Day 2 of burning with my Baby Bear. From my observations, there truly is a huge reduction in smoke when baffle is in place. Day 1 I had the baffle in place. I corrected my blunder and faced the door side of the baffle upward. Little to no smoke from startup all the way through hour 10 OF burning. Day 2, removed baffle while stove was cool in the morning (still a nice coal bed though!). Smoked heavily on startup and moderately to light once fully warmed up. Unless it was just due to changes in the wood I'm burning, its fasinating how much one plate of steel can make on smoke reduction.
Big storm coming this weekend. Indoor wood piles all stocked up and ready for some burning. I have 2 thermometers mounted - one on the upper side as WeldrDave shows (which is above the baffle) and one on the stove pipe just below the damper. From what I'm reading, I should try to keep stovetemp at or below 500? I already hit 600 twice (shut it down quickly) and feel like I really didn't have "that" hot of a fire - could have shoved a another split In! Chimney is acting as expected, excellent draft, no issues keeping temps within "hot but safe" zone. Again, totally new stove for me. Shack, your thinking 1/2 to 3/4 turn open on the draft knob is happy zone (considering each setup will have its differences including wood, chimney height, draft, parametric pressure, temperature, ect). I'm still trying to find the starting point.
I understand how you did that. My Bear is different inside. the upper step of the fire box is lined with fire brick...I will need to post some pictures after I clean it out once we warm up again. My understanding is that there were some differences between the building of the stoves depending on the fabricator.
Yes, correct and understood. You "can" remove those upper bricks. The lowers are the ones that will hold the heat also. The uppers gone will give you more of a quick radiant heat.
The reduction on a 15 foot test chimney by Fisher Research and Development was from 60 grams of particulate for every kg. burned down to 6 grams for every kg. burned. The theory was to roll smoke down into the flame and increase firebox temperature. Larger particles are prevented from escaping directly up the stack since particle size was the issue as stricter regulations went into effect in stages. By the third stage something was going to have to change to produce any stove and catalytic converters were in use on autos that were then designed for wood burners. Later, secondary combustion became what we have today. Only the double door stoves were fitted with baffles and I got the idea of putting one in a Mama Bear that was being tested in my kitchen for other reasons. Milk in the fridge door went sour overnight so I set up temporary shielding between the back of the stove and fridge about 6 feet away. That took care of the milk issue but the cement board wasn't going to stay propped up in the middle of the kitchen long. This was our only heat source that served as back up cooking and clothes drying all winter. So sitting at my PC looking at the side of the stove, I drew on the stove with chalk where I thought the baffle should go to divert the extreme heat forward INSIDE the stove instead of out. I had extra brick here so I set the bricks on their sides and sat a plate on them without the shield that night. I realized as soon as I lit it that the smoke was greatly reduced and realized how close to the "Smoke Shelf Baffle" in the later double doors mine was. I ended up making a few for friends and neighbors and realized with different chimneys I could fine tune them for the heat needed up the flue. It wasn't until the stove triathlon a few years ago that I realized if everyone would simply baffle their old stoves it would clean up the air a lot without the cost of a new stove. Instead of starting my own website for Fisher Stoves, I posted the well know baffle thread on Hearth that has over 77,000 views! All I was trying to do was prevent my milk from spoiling! It was a Brown Mama Bear too. The only original brown stove in my collection. Since then I tested the baffle in all the single door models on the same chimney. With baffle this was the only heat source in my 1850 square foot home all winter! The view from my PC contemplating how to direct the heat forward away from fridge.... With single cement board under tile the floor protection is just below minimum so I added the heat shield under it and the floor stayed cool. There is felt glued to bricks to prevent scratching floor since this is where all the stoves were later tested. One night of testing the Baby Bear and back to the larger stoves we went. I learned real quick to wedge a piece of firewood across the stove to hold the side bricks in place while I sat the baffle plate on top of them, then slide it rearward until it drops in place in the back. I took the measurements for some and made the plates to find their stoves were going when I got there. Crash the fire down and with welding gloves installed them over coals. It's that easy to put them in place once you've done it.
In 1977 there was a drawing revision sent to fabricators that could add a second course of brick to raise combustion chamber temperature. It wasn't to protect the side sheets. Not all fabricators added them and it wasn't mandatory. You can remove them. Here's a pic of the original print showing the new brick layout for Papa. I can't copy the full page, they are 2 X 3 feet in size;
Coaly, THANK YOU. I did not know it was safe to remove that second row of top bricks, I am sure that will make this much more straight forward to install a baffle. I appreciate the excellent information from you.
Thanks for the wisdom Coaly. I love the brown stove with bear feet and all. Tried this on a hot bed of coals with no luck - I was left with a load of unburnt splits. I was partially closing down the flue vent though - not fully. When learning a new stove, would I be best to leave the flue damper full open and work the air supply for awhile until I'm used to how it likes to run - then - learn how to work the damper after or would that be a waste of time? So far, it seems I need to be atleast a full turn open. My wood is 15-20% moisture. Only other thing I can say is my draft knob is rather sloppy and has alot of play in it.
I do not have a flue damper. So, now that changes things, I had forgot you had one. Coaly has "VAST" knowledge and has been doing this with Fishers for many years, I know the stoves well but not like him. The lower you can get your moisture in the wood, the easier this will be for you. As you said, run with the damper open and go from there. It's like learning to fly, you start simple "then" go to a much more sophisticated platform. Having the draft knobs a little sloppy won't be a factor unless they leak by when fully shut. And, never shut them tight! Expansion and contraction will come back to bite you trying to get them open sometimes. Also, removing those layer's of upper brick is "no big deal" at all but the lower is what needs to stay. Best of luck, you'll get it!