Buck 81 - internal heat shield warping

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buckfan

Member
Nov 24, 2013
7
Montpelier, Virginia
I've had a Buck 81 for 6 years now and we use it rather continuously in the cold months here in central Virginia. We love it, and it's performed well. I've noticed the internal heat shields (could also be called firebrick retainers?) on both sides have warped. Anybody else experience this? We do run it hot with mostly oak, but I don't really know what an overfired temp is. I do have a magnetic temp gauge on the left front face of the stove, and it's not unusual to hit 500-600 degrees. I actually called Buck a few years ago and asked about temp limits, and the tech basically said you can't hurt it. Regardless, I plan to weld in new pieces (looks like 3/16"), as well as putting a bead on a 3" split on the reburn chamber on the right side. Curious if anyone else has had to deal with this issue on their stove.

Buck 81 - internal heat shield warpingBuck 81 - internal heat shield warping
 
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That's some pretty serious damage and in a somewhat odd location. First time I can recall seeing that. Have you been in touch with Buck about this?
 
Could it be from humid air condensing in the stove over several summers, when running AC in the house? If so, you might need to cap off the chimney in the summer..
 
I've had a Buck 81 for 6 years now and we use it rather continuously in the cold months here in central Virginia. We love it, and it's performed well. I've noticed the internal heat shields (could also be called firebrick retainers?) on both sides have warped. Anybody else experience this? We do run it hot with mostly oak, but I don't really know what an overfired temp is. I do have a magnetic temp gauge on the left front face of the stove, and it's not unusual to hit 500-600 degrees. I actually called Buck a few years ago and asked about temp limits, and the tech basically said you can't hurt it. Regardless, I plan to weld in new pieces (looks like 3/16"), as well as putting a bead on a 3" split on the reburn chamber on the right side. Curious if anyone else has had to deal with this issue on their stove.

View attachment 249493View attachment 249495
I know this is an old thread, but those are not warped, they're rusted out. Seems the inside of the stove is filled with moist air during off season, you may need to cap you chimney and/or run a dehumidifier if your stove is in a damp basement.
 
I know this is an old thread, but those are not warped, they're rusted out. Seems the inside of the stove is filled with moist air during off season, you may need to cap you chimney and/or run a dehumidifier if your stove is in a damp basement.

Thanks for the response - I have never capped the chimney but obviously need to start.
 
buckfan,

Were you able to weld in the brick retainer? I am also located in Virginia and have the exact same problem. I searched online and your post came up. My Buck 81 stove was installed in January 2014 and I never noticed a problem until this year. The installer I purchased the stove from said that it occurred due to "overfires," but based on your post I feel like I never reached that point (I try to keep it at 650F and under). The humidity theory makes more sense to me.

Anyway, I was just curious how the retainer install went. Did you weld in the replacement with the stove indoors or did you have to remove it?

Pics below. I am planning to replace the air tubes soon.

Thanks in advance for your input!

Buck 81 - internal heat shield warpingBuck 81 - internal heat shield warping
 
We have a 10 year old Buck 74 and it looks like new inside yet. Must be a moisture thing I'm guessing.
 
I am planning to replace the air tubes soon.
And address the gap between the baffle boards. Smoke should be routed all the way to the front before exiting, so that the tubes have a chance to burn as much of it as possible.
We have a 10 year old Buck 74 and it looks like new inside yet. Must be a moisture thing I'm guessing.
I wondered if one could burn up the brick retainers, burning the stove hard. But I wouldn't expect the back retainer to be subject to as much heat, so that leaves the moisture explanation..
So how hot do you run your 74, and how/where do you measure the temp?
 
buckfan,

Were you able to weld in the brick retainer? I am also located in Virginia and have the exact same problem. I searched online and your post came up. My Buck 81 stove was installed in January 2014 and I never noticed a problem until this year. The installer I purchased the stove from said that it occurred due to "overfires," but based on your post I feel like I never reached that point (I try to keep it at 650F and under). The humidity theory makes more sense to me.

Anyway, I was just curious how the retainer install went. Did you weld in the replacement with the stove indoors or did you have to remove it?

Pics below. I am planning to replace the air tubes soon.

Thanks in advance for your input!

View attachment 307559View attachment 307560
It's interesting to hear that others have had similar experiences with their Buck 81. Here is the rest of my story since I posted. The warping and metal fatigue got progressively worse. I contacted my local dealer last October and they contacted Buck. The response was "They said they can ship us replacement tubes and brick retainers ($38 and $30 dollars per, respectively.) The brackets that hold the tubes are welded and would have to be repaired by a metal fabricator." I have done some metal fabrication and I asked an experienced welder to look at it too. It wasn't worth fixing as it would have been extremely difficult to work inside that space. They obviously built that firebox from the inside out. I even looked at cutting the top plate off, but it's welded from both the inside and outside. And I also noticed a small crack near the door, so I wasn't comfortable using the stove anymore. We really liked the stove, and maybe against better judgement, we bought a brand new Buck 81 online (really good price). Interestingly, the stove burns differently than our 2013 model. They definitely modified the air control to let less air in, so it doesn't burn as hot. And the movement of the air control slider is about 1" less than the old one. My guess is that their original design let the stove get too hot for too long (too much air), which led to overfiring, and the heat eventually weakened the 3/16" gauge firebox metal framework. That's just my guess. We are happy with the new stove, but we had to adjust the timing of how we adjust the air control after loading. Good luck to you.
 
And address the gap between the baffle boards. Smoke should be routed all the way to the front before exiting, so that the tubes have a chance to burn as much of it as possible.

I wondered if one could burn up the brick retainers, burning the stove hard. But I wouldn't expect the back retainer to be subject to as much heat, so that leaves the moisture explanation..
So how hot do you run your 74, and how/where do you measure the temp?
We run up to 675 once the stove shut down. Temp is measured at the upper right corner above the door. I'd we run our stove on the hot end most of the time. We are on a 3 plus year plan so our wood is always pretty dry contributing to the higher temps I'm guessing.
 
we bought a brand new Buck 81 online (really good price). Interestingly, the stove burns differently than our 2013 model. They definitely modified the air control to let less air in, so it doesn't burn as hot. And the movement of the air control slider is about 1" less than the old one. My guess is that their original design let the stove get too hot for too long (too much air), which led to overfiring
Huh, I thought most of the 2020 and later models were letting in more air in order to meet the tougher emission standards...🤔
We run up to 675 once the stove shut down. Temp is measured at the upper right corner above the door. I'd we run our stove on the hot end most of the time. We are on a 3 plus year plan so our wood is always pretty dry contributing to the higher temps I'm guessing.
Yep, that's also where I put my meter on the 91. I figured that was about where the actual stove top was intersecting the front wall of the box. Of course, your secondary stoves will be running hotter box temps than the 91 cat, where I was smoldering the wood a lot of the time and that heat was localized in the cast iron cat housing, and above it in a smaller area. My meter never got much above 500 or so.