Cookin' With Coal

Post by **Lightning** » Tue. Dec. 03, 2013 2:57 am

Photog200 wrote:When burning wood, it is over fired because it is being fed with air being sucked in from the top of the stove. Even though I have the air intake dampers completely closed so I have to control that with the check damper.

Yes I agree since I believe air leaks AND good draft are contributing.

Photog200 wrote:With coal, the air that is being sucked in from the top has the opposite problem, because it is taking air that should pass under the grates to operate it correctly, the coal fire does not get as hot as it should. (especially when in oven mode). I have to find a way to curb the air loss at these points I showed with the arrows in the photos.

This part I'm not on board with. I believe this is a common misconception. In order for the leaks to "take" part of the combustion air, the leaks would need to exceed the volume of the flue pipe (for example, opening the load door would accomplish this). I've proven this to myself by placing a manometer probe in the primary air feed and then adjusted the secondary and observed no change in pressure at the primary. By the looks of the leaks from the pictures, there is nowhere near that volume getting in the stove.

Photog200 wrote:I have already made some progress by plugging some leaks at the stove pipe.

Got pics of these leaks? I'm curious about this part.. More details?

Photog200 wrote:Thank you so much for your post because your points are very valid. This has been two weeks of a lot of experimenting and learning and I thank everyone for your support and good pointers. I love this forum!

Your welcome! This forum has helped me too, hopefully with combined effort, you'll be happy with your results with coal.

Outside of that, a manometer is cheap and easy to install and I think it would help diagnose your problem

Also, I don't know your level of experience so I would like to suggest too that maybe your coal bed isn't being built up high enough. I run mine 10 inches deep. A minimum of about 6 inches deep covering the whole grate is enough for a good even burn.

Sunny Boy · Post by **Sunny Boy** » Tue. Dec. 03, 2013 8:29 am

Lee,

He may not be able to get anywhere near that depth of coal bed with a kitchen range. My range can only hold about 6 inches depth of coal from grates up to the top of the fire brick liners. And just under 9 inches grates to the top surface of the stove. Some of the later Glenwoods are a bit higher, but not by much. His Clarion is likely closer to that than being able to get a 10 inch coal bed depth.

And trying to raise the coal bed any higher, yes, it will put out more heat, but that puts the now greater heat volume producing coal bed that much nearer to the top plates, . . . and closer to warping them. The top plates are only about 2-1/2 to 3 inches above the firebox liners. Coal bed depth to heat volume is limited to a very narrow "safe" trade off with a kitchen coal range.

The only time I over-load the bed is at night when I'm damping it down and it will be burning much slower and cooler. Then the ash door dampers are only open a bit more than the thickness of a sheet of paper, the direct (oven) damper is closed, and the MPD is also fully closed.

One other thing to bring up that Randy may be experiencing, . . . aside from whatever air leaks he finds.
For the first day, a new coal fire bed "wants" to burn hotter because there is fresh coal all the way to the bottom. The primary damper setting has to be closed more than usual to maintain the same output as a more "mature" coal fire.

I don't think Randy has yet been running it for more than a day or so on coal. After a day or two, If the bed is only shaken when needed and only until a few burning bits drop, the bed calms down. The bottom half of the coal bed is burning slower because of the higher ash content it keeps in normal, steady use. So, the total heat output is less for the very same primary damper (ash door) size opening. To get the same amount of heat output as a new fire takes a lot of grate shaking and putting fresh coal on until there is all bright yellow/orange glow throughout the entire ash drawer and it's dropping a lot of burning cinders. And as you know, that's not a good way to run it all the time.

Paul

Sunny Boy · Post by **Sunny Boy** » Tue. Dec. 03, 2013 8:41 am

"............... Outside of that, a manometer is cheap and easy to install and I think it would help diagnose your problem

"

Agreed ! Plus, by always using it to set dampers, I'm finding I'm using a couple of pounds less coal per day.

But my inexpensive pocket Dwyer mano is wearing out. So, two new Dwyer model 25's should be here in a couple of days. One for the range, and one for the Modern Oak 118 when I get it set up. Amazon.com had the best price with free shipping too.

Paul

windyhill4.2 · Post by **windyhill4.2** » Tue. Dec. 03, 2013 9:02 am

Paul,I have seen some pics.on CL of stoves with the I's & T's warped badly,figured they were over fired. Randy, could you put some sheets of foil over leak areas & set water kettles on top for weight to test if stove top leakage is the problem or not ? I am no expert on coal fired stoves,but have found that when I get stumped on a problem in my shop,( Lawn & Garden equipment) I have asked even my wife her opinion already & even tho she knows little about these things yet a few times she came up with an answer that left me wonder why I didn't think of that

Photog200 · Post by **Photog200** » Tue. Dec. 03, 2013 10:26 am

Sunny Boy wrote:Randy,
Have you tried covering the tips of those eyes and tees and all along the other edges with sand to see if that stops the run-away stove problem ?

How much check draft opening do you need with coal ?

Paul

The sand idea is a good one to see if that helps with the wood fires. Paul, it is only with wood that I need to use the check damper. I was having the opposite issue with coal. However, an update on this whole issue. Last night I used stove cement to plug up some holes on the stove pipe that I found to be leaking when doing the match test. I don't know why I did not think of this earlier because that is the first thing I thought of on my coal stove in the house. There were three spots that were leaking on the stove pipe...it made a huge difference in the draft issue for the coal. Before going to bed, I put it into oven mode, turned the pipe damper to 3/4 closed and closed the primary air damper to 1/4 open. This morning I went out to check the stove and had a nice slow fire going and it did not take long to wake it up. I can live with this! For a wood fire, I do not mind dampening it down with the check damper. For coal, it was just not getting hot enough to bake with or to cook with either if it was in oven mode. The way it is now, I can live with it! Yeah!
Randy

Photog200 · Post by **Photog200** » Tue. Dec. 03, 2013 10:32 am

windyhill4.2 wrote:Paul,I have seen some pics.on CL of stoves with the I's & T's warped badly,figured they were over fired. Randy, could you put some sheets of foil over leak areas & set water kettles on top for weight to test if stove top leakage is the problem or not ? I am no expert on coal fired stoves,but have found that when I get stumped on a problem in my shop,( Lawn & Garden equipment) I have asked even my wife her opinion already & even tho she knows little about these things yet a few times she came up with an answer that left me wonder why I didn't think of that

Dave,
Paul gave me a great idea to fill the cracks with sand and see if that helps with leakage. I rarely lift any of the lids except the ones over the fire pot, other than to clean the top of the oven. The sand would not even be obtrusive to leave right there in the cracks. After cleaning just fill them again. As in my other post, I think I took care of most of the leakage problem by fixing leaks around the stove pipe. The other leaks I think will be ok...at least enough to live with. The nanometer is a good idea as well!
Randy

Sunny Boy · Post by **Sunny Boy** » Tue. Dec. 03, 2013 11:04 am

Randy,

Ok, good that you don't need the check draft with coal and it went through the night with that much damper openings. congratulations on your first coal all-nighter !!!

That puts you in the ball park of what's normal operation. At most, your down to fine tuning is maybe all that's left.

If you think about how these ranges were designed with check dampers and large over the fire dampers, and how air-tight they were (or weren't) when new, I think you'll see that the designers knew there was always going to be a need for a dual-fuel kitchen range like yours and mine to use the check draft with wood. It's just the nature of how wood burns in them vs coal. And it's one more reason to just use coal.

If you get a mano hooked up to the Clarion, I think you'll find that with coal, you can close those dampers down even more at night if you want longer burn times. Mine draws fine with the primary closed to a sliver and the MPD closed all the way, with the mano reading .005 - .01 at night. I have a new CO detector four feet in front of the stove, up on a kitchen cabinet soffit where heat convection from the stove is forced to take the heat right past it. It's never gone off yet.

Paul

Sunny Boy · Post by **Sunny Boy** » Tue. Dec. 03, 2013 11:07 am

".......... The nanometer is a good idea as well!
"

I think that'll be wayyyy too small to read !

I think a "manometer would work better for ya !

Paul

Photog200 · Post by **Photog200** » Tue. Dec. 03, 2013 11:35 am

[quote="Sunny Boy"]".......... The nanometer is a good idea as well!
"

I think that'll be wayyyy too small to read !

I think a "manometer would work better for ya !

Paul[/qu
I think I had better slow down my typing!

Photog200 · Post by **Photog200** » Tue. Dec. 03, 2013 11:39 am

Sunny Boy wrote:Randy,

Ok, good that you don't need the check draft with coal and it went through the night with that much damper openings. congratulations on your first coal all-nighter !!!

That puts you in the ball park of what's normal operation. At most, your down to fine tuning is maybe all that's left.

If you think about how these ranges were designed with check dampers and large over the fire dampers, and how air-tight they were (or weren't) when new, I think you'll see that the designers knew there was always going to be a need for a dual-fuel kitchen range like yours and mine to use the check draft with wood. It's just the nature of how wood burns in them vs coal. And it's one more reason to just use coal.

If you get a mano hooked up to the Clarion, I think you'll find that with coal, you can close those dampers down even more at night if you want longer burn times. Mine draws fine with the primary closed to a sliver and the MPD closed all the way, with the mano reading .005 - .01 at night. I have a new CO detector four feet in front of the stove, up on a kitchen cabinet soffit where heat convection from the stove is forced to take the heat right past it. It's never gone off yet.

Paul

In the past I was only able to shut down the pipe damper to 3/4 or I would smell sulfur exhaust. Now with the leaks plugged, I bet you are right about being able to shut it down better.

At least now I know that all of the seams are sealed and so is the stove pipe. Any other leaks have to be coming from the top. I am heading out to run some errands and I am going to stop at Lowe's and see if I can find some black sand. I am sure I saw some in the sand blasting medium section. There is no reason I cannot leave the sand in most of the cracks until I have to clean over the oven. Will let everyone know how I made out.
Randy

Sunny Boy · Post by **Sunny Boy** » Tue. Dec. 03, 2013 11:59 am

Mine also leaked flue gases through the warped top plates if I tried to close the MPD almost all the way, without also closing the primary damper down to a sliver. I got new I's and T's and that all went away.

But I still have so much air leakage in under the top edges, and around the oven that getting the oven over 300 degrees is tough. A few stove restorers I've talked to said, that with it all properly sealed, I should be able to get the oven up to about 600 F on coal.

The good news is It's tougher for me to over cook, or burn anything in the oven. And with my level of cooking skill, . . . those air leaks may not be such a bad thing !

Paul

Post by **Lightning** » Tue. Dec. 03, 2013 12:00 pm

Hey Randy, glad to hear you had success with a fire thru the night! I agree that the leaky flue pipe was letting cool air in and hurting your draft. Good luck partner

windyhill4.2 · Post by **windyhill4.2** » Tue. Dec. 03, 2013 12:11 pm

Randy is now

after much

and we are all

,thanks Randy,you are helping to pave an easier road for others to travel when they get their coal ranges in place.

Photog200 · Post by **Photog200** » Tue. Dec. 03, 2013 2:46 pm

windyhill4.2 wrote:Randy is now after much and we are all ,thanks Randy,you are helping to pave an easier road for others to travel when they get their coal ranges in place.

Yes, Randy is a happy camper!

Sunny Boy · Post by **Sunny Boy** » Tue. Dec. 03, 2013 2:56 pm

There's a coal-burnin' smile !

Paul

Cookin' With Coal

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