New Buck 80 Burn Report and Operational Questions

[Ralphie Boy]

Okay, so the new Buck 80 insert is up and running. This is my first modern wood burner. I had an old, and I mean old, smoke dragon in my workshop that I only used from time to time and 2 open firepalces in the house.

The insert was installed by the dealer on Friday 01/18 but the first burn was not until Saturday because the Buck folks forgot to include a cat probe with the stove. I’m hoping this is not a sign of things to come! And wouldn’t you know it Saturday was near record heat with temps reaching near the 60° mark. No matter, I fired it up and opened all the windows and doors. Temps in the house approached the 80° mark in no time flat.

Temps outside have steadily dropped since Saturday’s high, with last night reaching a low of 5°. Temps in the house remained fairly constant at 72° to 74°. From 6am Monday until about 11:40pm Monday I only burned 6 pieces of 2 year old ash. At 11:40 the fire box had a nice bed of coals on which I placed 3 splits of 2 year old black locust for the overnight burn. At 6am this morning I still had big, chunky locus coals brightly glowing in the fire box and the house was 72° and the cat temp was 800°.

So far this is what I’ve noted about the 80:

It is fairly easy to reach a dangerously high cat temp with very little wood and all the air controllers closed. I wouldn’t have thought is possible to reach suck high temps so quickly and with so little air. I’ve twice had to open the bypass damper and crank the fan to it’s max to keep the cat from reaching the “too hot” mark on the probe. This worries me because I don’t know what is happening to the cat during the overnight burn.

The instructions that I downloaded from Buck and that came with the insert are very definite about loading the stove “from front to back” (n – s) yet in order to use wood of the maximum recommended length of 22” it has to be loaded side to side (e – w). I’m not sure what this means other than I may be forced to shorten a whole bunch of split and seasoned firewood in order to get the proper burn.

This monster makes a lot of heat! I am burning it most of the time with all the air controls fully closed and cat temps at about 1100°to 1300°. Does this sound correct? Is having so little air going to damage anything?

This morning I added 2 pieces of ash to the coals and the cat temp dropped to about 500° which is in the “inactive” range according to the cat probe. I opened the air controls, including the shotgun air, to their wide open position. And because the cat probe was reading in the “inactive” range, I opened the bypass damper until the cat temp cam up to just over 600°. Was this correct?

How do I know when the cat is working; that is what changes do I look for in the fire box? Or are there no visible changes?

Any other tips and tricks you kids may have for more efficient and safe operation would be greatly appreciated by this newbie!

 

[jeff_t]

It is fairly easy to reach a dangerously high cat temp with very little wood and all the air controllers closed. I wouldn’t have thought is possible to reach suck high temps so quickly and with so little air. I’ve twice had to open the bypass damper and crank the fan to it’s max to keep the cat from reaching the “too hot” mark on the probe. This worries me because I don’t know what is happening to the cat during the overnight burn.

I would try to make sure that the air controls don't have any slop in them. Seems like I've heard of this with the 91. I wouldn't worry too much about it going to bed. Once the biggest part of the off-gassing is over, the cat temps will stabilize and fall off.

The instructions that I downloaded from Buck and that came with the insert are very definite about loading the stove “from front to back” (n – s) yet in order to use wood of the maximum recommended length of 22” it has to be loaded side to side (e – w). I’m not sure what this means other than I may be forced to shorten a whole bunch of split and seasoned firewood in order to get the proper burn.

N/S loading is much easier to pack full, and no worries about a log rolling up against the glass. If you have a lot of too long stuff, you might want to think about shortening it. Some threads in the wood shed about doing this. It's not too bad. I have shortened about two cords since I got my stove.

This monster makes a lot of heat! I am burning it most of the time with all the air controls fully closed and cat temps at about 1100°to 1300°. Does this sound correct? Is having so little air going to damage anything?

Sounds about right. Cutting the air off and still having a clean burn is the beauty of a cat stove.

This morning I added 2 pieces of ash to the coals and the cat temp dropped to about 500° which is in the “inactive” range according to the cat probe. I opened the air controls, including the shotgun air, to their wide open position. And because the cat probe was reading in the “inactive” range, I opened the bypass damper until the cat temp cam up to just over 600°. Was this correct?

How do I know when the cat is working; that is what changes do I look for in the fire box? Or are there no visible changes?

The cat should start burning smoke around 500. You may not see any signs in the firebox itself. I don't know if you can see the cat glow in yours, but it doesn't have to glow to be working. No smoke out of the chimney is what you most want to see.

Congrats on the new unit. I'm sure you'll be quite happy with it. All the questions you asked you will be able to answer yourself after a little time. Enjoy!

 

[Ralphie Boy]

Thanks, great answers that ease my mind, except for that shortening part. And that won't be too bad. The lack of smoke is the first thing I noticed. While those around me are spewing smoke from their chimneys I've a very nice burn going and nothing coming out the chimney.

 

[mellow]

I have found that burning N-S the cat gets hotter than if I burn E-W. Mine will usually go up to 1500 with a full load then go down, anything below 1800-2000 is fine. I find it will hit the 1800-2000 if I load N-S.

Have a good dialog going in this thread about another buck stove you could glean some tips from it: https://www.hearth.com/talk/threads...unning-advice-tricks-and-tips-welcome.100464/

 

[jeff_t]

This is what I made to trim splits. It's not as bad as I thought it would be. Plus I get to make noise.

 

[Ralphie Boy]

This is what I made to trim splits. It's not as bad as I thought it would be. Plus I get to make noise.

View attachment 90424

Yep. I'm working on something much like that. I actually cut som today by using my sledge to pound a rack with about 1/3 cord against the birck wall of my house then I cut everything flush with the face of the rack. Perfect 18".

 

[PLAYS WITH FIRE]

I second the slop in the air controls! And is possible you have a long stack so a very strong draft? Also, I knocked some furnace cement off the seal of my liner to the collar on the insert and it burns much different now that I suck air through my collar. Maybe. Combination of things?

 

[begreen]

Thanks, great answers that ease my mind, except for that shortening part. And that won't be too bad. The lack of smoke is the first thing I noticed. While those around me are spewing smoke from their chimneys I've a very nice burn going and nothing coming out the chimney.

For longer burns E/W loading works well. Try bigger splits and see if that helps keep the cat temps in range.

 

[Ralphie Boy]

For longer burns E/W loading works well. Try bigger splits and see if that helps keep the cat temps in range.

I'm burning a bunch of smaller splits and was wondering about it b ut forgot to say anything about that in the post , I brought up some larger splits and will try them to see what goes on. Thanks!

 

[Ralphie Boy]

I second the slop in the air controls! And is possible you have a long stack so a very strong draft? Also, I knocked some furnace cement off the seal of my liner to the collar on the insert and it burns much different now that I suck air through my collar. Maybe. Combination of things?

Yep, found the "slop" in the air control mentioned by some. The shutter for all 3 air controllers slide on a rail made of a sheet metal stamping. The fix is easy; I just used the tip of a screwdriver to bend the sheet metal rail upwards, forcing the shutter toward the bottom of the insert making a tighter fit between the shutter, insert and rail. It makes the shutter slide with more resistance but it still operates easy enough. I found the left side easiest to fix now that the insert is installed. I haven't done the shotgun control or the right side yet. The shotgun should be easy to fix but the right side will involve removing a small faceplate held on by 2 sheetmetal screws to get at the shutter and rail. And that's asuming there is nothing else to get in the way. Wish I had known about it before it was installed it would have been much easier to just tilt the insert back a bit and bend the rails rather than try to fix it in such a tiny space.

NOTE TO FUTURE BUCK INSERT BUYERS: MAKE THE ADJUSTMENTS TO THE AIR SHUTTERS BEFORE THE INSERT IS INSTALLED! IT WILL BE MUCH EASIER TO FIX AND BE A MORE EFFICIANT FIX. I think that on the free standing stove version the fix would be very easy as the stove is off the ground on legs.

 

[Woody Stover]

Ralphie, glad to hear you've got your stove in and are "bucking the trend" of below-normal temps we're having around here now. Have fun!

It is fairly easy to reach a dangerously high cat temp with very little wood and all the air controllers closed. I wouldn’t have thought is possible to reach suck high temps so quickly and with so little air. I’ve twice had to open the bypass damper and crank the fan to it’s max to keep the cat from reaching the “too hot” mark on the probe. This worries me because I don’t know what is happening to the cat during the overnight burn.

I'm burning a bunch of smaller splits and was wondering about it, I brought up some larger splits and will try them to see what goes on.

The thinking is that the cat goes higher when the stove has no flame in the box since the flame isn't burning any smoke and it all burns in the cat. But I've also seen some higher cat temps on the Buck with flame in the box... I don't get concerned until it gets around 1800; I don't want it staying up there too long. But yeah, small splits tend to get burning all at once, resulting in a lot of smoke/gas going to the cat. I've been using some bigger splits along with smaller ones to fit into spaces at the top of the load. I'm not there all the time, so it's hard to say for sure but I don't think there have been many, if any, high cat temps since I've been loading like that. I'm trying to nudge my MIL into getting me more frequent temp readings; She leaves some gaps now, in which time the cat could've gone high and come back down by the time she gets the next reading. A couple days ago I saw one reading at about five hours into the burn, 800 on the probe, then a couple hours later 900. That seemed odd. I had a couple of Ash splits on the sides; Maybe they caught and, burning faster than the Oak, raised the temp. Or she could have misread the probe...
What about the ash drop? Are you seeing evidence of a little air coming in there, like more flame or glowing coals? There's an 80 in a stove shop here (not burning) , so I've gotten a good look at it. The ash drop is a little closer to the middle than on the 91. You've also got separate controls for each side of the airwash so you could compensate for ash drop air, if desired. On the 91, the right slider controls both airwash plates and the left slider is the shotgun air. I just make sure that there are no coals above the ash drop, and put some bigger splits over there. If I were to put small splits there, that left side would really take off.

The instructions that I downloaded from Buck and that came with the insert are very definite about loading the stove “from front to back” (n – s) yet in order to use wood of the maximum recommended length of 22” it has to be loaded side to side (e – w). I’m not sure what this means other than I may be forced to shorten a whole bunch of split and seasoned firewood in order to get the proper burn.

I'm guessing the manual says that so that the average joe can get maximum heat off the stove. We here at hearth.com are not average joes, we are innovators on the frontiers of combustion. "The rules do not apply to us." Before sawing off a bunch of splits, I would experiment a bit. Try burning E-W. As begreen mentioned, it should give you a slower burn and control the gassing of the load. If you need an E-W load to burn faster, or the splits in the back are burning too slow after the wood in front is gone, you can try the "tunnel of love," putting a trench in the coal bed running N-S to allow air to get to the back of the box. In addition, you could cut the airwash air and add shotgun air that would shoot through the tunnel. With a N-S load, you could rake the coals forward before loading, so that only the front of the splits catch at first instead of the entire load going at once like it would if there were coals under everything. It's a lot of fun with a new stove, trying different things and learning how to get it to do what you want. There's a lot of this stuff that I haven't tried yet, but will at some point.

This monster makes a lot of heat! I am burning it most of the time with all the air controls fully closed and cat temps at about 1100°to 1300°. Does this sound correct? Is having so little air going to damage anything?

No damage at all. Sounds like you're getting the hang of it pretty quick.

This morning I added 2 pieces of ash to the coals and the cat temp dropped to about 500° which is in the “inactive” range according to the cat probe. I opened the air controls, including the shotgun air, to their wide open position. And because the cat probe was reading in the “inactive” range, I opened the bypass damper until the cat temp cam up to just over 600°. Was this correct?

The 91 manual sez 700-900 to close the bypass and I shoot for around 700 with a few starter splits on the coal bed. The I close the bypass and run it up to 1000 or so and load up. Don't really know if it's necessary to take it up to 1000 but the cat will still be around 900 after I've loaded. It'll drop when I finally turn on the blower, though. But I know I can leave and the cat will take off. If I was there all the time, I would be experimenting more with different startup procedures. On reloads I try to get fairly big flame with the least amount of air possible. Running the air wide open doesn't seem to heat it up any faster, and may overfire the chimney or certain parts of the stove.

How do I know when the cat is working; that is what changes do I look for in the fire box?

Not really anything in the box, except maybe more flame under the combustor shield. The 80 looked like it had the same bypass setup as the 91. If so, you should be able to look in through the bypass rod hole and see the cat glowing. Like jeff_t said, it can be working but not glowing.

Any other tips and tricks you kids may have for more efficient and safe operation would be greatly appreciated

It's been a while since I was a kid...

Comparing the 80 to the 91, I noticed a few things. The box of the 80 is rectangular, the 91 is a trapezoid. The 80 only has firebricks on the floor of the box, so I'd imagine it will get up to temp in a hurry. Both use the same heavy 1/4 and 5/16 plate steel. As far as the "slop" in the air plates, my 91 isn't running away and I need a lot of heat so I haven't done anything yet to make the plates seal tighter. The 91 slider rods are half-inch flat stock and run through saddles welded to the bottom of the box. I was thinking I could wrap a piece of sheet stock around the bottom of the saddles to push the rods (and plates) up closer, if I wanted.

Remind us again, Ralphie, what sq. footage are you heating and what's the floor plan like, open or lots of walls? What's your chimney setup?

One last thing....have fun! Hmmm, I think I may have mentioned that already...

 

[WoodpileOCD]

Also, I knocked some furnace cement off the seal of my liner to the collar on the insert and it burns much different now that I suck air through my collar. Maybe. Combination of things?

What exactly are you seeing. My cement hardened, cracked and came off almost right away. Just left it that way so I know it is sucking air as well but don't really have anything to compare it to.

 

[PLAYS WITH FIRE]

I now have to close the air all the way or the temp will climb to uncomfortable temps! I did this about 2 weeks ago...no biggie.

 

[Ralphie Boy]

Ralphie, glad to hear you've got your stove in and are "bucking the trend" of below-normal temps we're having around here now. Have fun!

The thinking is that the cat goes higher when the stove has no flame in the box since the flame isn't burning any smoke and it all burns in the cat. But I've also seen some higher cat temps on the Buck with flame in the box... I don't get concerned until it gets around 1800; I don't want it staying up there too long. But yeah, small splits tend to get burning all at once, resulting in a lot of smoke/gas going to the cat. I've been using some bigger splits along with smaller ones to fit into spaces at the top of the load. I'm not there all the time, so it's hard to say for sure but I don't think there have been many, if any, high cat temps since I've been loading like that. I'm trying to nudge my MIL into getting me more frequent temp readings; She leaves some gaps now, in which time the cat could've gone high and come back down by the time she gets the next reading. A couple days ago I saw one reading at about five hours into the burn, 800 on the probe, then a couple hours later 900. That seemed odd. I had a couple of Ash splits on the sides; Maybe they caught and, burning faster than the Oak, raised the temp. Or she could have misread the probe...
What about the ash drop? Are you seeing evidence of a little air coming in there, like more flame or glowing coals? There's an 80 in a stove shop here (not burning) , so I've gotten a good look at it. The ash drop is a little closer to the middle than on the 91. You've also got separate controls for each side of the airwash so you could compensate for ash drop air, if desired. On the 91, the right slider controls both airwash plates and the left slider is the shotgun air. I just make sure that there are no coals above the ash drop, and put some bigger splits over there. If I were to put small splits there, that left side would really take off.

I'm guessing the manual says that so that the average joe can get maximum heat off the stove. We here at hearth.com are not average joes, we are innovators on the frontiers of combustion. "The rules do not apply to us." Before sawing off a bunch of splits, I would experiment a bit. Try burning E-W. As begreen mentioned, it should give you a slower burn and control the gassing of the load. If you need an E-W load to burn faster, or the splits in the back are burning too slow after the wood in front is gone, you can try the "tunnel of love," putting a trench in the coal bed running N-S to allow air to get to the back of the box. In addition, you could cut the airwash air and add shotgun air that would shoot through the tunnel. With a N-S load, you could rake the coals forward before loading, so that only the front of the splits catch at first instead of the entire load going at once like it would if there were coals under everything. It's a lot of fun with a new stove, trying different things and learning how to get it to do what you want. There's a lot of this stuff that I haven't tried yet, but will at some point.

No damage at all. Sounds like you're getting the hang of it pretty quick.

The 91 manual sez 700-900 to close the bypass and I shoot for around 700 with a few starter splits on the coal bed. The I close the bypass and run it up to 1000 or so and load up. Don't really know if it's necessary to take it up to 1000 but the cat will still be around 900 after I've loaded. It'll drop when I finally turn on the blower, though. But I know I can leave and the cat will take off. If I was there all the time, I would be experimenting more with different startup procedures. On reloads I try to get fairly big flame with the least amount of air possible. Running the air wide open doesn't seem to heat it up any faster, and may overfire the chimney or certain parts of the stove.

Not really anything in the box, except maybe more flame under the combustor shield. The 80 looked like it had the same bypass setup as the 91. If so, you should be able to look in through the bypass rod hole and see the cat glowing. Like jeff_t said, it can be working but not glowing.

It's been a while since I was a kid...

Comparing the 80 to the 91, I noticed a few things. The box of the 80 is rectangular, the 91 is a trapezoid. The 80 only has firebricks on the floor of the box, so I'd imagine it will get up to temp in a hurry. Both use the same heavy 1/4 and 5/16 plate steel. As far as the "slop" in the air plates, my 91 isn't running away and I need a lot of heat so I haven't done anything yet to make the plates seal tighter. The 91 slider rods are half-inch flat stock and run through saddles welded to the bottom of the box. I was thinking I could wrap a piece of sheet stock around the bottom of the saddles to push the rods (and plates) up closer, if I wanted.

Remind us again, Ralphie, what sq. footage are you heating and what's the floor plan like, open or lots of walls? What's your chimney setup?

One last thing....have fun! Hmmm, I think I may have mentioned that already...

We have a "raised ranch" with about 1500 sq.ft. on each floor. The upper level has the main living area with the living, dining and kitchen areas a very open floor plan and high vaulted ceilings. The bedrooms are on the left and right of a hallway located 23 ft. in front and to the right of the insert. The chimney is clay tile lined brick and took about 23 ft. of a 25 ft. 8in. flex liner. Unfortunately ther was not enough room for an insulated liner.

The lower level is beautifully finished and has a great stone fireplace, but my wife and I seldom use it.

With the adjustments I made to the air shutters, the unit is now fully in my control. I can keep the living areas at 72 degrees with cat temps around 1200 degrees and use less wood doing it. I'm no longer worried about a "run away" loading the fire box full and going to bed.

Woody, we are all kids at heart otherwise we would be playing with our toys the way we do!

 

[Woody Stover]

With the adjustments I made to the air shutters, the unit is now fully in my control. I can keep the living areas at 72 degrees with cat temps around 1200 degrees and use less wood doing it. I'm no longer worried about a "run away" loading the fire box full and going to bed.

Well, that didn't take too long. Glad to hear your new stove is doing the job.
I'll probably make that adjustment as well. I have no evidence that the cat has taken off recently, but it could if the stove was loaded with small stuff or the air was left too far open when establishing the load. It would be reassuring to know that anyone at my MIL's house could remedy the cat going high by simply cutting off the air. Today I was in town so I loaded the stove at 4:00 PM. As usual, had the coals shoved to the middle, no coals under the splits over the ash dump and only a few under the right side splits. My SIL stopped in two hours into the burn...stove 450, cat 1500. Intermittent lazy flames. Perfect. I thought maybe I could have her toss a couple more splits in the middle to extend the heat output, since I loaded earlier that usual. In the end, we decided to just leave well enough alone and not pull the tail of the dragon. Hopefully, it's just cruising out at this point. With the ability to cut the air further, maybe we will have more flexibility in operating the stove. But as it is, I can tell my MIL to close the air, and know that the stove won't be snuffed, which might be a possibility with the adjustment. Have you cut the air all the way yet, to see what happens? Hopefully, it just goes out, no backpuffing...