Improving emissions; Mama Bear in CA

[Carin]

Hi Coaly et al. Just stumbled across this forum looking for info on reducing emissions from my Fisher, which I now know to be a Mama Bear. (I'm in Rio Nido, California, about 15 miles west of Santa Rosa.) There's a fire in her now, so not going searching under or behind for weld marks or UL plates.

It looks like there used to be a Fisher retailer just a few miles from here, in Forestville. I'd bet that's where she came from. I've uploaded a few pictures, but they haven't been approved yet.

She desperately needs new stovepipe put in as it's full of little holes and literally coming apart at the seams. Dad, from whom I inherited the house and Mama, was famous for half-assing things so they worked well enough for his immediate purposes and never doing them "right" later on. I'd like to get her new pipes done right, and anything else that needs doing to have her running properly. Any tips?

 

[coaly]

Welcome to the forum;
Here's a thread that will address the emission issues that was added to the later double door stoves but was never a factory addition on the single door stoves;
https://www.hearth.com/talk/threads...d-fisher-more-heat-less-smoke-under-25.74710/

The baffle and making it burn clean is all about the operator and chimney more than the stove.
As far as the pipe goes, it is relatively thin compared to a stove and has a life expectancy as short as yearly burning coal, many years if it's thicker pipe and you take care of it with wood.

I gave you your own thread so others can follow and chime in if you post improvements or have any questions!

Many have added secondary burn tubes so they operate like a newer EPA stove, but that is best with a glass door stove and again depends on chimney and how much you're willing to put into it.

 

[Carin]

Ah, I see the pics got approved.

First is Mama's door. Note it's hinged on the left, which is more convenient with her placement in the corner than the more common right side hinge would be.

Mama Bear in Rio Nido CA

• Carin
• Dec 28, 2016

front

Here's a close shot of the patent information on the door.

Fisher Mama Bear in Rio Nido CA

• Carin
• Dec 28, 2016

Patent number (I'm guessing) on door

She has a side vent with a 90 degree elbow that seems to be permanently attached to the body. I think the discoloration is the result of rain water coming down the pipe. I know the cap has been taken off. I guess there was some problem with draft and taking the cap and spark arrester off was the quick fix. I intend to get this rectified.

Fisher Mama Bear in Rio Nido CA

• Carin
• Dec 28, 2016

side mount 90 degree pipe attachment

See that weird lump in the stove pipe? That's where the seam is buckling. The section of pipe below that has the same kind of buckle. A neighbor has said I'm supposed to have some kind of double walled pipe on Mama, instead of this single walled stuff. Does he know what he's about, or do I take this with the same grain of salt I have to take half his advice?

Fisher Mama Bear in Rio Nido CA

• Carin
• Dec 28, 2016
• 1

stove pipe literally coming apart at the seam

 

[Carin]

So if I'm understanding the mechanism of a baffle correctly, with my side vent I would need to have a plate cut that would match the slope of the top plate from the upper level to the lower level, and probably weld in a piece of angle iron inside that slope to rest the plate on toward the front, right? Fire bricks could still be used to support the back edge of the plate, making it easy to get the plate in place.

 

[coaly]

Single wall pipe is fine if you have 18 inches of clearance to wall. If less than that, you need double wall for close clearance down to 6 inches.
You can always use double wall to keep the flue gasses hotter for better draft. It only becomes necessary when connecting out a side wall with outdoor chimney all the way up, or extreme ceiling height above 8 feet where single wall cools the inner gasses too much before entering chimney.
Their spark screen may have repeatedly clogged with creosote or the cap itself rots away (even stainless) over time. They are a replacement item like stove pipe that doesn't last forever like the stove.

No welding necessary for baffle inside stove. No support across back is necessary either.
Simply support baffle plate on fire bricks placed at the sides. Make a cardboard template and set it on bricks when the stove is cold until you get the height and angle you want. Then you know the size to make the steel plate. It should be 5/16 thick mild steel. It can touch the bottom of outlet pipe inside stove and should be directed towards the lower bend. The opening smoke goes through should be the same square inch area as chimney flue. That is very important. If it goes just beyond the front bend under the lower top, raising and lowering the plate will adjust the smoke space where the exhaust travels through. This is adjusting the baffle for the chimney which is how you will get optimum efficiency and the cleanest burn.

That is an original welded elbow. Probably not attached to stove permanently. You should be able to tell by a weld on it if it was. It will be stuck on there for sure and may not remove without destroying it. You should not have to remove it for any reason unless it rusts through. They are very heavy compared to what you buy now. Keeping it dry should last a long ,long time.