Buck Stove Model 91 Issues

[WranglerBowman]

This is the 2nd year I've been using my Buck Model 91, I'm the 2nd owner, was made in 2009, and I feel like it's loosing it's effeciency and I'm noticing a difference in the way it's burning. The cat only has 2 years on it and when I inspected it this fall it was in excellent condition, less than 4 cords have been burned through it so far. The flames seem to be moving quickly when I have the air intake settings on a very low setting, like it's leaking air. I've replace the door gasket and that seemed to help a bit, but it's still burning like there's an air leak. Besides the cat gasket, window/door gaskets, and ash pan gasket does anyone know if there are other gaskets that I might be missing?

Also there is a piece of metal on the side of the stove that has bowed in, it's right behind the right small bay window where the steel face meets a piece of flashing that runs the whole height of the stove. Very hot air is blowing out of the gap where the metal has bowed in, but only when the fan is on. Has anyone else seen this? The picture is attached. I've stuffed gasket matierial into this gap but it's about a 1/4" wide, any recommendations?

 

[ridensnow23]

Did you vacuum out the cats when you inspected them?

Have you tried the dollar bill test on the door? New gasket may require an adjustment on the door latch to get a tight fit.

If it's leaking elsewhere, you could try a smoke test. Get it burning and turn the blower off. Light an incense stick and hold it next to all the gaskets area. Look to see if the smoke is being drawn in. That would indicate a leak.



Do you know how the metal got bent? Was it from heat or was it from transport and installation? Since it only leaks air when the blower is on, it sounds like that piece of metal is just some piece of facing and that you do not have an opening into the firebox. The blower pulls air from the underneath the stove and circulates it over the top of the fire box and out the vents in the front. Sounds like you are just losing this air out the side a bit. I'll take a look at my buck tonight. Assuming they are similar in design.

 

[davidmc]

 

[davidmc]

I'm like the other guys you have to be getting air. I'm on my 4th winter and have not had any issues. Do you know how it got bent? I wouldn't think you would be getting air from that since it just goes into the air jacket.

 

[WranglerBowman]

I have no idea how the metal got bent. Tuesday was the first time I had noticed that. The lighting in my basement isn't the best so it may have been like that for a while. I'm going to take that flashing off and flatten it out just because any imperfection will bother me...OCD.

I blew the cat off with 30 psi of air when I inspected it so I would think the cat is clean.

I have done the dollar bill test and the door seal is nice and tight. I think it's an exhaust gasket that's leaking. When I shut the air intakes all the way the fire just about goes out, or just smolders until I open the air intakes a little bit and then it takes off with turbulent flames when the intakes are barely open. When I reinstalled the cat houseing after I inspected it I left the nuts pretty loose just because I didn't know how much expansion there is when that fire is roaring and I didn't want over tighten. I wonder if it's too loose causing an exhaust leak, or the gasket is ripped from the install? Besides that cat gasket any one know if there is a gasket on the bypass damper? I don't remember inspecting this when I swept chimney in September. My chimney is 25' tall with a SS liner installed so I don't doubt that there is a strong draft.

I like the incense stick idea, I had been using a match that I kept relighting and blowing out to get good smoke but the basement has so many air leaks from windows and doors that the smoke kind of blows everywhere...I need to insulate and seal my basement up much better!

 

[PLAYS WITH FIRE]

from the instructions in the manual your operation sounds like the stove is operating fine and in fact may be operating this way because the wood supply is so so....When was wood cut, split and stacked and what type?

 

[ridensnow23]

from the instructions in the manual your operation sounds like the stove is operating fine and in fact may be operating this way because the wood supply is so so....When was wood cut, split and stacked and what type?

Yeah wood always needs to be considered. It's possible there is a gasket on the bypass. I know other companies use them. My model 81 has a cast iron flue collar. I remember there was a gasket for that too.

 

[PLAYS WITH FIRE]

If I understand correctly if he closes air off the fire smolders....that would say to me that there is no leak as the opposite would be true if there was, right?

 

[PLAYS WITH FIRE]

My friend Mark has the 91 and complained of similar situations with his when he'd burn, for instance, red oak that may be down for years and then split and burned later that week. When I helped him buck up some one day he was gonna burn it this year. I was like duuuuuuuuuude, you can do that and that's your problem. So we did find some good red elm that were leaners and then found out he doesn't run the stove properly. In 8 years he had never closed the cat bypass more than half way. I took a quick look at the manual and seen what each lever was and told him what to do. He actually called and thanked me up and down because he can bring his room temp up to like 80 in not time flat. He asked how I knew what to do and I told him," duhhh, I read the manual man"! So I will help him stock up on 4+ cords of red elm, lots of dead ones in his woods! for next year.
I may be wrong on this fellows problem but here in my neck of the woods, I'm like the wood burner doctor. (Joking)

 

[WranglerBowman]

I know where everyone is coming from with the wood. The wood I started the season burning with was 2 years old (split and stacked) been stored under a barn roof. Right now I'm burning wood that was dead leaners from a Hurricane 1.5 years ago. All was split in June and stored in my barn. I notice a difference in how long it takes the cat to get up to temp with the newer wood but the wood has been burning the same, turbulent, all season. I'm really leaning towards some kind of air leak around the exhaust or an exaust leak. Stoves been running straight since Jan 8th so maybe I'll shut it down this weekend and investigate.

 

[PLAYS WITH FIRE]

The rule of thumb is for most species cut, split and stacked for 1 year and oak can be up to 3. Sometimes you gotta do what you gotta do. I just broke into some cherry that had been CSS for almost 2 years and am havering problems. The way I stacked it and where it was stacked I can tell its not seasoned so I'll leave it alone. But I gotta keep the air open longer for it than my locust which is truly seasoned but like to save for cold weather. I think I've seen on here a 91 that the gasket around the cat was no good and the flames were too much even closed down because they would pass around the cat. Never hurts to check.....

Just to be sure, buy a cheap moisture meter and all doubt is gone.

 

[Woody Stover]

This is the 2nd year I've been using my Buck Model 91, I'm the 2nd owner, was made in 2009, and I feel like it's loosing it's effeciency and I'm noticing a difference in the way it's burning....The flames seem to be moving quickly when I have the air intake settings on a very low setting, like it's leaking air. I've replace the door gasket and that seemed to help a bit, but it's still burning like there's an air leak. Besides the cat gasket, window/door gaskets, and ash pan gasket does anyone know if there are other gaskets that I might be missing?

I've been running the 91 for a couple of seasons. I had trouble with air leaking past the ash pan gasket but I've worked on the gasket so that it seals better (I think replacing that gasket was a mistake; The factory gaskets are better quality high-density gaskets. Mine had frayed where the two ends meet, allowing a lot of air through the ash dump. Should have just patched the original gasket, because the new one did the same thing. The ends of the gasket need to be sealed with high-temp silicone to prevent them unraveling.) Does the flame get pretty active as the burn progresses? That's what mine was doing, and it was the left side of the load, over the ash dump, that was taking off with a combination of air wash air and ash dump air. The cat probe went up around 1800 on several occasions, and I want to avoid it getting that hot to prolong its life. I like to see the cat probe at maybe 1500-1600 max. I only use the shot gun air (left slider) when starting a load. Once I have the cat lit, I usually burn with the air wash (right slider) open slightly, or closed all the way, depending on the wood. Soft Maple and Cherry gas pretty quickly so I'll cut the air all the way. With Oak or Hickory, I might leave that slider 1/2-3/8" open. Anyway, until I can try a couple of my ideas to totally seal the ash drawer gasket area, here's how I load the stove to negate that ash pan air. After I burn a couple of 'sacrificial splits' to get the stove hot and the probe around 900, I'll load 'er up. I stack a couple of good-sized splits against the left wall with no coals under them. Those won't get a lot of air wash air until later so they won't be gassing early. Then I shove a pile of coals against them, over the inside edge of the ash lid. My thinking is that the coals will eat up some air that may be coming in around the lid, and the left side of the load won't take off and get too much wood gassing early. I'll then load the rest of the stove on some coals and use the shot gun air, not much air wash, to get the load burning from the center out. When I've recovered some probe temp, to about 900 again, I'll close the bypass and run a little flame until the cat lights. The probe shouldn't drop but a hundred degrees or so when I turn the blower on...then I know the cat is lit, even if it's not glowing (you can see the cat glowing later if you look in around the bypass rod hole, as you may know.) This stove isn't at my house, so I can't watch the entire burn every time. I've been piling the coals like this for a couple of weeks, and the times I checked on the stove later in the burn, it was running sweet. I'm fairly confident that the loads are now burning in a controlled fashion.

I blew the cat off with 30 psi of air when I inspected it so I would think the cat is clean.
When I reinstalled the cat houseing after I inspected it I left the nuts pretty loose just because I didn't know how much expansion there is when that fire is roaring and I didn't want over tighten. I wonder if it's too loose causing an exhaust leak, or the gasket is ripped from the install? Besides that cat gasket any one know if there is a gasket on the bypass damper? I don't remember inspecting this when I swept chimney in September. My chimney is 25' tall with a SS liner installed so I don't doubt that there is a strong draft.

Careful with that compressed air, you can blow the catalyst right off the substrate with too much pressure! I usually just gently blow the ash out with my mouth. I probably will just pull the cat once a year and give it the 50/50 distilled vinegar/distilled water simmer and rinse. It's a little work to get the cat out, and you need to replace the interam gasket and the frame-to-stove gasket when you remove it. And go ahead and tighten those nuts for the cat housing; You want that snug.
No, there's no bypass gasket. The plate just slides over the bypass hole in the top of the box. Any leaks in the exhaust path would be pulled up the flue by draft, and wouldn't cause your "turbulent flame." The draft has to pull fresh air into the firebox, before the exhaust, to cause an increase in flame. Since the seams are welded, the most likely other sources of air would be gasketed openings into the firebox. It could be one of the plates attached to the slider rods, but you can easily check those by looking at them with the blower control or ash pan front doors swung open. But the first thing I would check is the ends of the ash pan gasket to see if they have unraveled and left a gap.
BTW, if you don't have the manual, you can get it at buckstove.com.

 

[begreen]

Have you spoken with your Buck dealer? I would do this before attempting any fixes. It could be that someone missed a weld in your Buck. If so, who knows how this would play out over time. Get the dealer out there to see this gap.

 

[WranglerBowman]

The ash pan gasket isn't leaking enough to make a noticable difference. I'm sure the flames get more aggressive and turbulent as the burn continues due to the wood not being well seasoned. My thought with it being an exaust gasket was the fact that if I crack either the shotgun air or air wash slider the flames take off, which would be the case if the exaust gases are flowing more freely, like a gasket is missing or screwed up. I'm not aware of any Buck dealer around me and generally avoid dealers like the plague. I don't think a weld is missing because it was burning fine up until this year, I doubt a weld cracked as I'm only aware of the stove getting too hot on one occasion 2 years ago (cat got close to 2000F) when I was first learning how to drive the thing and it was fine for all of that season after that over fire. Def something to consider though. When I inspect the cat and it's housing I'll look around the fire box and see if I notice anything.

 

[Woody Stover]

If you can almost snuff the fire when you cut the air all the way, as you stated above, I don't think you have a major air leak. You may well be right about the wood; If it's not real dry it will tend to take off more as it dries out in the stove. Like I said, I cruise the stove with air wash only, and anything more than about 1/2" open on the slider will yield pretty active flames. But it is odd that it would be burning differently than before. I think a leak into the exhaust path (like a leak around the cat housing gasket or interam gasket) could result in a more unrestricted exhaust flow, but not as much as having the bypass open versus closed. But I guess the cat housing nuts could be really loose. If that were the case, you would see more smoke than before out of the stack because it would be bypassing the cat. Also, did you put in a new cat housing-to-stovetop gasket (the white rectangular one) when you had the cat out? In an case, there's no way air entering the exhaust path elsewhere could get back into the firebox and cause more flame.
Yeah, when you take the cat shield off you'll be able to see most of the welds except for the bottom ones. But just because you had the cat probe to 2000 doesn't mean you over-fired the stove. I think you would have to have the air wide open and a blazing inferno in the box to overheat this stove. It's constructed of heavy plate steel, 5/16" in the top. I have a surface thermo on the front left of the stove as low as possible without the door hitting it. That should be about where the top of the firebox intersects the front. Obviously that is going to read lower than the actual temp of the stove top. I've seen that meter up to 500 on a couple of occasions...not too often. I've shot the inside top of the stove a couple times with the IR gun but it's hard to do...kinda hot in there. I should open the bypass when the cat is up around 1500 or so, and try shooting the inside top then....

 

[WranglerBowman]

The stove is back up and running! Finally got to complete the task late last night. I removed the cat and was surprised to see how much ash has collected since I last cleaned it in September, see pics below. Overall it was still 75%+ open for air flow so not bad, just surprised how much had built up, probably from the softwoods I started the season with. I fixed the warped piece of metal on the side of the stove, not sure why it was warped but it's straight now. The cat is nice and clean and it got all new gaskets. I was surprised the nuts were a little sticky when I was removing the cat, guess the automotive antiseize cooks off pretty quick, only put a few dabs on when I last installed the cat houseing in Sept. When I was looking at the air intake restrictor plates for the sliders I noticed they are not even in position with each other, allowing more airflow into one side of the fire than the other! When I thought I had the intake just barely open it was actually about a 1/3 of the way open on the left side. I took the square plates off in September so I can bend the sliding rod slightly to let the square plates sit right up against the air inlets, to reduce air leaks. There a multiple holes on that slide rod and I guess I didn't have it lined up right when I put it back together. Things are squared away now and the stove is burning like it used to, much more efficiently. Do other people have multiple mounting holes for the air intake plates along the air wash sliding rod? Wondering if the guy before me drilled multiple holes in the slide ride and fooled with stove.

 

[Hogwildz]

That white haze on the front next to the bay window looks like the white haze from overfiring.
Might be the photo, and could be fine. Just something I noticed.
The bowed area as you described may also indicate overfire if the steel is warped.
Watch your your temps to avoid further warping.

 

[ridensnow23]

Wrangler, glad you got everything all sorted out.

My model 81 has the same issue where the primary air blocks are slightly our of sync. I'd say mine are maybe 1/8"-1/4" inch off. My slider only has one set of holes, so I was considering drilling new holes once the burning season ends. I'm willing to bet the buck began drilling extra holes in the slide to accommodate any variance they have from where the air intakes are cut in the bottom.

 

[WranglerBowman]

The white haze in the photo of the side of buck is actually ash or dust that was coming out of the side of the stove from the blowers because of the leak. I just don't dust my stove very often I guess. Like I said I only know of 1 time when I got the cat too hot and that was when I had just put a bunch of small splits on hot coals and forgot to shut down the air wash, was only like that for 30 mins or so but the cat temps were about 2000F. Probably not enough time to warp the stove. I really wish these stoves had thermostatically controlled blowers

Ridensnow23 - you're probably right, something to consider though when your having issues similar to what I had. Surprised I overlooked something so simple, just hard to see both air restrictor plates unless your head is underneath the stove.

 

[Woody Stover]

When I was looking at the air intake restrictor plates for the sliders I noticed they are not even in position with each other, allowing more airflow into one side of the fire than the other! When I thought I had the intake just barely open it was actually about a 1/3 of the way open on the left side. I took the square plates off in September so I can bend the sliding rod slightly to let the square plates sit right up against the air inlets, to reduce air leaks. There a multiple holes on that slide rod and I guess I didn't have it lined up right when I put it back together. Things are squared away now and the stove is burning like it used to, much more efficiently. Do other people have multiple mounting holes for the air intake plates along the air wash sliding rod? Wondering if the guy before me drilled multiple holes in the slide ride and fooled with stove.

I doubt that they drill more than one set of holes when assembling the stoves. Good to hear you got it straightened out. I'd better have a look and see if there's some ash that can be brushed or blown off without removing the cat. It's working fine but no harm in taking a peek....

 

[Woody Stover]

That white haze on the front next to the bay window looks like the white haze from overfiring.
Might be the photo, and could be fine.

That's probably just ash that was blown out of the gap in the convection jacket by the blower....

 

[Bmore]

The stove is back up and running! Finally got to complete the task late last night. I removed the cat and was surprised to see how much ash has collected since I last cleaned it in September, see pics below. Overall it was still 75%+ open for air flow so not bad, just surprised how much had built up, probably from the softwoods I started the season with. I fixed the warped piece of metal on the side of the stove, not sure why it was warped but it's straight now. The cat is nice and clean and it got all new gaskets. I was surprised the nuts were a little sticky when I was removing the cat, guess the automotive antiseize cooks off pretty quick, only put a few dabs on when I last installed the cat houseing in Sept. When I was looking at the air intake restrictor plates for the sliders I noticed they are not even in position with each other, allowing more airflow into one side of the fire than the other! When I thought I had the intake just barely open it was actually about a 1/3 of the way open on the left side. I took the square plates off in September so I can bend the sliding rod slightly to let the square plates sit right up against the air inlets, to reduce air leaks. There a multiple holes on that slide rod and I guess I didn't have it lined up right when I put it back together. Things are squared away now and the stove is burning like it used to, much more efficiently. Do other people have multiple mounting holes for the air intake plates along the air wash sliding rod? Wondering if the guy before me drilled multiple holes in the slide ride and fooled with stove.

Hey, recently found this old post. I was wondering what the square plates look like on your slider rods and how you got to them. I am putting together a model 91 and found extra plates in the ash pan. It looks like my sliders have small plated welded directly to them so I'm very curios where those holes were located that you adjusted. My Buck is a 1994 so may just be completely different. Thanks

 

[WranglerBowman]

Hey, recently found this old post. I was wondering what the square plates look like on your slider rods and how you got to them. I am putting together a model 91 and found extra plates in the ash pan. It looks like my sliders have small plated welded directly to them so I'm very curios where those holes were located that you adjusted. My Buck is a 1994 so may just be completely different. Thanks

Hey Bmore, the plate that's a rectangle (roughly 4"x4") that below the angled plate looks to be very similar to the sliders that are located on the air intake, however I think the previous owner modified mine or changed them out. My 91 has 2 slide handles, one for the shotgun intake (left side slider arm) which has a single slider located in the very front of the stove, center, bottom, right behind the metal shroud. Inline with shotgun air intake on the 2nd slider arm (right side slider arm) are 2 plates, same size, located near the corners of the front bottom of the stove. I can try and take a picture of the plates tonight. Does the plate on the left of the picture have a nut welded to it?