It takes me stove from a cold start about 30-40 minutes for me to put in some smaller pieces and get the flame and heat going and then drop in a few larger pieces on top of those and get them going. Roughly about the 40 minute mark I can shut the bypass and engage the catalyst. Somewhere between 600-800 degrees on the cat probe.
That sounds about like how I was running the 91, and the 30-40 minutes it took, except I wanted to see the cat glow fairly quickly after I closed the bypass, so I often took it to 800-900 before closing the bypass and trying for cat light-off.
I was pulling the coals into a N-S line in the center, then loading some quicker-burning woods on the coals, like White Ash or Cherry. They burn a little more vigorously and heat up the stove faster. Then I might have longer-burning woods like White Oak or Black Locust along the sidewalls of the box. This is 1/4" steel so it takes a good amount of heat to get the cat area of the stove hot enough for a good cat light. Or maybe try the opposite, putting some faster-burning wood in the lower corners, that would gas more in the latter stages of the burn and maybe keep the stove hotter at that point. It's all an experiment, so try different things and see how they work out.
I also ran some flame in the box for a while after closing the bypass to keep pumping flame heat to the cat to speed light-off.
The other part of the light-off equation is that you've gotta have enough wood burning and gassing in order for the cat to be able to light off with a strong glow.
You can see if the cat is glowing by looking in through the hole where the bypass rod goes through. You may have to move your head around a bit to get the correct angle, but you
can see it.
I don’t have a thermometer or radar to check the surface temperature.
Even with an IR thermo gun, it's hard to shoot the top of the firebox, which is underneath the convective space where the blower air comes out. I don't know that it can be done accurately. I ended up putting a magnetic surface meter on the front of the stove above the door off to one side, where the firebox top intersects the front. When the stove was cranking, the meter would read about 500 or so, cat meter maybe 1400. I didn't like the cat to go any higher than 1500, fearing damage to the cat which I read might result from prolonged operation in excess of 1500.
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I can tell you almost certainly the wood is wet still, for sure the oak. Hardwoods especially oak take 2-3 years to season when their split.
Agreed. I'm in southern IN and my Oak takes three years to get sub-20%. Of course that will depend on how it's stacked. Single-row and top-covered in a windy location, maybe you get it dry in two years. My stacks are three rows wide and in the trees where wind isn't as strong.
I don’t think they’re still wet. They burn no problem.
If the wood gets burning on two sides in less than a minute maybe it's drier than we think, but it just doesn't seem likely if only split for one year. Don't just test one split, test several of your biggest ones for a more accurate average of how dry it is.
Still looking for that 12 hour burn time cause I would love to only load it twice a day but right now I’m running on a 3 loads a day cycle.
I do think I’ve been leaving too many live flames going in the firebox though. After I read some other posts on older threads about the buck 91 I do think I need to close off my air controls a little better.
About how long do you leave the air controls open when putting in a new load? I’m a little confused on how much I need to let the wood burn before I close down the air controls. I don’t want to burn up the wood too much before closing it off. But I’m afraid of not getting it charred enough before closing it down too.
Obviously you're not going to get as long a burn out of the Sweetgum as you will with Oak. It will OTOH dry faster. I was doing 12-hr. loading with good woods like Oak etc. but the stove meter would be down around 250 and heat output would be waning.
As I mentioned, you have to burn in the load long enough to get sufficient wood gassing to feed the cat the smoke it needs for a strong light-off. Once I had closed the bypass, I kept some flame going in the box in order to light the cat quicker. But you don't want too big of flames, which could suck around the flame shield and hit the face of the cat, possibly damaging it.
Once I had the cat light well I generally had the boost "shotgun" air closed and the right airwash air open 1/8-1/4" to cruise the stove.
With a 4 cu ft box, you should be able to get longer, especially in shoulder season weather.
I burn with the air wide open until all is engulfed in flames.
But the times depend a lot on your draft imo. ....I have never gone beyond 20-30 mins. Often it's near 15 mins. But your mileage may be different than mine.
Although Buck claims 4 cu.ft, maybe that's with the cat flame shield and cat removed because I measured the loadable volume of the stove at a little under 3 cu.ft.
It's gonna be quicker to get your BK box with 1/8" steel hot enough for the cat to light, than it is the 1/4" steel of the mighty Buck. 😏
I assume the newer Buck has still got the thick steel box.
I had a stainless 8" liner, 21' on the Buck Bay 91 at my MIL's house, and with the air wide open you would have blast furnace-like fire in there. At 19' I'd expect his draft to be about as strong, assuming the chimney is lined all the way to the top.
When bringing the stove up to temp I wanted to strike a balance between a lively fire and the amount of heat that was staying in the box. Sure, you can heat up the box faster with the air open more resulting in a lot of radiant heat inside the stove, but you are also flushing more heat up the flue. Like Jerokyn, I felt that I was burning up the load too much with the air open too far.
