Here Come the KINKERS!!!

This is my first year burning anthricite. Overall I am quite pleased and am commited to using this fuel. The more I use this website, especially reading and learning from others experience, the more confident I become in my ability.

I have a dual fuel hot air furnace (Norseman 2500-Vogelzang)(very similar to HotBlast, etc.). It has a long narrow fire box: 26"l, 11"w, 12" deep, which I converted from the original dimensions which was V shaped......more condusive to cordwood. I have added an additional spin draft knob on the ash door, and also added a manual flue damper. Since the onset of heating weather I have learned how to start and maintain my fire. I understand issues such as draft, loading, poking, and shaking........although I suspect there might be some activity knowledge which is lacking.

OK, here it is: I can start, adjust fire & heat production, and keep it going for about 3 days, not much more. Why? The kinkers are killing me! And I am not referering to my neighbors who resemble the Flockers!

Seems that towards the end of the fires life, when it seems OK (top coals glowing and still throwing good heat) it is dying slowly. Now the fire box is about 85%-90% full, everything looks OK.....so I poke it ( which increases heat, at least momentarily) leave it for 10 mins, then add a thin layer of coal, wait another 10 or 15 minutes then shake. I shake until hot embers fall into ash pan. For a newbie like me this all seems to look fine, but the fire dies nevertheless. Until now, I would just clean it out and start over, knowing full well that something is lacking......but I need to heat my house so I do what must be done.

Well it has been a cozy weekend. 10 degrees outside, 72 degrees inside .....thanks to anthricite! I woke up and the house was down to 66. Checked the fire, same diagnosis. Rather than going thru all the expected effort just to throw good coal on a dying fire.....I just let it die. Then, I disassembled the remains very carefully......layer by layer. Top layer: glowing coals and partials. Next layer: dead burt coals. Bottom layer: ALL KINKERS! What's going on? I have been poking and shaking, monitoring draft, listening to this baby purr for 2 and 1/2 days.

Help me so I might have a continuous fire like everybody else. I am patient AND willing.

Ludlow Lou

As the coal burns, it forms a cone inside where the air has proliferated the most. the draft is from underneath as to "over" in a wood fire. A long firebox as you have may have several cones or one long cone. I have a pot bellied stove so mine is in the center of the firebox. I heap the coal in the center of a burning fire, maybe three or four scoops. what falls down the sides burns, and burns quite well. As the coal burns around the edges and the fuel within the coal nugget burns, it forms a compact ash which is a klinker. Eventually these klinkers build up and actually insulate the sides of the stove from convecting heat outward. If these klinkers aren't broken up into smaller pieces and withdrawn when you shake the grate, they will block the airflow which in turn starts the stove to go into shutdown mode. the cone of fire in a stove must be a bright orange color to be efficient. once it starts to go to a subdued orange, then red, your stove will go out.

Check this thread out Poker

Several of us have made our own pokers. You have to figure out how to bust up the clinkers that works best for you. We all have been getting these clinkers because of the changes in weather it seems.
Also check out Damn Clinkers

Lou,
are you stirring while poking,if so only push down on the top of the bed.You can level off top just don't mix the ash with the hot coals,that will make klinkers.
I have found out I shake,poke/push down/level off/load witch works for me.
When I poke or push down it feels tacky or sticky,just don't mix the bottom ashes with the hot coal
You might be burning too hot
Maybe try to clean klinker from underneath daily, if possible
will your grates open enough to let the clinkers drop

Hope that helps you

Thats good advise Dennis,

I have also found that its best to just poke lightly till you see a little collapse. Sometimes, a few heaping scoops of fresh coal will do the trick before shaking. Other times, I might have one on the side of the pot that I need poke off. It's best not to try and get them all at the same time after a hot burn. Too much and you go past the point of return, then it takes 2 hours to get the stove back to high temps (even after shaking the crap out of it). Best to check and tap on each load pre shake, and get a good shake out. That way they don't build up to the point of a hassle. It's a bit art and science and everyones stove and set-up are individual, but once you get that feel (Stove Whisperer) Your good to go.

Hey partner, I have a similar firebox, long with the V shape - probably same grate system. I made a tool out of bracing material to deal with the clinker issue. I took several pictures to show you. The smaller end I twisted into a 90 degree angle. This is the end that I push up from underneath between the grate and the grate frame. I thrust it back and forth (front to back) to bust clinkers into small peices that will shake down thru the grates. It seems to be working very well for me so far! I've been running the same fire for over 3 weeks now. Maybe you could try something like this. I hope this helps

Thanks for the pics: Lightning! Based on responses, it appears I need to try working the clinkers from the bottom. Another learning assignment. it is worth it. Still cozy here at 70 degrees.

You say you got a similar firebox? What is the brand and model? Just curious. Thanks. LOU

I have a very different stove and grates than you do lou, but I have had simmilar though less severe cases of clinkers and ash buildup trying to smother the fire.
So far (knock on wood) I have always been able to get the fire breathing right again.

If the fire is dieing around the edges I poke down around the edge of the fire box only. Work the poker up and down, but don't stir it around.

If the fire is dieing all over I "rake the grates", that is use an el shaped poker rod with about 4 inches of rod on the el part. Open the ash door and poke up thru the openings in the grate and work the rod up and down and around to break up the clinkers and dislodge any compacted ash. Then shake the rod back and forth and the ash will fall down thru the grates. Then follow up with another shake down of the grates in the usual way.

If you attack the ash/clinker buildup before the fire dies too low, you can do both of the above operations without killing the fire you have left. I occationaly do both operations just to clean the stove out good.

LudlowLou wrote:Thanks for the pics: Lightning! Based on responses, it appears I need to try working the clinkers from the bottom. Another learning assignment. it is worth it. Still cozy here at 70 degrees.

You say you got a similar firebox? What is the brand and model? Just curious. Thanks. LOU

Yer Welcome partner! I just finished grinding clinkers with my "Slicer". As soon as I thrust it back and forth a few times I get a more intense orange glow radiating downward thru the grates as fresh air is able to easily climb up thru the coal bed. I use it every time I shake the grates.

My furnace is a Clayton 1537G. I believe the newer version is called a HotBlast by US Stove Company. I was passing messages with a guy with a Vogelzon. He actually made a grate for his furnace. He had pictures of the grate that came with his furnace and we decided they are most likely the same.

Well, I have a different method of dealing with klinkers. Being an old blacksmith, I learned coal burning in a coal forge. There you had no choice but to clean the fire of klinker pulling it up from the bottom and taking it out the top of the fire. I have three tools I use, a coal rake, a straight poker and a pair of tongs.

It takes practice to spot and remove klinkers, but once you master it, you can get a perfectly clean fire if you want to... I get klinkers when I'm running hot like in this cold spell. I've actually pulled out some huge ones lately...

Take the straight poker and reach into the bottom of the fire. I can feel the klinkers, when they are hot, they feel "sticky" sort of like taffy. Then I get the poker under them and bring them to the top of the fire. Once they are coming up, you can see them They tend to look "hotter" than the burning coal with dark fine edges. Then I grab them with the tongs and take them out. It gets a little tricky to bring them to the top without breaking them up into small pieces. Big ones I can get up close to the top but they will break into smaller pieces, maybe two or three chunks. I do this through the whole fire pot feeling for clinkers and then pulling them to the top of the fire, using the tongs to pull them out. Then I take the coal rake and re-make the fire so it burns well.

The tricks are learning how to feel them, bring them to the top of the fire in mostly one piece and knowing what they look like in a glowing bed of burning coal...

dj

A CLINKER is melted ash. If you are burning coal hot enough to reach the Ash Fusion Temperature [AFT], then if there is any compression of the coal bed, then the melted ash fuses together into a lump or clump.

The V-shaped fireboxes are very bad at forming clinkers because the sloped sides of the firebox act like a funnel to concentrate the ash at the center on top of the central shaker grate.. So as the hot fire burns, and the coal is reduced to ash, the weight of the coal above forces then ash down the narrowing firebox, and the ash is jammed together forming the clinkers covering the grate, blocking the oxygen to the fire.

I used to use a poker and pull clinkers out from under the burning coal. but sometimes the clinker broke and was in too many pieces and I'd just have to let the fire go out, clean it out and start over again.

With a fresh bed of coal, the heat output of the fire was restored again for a few days. I rarely got more than 5-6 days without having to clean out the firebox.

Greg L

LsFarm wrote:A CLINKER is melted ash. If you are burning coal hot enough to reach the Ash Fusion Temperature [AFT], then if there is any compression of the coal bed, then the melted ash fuses together into a lump or clump.

The V-shaped fireboxes are very bad at forming clinkers because the sloped sides of the firebox act like a funnel to concentrate the ash at the center on top of the central shaker grate.. So as the hot fire burns, and the coal is reduced to ash, the weight of the coal above forces then ash down the narrowing firebox, and the ash is jammed together forming the clinkers covering the grate, blocking the oxygen to the fire.

I used to use a poker and pull clinkers out from under the burning coal. but sometimes the clinker broke and was in too many pieces and I'd just have to let the fire go out, clean it out and start over again.

With a fresh bed of coal, the heat output of the fire was restored again for a few days. I rarely got more than 5-6 days without having to clean out the firebox.

Greg L

Greg this is usually the problem I have. I have found a way to not have to dump the fire but it's not 100% perfect. I left the coals almost burn out when it gets to the bottom where it's almost all ash and then I throw fat lighter wood on the coals and then I put a log on there and let it get burning after I have some wood ash I bust up the clinkers as best as I can from bottom and top. It restores a good heating fire again but it's probably just as easy to dump the stove. The only thing it saves me on is less ash being airborne and with the newborn I have started to be extra cautious of dust/ash . Hopefully the base heater I buy will solve most of these issues.

If you are looking for a baseheater, try to buy one with the rotating rows of three sided grates, that often are geared together. they will grind up coarse ash and small clinkers. I also think that most baseheaters will not have to be pushed as hard [run at high temps] so you should not get many if any clinkers.

I used to keep a pair of 1/4 splits, some paper next to the Big Bertha hand fed. if when fishing for clinkers, I ended up with no fire, like you, if there was any heat in the fire remaining, I just put down the splits, making a 4" wide corridor, put in several crumpled up pieces of paper, and I almost couldn't get that done before the heat caught the wood on fire, once it was burning well, I'd add coal on top and it was on it's way for a few more days.

I since that time converted 'Big Bertha' to a stoker with an IRON Fireman, and now I'm using a 'modern' 1950 AA260 stoker boiler. Unless I have to for some reason, I'll not go back to a hand fed.

Greg L.

*** Unless I have to for some reason, I'll not go back to a hand fed.****

Hey Greg what ever happened to that TLC 2000 you were working on.

LsFarm wrote:A CLINKER is melted ash. If you are burning coal hot enough to reach the Ash Fusion Temperature [AFT], then if there is any compression of the coal bed, then the melted ash fuses together into a lump or clump.

The V-shaped fireboxes are very bad at forming clinkers because the sloped sides of the firebox act like a funnel to concentrate the ash at the center on top of the central shaker grate.. So as the hot fire burns, and the coal is reduced to ash, the weight of the coal above forces then ash down the narrowing firebox, and the ash is jammed together forming the clinkers covering the grate, blocking the oxygen to the fire.

I used to use a poker and pull clinkers out from under the burning coal. but sometimes the clinker broke and was in too many pieces and I'd just have to let the fire go out, clean it out and start over again.

With a fresh bed of coal, the heat output of the fire was restored again for a few days. I rarely got more than 5-6 days without having to clean out the firebox.

Greg L

I don't have problems with my fire going out particularly. Rather I notice that the heat output isn't what I would expect as the clinkers take up space, suck out the heat and there is less space for good burning coal in the fire pot. But that's probably just the design of my stove. I can certainly see how the geometry you describe could result in loosing the fire. As far as having to let the fire go out to clean it, well, I've never met a stove yet I couldn't clean the clinkers out of and keep it going... One thing is learning your stove. It seems to me that each stove has it's preferred locations for forming clinkers. Once you get that figured out, then you have to figure out how to coax them to the top of the fire to get them out without them breaking up too much. You didn't mention using tongs, you got to have tongs to clean these out...

dj