead of trying to search based on the issue. Even when trying to decide on whether to buy the stove, I never saw as many threads as I recently came across. A lot to read through still. So just want to apologize for not being more thorough in my searches.

IMG_3614.jpg IMG_3615.jpg IMG_3616.jpg IMG_3617.jpg IMG_3618.jpg IMG_3619.jpg
 

Sailrmike

Feeling the Heat
Sep 20, 2017
295
06371
Not sure what is happening now. Realized there was a gap between the collar and stove and the company came out and fixed it last Wednesday. Prior to this cat probe temps were getting up to 2000 range a few times, but was attributing that to overactive cat, but now not sure.

Since the fix, I've had fires that maxed out the cat probe thermometer. First was on Friday morning after a cold start. Once the fire was going good I left both air controls set at low burn to get some good heat started and walked away. About 30 minutes later I checked and the probe was pegged out and had strong flame (secondary flame?) as shown in the first and second pictures below. Shut air controls all the way and then checked the stove temperature. Top was 400 in the middle and dipped down on both sides. Front of the stove highest temp was 663 with slightly lower temps farther out from center. This lasted about 30 minutes then the probe started to drop and eventually got into the normal range.

Second time was after a big reload later for that night. Once the new wood had a good char I shut down the air supply and flames died down with just one small flame that went for about 20-30 minutes then no flame and just glowing wood. At that point the probe was in the 1800 range. Fell asleep in the chair and woke up to strong flames similar to the picture, but top third of the glass was clear, and the rest was completely dark (both lower corners of the glass had some build up already). The probe was again pegged out. This again lasted for about 30 minutes and then slowly began to settle down and eventually get back into the normal range. Stove temps were similar.

Did it again the next night after a big reload. Once again let the wood get a good char and then shut the air controls all the way. A little flame for a while and then just glowing wood. After 30 minutes or so the secondary flames start suddenly and the probe got into the 1800 range and then a little while longer it was pegged out again. Once again this lasted for about 30 minutes and then it started to settle down.

Am I still getting too much air somehow even with the supplies shut all the way, or shutting down too soon? Hopefully haven't done too much damage to the cat.

On another note, I'm suddenly finding more older threads on the 91 that for some reason didn't come up in the way I searched before. Or maybe didn't look back far enough. Just put in 91 instead of trying to search based on the issue. Even when trying to decide on whether to buy the stove, I never saw as many threads as I recently came across. A lot to read through still. So just want to apologize for not being more thorough in my searches.

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I have always thought that 1600°F is the temp at wich the coating on the catalyst fails. Maybe @BKVP can correct me if I'm wrong, but I would avoid burning over 1600°F. Has your installer measured draft while the stove is burning?
 

BKVP

Minister of Fire
I have always thought that 1600°F is the temp at wich the coating on the catalyst fails. Maybe @BKVP can correct me if I'm wrong, but I would avoid burning over 1600°F. Has your installer measured draft while the stove is burning?
Yes, regardless of whether you have a catalyst used to roast coffee beans or clean up emissions in a wood stove, the wash coat (which bonds the precious metals to the substrate) converts from a textured area to a flattened out surface. Of course you need an electron microscope to see the actual change. This loss of surface area will reduce the efficacy of the combustor to clean up the emissions. I would contact the manufacturer to ask how they might best reduce likelihood of continued threshold temps of 1600F+ temps.
 
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Kvic

New Member
Sep 12, 2021
93
Middle Tn
I have always thought that 1600°F is the temp at wich the coating on the catalyst fails. Maybe @BKVP can correct me if I'm wrong, but I would avoid burning over 1600°F. Has your installer measured draft while the stove is burning?
Installer has never measured draft other than the helper feeling the draft on his face during install. From my experience with the install, I don't know if they would even know how to do this.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
Yes, regardless of whether you have a catalyst used to roast coffee beans or clean up emissions in a wood stove, the wash coat (which bonds the precious metals to the substrate) converts from a textured area to a flattened out surface. Of course you need an electron microscope to see the actual change. This loss of surface area will reduce the efficacy of the combustor to clean up the emissions. I would contact the manufacturer to ask how they might best reduce likelihood of continued threshold temps of 1600F+ temps.
Thanks, was planning on calling Buck tomorrow to see what they have to say. Definitely want to try and figure it out before the temps drop again.
 

mellow

Resident Stove Connoisseur
Jan 19, 2008
5,383
Salisbury, MD
I would take an incense stick around the door and any of the other openings to see if you are getting extra air leaking in, I had to seal my ash dump in one of my stoves since it was leaking huge amounts of air in.

Link to the old post about it with a stove that is similar to the 91, might be your issue as well:
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
What size liner is the stove connected to? How tall is it?
 
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Kvic

New Member
Sep 12, 2021
93
Middle Tn
What size liner is the stove connected to? How tall is it?
8" insulated liner and about 15-16' tall.

Read through some older posts about the air control plates not sealing tightly, so took a look at mine. There are some small gaps around a couple of the plates, but they also have holes drilled in them. Burn instructions have changed as well. In the older threads they recommended 1/8 to 1/4 open on the main air supply. Now it says to shut it all the way.

IMG_3635.jpg IMG_3638.jpg IMG_3639.jpg
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
I would take an incense stick around the door and any of the other openings to see if you are getting extra air leaking in, I had to seal my ash dump in one of my stoves since it was leaking huge amounts of air in.

Link to the old post about it with a stove that is similar to the 91, might be your issue as well:
Thanks, I'll give that a try.

I'm beginning to think it might be the shotgun air control that is under the front middle of the stove. I've noticed the wood glows brighter in that spot. Haven't even used the ash dump, it's just as easy to scoop them out. I think I'm going to remove all the ash and take out a couple of the firebrick to see what the gaps look like from above.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
Finally got a call back from Buck Stove. They said it sounded like the stove was doing what it's supposed to, and that it may be a bad cat probe, so they're sending out a new one.

In the meantime, I did the dollar bill test and incense test. Dollar bill test showed that I may not be tightening the door handle all the way at times, because I could tug on the bill and make it move. But if I pushed the handle down with a little more force, couldn't move the bill at all. Tried the incense with the door shut with the minimal force, and didn't see any smoke getting drawn in, so not sure if that has had any impact, but will push it down fully from now on.

Put the incense under the stove, and smoke was being drawn in around the inlet block off plates where there were gaps. It actually looked like the smoke was drawn more to the gaps than the holes in the plates. Adjusted the plates, and shimmed under the one side where there was some slack on the right side.

Fired up the stove that night. Let 3 splits get to coaling and then added 5 splits on top and shut the air down once they were going good. Probe got up to the 1900 range but no higher. Wasn't a full reload like before as it hasn't been as cold, but will be able to load it out with cooler temps this weekend.
 

Highbeam

Minister of Fire
Dec 28, 2006
19,773
Mt. Rainier Foothills, WA
It’s nice that you have access to those extra holes in the plates. For testing purposes, you could try blocking them.
 

Kvic

New Member
Sep 12, 2021
93
Middle Tn
It’s nice that you have access to those extra holes in the plates. For testing purposes, you could try blocking them.
Thank you, that helps confirm what I was thinking of doing next if the new probe doesn't read differently.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,751
South Puget Sound, WA
If the dollar bill pulls out, but with tension, then the gasket is working.
 
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