Correct size Fisher Stove

[Tylerc78]

I am going to be building a vacation cabin on some property I have within the next few years. I would like to start keeping my eye out for a nice older fisher stove to put in it eventually. I grew up with a double door fisher, either grandpa or grandma size. My question is the cabin will be aprox 900-1200 sq feet downstairs with an open loft upstairs. What size should I be looking for, or does it matter that much? I really like the double door stoves also for the nostalgia of growing up with one. But would that be too much stove? Any advice and suggestions appreciated. Thanks so much

 

[coaly]

Welcome to the Forum;
Depends on the construction, insulation, windows.....
I have a log cabin about 800 sf in NE PA with a Mama Bear now, but when the ceiling is insulated and done, I'll have to go to a Baby Bear. Solid logs are not a good insulator, but they do absorb heat and radiate it back in, as much as they lose to the outside as well. So you get a certain amount of mass heated over time in the logs to help offset the loss. I use it weekends and get there with it cold, so a larger stove is nice to bring it up to temp quick. If you ever want to go to a newer more efficient stove, you'll need a 6 inch chimney, so I'd go with an insulated 6 inch either way. The double door will work fine with it, and you'll never need to crank it up requiring a full 8 inch flue anyway. It's my only cooking and water heating source, so I like the single door with larger cook tops. Main difference is fire viewing is possible with a double door, so if that's a requirement, you may want that. Otherwise the front to back burn you get with a single door, a larger stove top, and more efficient stove with much smaller outlet is the way to go. Papa is going to be too much. Mama takes a larger fuel load than Baby for overnight burns. If you were going to live in it and keep it going constantly, Baby would be enough (with insulated walls and roof) since once heated, it doesn't take as much. So it depends on the use too.
If you want double door for fire viewing, watch for a Honey Bear that is a smaller version of a Grandma with 6 inch outlet and rear heat shield for closer installation in smaller areas. As Goldilocks would say, "the Honey Bear is just right" !



Legs or pedestal versions were available, or convertible with outside air intake.

 

[Northwoods555]

Baby Bear heat going up the chimney?

Hello, and apologies if I'm doing this wrong... But: I have a 16' X 20' traditional scribed log cabin in northern Minnesota. It has single pane windows in the gable ends and has a loft, but only one small single pane window below. I have calked it, the roof is insulated, the logs have wool between them, and it is reasonably air tight for a rustic cabin.

So, for the past five years I have been trying to make my Fisher Baby Bear work for this cabin. I wanted that stove and it should work! Thanks to your site and instructions, I've built a wonderful baffle a couple years ago (it definitely improved things immediately). But it's the second week of deer camp and November 15th. We have a foot of snow on the ground and it was 15 below the other night.

When it was still only 32 degrees out, we could only get the cabin to about 65 degrees after days of burning. We only have birch and maple, but it's very dry from years of seasoning indoors. The stove works like a rocket and has amazing draft. It just roars if you want it to, or you can shut the fire off with the door spinner as you Fisher people all know. The new baffle plate helped route that heat around before just shooting up the chimney. The chimney is 20' straight up, of double wall 6" pipe and I fear that maybe this is the problem. I have no heat coming off the pipe at all after it shoots out of the stove.

It's a beautiful old Baby Fisher and I want it to work. I have read that they could work in a 1500 sq.ft. application, but I only have about a 400 sq.ft. space. I use a fan too to move the air around, yet I can't get it to heat the cabin past a feeble degree. I believe it should be running us out of the cabin after the logs are all warmed up. Am I wrong?

My question is... Should I go back to single wall stove pipe? Use a Magic Heat contraption, or maybe put in a chimney damper (even though I have read here that they didn't call for one in the manual)???

Has anyone else dealt with this issue? I can certainly post photos if that would help...

Thanks for the great information.

 

[coaly]

Sounds like too much is going up the chimney and the stove is left with too little to radiate inside?

What exactly is the chimney? Double wall "pack" type or triple wall with or without insulation.
How high is the ceiling?
Length of double wall connector pipe?
Height of chimney flue? (or how many sections if it is insulated 3 foot sections)
Do you have a flue damper as well?

I would get a probe type thermometer and see what temperature the exhaust gas is a couple feet above the stove, then check it higher just before it dumps into chimney. You want to see about 1/2 the stove top temp before the chimney flue. (when smoke is present)

 

[Northwoods555]

Thanks. Excellent information. I will get out there and take the measurements and do as you suggest. But for the moment:

The below roof, two 3' sections plus shorter section, are black double wall and the three 3' sections above the roof/cathedral box are the stainless double wall, all sold by Menards. No idea how they are insulated.

The ceiling peaks up about 20 feet.
Total rise out of the stove is like 22+ feet to get above the roof ridge.
No flue damper, but I bought what I need and plan to install one...

 

[coaly]

You need to get temperature measurements inside the double wall pipe with a probe type thermometer for double wall pipe.
Thermometer on stove top will tell you if the stove is getting hot enough to heat the area.
You can always put a screw in the test hole at the ceiling when you know how hot to burn to achieve high enough temps just below the ceiling support box. (roof mounted support box in your case)
See if you can maintain about 300* f. inside the inner double wall pipe where it dumps into chimney at mid burn with 600* stove top. Baby Bear was rated for up to 1000 square feet with a 8 foot ceiling with insulated walls as well as ceiling. Logs transmit heat directly through quite well, so the insulation factor is very low. But it's a time thing with log homes to keep them warm over extend periods of time until they radiate heat back into the structure using the mass as well. This takes a long time and you're probably heating yours like I do mine, getting there with it freezing inside. Mine is machined logs from Finland that fit very tight with insulation between them, but I still went with a Mama Bear since it's 792 square feet plus cathedral to the roof. It would be ok with a Baby Bear if lived in and kept warm constantly, but I need more than the normal amount of heat required for short periods of time and can't take advantage of the thermal mass. Mama holds a lot more for overnight burns and it's my only cook stove and water heater, so I need the larger top as well. We can see a month of below freezing temps but rarely go below zero.

 

[Northwoods555]

I can't thank you enough... I absolutely plan to get the probe and do the tests you advise.

What you describe makes me think that I may just have too small of a stove for the cabin thermal mass/ambient temperature characteristics... We rarely use it for more than the week and the most is 2 weeks during the deer season and it's always at zero to 20 below it seems somewhere in there. So what you describe illustrates some of my likely problems. I had no idea...

I only have the 320 sq. ft. at floor level, but the loft and vaulted ceiling add another almost 400 sq ft. (very approximately) with glass windowed ends and only 2" of foam/ 2X6"pine T&G/steel roof. (Sorry, my earlier dimension estimation was just a guesstimate).

Too bad if it turns out the Baby Bear is too small for the situation, cause I love this Baby Bear, but that just might be the problem...

I appreciate the helpful response.

 

[Northwoods555]

Well, I don't know if this is how it works or not still... I have been careening through the manuals that Coaly put on about the Fisher stoves.

So it's been almost five years since I we spoke and Coaly helped me out. But I have tried a bunch of things and gotten improvements each time (It used to peak at 65 degrees F at 15 or 20 F below, and now it's up to 75-ish with a lot of time, work, and attention).

But it's been another four or five years now and that it is time to change out my Baby Bear for another... I have not found a reasonably priced Mama or Grandma stove here, but I did get a Goldilocks and a Grandpa Bear stove. The Grandpa is of course HUGE (and heavy) for my small space...

And the Goldilocks, although it looks a little bigger, is rated in the manuals as covering the same approximate space as the Baby Bear... I have done measurements to get an idea of the volumes inside of the Baby Bear and the Goldilocks, but none of the measurements really line up with the manuals listed measurements on the site.

So, I could try the Goldilocks to see if it would work, or I can just say the heck with it and put the monster Grandpa in. Or I guess I could wait till I find a Grandma or Mama Bear too...

But I guess my question is: just wondering if I should even bother trying the Goldilocks since it is listed so close in performance to the Baby Bear anyway???

What would you guess??


Thanks

Northwoods555
Ely MN

 

[coaly]

Goldilocks will heat a larger area than Baby. Goldi is a purpose built stove for closer clearance to rear wall, and outside air intake for manufactured housing which also makes it more efficient in a conventional built home using outside air instead of indoor air pulling cold air from outside from wherever it can.
I'm assuming your chimney is 6 inch ID to match connector pipe?

Goldilocks has an internal factory baffle, did you add one to your baby Bear?
A Mama with baffle would be much more suited for the larger upper loft area.
If you get there and it's really cold inside, go even larger.

Heat output goes by surface temperature of each square inch of surface area, not firebox size.
Do you have surface temps and flue gas temps? Without thermometers, your guessing. Some numbers would help a lot.
Is a flue damper being used in the pipe above stove?

 

[Northwoods555]

Thank you so much for all the information and patience. As before, your willingness to share your vast knowledge is incredibly valuable to me.

I do have a 6" chimney in place at the cabin, and the Goldilocks stove itself has a 7" ID opening and there is a 7" to 6" adapter in place.

I did add a good baffle to the Baby Bear and that really did seem to help.

Good to know about the firebox size not being an indicator of stove ability...

I did fail at the task of doing the probe temps last time, so I will have to do that now. I did check temps at the Baby Bear stove and pipe with a surface thermometer, and at times I think it was nearly 500F if that sounds right. 300F was more common at the stove top or close pipe exterior. But I can't remember and I may be mistaken...

I did install a flue damper above the Baby Bear stove and that seemed to help as well.

Later still I removed the side bricks too, but I am not sure that was helpful or not. I have read quite a few arguments for and against it. One advocate argued that the Baby Bear stove had such thick steel, that we'd all be dead before it burnt the wall out... I don't know...

I understand what you are saying about the logs, and the temps of the logs at startup, and their insulative properties. And as the deer season progresses, obviously it does get warmer inside to a point, but never quite enough. (This year I brought in a torpedo heater to compensate/augment the temps inside).

Here below is the Goldilocks (I believe based on all the reading I've done on your forum). There is no tag ID at all. There is a hot water pipe loop in the back. Not sure if there is supposed to be a gasket in the door or not on the Goldilocks, but there is one on it... The doors have nickel plating. It's missing the cap on the right control spinner... and it's 23.5" wide across the top.

Do you agree that it is a Goldilocks? Based on what you said, I think I will go another year and put the Goldilocks in place. It should fit right into the Baby Bear space unlike the giant Grandpa Bear.

Oh, since I don't plan on cutting a hole in the floor of my cabin, do I need to do anything with the pedestal tube/intake vent? Or am I missing the point? Can it be bypassed or not used at all for my situation? It might be a dumb question, but better safe than sorry and now's the time to ask...

Thanks for the help!

Northwoods555
Ely, MN

 

[coaly]

Your stove is a Teddy Bear. (not certified for mobile home use) Nickel plated with optional "Nickel Heat Shields" inside the doors.

It uses inside air through the door intake air vents. Goldilocks is the same firebox with an air intake system up through the pedestal. Goldilocks does not have air openings in the doors and only the left knob turns which operates a flap across the front connected to the pedestal.

It came with a screen for open door burning, so it can be used as a freestanding fireplace as well. It is not considered a radiant heater in Fireplace Mode. The screen is the same (called Contemporary style) as used on Goldilocks, Grandma and the "Fisher Fireplace Insert".
A flue damper is required, you did good reducing to 6.

Keeping the brick in place reflects more heat back into the firebox for more complete combustion. The hotter the firebox temp, the finer the ash burns down and the cleaner the stack stays as well as the air.

If the top left picture has the door latched, the latch rod is out of adjustment. The right side handle should be the same angle as left when closed and latched.

My avatar is currently a Ganz Teddy Bear that was given away with that model stove by Canadian dealers.

 

[Northwoods555]

Wow... Thanks again! The guy I bought it from had said it was a Teddy Bear, but not sure what I read that made me think it was a Goldilocks. I've read so much and seen so many mislabeled Fisher stove photos, that I seem to be easily confused now...

GREAT to know that it is a regular wood stove without the pedestal ducting (for my needs anyway). I had wondered how it could have both draft types... But all I do is burn wood, I don't actually know anything...

Yes, I did notice the door handles were out of whack. I was planning to see if I could solve that.

Also, I did get the screen with it. Which is another reason I' was hoping to be able to use it instead of the Grandpa Bear.

I will put bricks back in it then. It came from the seller without them.

Is it supposed to have the door gasket then?

How high above the stove is optimal for the flue damper placement?

Was the water exchanger loop an option or did someone just do that?

Also, the internal baffle is rolled in toward the flames. Was that baffle plate a flat sheet when it was new? It's mounted at like a 45 degree angle, but once the plate passes the side support angle irons, the plate rounds downward toward the ground. Should that be bent back to the 45 degree angle?

Lastly, one of the caps for the Ez-Spin draft spinners is missing it's decorative center cap. I searched high and low last night for something on it with no mention anywhere - that I could find anyway. Is this by chance just a regular 1" electrical hole cap plug?



Thank you so much. I really appreciate your time getting me pointed in the right direction on this!

Sincerely,

Northwoods555
Ely, MN

 

[coaly]

No door gasket.

Placement of flue damper does not matter. Put it where it is comfortable to reach. It is a variable resistance to slow chimney draft when necessary. Like a valve in a water line, it doesn't matter where it is installed, it slows the velocity of the rising gasses. This reduces draft reducing the amount of oxygen going into the stove. So it is a chimney control that affects the stove.

No hydronic system, that would be added by previous owner.

The baffle should be flat. If it removes easily, set it on a solid object and beat it back flat with large hammer. (with hearing protection)

Cap covers are difficult to find. Simply remove the remaining one to make them match. Most stoves did not have them.
I'm not sure what electric cap plug you're referring to, but don't use anything galvanized due to electrolysis generated between the dissimilar metals of cap and cover.

 

[Northwoods555]

Perfect, thanks. Sorry to ask so many questions, but you sure have helped me out! I've learned so much... Thanks.

This is what I meant by hole plug. Often used in electrical panels and otherwise for plugging holes in sheet metal. Looks exactly, or very much like the one I took out of the EZ spin knob. I just have to see if they come in a 1" size or not. I believe they do. This one is made of chromed steel so it would be a dissimilar metal since the cap is aluminum, but so is the one that is in there (as well as the bolts).

It must be the galvanizing that causes the issue?. The original decorative cap is steel. I presume that is from the factory new... Not that important, but dresses it up and looks nice on there...



Thanks again Coaly. I mean to leave you alone again for a few years. Really thanks again!

Northwoods555
Ely, MN

 

[coaly]

Yes, galvanized coating is zinc which causes more electrolysis between materials such as aluminum, brass, copper. Chrome, stainless or iron isn't near as corrosive to alluminum. When materials are wet, it is much worse.

As an example, take a penny and touch it to the tip of your tongue. Then try a nickel the same way. Both taste the same, or no taste at all. Now put them together and touch the tip of your tongue. It will be a lemon or sour taste. This is a minute electrical current flow between the dissimilar metals. If you leave different metals such as coins against each other in a pile for long enough, you will see the imprint of the other coin on the one it was touching. This is the electrons moving from one to the other, and what causes corrosion in plumbing when minerals in the water from the ground come in contact with dissimilar metals to them.

If you find a cap that looks the same, let us know! I never tried to find a replacement. Could be something simple.

 

[Desmond]

Wow! I can't believe that the baby bear wouldn't heat your cabin! I also have a small cabin and use a baby bear. But, I have normal stove pipe until it goes into the insulated chimney and a pipe damper about 18" above the stove. A lot of heat is generated just off the pipe. I also installed a good baffle. I would think your loft would be really cozy because of the rising heat. But, it sounds like you already have a replacement stove. Good luck and let us know how you make out.

 

[Don H]

You're looking for a steel "knockout plug", size will be 1", as measured on my Mama bear which has original covers.
These will be found in the electrical section of your local Big Box store but the ones I've seen are a different shape, convex instead of flat.

McMaster-Carr sells the ones that look like the originals but you have to buy a pack of 25 and pay shipping.
https://www.mcmaster.com/knockout-plugs
Maybe check an electrical supply house?

The plugs on my Mama are steel, painted black (maybe anodized), the draft knobs of course are aluminum.

 

[Northwoods555]

Thanks so much you guys. I really appreciate the help and advice.

I found it sad, if not hard to believe, that the Baby Bear wouldn't keep the cabin warm as well, but to be fair, the cabin is relatively big and maybe not as insulated as it should/could be. Also, we don't really have oak or other good hardwoods here except birch and some maple, and we are accustomed to 20F and 30F below temps that make a huge difference when trying to keep a space warm compared to 15F or 20F above.

I did do some of the improvements to the Baby Bear such as the baffle, and going back to straight pipe - and those definitely helped.

I believe I have found the 1" caps here in Minnesota for the EZ spin draft knobs, and so that probably isn't going to be a problem. Thanks.

And today the last of the work on the Teddy Bear replacement stove is occurring as soon as I get off the computer here, and I'll haul it out to the deer shack cabin for a trial. It's still below freezing, so if I hurry, I can maybe get a chance to try it out a little bit anyway...

Here are some photos I took yesterday to maybe help with the perspective a little bit. The log cabin is 16 X 20 plus an 8' loft on front. Single pane windows on both ends, one small side window, and one door window. No insulation in the floor yet, 2" pink foam in the ceiling and wool between the logs.

The other photos show the Baby Bear in relation to the floor space and from above in the loft. And the last photos are of the "new" Teddy Bear after fixing the door latch position (the mechanism seen above in the baffle photo had warped and snapped in half, allowing the latch lever go too far down) and adding a larger baffle than the original seen lying in front of it (probably a dumb idea, but I can always cut it smaller). Let me know if that is stupid... I had to fabricate a matching door pin to replace the carriage bolt that was there, and now I just need to put the bricks in, put the EZ spin with caps back on, polish the nickel on the doors, paint the stove, and then heft it out and into the cabin... I hope it works... I sure will miss the little Baby Bear though... Thanks for your help, especially you Coaly!

Northwoods555
Ely MN

 

[coaly]

Make sure the baffle has an unobstructed opening above it of 28 1/4 square inches minimum. That is the square inch area of the 6 inch round chimney flue that you can't reduce the area smaller than. That is a good size for a straight up 6 inch insulated chimney with 8 foot ceiling. Higher ceiling, elbows, horizontal runs, all require more heat to be left up, so the opening area would need to be larger. I make the plate for the smallest opening, then shim or adjust the plate angle to adjust opening as necessary.

If the firebricks are new, or have not been used for a while, they absorb moisture from the atmosphere and the first fire won't seem to get the stove very hot. The first fire in my new Goldilocks I didn't think it was going to heat my house! The second night it drove us out. Amazing how much heat is removed from evaporation and steam carried up the stack until they are dry. The first fire after sitting all summer can be the same way.

Not sure if I asked you way back when, but when you fire it and bring the building up to temp, how long do you use it? Logs are a very poor insulator, in fact they radiate heat right through to the outside, as well as radiate back inside after they have been warmed. This takes quite a while and is best when lived in constant all winter. Less than a few days use, you would need to oversize the stove as I did since it is a recreational cabin. Mine was a kit brought from Finland with premium machined logs, triple pane windows, made for extreme conditions. 33 X 24 outside dimensions, no loft but cathedral ceiling. Mama Bear due to occasional use as well as a larger cook top since it is my only cook and hot water heating. If I was going to live in it, I would have a Kitchen Queen 380 in it.

 

[Piney]

We live where it still gets to be -40. I can tell you, as far as cabins go, that walking in to an idle 12'x24' cathedral ceiling in the dead of winter meant three days of burning before you could say the place was truly 'heat soaked'. Warm after a few hours but not everything you could touch.
That cabin had an Orley in it though. Went faster when a grandma bear was put in, even after expanding the cabin. 2x6 construction, insulated with double pane windows.

.

Not sure if I asked you way back when, but when you fire it and bring the building up to temp, how long do you use it? Logs are a very poor insulator, in fact they radiate heat right through to the outside, as well as radiate back inside after they have been warmed. This takes quite a while and is best when lived in constant all winter. Less than a few days use, you would need to oversize the stove as I did since it is a recreational cabin. Mine was a kit brought from Finland with premium machined logs, triple pane windows, made for extreme conditions. 33 X 24 outside dimensions, no loft but cathedral ceiling. Mama Bear due to occasional use as well as a larger cook top since it is my only cook and hot water heating. If I was going to live in it, I would have a Kitchen Queen 380 in it.