Old Fisher wood stove

[nshif]

Ive just acquired an old Fisher ( I think mama bear). It has an 8" flue opening on the top upper ledge
and another 8" opening in the top back with a weighted damper in it. Does any one know what this is for......is it a combustion air intake? can i just seal it off and use the front vents? It will only be used as temp heat while building a house then will end up in the basement . Thanks in advance for any info

 

[elkimmeg]

can you post a picture the weighted damper sound like a barometric one.
Why does not buy a stove when they know nothing about them? sorry I had to ask. well you came to the right place .
Are you sure it can ;legally be installed? many old fishers wer not labled and listed Today's code require labling and listing to obtain a permit. I hope neighbors home aren not too close to yours you have a polluting smoke belching beast.
Check the back of the stove for the lable o and listing look for UL certification If you have it you are part way home. Many states require stoves to be EPA certified for cleaner burning less emmisions all stove sold after 1990 had to be EPA cert.If you live in one of these states you cannot install that stove. My point being you should have asked and gotten educated before purchasing a stove where you know nothing about I wrote a primer Wiki, on this site to educate and help potential owners from making many common mistakes. Welcome to the forum I wish you had posted your concerns and question prior to purchase. Really not trying to be hard towards you

 

[nshif]

Im Aware this stove is not up to code ....it is only a Temp heating device so I can work through the winter, witch includes building a hearth for a new epa certified stove. which is required. I have no neighbors close and those I do have are using acient stoves that blech smoke. I just want to know what the other hole is for.

 

[BrotherBart]

Im Aware this stove is not up to code ....it is only a Temp heating device so I can work through the winter, witch includes building a hearth for a new epa certified stove. which is required. I have no neighbors close and those I do have are using acient stoves that blech smoke. I just want to know what the other hole is for.

Dave_1 will be along before long. He is the house Fisher guy.

 

[Dave_1]

Nshif,

The following link explains why there is confusion about Fisher heater identification.

(broken link removed to http://www.northweststoves.ca/faq.html#w)

Since there were 25 separate steel fabricating shops throughout USA & Canada clearly the heaters are not the same cosmetically & or by dimensions despite their respective names. Such is proven repeatedly by the pictures & dimensions given for Fishers heaters that are sold on ebay.

For example, note that in the following link the Fisher is called a MaMa bear yet has only one door with two air inlet screws, & a odd looking 6” flue out the back.

http://cgi.ebay.com/MAMA-BEAR-FISHE...ryZ41987QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

In comparison our Fisher Grandmother (MaMA) bear has two doors with one air inlet screw on each door, an 8” flue 3” out the back at the top of the heater.

We do not have two 8" holes in our heater. An external damper was recommended installed in the first section of stovepipe by our seller. Since it caused creosote it was removed before the 2nd year burn.

So, unless you are an experienced wood burner that is burning wood with less than 10% moisture content, I recommend removing your damper if that is the flue you are going to use.

By running our heater according to a Condar's instructions regarding their chimney temp gauge, we get little smoke / creosote.

Perhaps Elk / hearth dealers will tell you how to properly seal the extra flue hole that you are not going to use in order that you can meet code?

Sorry, wish I could be of more help but have never seen a Fisher that you describe.

Good luck with it

Dave

 

[nshif]

Dave thanks for the info. here are a few pics perhaps that will help

 

[Todd]

Looks like a homemade job to vent out the back so it would fit in a fireplace. I would weld a permanent seal on it and vent out the top.

 

[webbie]

Todd is correct - this was modified, but me thinks it was modified with the barometric in an attempt to make it burn better or somthing like that - BUT, the baro should have been just placed in the stove pipe....stupid, stupid, stupid.

You will want to 100% seal off the rear flue (cast or steel plate bolted on the rear of stove) if you want to use this as a temp space heater.

 

[Dave_1]

Nshif,

You could make money teaching the ebay sellers how to take good pictures.

In the 2nd pic the damper appears to be within a sleeve that has been inserted into the flue. Is that correct?

The damper also appears to be automatic in that there is not a manual adjustment. Is that correct?

If there are welds fastening the unit to the flue it was factory designed.

If there are no welds then the owner got cleaver, not the manufacture. Apparently the guy had HVAC experience & to avoid installing a damper in the chimney decided to control the heater output with an automatic barometric draft regulator.

Go to
(broken link removed to http://www.fieldcontrols.com/draftcontrol.php)

then scroll down to “How Draft Controls Work” & look at the drawing.

In your case the control is below & to the back of the heater but the principle is the same.

Can you read the manufacture of the damper & the model #? What are they?

Read about the above configuration & procedure a while back but didn’t copy the file. From the article the idea was that by extending the pipe to an outside air source the operator not only saved using heated air to run the heater but was not depleting breathing air as well.

(Forgot to post the Condar temp info in my last remarks.)

(broken link removed to http://www.condar.com/meteruse.html)

Dave

 

[Dave_1]

Note question & answer in bold

<snip>

[Question]

"I have a Lakewood stove and, after reading your article on draft controls (issue 77, page 40), I installed a Field barometric draft control on the stovepipe, positioning it 12 inches above the stove.

Before the draft regulator was added, my chimney required cleaning once a week, but I can now run the stove for at least a month with no appreciable buildup in the pipe. However, just recently a layer of creosote has accumulated on the back of the control, causing the regulator to be unbalanced and making it stay open. (The control was factory-set.)

How can I get the creosote off the control and avoid this problem in the future? Can I mount the draft regulator below the stove outlet in order to prevent the buildup, and still have the regulator work?

[Answer]

Creosote buildup on the interior surfaces of a barometric draft control is a common occurrence. And you are correct that the weight of the accumulation on the hinged flap can effectively change the draft setting of the device. In addition, creosote deposits can cause the flap to stick in the closed position. Neither of these conditions is particularly hazardous, but they can decrease-or eliminate-the effectiveness of the draft control.

Cleaning is possible. Most barometric draft controls can be disassembled. Some of the creosote can be brushed or scraped off, but in most cases, a solvent (such as Cleans Up) will be helpful for removing sticky deposits. Your suggestion of installing the device below the stove outlet of your rear exit stove is a good one. I have not tried it myself, but I think it will work to eliminate most of the creosote buildup, without diminishing the original draft-controlling and creosote-reducing functions of the device. (The reason creosote accumulates in the barometric draft control, while the control reduces creosote buildup further up the chimney, is primarily the result of inadequate mixing of the air and smoke in the control itself. Because of the flow patterns inside the device, pure, undiluted smoke is in contact with much of the interior surface.) Jay Shelton."

<snip>

(broken link removed to http://www.motherearthnews.com/Livestock_and_Farming/1983_November_December/Ask_Our_Experts)

 

[begreen]

Weekly chimney cleaning? Hello, that seems like a lot of unburnt gases heading up the chimney. Assuming that this is not due to burning wet wood, even once a month would be unusual. I would think that a modern, more efficient stove would pay for itself pretty quickly at the current rate of cleaning.

 

[BrotherBart]

Weekly chimney cleaning? Hello, that seems like a lot of unburnt gases heading up the chimney. Assuming that this is not due to burning wet wood, even once a month would be unusual. I would think that a modern, more efficient stove would pay for itself pretty quickly at the current rate of cleaning.

I think the guy wrote that in 1983 BG.

 

[begreen]

Well, I hope he's learned by now, sheesh. :red:

 

[Dave_1]

BeGreen,

Weekly chimney cleaning? Hello, that seems like a lot of unburnt gases heading up the chimney.

Right!

Assuming that this is not due to burning wet wood, even once a month would be unusual.

Wrong assumption. More than likely it was due to wet wood because even today most burners assume that if the wood has been up 6-9 months it is ready, even though it has been left out in the rain. Without a moisture meter isn't that a faulty assumption?

I would think that a modern, more efficient stove would pay for itself pretty quickly at the current rate of cleaning.

Right! However, if nshif’s Fisher is fed wood with a mc of <10% he will experience a considerable improvement over creosote.

Remember this thread?

https://www.hearth.com/talk/threads/3323/

and the suppressed admission by the EPA as to the reality of performance of the new EPA p2 heaters?

<snip>

"Note that in Table 1 the “conventional“ heaters were only twice as dirty as the EPA p2 heaters, not 10 times as is to often claimed ….”

<snip>

And, as BB pointed out, the article cited to nshif was 1983. It was cited in order to explain the reason for his Fisher’s damper location. But since you raise the excellent point about “wet wood“ being a possible contributor, here is what an expert said was acceptable mc for wood burning back then:

https://www.hearth.com/talk/threads/3323/

<snip>

"Rule 5: Avoid excessively wet, or dry, wood. Logs that are too dry pyrolyze very quickly, overloading the combustion zone with volatile gases . . . while very moist timbers can inhibit effective combustion by absorbing heat for evaporation. Standard air-dried soft or hard firewood (with about 20 to 25% moisture content) seems to be the cleanest-burning fuel. "

<snip>

Note I took exception to his remarks:

"Exception to the following. Note the article was written in `81, before pellet heaters. (Pellets usually have less than 10% mc.) So in rule # 5, where he cites 20-25% mc for wood as acceptable, he had not seen a pellet heater in operation. As time goes by the observant wood burner is going to realize there are real advantages in burning wood that is at or below 10% mc.

So if nshif burns wood with a mc of <10% he will burn clean, provided he controls the rate of burn according to a thermometer.

Have a good one,

Dave

 

[Todd]

Hey Dave,
How are you going to get firewood <10% mc without a kiln? And if you do get it that dry wouldn't the relitive humidity bring it back up over 10% anyway? I don't think you can get wood that dry unless you live in a desert. Humidity will keep it around 15-25. Maybe your taking readings from the end grain and not cutting the piece in half to take an inside reading?

 

[nshif]

Dave
That is exactly what the damper is ( Field Control ) So I know that was added. But the 8" hole out the back is exactly like the one on top. Either someone was a very good metal smith or it was factory installed. It could not be used as a flue attachment because the baffle inside blocks it off from the firebox and only opens to the flue hole on top. Perhaps smoeone had a bad draft problem on their top flue and this was the solution? Anyhow for my needs ill just remove the FC damper and seal the rear hole. Thanks for the info and the links, good reference for future use. And Thx all for the responses. Oh its not that I take good pics, its the camera, I just point and shoot!
Norm

 

[Dave_1]

Hi Todd,

My meter is a Delmhorst "J-lite"

(broken link removed to http://www.delmhorst.com/pdf/jlite.pdf)

Have always accepted it’s reading as the small chimney accumulation of creosote / ash seems to confirm it. The pins used are for wood up to 6/4, see page 4. Yes, larger wood requires a “26 ES slide hammer”, which I don’t have, to correctly read mc in larger sized wood. Could my meter be bad? Sure, so the next time I’m near Harbor Freight will get one of theirs & compare the two.

How are you going to get firewood <10% mc without a kiln?

By exposing the cut end of the wood to un-shaded sun which is protected by store front glass. Air dried 6/4 sticked lumber becomes 12% mc in @ 2 years inside a shop without sun exposure.

And if you do get it that dry wouldn’t the relitive humidity bring it back up over 10% anyway? I don’t think you can get wood that dry unless you live in a desert. Humidity will keep it around 15-25

To date 12% is the highest the mc has read on my wood pile, but then I only read at the ends after rain.

Maybe your taking readings from the end grain and not cutting the piece in half to take an inside reading?

I usually measure the splits / rounds at their ends & in their approximate center.

However, my point to BeGreen was that a mc of 20-25% plays a far greater role in creosote buildup than the wood heater experts thought in the early `80’s when running their tests. Thus the problem of creosote with dampers. And that 20% is a high mc is also proven by the pellet eaters whose mc is 8-10%, depending on who you read.

So are pellets susceptible to humidity? Then why doesn’t their mc vary from 15-25%?

I once brought in three 6” rounds after cutting to put in our wood cradle for decoration. Since they were 18” from the heater for 2-½ years I thought one rainy night they would be dry. Not so, they sizzled like steaks.

(broken link removed to http://extension.missouri.edu/explorepdf/agguides/forestry/G05450.pdf)

(See page 2 & note “Seasoning Wood”)

Have a good one,

Dave

 

[Dave_1]

Nshif,

Either someone was a very good metal smith or it was factory installed.

Was the sleeve containing the Fields Control (FC) welded to the flue? If not I suspect a HVAC tech or engineer had it made. After toying with the FC setting in the heat run mode he discovered the optimum setting for efficient burn. He then most likely nearly shut the air input screws on the Fisher & relied on the FC automatic barometer to control the fire.

If you went to the FieldsControl link & scrolled down to the drawing I cited that basically is how they operate. In your situation the Fisher would be fed air into the back to control the fire.

It could not be used as a flue attachment because the baffle inside blocks it off from the firebox and only opens to the flue hole on top.

Right, understood that once I saw your pics. And I still say you could make money showing the ebayers how.

Have a good one,

Dave

 

[nshif]

Dave
I agree with your idea but for my temporary application I just dont need it. Its only being installed for heat while the interior finish is done, after that a real stove will be installed and the Fisher moved to the basement/workshop as a heat source in winter. Then i may play with the FC to see how it works but for now it just isnt needed. Again thanks for all your input., it was very helpful.
Norm

 

[Todd]

Hi Todd,

My meter is a Delmhorst "J-lite"

(broken link removed to http://www.delmhorst.com/pdf/jlite.pdf)

Have always accepted it’s reading as the small chimney accumulation of creosote / ash seems to confirm it. The pins used are for wood up to 6/4, see page 4. Yes, larger wood requires a “26 ES slide hammer”, which I don’t have, to correctly read mc in larger sized wood. Could my meter be bad? Sure, so the next time I’m near Harbor Freight will get one of theirs & compare the two.

How are you going to get firewood <10% mc without a kiln?

By exposing the cut end of the wood to un-shaded sun which is protected by store front glass. Air dried 6/4 sticked lumber becomes 12% mc in @ 2 years inside a shop without sun exposure.

And if you do get it that dry wouldn’t the relitive humidity bring it back up over 10% anyway? I don’t think you can get wood that dry unless you live in a desert. Humidity will keep it around 15-25

To date 12% is the highest the mc has read on my wood pile, but then I only read at the ends after rain.

Maybe your taking readings from the end grain and not cutting the piece in half to take an inside reading?

I usually measure the splits / rounds at their ends & in their approximate center.

However, my point to BeGreen was that a mc of 20-25% plays a far greater role in creosote buildup than the wood heater experts thought in the early `80’s when running their tests. Thus the problem of creosote with dampers. And that 20% is a high mc is also proven by the pellet eaters whose mc is 8-10%, depending on who you read.

So are pellets susceptible to humidity? Then why doesn’t their mc vary from 15-25%?

I once brought in three 6” rounds after cutting to put in our wood cradle for decoration. Since they were 18” from the heater for 2-½ years I thought one rainy night they would be dry. Not so, they sizzled like steaks.

(broken link removed to http://extension.missouri.edu/explorepdf/agguides/forestry/G05450.pdf)

(See page 2 & note “Seasoning Wood”)

Have a good one,

Dave

It sounds like you built your own kiln. I agree the dryer the better. I have a similar meter and I get similar readings on the end grains as you. But when I cut a piece in half and take an inside reading, it jumps up to anywhere between 15-25% depending on type and size of firewood. So, do you average an inside/outside reading or go with the wetter inside reading. I go by the inside reading. I don't have full sun exposure, so I'm trying to get a couple years ahead on firewood to make sure it's dry as it can be.

Happy Burning,

Todd

 

[Dave_1]

Todd,

Since nshif is satisfied then we are not “hijacking” his thread so will now address your questions & ask some for your consideration.

I have a similar meter and I get similar readings on the end grains as you.

Then you have a Delmhorst? What model is your meter?

But when I cut a piece in half and take an inside reading, it jumps up to anywhere between 15-25% depending on type and size of firewood.

How long has the butt end been exposed to the un-shaded sun when you take that inside reading of the round?
What size is the round?
Has the wood been fully protected from wind driven rain for at least two years?
Is there a 6 mil plastic vapor barrier under your pallets / timbers / blocks etc that the wood sits on?

So, do you average an inside/outside reading or go with the wetter inside reading.

No, when mine are 2 years the middle is also 6%.

Again, please understand that I do not have the “ES 26 slide hammer“ Delmhorst states is necessary to accurately measure wood thicker than 6/4. To be sure that others that read our posts understand this point I will state what is obvious to you since you are familiar with a moisture meter.
The 2 probes on my meter are 5/16”, so when stuck into wood they test only the mc between the 2 pins at a depth of only 5/16“.

I burn mostly splits that average 22-½” L x 4-½” W x 4-½” D. I just went out & read one that was put up in Feb `06. The wood is red oak. The sun end read 6%, the rear 10%, & the center 12-15%. In the 24’ x 7’ front row of my wood shed there were a couple rounds but their at the bottom of the pile in the center. There is another row of wood directly behind the glass front row so I’d have to mine the second & first rows in order to get those rounds out to split & read. Sorry. Will pm you the readings when I get to those rounds sometime this winter (2006-07).

I don’t have full sun exposure, so I’m trying to get a couple years ahead on firewood to make sure it’s dry as it can be.

Good plan! Get as much sun as possible, keep the wood as dry as possible, & you will also have less creosote.

Think back to your biology class & recall how the petals on a flower were sustained with moisture from the soil. The same principle applies to the leaves on trees. The sun is the engine that causes the sap to rise in the tree via capillary action to the leaves. It is that engine that draws the moisture out when the cut end faces the un-shaded sun.

The explanation that the sap returns to the roots in the winter is wrong. What happens is that the temp is too cold to allow the sap to freely flow, so the tree sheds its leaves & caps off the hole left with a bud that in turn becomes a leaf in the spring. Hardwood sap is thicker than softwood. That is why there is no hardwood in the upper north. But @ the artic circle the temp becomes too cold for even soft wood to grow.

Good luck with it,

Dave

 

[Todd]

Todd,

Since nshif is satisfied then we are not “hijacking” his thread so will now address your questions & ask some for your consideration.

I have a similar meter and I get similar readings on the end grains as you.

Then you have a Delmhorst? What model is your meter?

But when I cut a piece in half and take an inside reading, it jumps up to anywhere between 15-25% depending on type and size of firewood.

How long has the butt end been exposed to the un-shaded sun when you take that inside reading of the round?
What size is the round?
Has the wood been fully protected from wind driven rain for at least two years?
Is there a 6 mil plastic vapor barrier under your pallets / timbers / blocks etc that the wood sits on?

So, do you average an inside/outside reading or go with the wetter inside reading.

No, when mine are 2 years the middle is also 6%.

Again, please understand that I do not have the “ES 26 slide hammer“ Delmhorst states is necessary to accurately measure wood thicker than 6/4. To be sure that others that read our posts understand this point I will state what is obvious to you since you are familiar with a moisture meter.
The 2 probes on my meter are 5/16”, so when stuck into wood they test only the mc between the 2 pins at a depth of only 5/16“.

I burn mostly splits that average 22-½” L x 4-½” W x 4-½” D. I just went out & read one that was put up in Feb `06. The wood is red oak. The sun end read 6%, the rear 10%, & the center 12-15%. In the 24’ x 7’ front row of my wood shed there were a couple rounds but their at the bottom of the pile in the center. There is another row of wood directly behind the glass front row so I’d have to mine the second & first rows in order to get those rounds out to split & read. Sorry. Will pm you the readings when I get to those rounds sometime this winter (2006-07).

I don’t have full sun exposure, so I’m trying to get a couple years ahead on firewood to make sure it’s dry as it can be.

Good plan! Get as much sun as possible, keep the wood as dry as possible, & you will also have less creosote.

Think back to your biology class & recall how the petals on a flower were sustained with moisture from the soil. The same principle applies to the leaves on trees. The sun is the engine that causes the sap to rise in the tree via capillary action to the leaves. It is that engine that draws the moisture out when the cut end faces the un-shaded sun.

The explanation that the sap returns to the roots in the winter is wrong. What happens is that the temp is too cold to allow the sap to freely flow, so the tree sheds its leaves & caps off the hole left with a bud that in turn becomes a leaf in the spring. Hardwood sap is thicker than softwood. That is why there is no hardwood in the upper north. But @ the artic circle the temp becomes too cold for even soft wood to grow.

Good luck with it,

Dave

Sorry if I highjacked the thread. My meter is a Neiko EM-2G. It also has 2 spikes and reads from 7-35%. My wood is stacked in a Holz Hausen and not covered so the air can circulate better throughout. I have limited space and little sun but good wind tunnel betwen me and neighbors house.

That's great you can get that low a reading inside and out. Mine seems to read different with the weather. Probably because it's out exposed to the weather. I think I might go ahead and cover it. For me a couple dry days and I get under 10% outside reading. Wet rainy days the radial cracks disapere and the reading goes up. I store a weeks worth of wood inside next to the stove, and after 1 fire the wood really opens some cracks up and the meter readings don't even register on the outside. I'll have to check the inside on those.

 

[Dave_1]

Todd,

You didn’t hijack. I made the statement for a moderator’s benefit, who seems to shoot first & read latter. :lol:

My meter is a Neiko EM-2G. It also has 2 spikes and reads from 7-35%.

How long are the spikes?

My wood is stacked in a Holz Hausen and not covered so the air can circulate better throughout. I have limited space and little sun but good wind tunnel betwen me and neighbors house.

BroBart’s procedure is similar to yours,

"

I have left wood on my wind tunnel breezeway for five years and it never reached 6%. If it had I would have been afraid to smoke anywhere near it. Kiln dried dimensional lumber for construction is six to eight percent.

https://www.hearth.com/talk/threads/3359/

so I asked him on that tread to make a test since the sun does a better job:

That's great you can get that low a reading inside and out.

I went out & split the split, that I gave you readings on in my last post, the center was 26% but it has been drying just 8 months.

Mine seems to read different with the weather. Probably because it's out exposed to the weather.

Exactly, it is the surface mc you are reading & it happens to me also.

I think I might go ahead and cover it.

Good idea! But be sure to double lap your tarp, unless your are certain that it has been waterproofed. If it has not you will trap moisture underneath. Run your hand underneath the tarp early one morning & you will understand my point.

For me a couple dry days and I get under 10% outside reading. Wet rainy days the radial cracks disapere and the reading goes up.

My cracks remain, I have have never measured to see if they shrink.

I store a weeks worth of wood inside next to the stove, and after 1 fire the wood really opens some cracks up and the meter readings don't even register on the outside. I'll have to check the inside on those.

Please pm me when you find out. My three decorative rounds must have been @ 25% that night. :lol:

Have a good one,

Dave