Fisher Grandma...Catalyst question...

[BigAmish]

I just upgraded to a Fisher Grandma to heat our home. It came with a catalyst that attaches to the back. I've been doing a LOT of reading about the catalysts, and there are MANY conflicting opinions. My question is, Do I want it on my "new" stove or should I leave it off when I install it??? I've been using wood stoves on and off my entire life but never even heard of them until now. Thank you in advance for all your help

 

[coaly]

I'll move this to the Classic Forum since there was no catalyst on a Fisher. It will be viewed by many more experienced with them there.

Personally I'd use it while it works since it won't cost you anything, and probably not replace it when the time comes. After you try it, you may never go back. I'm not that adventurous.

 

[BigAmish]

I'll move this to the Classic Forum since there was no catalyst on a Fisher. It will be viewed by many more experienced with them there.

Personally I'd use it while it works since it won't cost you anything, and probably not replace it when the time comes. After you try it, you may never go back. I'm not that adventurous.

I've asked two questions here in my one year of membership and put them BOTH in the wrong place! Thanks for moving it and for the advice I'm also concerned bc the 8 inch piece that comes out of the back of the stove is a thin gauge and the catalyst it cast iron and heavy. Will it be ok to just have the thin piece coming out the back and into the stove pipe??? Thanks again...

 

[coaly]

Need pictures. The older stoves did use a thinner gauge round pipe. But I think that was in the years of single door stoves before 1976. Are you referring to the vent pipe welded to the stove as being thin, or a piece of connector pipe inserted into the stove connector?

It's not you, normally any Fisher questions should be asked there, but yours isn't Fisher specific since it's an add on. Since Fishers were not Cat stoves, I figured more would see it in the Classic section that have experience with them on other stoves.

Later Fisher double door stoves had a factory baffle to direct smoke back into the flames and increase combustion chamber temperatures. That was their attempt to reduce emissions before 1988 when the stricter EPA laws went into full effect. They failed, and the surviving manufacturers were approved due to catalytic combustion removing smoke particles. Since the reason for the cat is to burn smoke, installing a baffle to reduce smoke and take advantage of its heat inside the stove is easier and cheaper than a cat. If you go to add one, read over the baffle thread in the Fisher Forum. If located within the burn zone at flame tips too low, the flame impingement from the plate absorbs too much heat from flame contact lowering combustion zone temps. So there is a fine balance where they work the best taking thickness, angle and height into consideration.

Is there an Amish settlement on Long Island I don't know about? I worked on a steam traction engine of a potato farmer on L.I. years ago. A Peerless. He has a collection of them now.

 

[BigAmish]

Need pictures. The older stoves did use a thinner gauge round pipe. But I think that was in the years of single door stoves before 1976. Are you referring to the vent pipe welded to the stove as being thin, or a piece of connector pipe inserted into the stove connector?

It's not you, normally any Fisher questions should be asked there, but yours isn't Fisher specific since it's an add on. Since Fishers were not Cat stoves, I figured more would see it in the Classic section that have experience with them on other stoves.

Later Fisher double door stoves had a factory baffle to direct smoke back into the flames and increase combustion chamber temperatures. That was their attempt to reduce emissions before 1988 when the stricter EPA laws went into full effect. They failed, and the surviving manufacturers were approved due to catalytic combustion removing smoke particles. Since the reason for the cat is to burn smoke, installing a baffle to reduce smoke and take advantage of its heat inside the stove is easier and cheaper than a cat. If you go to add one, read over the baffle thread in the Fisher Forum. If located within the burn zone at flame tips too low, the flame impingement from the plate absorbs too much heat from flame contact lowering combustion zone temps. So there is a fine balance where they work the best taking thickness, angle and height into consideration.

Is there an Amish settlement on Long Island I don't know about? I worked on a steam traction engine of a potato farmer on L.I. years ago. A Peerless. He has a collection of them now.

LOL No Amish... I grow an Amish beard in the winter bc Wifey won't kiss me if I have hair around my mouth... My ancestors were LI potato farmers My Granny is the only remaining one but she's in assisted living in MD now... I'm going to try to take pics of the stove w/o the cat and post them. It's a Grandma with the two doors... Sometimes, even when I know what I'm looking at, I don't know the proper names of the pieces I want to describe... I'll post pics as soon as I can figure out how...

 

[BigAmish]

Need pictures. The older stoves did use a thinner gauge round pipe. But I think that was in the years of single door stoves before 1976. Are you referring to the vent pipe welded to the stove as being thin, or a piece of connector pipe inserted into the stove connector?

It's not you, normally any Fisher questions should be asked there, but yours isn't Fisher specific since it's an add on. Since Fishers were not Cat stoves, I figured more would see it in the Classic section that have experience with them on other stoves.

Later Fisher double door stoves had a factory baffle to direct smoke back into the flames and increase combustion chamber temperatures. That was their attempt to reduce emissions before 1988 when the stricter EPA laws went into full effect. They failed, and the surviving manufacturers were approved due to catalytic combustion removing smoke particles. Since the reason for the cat is to burn smoke, installing a baffle to reduce smoke and take advantage of its heat inside the stove is easier and cheaper than a cat. If you go to add one, read over the baffle thread in the Fisher Forum. If located within the burn zone at flame tips too low, the flame impingement from the plate absorbs too much heat from flame contact lowering combustion zone temps. So there is a fine balance where they work the best taking thickness, angle and height into consideration.

Is there an Amish settlement on Long Island I don't know about? I worked on a steam traction engine of a potato farmer on L.I. years ago. A Peerless. He has a collection of them now.

 

[BigAmish]

 

[BigAmish]

Need pictures. The older stoves did use a thinner gauge round pipe. But I think that was in the years of single door stoves before 1976. Are you referring to the vent pipe welded to the stove as being thin, or a piece of connector pipe inserted into the stove connector?

It's not you, normally any Fisher questions should be asked there, but yours isn't Fisher specific since it's an add on. Since Fishers were not Cat stoves, I figured more would see it in the Classic section that have experience with them on other stoves.

Later Fisher double door stoves had a factory baffle to direct smoke back into the flames and increase combustion chamber temperatures. That was their attempt to reduce emissions before 1988 when the stricter EPA laws went into full effect. They failed, and the surviving manufacturers were approved due to catalytic combustion removing smoke particles. Since the reason for the cat is to burn smoke, installing a baffle to reduce smoke and take advantage of its heat inside the stove is easier and cheaper than a cat. If you go to add one, read over the baffle thread in the Fisher Forum. If located within the burn zone at flame tips too low, the flame impingement from the plate absorbs too much heat from flame contact lowering combustion zone temps. So there is a fine balance where they work the best taking thickness, angle and height into consideration.

Is there an Amish settlement on Long Island I don't know about? I worked on a steam traction engine of a potato farmer on L.I. years ago. A Peerless. He has a collection of them now.

 

[BigAmish]

I hope I posted them right. That's the thin pipe coming out the back. Inside that pipe feels like what i would describe as a roofing shingle or tar paper type material...

 

[BigAmish]

Need pictures. The older stoves did use a thinner gauge round pipe. But I think that was in the years of single door stoves before 1976. Are you referring to the vent pipe welded to the stove as being thin, or a piece of connector pipe inserted into the stove connector?

It's not you, normally any Fisher questions should be asked there, but yours isn't Fisher specific since it's an add on. Since Fishers were not Cat stoves, I figured more would see it in the Classic section that have experience with them on other stoves.

Later Fisher double door stoves had a factory baffle to direct smoke back into the flames and increase combustion chamber temperatures. That was their attempt to reduce emissions before 1988 when the stricter EPA laws went into full effect. They failed, and the surviving manufacturers were approved due to catalytic combustion removing smoke particles. Since the reason for the cat is to burn smoke, installing a baffle to reduce smoke and take advantage of its heat inside the stove is easier and cheaper than a cat. If you go to add one, read over the baffle thread in the Fisher Forum. If located within the burn zone at flame tips too low, the flame impingement from the plate absorbs too much heat from flame contact lowering combustion zone temps. So there is a fine balance where they work the best taking thickness, angle and height into consideration.

Is there an Amish settlement on Long Island I don't know about? I worked on a steam traction engine of a potato farmer on L.I. years ago. A Peerless. He has a collection of them now.

From rereading your post I'm thinking maybe it's a baffle instead of a cat??? It was honeycomb looking inside it... and had knobs and kinda turns like a flue...

 

[turn_n_burn]

Generally, I would say that any honeycomb stuff is cat material, but if it's made by Fisher I doubt it's a REAL catalytic converter. They're usually some type of high-temp ceramic. My baby bear has been converted to just have the flue pipe come right out of the top of the upper stepped part of the firebox, not out the back. I've read the Fisher literature and they are tight-lipped about what goes on inside that little rear flue connector, but I could surmise that they attempted to make a metal honeycomb that would get really hot and recombust some of the smoke passing through. It's easier to maintain a high temp inside a metal grid that smoke passes thru than a big open space of air. Plus it would create something related to a kinda-somewhat Karmann-type vortex to induce turbulence, which mixes air and particulates, and will generally combust better that way. It's the same principle that created the little vortices that made the mass airflow sensor on my Eagle Talon 4-banger's air intake work properly, only this mixes the smoke and hot gases better instead of making the flow less laminar when hitting my intake runners. I could be wrong, but I always like to venture a guess. I think the Fishers had some kind of barometric damper in the unit that assisted this, but I can't remember. Mine had been hacked and converted to top-exit before I got it. That tarpaper or roofing shingle texture could be to assist this also (the turbulence), or could just be a bunch of creosote/clinker buildup too. I tried to pay attention in Physics class but it was difficult. If mine really gets going with the draft cap wide open it chuffs like an old steam locomotive on crack and scares the piss out of me.

 

[BigAmish]

Generally, I would say that any honeycomb stuff is cat material, but if it's made by Fisher I doubt it's a REAL catalytic converter. They're usually some type of high-temp ceramic. My baby bear has been converted to just have the flue pipe come right out of the top of the upper stepped part of the firebox, not out the back. I've read the Fisher literature and they are tight-lipped about what goes on inside that little rear flue connector, but I could surmise that they attempted to make a metal honeycomb that would get really hot and recombust some of the smoke passing through. It's easier to maintain a high temp inside a metal grid that smoke passes thru than a big open space of air. Plus it would create something related to a kinda-somewhat Karmann-type vortex to induce turbulence, which mixes air and particulates, and will generally combust better that way. It's the same principle that created the little vortices that made the mass airflow sensor on my Eagle Talon 4-banger's air intake work properly, only this mixes the smoke and hot gases better instead of making the flow less laminar when hitting my intake runners. I could be wrong, but I always like to venture a guess. I think the Fishers had some kind of barometric damper in the unit that assisted this, but I can't remember. Mine had been hacked and converted to top-exit before I got it. That tarpaper or roofing shingle texture could be to assist this also (the turbulence), or could just be a bunch of creosote/clinker buildup too. I tried to pay attention in Physics class but it was difficult. If mine really gets going with the draft cap wide open it chuffs like an old steam locomotive on crack and scares the piss out of me.

That's a LOT to soak in at one time... LOL! I'm going to reread it a few times... The only things I can tell you at this time is the material inside the pipe is NOT build up of any kind. You can see it in the pic, it's the stuff set in about an inch inside the pipe, and it musta been put there for some reason...Also, inside the "cat" doesn't "feel" like honeycomb, it's SOLID and "LOOKS" like honeycomb, if that's a better description! Thank you so much

 

[CamFan]

We used to sell stoves to the government for Indian Reservations. They required catalytic converters installed. They were inline and could be removed after installing if they wanted.

 

[coaly]

I've read the Fisher literature and they are tight-lipped about what goes on inside that little rear flue connector, but I could surmise that they attempted to make a metal honeycomb that would get really hot and recombust some of the smoke passing through. It's easier to maintain a high temp inside a metal grid that smoke passes thru than a big open space of air.

I think you are referring to the air intake box located within the top vent. It is a separation between exhaust and rear intake for barometric damper. No catalyst and no smoke passed through it. It is simply an air intake for chimney to control excessive draft by introducing cooler air into chimney, the same way a T would do on a barometric damper. This is not a barometric stove. They were on some model III's after 1980 shown below;

 

[bholler]

I think you are referring to the air intake box located within the top vent. It is a separation between exhaust and rear intake for barometric damper. No catalyst and no smoke passed through it. It is simply an air intake for chimney to control excessive draft by introducing cooler air into chimney, the same way a T would do on a barometric damper. This is not a barometric stove. They were on some model III's after 1980 shown below;

yes and it was a bad design plain and simple.

 

[BigAmish]

I think you are referring to the air intake box located within the top vent. It is a separation between exhaust and rear intake for barometric damper. No catalyst and no smoke passed through it. It is simply an air intake for chimney to control excessive draft by introducing cooler air into chimney, the same way a T would do on a barometric damper. This is not a barometric stove. They were on some model III's after 1980 shown below;

View attachment 161403 View attachment 161404 View attachment 161405

What I'm referring to looks more like pic #1. It's NOT square. It's round, looks like a honeycomb, and is inside a cast iron cylinder. It has two tabs and functions like a dampener. It was attached to the round flange that comes out of the back of the stove pictured in my pics above. I hope this helps to clarify... Thanks!

 

[coaly]

You don't have a Fisher part designed as a part of the stove. Yours is an add-on combustor you open to get started, then close like a damper to direct smoke through it when hot enough to ignite smoke going through it.
The 3 pictures are the same stove. (showing turn_n_burn what he's reading about. Not a combustor like yours) The left, is the back with Barometric Damper installed in the rear opening. It is a flapper that opens when the chimney is too hot allowing air up chimney giving the same effect as closing a manual pipe damper. The flap closes when cool to allow the chimney to heat up giving the same effect as a manual damper when open. They respond to atmospheric pressure changes and wind instantly giving precise control of the draft and steady intake air coming through stove. The center picture is looking down into the top vent (exhaust outlet) with stove facing you. The box is open towards the rear so air can enter into chimney pipe, through barometric damper, not into the stove. The pic on the right is the box from inside the stove looking up. It takes up a little bit of the flue outlet area. This would be perfect on a coal stove, and work fine in an over drafting chimney, except in the case of a chimney fire. It would open the flap sensing too much draft allowing cooler indoor air into the chimney to slow draft during normal operation, but when the fire is in the chimney, opening to allow air in is exactly what you don't want to feed the fire oxygen. They belong on a coal stove where there is no creosote accumulation.