2020-21 Blaze King Performance Thread (Everything BK)

[AndrewU]

So what does your experiment tell us about use of the bypass? Should we be leaving the bypass open for a certain amount of time after a reload even if the stove is quite hot due to reloading with significant fuel remaining? I’ve been closing the bypass right away assuming I get the new load in quickly, and the stove was hot. Obviously I leave the bypass open if reloading on a barely adequate coal bed until the cat probe shows active again.

 

[Nealm66]

I’d also like to know if it’s best to crank the stove up for a bit before reload if there’s still a good bed of coals? Is this for better emissions or cat life or both? Or is it better for the cat not to be opening the door when everything is glowing red

 

[kennyp2339]

I think I've always credited @Highbeam with the thought process of never put cold or wet wood in a hot stove with a closed by-pass due to cat shock, I always bring in at a minimum full days worth of wood and let it warm up to room temp before loading it in the stove. This was back in the ceramic cat days

 

[kennyp2339]

I’d also like to know if it’s best to crank the stove up for a bit before reload if there’s still a good bed of coals? Is this for better emissions or cat life or both? Or is it better for the cat not to be opening the door when everything is glowing red

Crank the stove up before loading, but always open the by-pass before opening the loading door to, thermo shock can cause scaling I think.

 

[Nealm66]

I always open the bypass before I open the door. I usually close it up right after I load but my woods always pretty warm and cat meter never gets close to stahl. I guess I’m curious why it needs to be so hot before reloading. If it’s to help with the cat from falling below the needed temp, it seems like just cranking it up for the bake kind of eliminates the need if the woods good and dry and there’s a good base of coals?

 

[BKVP]

So what does your experiment tell us about use of the bypass? Should we be leaving the bypass open for a certain amount of time after a reload even if the stove is quite hot due to reloading with significant fuel remaining? I’ve been closing the bypass right away assuming I get the new load in quickly, and the stove was hot. Obviously I leave the bypass open if reloading on a barely adequate coal bed until the cat probe shows active again.

Always close bypass once active and on reloads if already active.

 

[stoveliker]

So to all you that care, I have been studying (real-world) cat quenching. Don't call animal control, this is the effect of cold air or cold fuel load on an active combustor temperature. Piece size used was what might be deemed "normal" for loading as opposed to the kindling piece size that might be used for starting a fire. All experiments were run for 5 consecutive days, then the next scenario was employed. Thermostat setting was consistently left at 5:00 o'clock setting (I would provide degree of angle, but this group would start taking their stoves apart and measure!) and never adjusted either higher or lower.

FIRST SCENARIO:
Effect to combustor temperatures with no fuel being added. Loading door left ajar 60 seconds. Conditions at time door is opened: 25lbs remaining of 60lb load (40% remaining). Cat temp 970 and 60 seconds later (door fully ajar) Cat temperature 570. Loss of 200F, just over 20% of preopening cat temperature. These are the 5-day averages.

SECOND SCENARIO:
Effect to combustor temperature with 40lbs of fuel added (no more than 5 pieces), door left ajar for full 60 seconds, even though fuel was loaded in 34 seconds (avg). Fuel load came directly off wood pile in outdoor wood shed. Ambient temps were 48/32 (avg) over the 5 day period. Cat temp 1190 and 60 seconds later cat temp was 300F cooler at 890F, but dropped an additional 200 degrees (690F) within 5 minutes. So 6 minutes after opening the loading door and adding 40lbs of "cold wood" and closing the loading door, the combustor dropped just over 40% with a total loss of 500F. Recovery to origin point of 1190 was 22 minutes from door opening.

THIRD SCENARIO:
Effect to combustor temperature with 40lbs of fuel added (no more than 5 pieces) door left ajar for full 60 seconds, even though fuel was loaded in 34 seconds (avg). Fuel load came directly off wood pile in outdoor wood shed. Ambient temps were 29/23 (avg) over the 5 day period. Cat temp was 1300 and 60 seconds later cat temp was 320F cooler at 980F. NOW GET THIS, the combustor temp dropped an additional 470F within 5 minutes. This mean 510F was combustor temperature (550F+ is deemed "active"). Now this is quenching! It took 36 minutes to reach 1290F combustor temp.

FOURTH SCENARIO:
Effect to combustor temperature with 40lbs of fuel added (no more than 5 pieces) door left ajar for full 60 seconds, even though fuel was loaded in 34 seconds (avg). Fuel load came directly off wood pile in outdoor wood shed. Ambient temps were 34/28 (avg) over the 5 day period. However, for this 5 day period, daily loads were placed 24" away from the stove and let sit for 12 hours. Cat temp was 1157 and 60 seconds later cat temp was 270F cooler at 887F. The combustor temp dropped an additional 170F within 5 minutes. Combustor temperature reached 1164 within 14 minutes of loading. This was the fastest recovery, least amount of quenching of all scenarios.

A bit about the fuel: All fuel cut from the same trees 5 years ago. Black locust, heavy bark on all pieces (1-2" thick). Range m/c of fuel using 1" pins on Delmhorst J2000, 15-19%

Moral of the scenarios: If you want to minimize quenching, try to bring your next fuel load into the stove room about 12 hours ahead of loading. Mind you, at any point after loading, I could have turned up the thermostat to incentive increased combustion rate and operating temperatures. In doing so, more gases would be produced at a faster rate and the combustor temperatures would have recovered at a faster rate.

Nice study, thanks for the data! Much appreciated!

Did you immediately close the bypass upon closing the loading door in these cases? (B/c the cat gauge would be indicating "active" - b/c that was it's state 5-10 mins ago...)

Would you advice not doing so for the worst case (cold wood)?

 

[stoveliker]

Nice study, thanks for the data! Much appreciated!

Did you immediately close the bypass upon closing the loading door in these cases? (B/c the cat gauge would be indicating "active" - b/c that was it's state 5-10 mins ago...)

Would you advice not doing so for the worst case (cold wood)?

Well, sorry for the repeat - I replied to @BKVP s post without seeing these responses that were on the next page for me already.

 

[BKVP]

Nice study, thanks for the data! Much appreciated!

Did you immediately close the bypass upon closing the loading door in these cases? (B/c the cat gauge would be indicating "active" - b/c that was it's state 5-10 mins ago...)

Would you advice not doing so for the worst case (cold wood)?

Yes

 

[Poindexter]

Moral of the scenarios: If you want to minimize quenching, try to bring your next fuel load into the stove room about 12 hours ahead of loading.

I have been bringing the next load of wood up to the hearth as soon as the hearth is clear for seven years now. Intersting side benefit of being lazy I guess. I load the stove off the hearth in the afternoon when I get home from work, then bring up what I need for tomorrow morning and tomorrow afternoon... Didn't realize I was helping the combustor too.

 

[Indianawood]

Still not sure what time it is ha ha, is this 2:00 ?

I made this using a target for target practice. Self stick.
I Googled a clock face on my phone, turned off the lights and laid the target on my phone and traced the lines. It's just nice to know exactly where you are setting it, especially for night burns.
My disclaimer : not trying to start a swoosh war, just giving ideas for easier reference points

 

[Highbeam]

I made this using a target for target practice. Self stick.
I Googled a clock face on my phone, turned off the lights and laid the target on my phone and traced the lines. It's just nice to know exactly where you are setting it, especially for night burns.
My disclaimer : not trying to start a swoosh war, just giving ideas for easier reference points

Whatever you want. Surprised you went with permanent marker for your first mark. I prefer some sort of marking for repeatability.

I tried adding two honking splits to a 50% full firebox last night with no attempt to burn in the new load by cranking up the thermostat like usual. So no “char”. Cat temperature immediately climbed and regained any losses but the flue got a new layer of gunk on it. While it is possible to just throw more wood in and close the bypass immediately while never touching the thermostat, I will return to at least a few minutes of open bypass full throttle charring before closing down for the long burn. Too much pollution even if thermal shock to the cat is unlikely.

My nice and dead grass tan colored flue probe is now a dark Kona color and thick with soot. Time to burn things clean to make it right.

 

[Nealm66]

Good or bad, everything is good information for us newbies. My setting didn’t work last night with regular fir. My stove is downstairs in a room with a non insulated concrete floor and it dropped down to 30 outside. Still was 67.8 in the target spot upstairs. Not too bad. I believe my full load of Idaho logs could have easily went 30 hours at that setting. So amazing! Heading out to dump a couple small fir snags for the drying rack. Do you always crank your stove up before reloads highbeam? I’ve been cranking up, open bypass, rake coals level, load, close bypass, leave cranked for 10. I’m wondering if maybe easier on cat if maybe it wasn’t so hot when a guy opens the door?

 

[Holiday]

I tried adding two honking splits to a 50% full firebox last night with no attempt to burn in the new load by cranking up the thermostat like usual. So no “char”. Cat temperature immediately climbed and regained any losses but the flue got a new layer of gunk on it. While it is possible to just throw more wood in and close the bypass immediately while never touching the thermostat, I will return to at least a few minutes of open bypass full throttle charring before closing down for the long burn. Too much pollution even if thermal shock to the cat is unlikely.

That's interesting as I figured the cat would have cleaned it up. I guess there was just too much smoke initially at the beginning for it to burn it all then?

 

[Greenback]

Hi all, so I got lucky and was able to find all the required rigid oval liner to get my insert installed properly. The insert is located in the in the fairly centrally living room in a internal brick fireplace on the main floor (1700sq ft) of the house. House also has a 1100 sq ft insulated but unfinished basement.

Its up and running now and really enjoying it (insert was a 2010 model still in the crate when I picked it up), but I have a couple questions about its operation- mainly in regards to thermostat operation.

I'm new to wood burning, especially cat style, so I'm just trying to sort out if my thermostat is operating properly.

From WFO on the thermostat, all the way down to 50%, there appears to be no visible change in the flames in the firebox, this seems to be true when I adjust the Tstat and any point in the burning cycle (just after reload all the way to just ambers remaining). The temp on the cat thermometer also indicated no change from 50% and higher on the Tstat. But 50% and below you seem to get very instant and controllable feedback from the insert. Is this normal?

Also when setting the up the fireplace for overnight burns, I'm struggling to get any consistency (even with somewhat similar overnight outside temps). Ill load the firebox up and set the Tstat to a fairly low setting. I'll hear the furnace kick on between 4-6am in the mornings when it seems the fireplace can no longer keep up. Sometimes I'll find there was hardly anything left burning when I check the fire at 7am, which would make it understandable that the furnace took over, but other mornings there will be plenty of wood remaining,enough to crank the stove up to high for 2-3 more hours of burning before reloading.

Should the Tstat not be regulating to add more air to maintain temperature on those mornings given that there is plenty of fuel left to burn? Or are my expectations a little too high for a basic mechanical thermostat? I'm very impressed with the insert so far, just curious if my described Tstat operation is normal because so far to me it seems closer to an air control than a thermostat.

Im burning consistent wood from the same tree (ponderosa pine) at 11-16% moisture, burns very well considering its just pine. I can maybe eek 14 hour burn times out of the stove so far, but the last few hours definitely can't keep the house above 70*. Hard to say for sure as I'm struggling to get consistent predictable results.

I also need to figure out a way to better distribute the heat throughout my house, but thats for another thread. Thanks for reading!

 

[kennyp2339]

all the way down to 50%, there appears to be no visible change in the flames in the firebox, this seems to be true when I adjust the Tstat and any point in the burning cycle (just after reload all the way to just ambers remaining). The temp on the cat thermometer also indicated no change from 50% and higher on the Tstat. But 50% and below you seem to get very instant and controllable feedback from the insert. Is this normal?

Yes normal, more then likely the t-stat is already opened and taking in air so you wont see the change, when you set it at the 50% or below your hitting the mark on the t-stat with the heat to close it and reduce the air.

Should the Tstat not be regulating to add more air to maintain temperature on those mornings given that there is plenty of fuel left to burn?

You might have the setting set to low, when I load up for the night I'll put a char on the wood for 10-15min then close the t-stat to 1 O'clock (thats my bread and butter setting atm) but what I do is set it to 1, then ever so slightly nudge it up a hair, it prob doesnt do anything but in my head I feel like it takes the tension off and puts it into the positive area for a faster

Im burning consistent wood from the same tree (ponderosa pine) at 11-16% moisture, burns very well considering its just pine. I can maybe eek 14 hour burn times

Thats pretty good for ponderosa pine, try collecting something with more btu's (doug fir, larch, birch, red cedar) or use bigger splits and pack that fire box full.
opening.

 

[Highbeam]

That's interesting as I figured the cat would have cleaned it up. I guess there was just too much smoke initially at the beginning for it to burn it all then?

Too much smoke, too cold of smoke, I don’t know. I can’t say if it was smoking out of the chimney but flue temps and cat temps were plenty high to burn a normally charred load clean.

Do you always crank your stove up before reloads highbeam? I’ve been cranking up, open bypass, rake coals level, load, close bypass, leave cranked for 10. I’m wondering if maybe easier on cat if maybe it wasn’t so hot when a guy opens the door?

Yes for your first question. I tried an experiment in the spirit of discovery and I’m going back to charring all new loads at full throttle.

I bypass the hot cat for a few minutes before opening the door to hopefully reduce thermal shock. Also to get the flue warmed up and flowing to reduce smoke rollout.

 

[Greenback]

Thanks for the feedback, as I said I'm still in the learning stages.

I've had the Tstat on lowest possible setting overnight with a full firebox and woken up to just a few ambers going 9 hours later. Ive also had it on the 3rd lowest dot overnight, expecting it to be extinguished well before the morning, but find 2-3 more hours of fuel left if I crank up the Tstat, in both circumstances the furnace has taken over the heating of the house before I wake up. House thermostat is about 17 feet from the fireplace down a hallway.

I have some douglas fir, but it needs more time to dry, I measure 17- 23% MC average on it, but I'm not sure I trust those numbers as I did a full load of fir and the seasoned pine definitely burnt better and longer.

 

[Highbeam]

Thanks for the feedback, as I said I'm still in the learning stages.

I've had the Tstat on lowest possible setting overnight with a full firebox and woken up to just a few ambers going 9 hours later. Ive also had it on the 3rd lowest dot overnight, expecting it to be extinguished well before the morning, but find 2-3 more hours of fuel left if I crank up the Tstat, in both circumstances the furnace has taken over the heating of the house before I wake up. House thermostat is about 17 feet from the fireplace down a hallway.

I have some douglas fir, but it needs more time to dry, I measure 17- 23% MC average on it, but I'm not sure I trust those numbers as I did a full load of fir and the seasoned pine definitely burnt better and longer.

I'm afraid you're using the thermostat backwards. The inserts have/had dots and the thermostat is backwards from the stoves. Can you please verify which direction you are turning the knob for "lowest possible setting"?

 

[Highbeam]

Just another fir day. Wish it was Friday!

 

[Nealm66]

Something I’ve noticed, although the outside temperature might be the same, wind chill and whatever else can make my wood burn a lot different at same outside temps. Another thing I got to thinking was how/why the one big chunk basically cooked us out of the house the other day with a high of 37, I stuck it on a bunch of press log coals which I’m beginning to notice have a long life. So many variables. I still haven’t figured out wth all the #’s mean on my fancy weather station are exactly. And of course I lost the directions. Probably google the manual one of these days lol. One things for certain, if you’re waking up to a few hot coals with a king stove you probably wouldn’t have had any coals with anything else if it’s operating correctly.

 

[stoveliker]

Something I’ve noticed, although the outside temperature might be the same, wind chill and whatever else can make my wood burn a lot different at same outside temps. Another thing I got to thinking was how/why the one big chunk basically cooked us out of the house the other day with a high of 37, I stuck it on a bunch of press log coals which I’m beginning to notice have a long life. So many variables. I still haven’t figured out wth all the #’s mean on my fancy weather station are exactly. And of course I lost the directions. Probably google the manual one of these days lol. One things for certain, if you’re waking up to a few hot coals with a king stove you probably wouldn’t have had any coals with anything else if it’s operating correctly.

The wind-chill is just the wind speed. So it'll affect the draft as compared to the same temp without wind (chill).

 

[Nealm66]

This

 

[Nealm66]

I’m guessing it’s telling me it’s 24ish with the windchill?

 

[Greenback]

I'm afraid you're using the thermostat backwards. The inserts have/had dots and the thermostat is backwards from the stoves. Can you please verify which direction you are turning the knob for "lowest possible setting"?

The thermostat on my insert says HIGH at 12'oclock, and LOW at about 6:30ish. The dots fill everything in-between from 1:00-5:30 (8 dots between high and low). So turning clockwise is decreasing the heat output.