Buck Stove 85 question

[brian89gp]

Just (finally) installed my Buck Stove model 85. It has 40' of 6" insulated SS flex for the flue and it drafts real real good. My question is on the the correct air damper settings (it has no flue damper), how far do I choke it down to? 3/4 of the way closed and it still burns quickly through wood with a firebox full of flames, the manual states 1/2 closed for the damper for burning but at 1/2 closed it is burning HOT. How do I go about finding the correct setting to let it cruise at?

My parents have the same stove, but with a 8" SS liner that is only 20' or so and it behaves entirely differently. Any more then 1/2 closed and it will almost kill the fire.

Comments/suggestions/tips?

 

[PLAYS WITH FIRE]

You got a 40' liner! I would choke it all the way down ans let it pull the air through the secondary intake... You are drafting toooo much possibly. I bet choking all the way and you still have good flame action. You may find you want to find a way to limit draft with a damper you install.

 

[brian89gp]

I definitely don't have any trouble starting or restarting a fire, thats for sure.

100% closed will smolder the fire. What visual cues should I be going for when choosing how far to close it down? Even though it is an inside chimney and it is an insulated liner, I am still paranoid about creosote buildup and don't want to close it down too far.

At 3/4 I know I am burning hot/clean. Little to no smoke out the stack, glass stays clean, enough flame action to somewhat light the room. But a load of silver maple will only last maybe 2 hours and a load of black walnut with a 5" diameter branch of osage orange was a small ash covered coal bed after 6 hours.

 

[brian89gp]

Pic of a half load of silver maple a few minutes after closing it down to 3/4 closed from 1/2.

 

[brian89gp]

7/8 closed. 20 minutes after the last pic, and about 1 hour after putting the wood in.

 

[brian89gp]

7/8 closed seems to keep a nice coal bed going. Will try that tonight.

I picked up a magnetic stove thermostat, where on the stove can I put it and what temp ranges am I looking for? The liner is stainless and also insulated so I can't really stick it to where the instructions say to put it.

The draft is quite strong on this one, I am finding it almost impossible to even get a hint of smoke smell into the house when opening the door. Got to be quick about it with the door open though as a mini inferno kicks up within a minute or so.

 

[begreen]

Close the air down as far as it will go once the fire is fully engaged. You may need to do this in steps, but get to fully closed with that draft.

Buck lists the max flue height as 20ft. for the freestanding version of this stove which seems ultra conservative. Still, I suspect as temps get colder you are going to have an issue with too strong draft. The insert probably should have been installed with a 5 or 5.5" liner.

 

[brian89gp]

Buck lists the max flue height as 20ft. for the freestanding version of this stove which seems ultra conservative. Still, I suspect as temps get colder you are going to have an issue with too strong draft. The insert probably should have been installed with a 5 or 5.5" liner

Hmmph. Could you explain the smaller diameter flue thing? Not doubting, just don't grasp the concept. I know a 5 or 5.5 would have been a hell of a lot easier to pull up the chimney.

I did call Buck tech support just now and ask specifically about flue length and they said that there is no limit as long as you are able to clamp it down far enough to get a good burn with whatever setup you have.

 

[begreen]

The smaller pipe will pass a lower volume of air thus reducing draft. Interesting that they have a limit pictured (fig 12D on page 27) in the manual for this stove, but the tech said 40ft is fine. Maybe that is a typo? Ultimately he/she is correct. If you can maintain good control of the stove then it should be ok.

 

[PLAYS WITH FIRE]

The best place to put your thermo is where a laser tells you. Mine is an insert so I am limited but mine (2) are about 6" below the top on the front left and right. Smolder can be relative so maybe you are seeing the secondaries going and not so much flames on the wood? I usually get mine going to about 500 and had been closing it down in steps to all most completely closed. It is possible that your are closing down too early.

 

[brian89gp]

Top right corner on the face, a 3/4 load of silver maple, closed down 100%, and it is reading 525*. Right after the wood was added it was running at 550 or just above. Thermo is a magnetic Imperial brand I picked up at Lowes.

If I don't close it down as soon as the wood is lit (5-10 minutes, new wood on coal bed), it gets real hot.

While in the safe zone (barely), I am screwed if I need to clamp the fire down to control it for any reason. Could a bad door gasket cause some of this (I know the flue is probably too long causing too much draft, just trying to eliminate cheap possibilities first).

 

[brian89gp]

Holding steady at 450*, both before and after adding a new log. 100% closed down.

I apologize for my frantic nature, the run away stove was scaring me.

 

[PLAYS WITH FIRE]

The gasket could cause it and a simple way to check is the dollar bill test. Insert bill, close door tight if bill comes out easy you need new gasket. Do this all around the seal. What confuses me though is you said if you close the air all the way the fire smolders.....to me the stove is tight from this detail.

 

[PLAYS WITH FIRE]

I posted after your last....

I run mine like this. I get it to 500 ish while shutting it down to almost completely closed, sometimes completely closed. The temp will climb when shut down to keep the heat in the box and not up the stack. I add wood when the temp drops to about 200 to 300. I then go through the same process. If you close down to late the temp will climb on you and sometimes too much! With a 40' stack I would shut down earlier and get to know the characteristics of the stove so not to freak yourself out!

If you do feel it is getting out of control. Open the door for a bit and watch the temp drop. Epa stove are made to keep the heat in. Be careful of the baffle on top of the tubes. Make sure it/they are on the tubes and not overlapped. The only place air/exhaust is up the front. Not the sides, middle or back if that makes any sense?

 

[brian89gp]

What confuses me though is you said if you close the air all the way the fire smolders.....to me the stove is tight from this detail

Mostly coals with only some flames, I considered it smoldering but I was wrong.

I run mine like this. I get it to 500 ish while shutting it down to almost completely closed, sometimes completely closed. The temp will climb when shut down to keep the heat in the box and not up the stack. I add wood when the temp drops to about 200 to 300. I then go through the same process. If you close down to late the temp will climb on you and sometimes too much! With a 40' stack I would shut down earlier and get to know the characteristics of the stove so not to freak yourself out!

Yea...I was freaking out. The liner is popping, the stove is radiating heat so bad it is hard to get within 1-2' of it, the room it is in was 100*, the blower stopped (overheated I guess), and once I found the thermometer and put it on the cast iron flue collar it was easily above 800.

If you do feel it is getting out of control. Open the door for a bit and watch the temp drop. Epa stove are made to keep the heat in. Be careful of the baffle on top of the tubes. Make sure it/they are on the tubes and not overlapped. The only place air/exhaust is up the front. Not the sides, middle or back if that makes any sense?

Your baffle, plate of steel maybe 1/8" thick? Is yours flat or warped upward in the middle along the front to back middle line? Mine has a little space left and right but when I replaced the insulation quilt on top of the baffle it fills this gap. When looking flames only come over and around the front edge by the door. I bought my stove used so I do not know what this baffle is supposed to look like.


Thank you both for your help. I am still a bit freaked out, but now I know at least one thing not to do.

 

[jolby]

My baffle is just as yours with the space covered by the insulation blanket. PWF and begreen covered it pretty well. I do pretty much like PWF but last night my Condar Inferno therm topped out in the too hot zone at 700 so i could have shut it down a bit earlier. My manual says that if the connector to the flex pipe glows red then it is overfiring. I try to load just to the visible top of the firebricks and that gives me some consistency with what to expect. Maybe if you let your stove cool a bit more before reloading it you might get it under control easier.

As far as the gasket is concerned, i have had to tighten my door handle to get the door to shut tight enough to pass the dollar bill test.

 

[PLAYS WITH FIRE]

The baffle can be straightened...take it out, put it somewhere to bend it the opposite direction and reinsert. You don't want to bend too much it could crack. I think the use of this is not so good but lots use it. You can find other material that is talked about here that will not bend or warp but you can break it. It's something along the lines of a ceramic fiber board. That's what cam in mine and when I first got it. I thought it was like packing material and almost tossed it.

Like the other fellow said put new load in at a lower temp like 200 degrees. With suck a long stack you can probably get the stove up to 500 in a minute or two (joking)! I had to teach the wife this because she would keep feeding and feeding. I told her to do it in cycles, get it hot choke it down a bit and let it go till it is about 200 to 300. She said that can be hoooours, I said that's the idea.;-)

 

[brian89gp]

Will do, thanks for the help.

It seems to depend a lot on the wood I use too. The maple and sweet gum goes up fast and is hard to control, but the black walnut, locust, and osage orange I have to open it to 3/4 closed to keep a good burn going. Now those other harder woods might not be seasoned as well as the maple though.

 

[begreen]

Locust needs more air on our stove too. I heard the same about osage orange.

 

[brian89gp]

I've started to get the hang of it. The load, burn at 500-600 down to 200-300 and then reload method is helping out a lot. The continual loading I was doing was not working at all. Also figured out that 5 minutes full open after a reload, 5 minutes at 2/3 closed, then all the way to 90-100% closed for the remainder of the burn. Any longer then the two sets of 5 minutes I get up into the 700* range quickly.

On the buck stove there is a cast iron collar that clamps to the top (the 8" version is at the below link) that the SS flex flue adapter then goes into. The couple stove and chimney people I have spoken to suggested a flue damper of some sort to remedy the strong draft, what are peoples thoughts on having a steel plate cut with a 5.5" or 5" ID opening with the OD cut to fit inside the collar to act as a fixed damper?
https://www.hearth.com/talk/threads...-there-is-no-collar.86042/page-2#post-1226042

 

[PLAYS WITH FIRE]

Im happy that helped you. The plate idea is not a bad idea if it could tried cheap. Is it necessary? When you shut the stove air down completely when it is in the temp range you normally do this. Are the flames like really slow and lazy and go from the wood to the tubes?

 

[brian89gp]

Depends on the wood. Silver maple and sweet gum are not so lazy but also not crazy and secondaries will be lit with it fully closed. Black walnut is lazy and usually requires some air for secondaries to be lit.

 

[begreen]

I would keep this steel plate option open for later in the season. It may be a good idea, but right now you are learning the stove. Let the stove cool down like you are doing before reloading, especially with quick to burn wood. If you do decide to have a plate made, consider just restricting the front part of the collar. Maybe the front third. This metal will get quite hot, so I'd suggest making it out of stainless or thick steel.

This is the general idea I had in mind:

 

[clemsonfor]

Those flames on 7/8 are still pretty big. Id close 100% like u did. That is one tall chimney, but like said that long of a chimney will draft well. It will pull air up that thing super fast and as the diameter gets smaller it cant suck as much air, but it will be ok as that long of a pipe will be moving the air faster than a 15ft chimney of the same diameter.

 

[brian89gp]

I was looking at the intake controls, they are a sliding plate that cover/uncover a hole in the bottom of the firebox. To the best of my flashlight abilities I could not find a secondary air intake anywhere, just one of these slides on each side of the stove. The intake hole is around 1" x 2".

From what I could see the slides are really loose with roughly a 1/16" gap between the plate and the plate the intake hole is in, so even when fully closed it is letting in some air. I might cut a piece of sheet metal to go under the slide to push it up closer to the plate the hole is in in order to close the air gap some. I would at least have the option to close it down further then is possible stock that way.

My concern, brought to light by an earlier post from begreen, is that I am currently burning in temperatures in the mid/high 30's overnight. I don't want to find out the hard way on that single digit or below zero night that the draft is too strong to control and the stove starts a race to glowing temps.