Blaze King install puzzle

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Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
Having done much oak and much pine lately, I can second @Highbeam : for softwoods (pine at 15-16%) I don't go 30 minutes. For (red, 18%) oak, I do. But I do keep an eye on my flue temp, and (given my tall chimney) "full throttle" means i go full, and slowly dial back keeping the flue below 900-950 F once it gets hotter.
Where and how do you mount a thermometer on the flue, or pipe? Or you just take readings with handheld infrared thermometer? I'm waiting for a stove thermometer to arrive in the mail, along with the moisture tester I ordered a month ago.
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
Why do you care if the cat thermometer goes past the white? The cat thermometer has one important or relevant data point which is the active/inactive line. It can be considered an idiot light or on/off switch. Does your owner’s manual tell you to never let the cat meter rise above the white active area?

I admit that I don’t do the 30 minute full throttle bypass closed routine per the manual. I burn softwoods and after 15-20 minutes my flue temps are getting dangerously high so I reduce air at that point and prepare for the cruise. I use the flue thermometer after closing the bypass.
Note that I found my old digital camera (seldom used) and took some pictures, posted above, with my response to moresnow.
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
Why do you care if the cat thermometer goes past the white? The cat thermometer has one important or relevant data point which is the active/inactive line. It can be considered an idiot light or on/off switch. Does your owner’s manual tell you to never let the cat meter rise above the white active area?

I admit that I don’t do the 30 minute full throttle bypass closed routine per the manual. I burn softwoods and after 15-20 minutes my flue temps are getting dangerously high so I reduce air at that point and prepare for the cruise. I use the flue thermometer after closing the bypass.
The owners manual doesn't warn against cat meter rising to six o'clock but I read elsewhere on the site of the company that actually makes the cats that they are damaged over 1800 degrees.

Re: "I use the flue thermometer after closing the bypass":

Does that mean you check the flue (or stove pipe?) temp when you re-load? I'm assuming you close the bypass immediately after loading.
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
The vermi-cement is outside the pipe and has no contact with the exhaust. It's just the moisture in the exhaust condensing. Maybe its not really an extreme amount of moisture but looks like a lot because most or all of it happens to be visible, instead of draining invisibly back to the stove. It happens to be collected where the chimney pipe meets the short section of horizontal stove pipe, and released (into a metal container I put below) drop by drop from the bottom of a seam in an adjustable fitting that created the horizontal.

If I have collected almost a quart in almost a week of burning, maybe that's not an unusual amount of liquid. But there shouldn't be any liquid. There shouldn't be any condensation at all.

Running on low, with the knob set at the very beginning of the white band, the dripping continues until the wood is charred, even with dry pallet and 2X wood. But running on High, there is little or no dripping as the wood is "conditioned," but the cat temperature gets extremely high.

I have a plan for eliminating the short horizontal and the 90 elbow and maintaining the 30 inch vertical rise, and still have the required 6 inch minimum distance of the thermostat box from the wall. It might be good that I tried it this way first, because it made the problem of condensation visible and otherwise it might have gone undetected.

View attachment 289698 View attachment 289699 View attachment 289700 View attachment 289701
Note that I used one "cheap" 24 guage 90 degree fitting, and the rest is 22 guage black, and from the wall up evereything is 22 guage 316 stainless. I used the 24 ga. 90 because it's only temporary. I plan to change to just one 45 between the wall and telescoping vertical stove pipe.

The angle fitting with the seam that drips is the 24 guage one. The diagonal direction of the pipe into the wall is caused by following the path of the old oil heater exhaust channel through the concrete. You can see that a large area had to be sawed and chiseled out, and then refilled with high-strength concrete afterwards using a form around the pipe and inserting a vibrator through small holes in the form to ensure that there are no air pockets in the cement, and the whole area is actually stronger than new.
 

Highbeam

Minister of Fire
Dec 28, 2006
19,858
Mt. Rainier Foothills, WA
The owners manual doesn't warn against cat meter rising to six o'clock but I read elsewhere on the site of the company that actually makes the cats that they are damaged over 1800 degrees.

Re: "I use the flue thermometer after closing the bypass":

Does that mean you check the flue (or stove pipe?) temp when you re-load? I'm assuming you close the bypass immediately after loading.
Your cat thermometer does not have numbers. You don’t know if 6 o’clock represents 1800 or if that meter is even accurate for determining the catalyst temperature as used to determine that 1800 limit. The owner’s manual tells you how to operate the stove and I don’t recall any directions based on the reading of that cat meter after it reads active.

I certainly check the flue meter after reloading. I don’t close the bypass immediately, I wait to see an active and rising cat meter or a flue temperature above 500. I prefer not to send cold/wet smoke through a ripping hot catalyst. I run full loads as much as possible so a 50# load of ice cold wood takes a few minutes to get going.
 
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Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
Your cat thermometer does not have numbers. You don’t know if 6 o’clock represents 1800 or if that meter is even accurate for determining the catalyst temperature as used to determine that 1800 limit. The owner’s manual tells you how to operate the stove and I don’t recall any directions based on the reading of that cat meter after it reads active.

I certainly check the flue meter after reloading. I don’t close the bypass immediately, I wait to see an active and rising cat meter or a flue temperature above 500. I prefer not to send cold/wet smoke through a ripping hot catalyst. I run full loads as much as possible so a 50# load of ice cold wood takes a few minutes to get going.
I saw on another thread the picture of an almost identical-looking cat thermometer, that was said to be made by the same company that makes this one, that does have numbers on it, a round black-and-white guage with 500 marked at the beginning of the same white band, and so on.

All the wood I've been loading is about 70 degrees F (from the indoor drying stack) when it goes in. I see the good reason for not thermal-shocking the cat. I even worry about the air hitting it during the few seconds that it takes to re-load, even though the bypass is open. How long have you had to wait to close the bypass if the cat is over 500 but the flue temperature isn't? Where and how do you mount a flue thermometer or take the readings?
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
I saw on another thread the picture of an almost identical-looking cat thermometer, that was said to be made by the same company that makes this one, that does have numbers on it, a round black-and-white guage with 500 marked at the beginning of the same white band, and so on.

All the wood I've been loading is about 70 degrees F (from the indoor drying stack) when it goes in. I see the good reason for not thermal-shocking the cat. I even worry about the air hitting it during the few seconds that it takes to re-load, even though the bypass is open. How long have you had to wait to close the bypass if the cat is over 500 but the flue temperature isn't? Where and how do you mount a flue thermometer or take the readings?
The thread (I lost the link) also explained how to fix the cat thermometer when it gets out of calibration, by adjusting the nut to match room temperature. It has numbers 1000, 1200. 1400, 1600 etc. with the small marks, whereas there are just marks with no numbers on this BK cat thermometer.

Note that I finally took some pictures, posted in my response to moresnow.
 

Highbeam

Minister of Fire
Dec 28, 2006
19,858
Mt. Rainier Foothills, WA
I saw on another thread the picture of an almost identical-looking cat thermometer, that was said to be made by the same company that makes this one, that does have numbers on it, a round black-and-white guage with 500 marked at the beginning of the same white band, and so on.

All the wood I've been loading is about 70 degrees F (from the indoor drying stack) when it goes in. I see the good reason for not thermal-shocking the cat. I even worry about the air hitting it during the few seconds that it takes to re-load, even though the bypass is open. How long have you had to wait to close the bypass if the cat is over 500 but the flue temperature isn't? Where and how do you mount a flue thermometer or take the readings?

So yes, you can buy a cat meter with numbers from condar. I did and I enjoy it. You can not assume that the BK meter or its tick marks correspond in any way to the numbered condar meter. There’s a reason BK chose a non numbered temperature gauge. Same reason that your thermostat doesn’t have numbers.

Minimize open door time when reloading or when the cat is hot. Even with the bypass open, the catalyst is still exposed to cold air from the door.

I have had to wait several minutes after reloading and closing the door before closing the bypass when flue temps retook 500 (internal) and rising. I measure internal flue temps with a probe meter in my double wall pipe. Catalysts need 500 degree exhaust to activate on their own so I chose that number as a reasonable threshold to close the bypass. I don't think that this is in the manual but I know that cold, wet, steam/smoke from the first minutes of combustion isn't something I want to sent into that ripping hot cat.

Measuring flue temperature on your single wall is as easy as shooting the surface with your IR gun at 18” above the stove or setting a magnetic surface thermometer in the same place. Your target temperature is 250 for closing the bypass and 500 for redline.

Just imagine owning a fine stove from the other great cat stove manufacturer Woodstock. Many of their stoves don't even have cat thermometers! I think that you are worrying far too much about cat temperature. The Bk's highly engineered combustion systemwas designed to not overtemp the catalyst excessively so long as the bypass is shut, you're burning regular fuel, and door seal tight.
 
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stoveliker

Minister of Fire
Nov 17, 2019
5,210
Long Island NY
Where and how do you mount a thermometer on the flue, or pipe? Or you just take readings with handheld infrared thermometer? I'm waiting for a stove thermometer to arrive in the mail, along with the moisture tester I ordered a month ago.

18" above the stove top. It's a Condar flue probe - i.e. you have to drill a hole to stick the thing in (rather than it being a magnetic one on the surface which is less accurate on single wall, and impossible to use on double wall).
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
The moisture tester that I ordered on December 16 finally arrived yesterday and I took some readings on the split cordwood. Large thick pieces ranging from the upper 30s to upper 20s. The under-the-bark readings from pieces with bark on were the highest. Small pieces are measuring about 20 if I can split them further.

With this dry indoor heat (in the 70s and 80s) and the fan being on 24/7 at least some of the stack should be dried to 20 or less pretty soon. Meanwhile I am not using very large pieces and pieces with bark, and I'm adding in some pallet pieces and 2X scraps that I know are dry enough. I'm running mostly at the highest temperature setting now, to stop or reduce drops of moisture dripping from the angle fitting seam. The concrete wall keeps getting warmer day by day, a thermal mass that might eventually begin to help reduce condensation instead of causing condensation as the uninsulated pipe goes through it.

I wonder how effective (how insulating) the vermiculite cement is in the vertical chimney pipe. I used a recipe very high in vermculite (medium size flakes) and minimal in Portland cement, not too wet, and hand mixed to keep it loose. I hope the average 2 inch thickness, only one inch in some places, is enough.

I shut down the stove yesterday and checked everything. There were dry flakes of creosote in many parts of the stove, especially in the corners. Maybe the stove should be more rounded instead of square so this doesn't happen. There was some dry soot in the bypass area. The cat looks good, no sign of cracks, some light ash but no creosote in that area. The three gaskets all look good.

I'm not starting the other BK stove, the Princess insert, until I learn how to use this King 40.
 

stoveliker

Minister of Fire
Nov 17, 2019
5,210
Long Island NY
Well, there you have it. Your wood is far too wet.
A week or two there is not going to bring a 30 pct piece to below 20 pct.

I cycle back to getting dry wood (or sawdust logs). You do run the risk of damaging the cat especially when loading wet wood in a hot stove; you are shocking the cat then.

All the rest doesn't really matter much until and unless you have dry wood as specified in the manual.
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
The moisture tester that I ordered on December 16 finally arrived yesterday and I took some readings on the split cordwood. Large thick pieces ranging from the upper 30s to upper 20s. The under-the-bark readings from pieces with bark on were the highest. Small pieces are measuring about 20 if I can split them further.

With this dry indoor heat (in the 70s and 80s) and the fan being on 24/7 at least some of the stack should be dried to 20 or less pretty soon. Meanwhile I am not using very large pieces and pieces with bark, and I'm adding in some pallet pieces and 2X scraps that I know are dry enough. I'm running mostly at the highest temperature setting now, to stop or reduce drops of moisture dripping from the angle fitting seam. The concrete wall keeps getting warmer day by day, a thermal mass that might eventually begin to help reduce condensation instead of causing condensation as the uninsulated pipe goes through it.

I wonder how effective (how insulating) the vermiculite cement is in the vertical chimney pipe. I used a recipe very high in vermculite (medium size flakes) and minimal in Portland cement, not too wet, and hand mixed to keep it loose. I hope the average 2 inch thickness, only one inch in some places, is enough.

I shut down the stove yesterday and checked everything. There were dry flakes of creosote in many parts of the stove, especially in the corners. Maybe the stove should be more rounded instead of square so this doesn't happen. There was some dry soot in the bypass area. The cat looks good, no sign of cracks, some light ash but no creosote in that area. The three gaskets all look good.

I'm not starting the other BK stove, the Princess insert, until I learn how to use this King 40.
Also, the draft seems to be good. NO back-puffing of smoke whenever I open the door. When I shut down and inspected the stove yesterday there was no downdraft, no sign of the slight negative pressure I had noticed sometimes at the end of the chimney pipe before I installed the stove.

My current worries are: (1) that the uninsulated 2 foot (about 30 inches) run of pipe through the wall is causing condensation, and (2) that there is not enough thickness of vermiculite insulation around the chimney pipe. Even after removing the clay flue, there was still barely enough room for the 8 inch rigid ss liner. Also, the three-foot extension above the chimney top is single wall not insulated.

Would it be a good idea to monitor the temperature of the exhaust at the chimney cap? How high must the exhaust be as it goes out to prevent condensation all the way up? When the stove is set low for a slow burn and the stove pipe is just warm inside the house the exhaust temp at the top of the chimney must be cool.
 

stoveliker

Minister of Fire
Nov 17, 2019
5,210
Long Island NY
Flue gases must be above 220 F to avoid condensation. Preferably above 250 F.
 
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bholler

Chimney sweep
Staff member
Jan 14, 2014
29,116
central pa
Flue gases must be above 220 F to avoid condensation. Preferably above 250 F.
That is at the top of the chimney as well. Especially with questionable insulation his temps at the bottom need to be considerably higher
 
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stoveliker

Minister of Fire
Nov 17, 2019
5,210
Long Island NY
Yes, I've said that many times on this thread. If water can condense just above the stove, it's far, far too cool.
 
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Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
Well, there you have it. Your wood is far too wet.
A week or two there is not going to bring a 30 pct piece to below 20 pct.

I cycle back to getting dry wood (or sawdust logs). You do run the risk of damaging the cat especially when loading wet wood in a hot stove; you are shocking the cat then.

All the rest doesn't really matter much until and unless you have dry wood as specified in the manual.
Even 20 is much too high for this stove, isn't it? The manual says not to use wood that is TOO dry either. I'm hoping to produce 15 percent moisture wood but will need to create a solar-heated wood drying area, not just an outdoor stack.

If it really is possible to do 40 hour slow burns with this stove and not create creosote by using dry-enough wood, then the expense will be worth it.

I thought of weighing some pieces from the indoor stack now, and see how much less they weigh as they dry over time. I'm sure there are figures or a chart somewhere comparing the weight of a piece of wood or a cord of wood at different moisture levels.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
29,116
central pa
Even 20 is much too high for this stove, isn't it? The manual says not to use wood that is TOO dry either. I'm hoping to produce 15 percent moisture wood but will need to create a solar-heated wood drying area, not just an outdoor stack.

If it really is possible to do 40 hour slow burns with this stove and not create creosote by using dry-enough wood, then the expense will be worth it.

I thought of weighing some pieces from the indoor stack now, and see how much less they weigh as they dry over time. I'm sure there are figures or a chart somewhere comparing the weight of a piece of wood or a cord of wood at different moisture levels.
No 20 is not to high. And you won't get it to dry in our climate without a kiln.

And yes 40 hour burns certainly are possible with good fuel. But that will be at an extremely low btu output
 

stoveliker

Minister of Fire
Nov 17, 2019
5,210
Long Island NY
I have done 20 pct wood. It doesn't work well. I don't know how <15 pct goes, I have mostly 16-18 pct. He has water problems. Hence his 20 pct is too high.

Regardless, it needs more heat to work properly.

And yes, the stove can do the 40 hrs. I've seen stories of 60 hrs. Stories, but still.
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
That is at the top of the chimney as well. Especially with questionable insulation his temps at the bottom need to be considerably higher
That is at the top of the chimney as well. Especially with questionable insulation his temps at the bottom need to be considerably higher
Even if the exhaust is 300 or more at the top (I'm sure mine isn't) if the surface of the pipe is below a certain temperature there can still be condensation???

When this stove is running the slowest with exhaust coming out just warm instead of hot, I see now that it is impossible to overkill pipe insulation.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
29,116
central pa
Even if the exhaust is 300 or more at the top (I'm sure mine isn't) if the surface of the pipe is below a certain temperature there can still be condensation???

When this stove is running the slowest with exhaust coming out just warm instead of hot, I see now that it is impossible to overkill pipe insulation.
If the exhaust is 300 at the top you won't have condensation
 

Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
No 20 is not to high. And you won't get it to dry in our climate without a kiln.

And yes 40 hour burns certainly are possible with good fuel. But that will be at an extremely low btu output
How do you get yours at or below 20 percent, assuming you do not use a kiln. I'm imagining a solar-heated space instead of a kiln. If kiln drying is needed that negates the advantage of efficiency of this type of stove.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
29,116
central pa
How do you get yours at or below 20 percent, assuming you do not use a kiln. I'm imagining a solar-heated space instead of a kiln. If kiln drying is needed that negates the advantage of efficiency of this type of stove.
Time.

I need less time than many because I have ideal drying conditions. I have a large asphalt parking lot that I stack on the edge of with lots of sun and wind. Depending on how humid a summer is I can get it below 20% in a year. But sometimes it takes 2. Some people need 3. I also am typically cutting standing dead trees which gives me a bit of an advantage.

I have messed around with solar kilns and they do work
 
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kennyp2339

Minister of Fire
Feb 16, 2014
6,594
07462
Green wood takes 3years split and stacked for me to get below 20%
 
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Slate Dale

Member
Dec 27, 2021
159
Slatington, Pennsylvania
If the exhaust is 300 at the top you won't have condensation
The inside surface of the three-foot single wall extension above the chimney top, in very cold weather like this, might still be cold, I'm guessing. I don't have experience to know. In weather like this if there is very little volume of exhaust coming up from a very slow burn, the outside air temperature might "win," I'm guessing.

The venting for the next BK stove I install will definitely have insulation OVER the insulation, and maybe even more insulation.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
29,116
central pa
The inside surface of the three-foot single wall extension above the chimney top, in very cold weather like this, might still be cold, I'm guessing. I don't have experience to know. In weather like this if there is very little volume of exhaust coming up from a very slow burn, the outside air temperature might "win," I'm guessing.

The venting for the next BK stove I install will definitely have insulation OVER the insulation, and maybe even more insulation.
The extension absolutely should not be uninsulated. It should be a section of class a chimney