My 40(ish) Year Old Grandpa

[Hooverscon]

Greetings!

I just purchased a "new" 1977ish Fisher Grandpa Bear wood stove that I will be picking up within a month. Its life primarily consisted of being a show piece for a large cabin in Northern Wisconsin. I have a few questions regarding this wood burner. I have been looking on this forum of a while (as a non-member) trying to find more info related to the Grandpa bear. I plan on using this wood burner in my partially finished barn (approx. 2000sqft). There are no water lines to this barn... I do not plan on heating the barn throughout the entire winter. Here are my questions.

1) What is the "burn time" for this unit under normal conditions. Is it possible to get a 12 hour burn?
2) Is this a good wood burner for my application? I did not want a newer unit... I like the older vintage look.
3) just for kicks. What are some other brands you guys/gals would have recommend?
4) Is this entire stove cast iron or is it steel with cast doors?
5) I understand this isn't the most user friendly burner... what is the biggest issues found with this stove
(current/previous owners please weigh in)

Ill be posting pictures of the barn in the near future. Thanks for all the help!

 

[coaly]

Welcome to the Forum,
As far as burn times, manufacturers consider a burn time from the time it is lit until you can still load paper, cardboard and kindling and get it going again without a match. That doesn't say much for heat output in the last hours. Real world times for useabnle heat depend on fuel (chimney as well) and operation. (experience) It also depends on coals and how long a stove has been going. If you first light it and let it go out, 8 to 10 hours with good oak when you get the hang of it. However, if you fire it over and over reloading as necessary burning 24/7 for many days, you should accumulate a good coal pile. This again depends on air adjustment, chimney, experience and fuel. You get more steady heat if you burn by the method of removing a little ash from the front where it burns down behind intakes the most, each morning, then rake it forward to build your new fire on the coal pile. The main reason for burning this way is not to need it to go out to remove dead ash. I've burned 24/7 a couple days and had enough coals on a warm day to not load them in the morning, remove some ash from the front and rake ahead between 3 or 5 PM and it takes off with just kindling. Don't expect much heat from just coals, but it prolongs burn time.

Yes it's good for your application.
Papa has about the same output with a 6 inch outlet so is more efficient and has a larger cook top. The double door was made as a Fireplace to view the fire so there are trade off for that feature. I would connect to a 6 inch insulated chimney flue. It is against code to reduce more than 1 inch, but the stove was designed with the 8 inch outlet for open door burning to prevent smoke roll in. many are reduced to 6 and work VERY well and even work well with an added baffle plate. (recommended as well, see the baffle thread)

1/4 inch steel plate with 5/16 thick steel plate top. Cast iron doors. There are no cast iron Fishers. Bob Fisher was the first to fabricate a stove made from steel plate and is credited with the advent of the "air tight" stove. (no seams or multiple parts to leak from many castings bolted together with gasket material)

Very user friendly, not sure what you mean by that. You can't abuse a cast iron stove like one made from steel plate. (overheating or quick temperature swings)

The deep single door stoves ignite quicker and fit wood better, but this will light extremely easy with no smoke issues inside. This again depends on the chimney. EVERY stove uses the chimney to make it go. So any stove brand will work with a good drawing chimney, NO stove brand will work with a poor drawing chimney.

 

[coaly]

I'm not going to dodge the other brands question.
All the other brands of the time were copies of yours. Timberline and Frontier were the first to make double doors that size and were originally Fisher fabricators. The double door idea was actually Jake Jackson's who was a Fisher fabricator that took the idea to Bob first and when Bob wanted no part of door problems allowed him out of his Fisher fabricating contract and he went on to become Frontier. Buffalo and Berkshire are very similar and competed with Fisher as well as Baker and Fire Boss. Alaska Stove Works from PA got in on the game, All-Nighter, (another Fisher fabricator) Huntsman made a double door from the old Atlanta Stove Works to compete in the new fabricated steel stove market. Kodiak, Lakewood, Oldtimer, Penn wood, Schrader, Sierra, Tri lakes, Vestal, Woodland, Wood Saver and Woodsman. All those are built very close to the same specs and any steel plate stove is very fixable with a grinder, torch and welder. (there are others, but these were the main stream names and unmarked stoves are still plentiful from local shops, many are high quality, some not so much)

Fisher decided instead of fighting all the stove makers with patent rights,(even got along well with some sharing shipping or material) they would simply make the best and offered more accessories such as blowers, different feet, and later nickel or brass plated doors and glass doors. They also offered 10 colors which was the first to offer any stove in anything other than black. The rest soon followed. They were the leader in the day and I believe overall made more stoves than the others combined worldwide. Most of the others were more local to their area but are found across the country but seemed to have their followings more localized. Most of them were related through the industry to Fisher licensees, suppliers and haulers that designed their own and ended up competing with Fisher. They all work comparably well, but you'll find more information for Fisher (here) and when it comes to needing manuals and UL Listings that can make a big difference of what is more desirable.

 

[Hooverscon]

I am amazed at the knowledge you have with wood stoves! I really appreciate all the help! As for the "not user friendly" part, I think it had to do with comparing the older wood burners to the newer ones that met EPA guidelines.

I have always been under the impression that less is more! I wanted a simple/bullet proof design that could handle some of my noone mistakes!! I will be burning seasoned Oak and locust so hopefully that will help the burn time as well.

You definitely helped ease the nerves of me buying it haha. Fortunately for me, the barn that Grandpa B is going into already had a 6" chimney. I was concerned about going from a 8" down to a 6" flue. I will be posting some pictures shortly. Thanks again

 

[coaly]

My experience with an EPA stove in your case is they need much more constant loading to keep the temp up since as the secondary ignition burns, you have more time as it slows and everything is in the coal stage longer. Maybe fine in a smaller insulated home, but you need some intense heat which is what you'll get with that one.

With stoves, heat output goes by square inches of surface area and temperature of each square inch of that area. The more surface area, the more BTU, plus the larger loading area. It will eat much more wood than an EPA stove but will also create more heat. (in the same amount of time) Others may disagree saying you get more heat from each piece of wood, which is true, but it's over a longer time period as well. Think of it as a 4 cylinder truck that rolls along fine with very little fuel consumption until you get to a hill. It lacks power just like the newer stove lacks BTU when you need lots to bring a cold barn up to temp all at once. This will do that much faster and require loading when the barn warms up, but you will be warm. The temperature of each square inch can vary greatly, so the sides go from warm at the bottom to quite hot near the top. Most comes off the top. This will radiate in all directions unlike most newer stoves made for closer clearances that are designed to radiate from front and top. I have a Mama Bear in a log cabin that is unheated when I get there that outperforms a neighbors new Lopi in the exact same kit cabin from Finland. Mine is in the center and radiates in all directions and I'm away doing things for hours compared to his tucked in a corner that he needs to reload every 2 hours to keep the secondary burning strong enough for good usable heat. He can't boil water or cook on the top of his. That is my only water heating and cooking appliance! I'm told his is undersized so that's why such frequent loading or he's cold.

What type chimney do you have? Prefab metal straight up? There are 3 types of that material. Pack, which is double wall with heavy dense insulation, triple wall with the inner liner insulated with lightweight fiberglass insulation (both are comparable) and an older style which uses air between the 3 walls. This later type i snot recommended and air cools the inner flue liner too fast. You will use all your heat keeping the flue hot and the stove will produce little heat. That is why I mentioned the chimney makes a huge difference in heat output. The less up the stack, the more usable BTU inside. But you can't get stingy and not allow enough up since below 250* f at the top condenses causing creosote. There is a fine balance of radiating with the stove waste up the stack. Get a thermometer for the connector pipe so you have a basis to judge what you're doing while smoke is present.

 

[Hooverscon]

This is where I could definitely use more advice... I checked the county auditor website to see how large my barn is (just moved to the house last year). The front barn is roughly 1200Sqft, the other barn is 1500sqft. The barns were built within 5-8 years of each other. Both are "insulated" with 12ft ceilings. They are joined together by a standard size door. How they currently sit: there is a 8in chimney in the front barn (located in corner) and a 6in chimney in the other barn (offset about 5 feet off the wall). What barn do you think I should run the Grandpa in? do you think is possible to heat both barns by keeping the door open and using fans? If not, I will just shuffle the cheaper wood stove that I already have (see below). As for the chimneys... I have no idea what type I have. The silver chimney (see below) seems to be a single wall? I'm thinking of calling a technician to install a new 6in pipe. as far as clearance, I heard that the Grandpa needs 48" from the wall. I believe I will need to throw a elbow on the current 8in pipe to move it to a safer distance. What type of chimney would you recommend?

 

[coaly]

The single wall inside is connector pipe.
Clearance for that is 18 inches to combustible and 6 inches for double wall close clearance pipe if necessary. For efficiency and a cleaner chimney it is best to run double wall pipe when over 8 feet. Single wall looses too much heat and you end up with a cooler chimney causing creosote or using more wood to try to keep it hot enough. So the more efficient the stove, the more efficient the chimney has to be since it won't have enough heat to make it work. The rising gasses in the chimney are what makes a low pressure area in the stove, which allows atmospheric air pressure to PUSH into the stove feeding the fire oxygen. So you can see how the chimney is the engine that makes the stove work. It's not there to just let the smoke out.

The chimney starts with the support box at the ceiling. That SHOULD support the first chimney section and a large flashing piece should be outside where it penetrates roof. IF the pipe is the same single wall outside, you have NO chimney.
Outside the measurement for a pack type chimney will be 2 inches larger than the inside, so a 6 inch inside will be about 8 inches outside. 8 will be 10 outside. The triple wall will measure larger outside. Most are sections put together with a twist lock type connecting system, so you should pull the last top section off to see what it is inside.
All unlisted stove minimum clearance to combustible in US is 36 inches. That can be reduced down to 12 with the correct shield.

I can't tell from the picture if the silver looking pipe is steel that was painted black from the factory or if someone painted galvanized vent pipe. (not made for stove use) Connector pipe is a thicker gauge and cannot be galvanized (plated) since the zinc coating burns off and is very toxic inside.

 

[Hooverscon]

Do you recommend I run a 6in single wall stove pipe to the ceiling support then connect that into a 6in double wall chimney? Or can I run a double wall all the way up? I have greater that 5ft to the nearest wall. Side note, during the summer months I notice that during a hard rain the floor will become moist. Should I elevate the Fisher? Thanks again. Oh yeah, one more question! what brand pipe do you recommend for these older stoves?

 

[coaly]

Both double wall pack chimney and triple wall are tested for the same temperature rating, so it's not a safety factor.
I prefer triple wall because is lighter, but it requires a much larger hole through roof, and on small homes the double wall looks better being much slimmer. The first metal chimneys were air cooled which was not recommended by fisher back then and stated not to use them in the manuals. Fisher and their dealers supplied Simpson Dura-Vent and they also made intake and exhaust kits for Fisher products that were listed for their use. They are available at most Home Depot stores and Lowe's carries the double wall pack type.

It is not necessary to use double wall connector pipe for close clearance in your install, but it is more efficient as it keeps the rising flue gasses hotter where they enter the chimney. Since the object is to keep the flue gas temp above 250* to the top of chimney, the less loss from the cooling of single wall pipe, the more heat you can keep in the stove to radiate into the building instead of leaving it up the stack to keep the chimney flue the correct temperature. You do get radiation off the single wall pipe indoors, but the stove is where the mass is to radiate into the room for the best efficiency.

An example is when using a surface thermometer on the single wall pipe. It will read about 1/2 the inner flue gas temp measuring on the outer surface. If you run the stove with single wall pipe, you may need very high temperatures exiting the stove to still have about 300* or more where it enters chimney that further cools as it rises up chimney flue. (chimney height is another factor requiring more heat) Double wall pipe will not loose as much heat before it is dumped into chimney, so you can run a baffle in the stove or damper the flue exhaust down to save the wasted heat. The dollars spent in good double wall pipe will pay off in fuel savings over time. I would consider it with a vertical run over 8 feet.

 

[coaly]

What will the floor protection be? (if it's a combustible material now)

 

[Hooverscon]

Hey Coaly sorry for the delay. I was able to look at the chimney setup... It is a Supervent (made in Ontario) Double-walled chimney with a single wall stove pipe. I am planning on buying a telescopic 6" double wall stove pipe soon. The barn is insulated with Georgia-Pacific Foil insulation (ceiling). I haven't been able to find out much info regarding wood stoves being installed through them. The stove will be on a sealed concrete floor... So I shouldn't have a problem with that (beside the occasional wet floor after heavy storms.

 

[coaly]

OK, simply set it up on bricks to raise it from any moisture. Makes it easier loading too.

That is the brand name carried by Lowe's called the pack type.
They are a little higher priced than Dura-vent at Home Depot, but Lowe's stocks them year round compared to most Home Depots stocking them only seasonally.

 

[Hooverscon]

Hey Coaly! I am up and running with the new stove (pictures to come). I have been having a hard time figuring out the proper "setting" for the damper and the air flow knobs. Is there a proper way to get the fire running? I've read to keep both air controls wide open then turn them down as you go.... Then I've read the exact opposite. Can you give me your two cents

 

[coaly]

There is no proper setting for a flue damper since the damper is a chimney control which affects the stove. A larger diameter chimney, or exterior masonry chimney requires much more heat, so the more open the damper needs to remain.

So start leaving the flue damper open until you get a thermometer on the connector pipe.

Open air dampers a few turns. (this is the only time they will be open this far)
Light paper, cardboard, kindling.
Close down to about 1 1/2 turns to slow fire if it roars up the stack once started. You don't want to waste too much heat up the stack at this point since you need it to heat and ignite larger pieces as they are added to fire. One use for the damper is to slowly close it until the roar up the chimney stops.

The damper is a variable resistance that slows velocity of rising gasses. This in turn slows the incoming air. You don't want to shut the air dampers down too far at this point to slow the fire since it needs all the oxygen it can get until the fire is established.

Once up to temperature, the air dampers should be 1/2 to 1 turn open. Adjust more open or closed for needed heat.
The purpose of thermometer is giving you an idea of just how much heat is being lost up the chimney. Your insulated chimney has little loss once the flue gases are in the insulated flue sections. Pipe higher than an 8 foot ceiling drops in temperature as the single wall allows the pipe to cool. The magnetic pipe thermometer will read approximately 1/2 the actual inside flue gas temp. The critical temperature you must maintain when smoke is present is 250* f. to the top of chimney. Lower than that will allow water vapor (from combustion, not necessarily moisture from wood) to condense, wetting the flue walls which allows smoke particles to stick. This is creosote which can form rapidly if the inner flue temperature is too low.
The thermometer reading is simply a basis to judge the inner flue gas temp as you go up the pipe. Once you know what temp you have just below the support box compared to a few feet above the stove, you have an idea what temp to strive for where it is easy to see. This changes drastically with higher connector pipe or increasing chimney diameter. So no one can give you exact settings of air and damper. These settings change with fuel, atmospheric pressure, temperature, and many other factors. Bottom line is time will tell if you're running too cool forming creosote, so check often until you know how much you are creating.
Page 13 in your owners manual gives fire lighting instructions as well.

 

[bholler]

Both double wall pack chimney and triple wall are tested for the same temperature rating, so it's not a safety factor.
I prefer triple wall because is lighter, but it requires a much larger hole through roof, and on small homes the double wall looks better being much slimmer. The first metal chimneys were air cooled which was not recommended by fisher back then and stated not to use them in the manuals. Fisher and their dealers supplied Simpson Dura-Vent and they also made intake and exhaust kits for Fisher products that were listed for their use. They are available at most Home Depot stores and Lowe's carries the double wall pack type.

It is not necessary to use double wall connector pipe for close clearance in your install, but it is more efficient as it keeps the rising flue gasses hotter where they enter the chimney. Since the object is to keep the flue gas temp above 250* to the top of chimney, the less loss from the cooling of single wall pipe, the more heat you can keep in the stove to radiate into the building instead of leaving it up the stack to keep the chimney flue the correct temperature. You do get radiation off the single wall pipe indoors, but the stove is where the mass is to radiate into the room for the best efficiency.

An example is when using a surface thermometer on the single wall pipe. It will read about 1/2 the inner flue gas temp measuring on the outer surface. If you run the stove with single wall pipe, you may need very high temperatures exiting the stove to still have about 300* or more where it enters chimney that further cools as it rises up chimney flue. (chimney height is another factor requiring more heat) Double wall pipe will not loose as much heat before it is dumped into chimney, so you can run a baffle in the stove or damper the flue exhaust down to save the wasted heat. The dollars spent in good double wall pipe will pay off in fuel savings over time. I would consider it with a vertical run over 8 feet.

You are absolutely correct about the safety factor being the same but performance is much better with double wall insulated chimney pipe. The triple wall has half the insulation and relys on air cooling to keep outside temps down. That means you need to send more heat up the chimney to maintain proper temps all the way up.

 

[coaly]

You are absolutely correct about the safety factor being the same but performance is much better with double wall insulated chimney pipe. The triple wall has half the insulation and relys on air cooling to keep outside temps down. That means you need to send more heat up the chimney to maintain proper temps all the way up.

I guess the reason I prefer triple wall is due to ordering Amerivent pack chimney from Woodman's when I used them as a supplier when I was in the gas heating business. When I needed solid fuel burning parts I'd order from them since I was a part of their dealer program. The double wall heavy stuff was always dented and damaged in the boxes I received due to the weight getting banged around. Maybe they crashed off the conveyor belts at UPS, it was always a PIA to hide the dents. This was around the early 2000's, so I don't know if the efficiency between the two was discussed much back then. I would have dealt with the dents had I known it was much better !

 

[bholler]

I guess the reason I prefer triple wall is due to ordering Amerivent pack chimney from Woodman's when I used them as a supplier when I was in the gas heating business. When I needed solid fuel burning parts I'd order from them since I was a part of their dealer program. The double wall heavy stuff was always dented and damaged in the boxes I received due to the weight getting banged around. Maybe they crashed off the conveyor belts at UPS, it was always a PIA to hide the dents. This was around the early 2000's, so I don't know if the efficiency between the two was discussed much back then. I would have dealt with the dents had I known it was much better !

No problem the triple wall is fine. But double wall is better without a doubt. We use centos which is packed really well.

 

[Hooverscon]

I appreciate the help! I've been outside for the last few hours getting the fire going and enjoying the bada$$ stove. I do have a thermometer that I placed about 3ft off the stove on the double walled pipe . The temperature is showing 300-350. My question to the pros is this... Does it matter how long it take to get the pipe temperature above 250 degrees? Will it cause creosote build up if I light a fire every few days... allow the stove to heat up to temperature and slowly come down until the fire is out? Since I am new to wood stoves, how frequently should I check for creosote build up? My plan was to have a local certified chimney service company come out and clean it for me while I ask questions.

Thanks again for all the help everyone! I really appreciate it!

 

[bholler]

I appreciate the help! I've been outside for the last few hours getting the fire going and enjoying the bada$$ stove. I do have a thermometer that I placed about 3ft off the stove on the double walled pipe . The temperature is showing 300-350. My question to the pros is this... Does it matter how long it take to get the pipe temperature above 250 degrees? Will it cause creosote build up if I light a fire every few days... allow the stove to heat up to temperature and slowly come down until the fire is out? Since I am new to wood stoves, how frequently should I check for creosote build up? My plan was to have a local certified chimney service company come out and clean it for me while I ask questions.

Thanks again for all the help everyone! I really appreciate it!

When you say thermometer on the double wall do you mean a magnet thermometer on it or a probe in it?

 

[Hooverscon]

Yes, the magnetic thermometer.

 

[bholler]

Yes, the magnetic thermometer.

A magnetic thermometer on double wall is completely in effective. If you were running 350 on the outside of your double wall you were probably over firing your stove that is really hot. You need to get a probe thermometer.

 

[Hooverscon]

I ran another few test today. I am using the Rutland magnetic thermometer. The double walled pipe was reading 250-325ish during the peak time of the burn. The thermometer is about 3 feet off of the stove. I ran another fire with the magnetic on the stove top. My readings were between 450-550 degrees. I ran it with the damper open and the air flow caps between 3/4 to 1 turn open. Do you feel this is a better reading?

 

[Hooverscon]

Here is the current set up.

 

[coaly]

Your magnetic thermometer is ONLY for single wall pipe. The only way with double wall is the probe type to test the inner temperature which will be actual flue gas temp.

 

[coaly]

Here is the current set up.

With an approved shield, you can reduce up to 66% of the required 36 inch clearance which is 12 inches to combustible. (measuring to combustible, not shield)

https://www.hearth.com/talk/threads/wood-stove-wall-clearances-primer.147785/