New Participant; First Post/Soot buildup on chimney cap.

Very pleased to have found this forum. This is my first time here so your advice and tips on using this site are welcomed. I live in N.W. Ohio and just installed a new-old stock Lopi combination stove. I lined my chimney with 6" stainless 22ga. A friend helped me built a nice chimney cap to cover clay flue tiles on chimney top. In just a month the 1/2" diamond mesh is completely plogged. I notice this when the smoke could not exit the cap and began pushing its way down the other flue that goes to the basement fireplace 35 feet below! I will try to attach pic of the cap we built. Does this mean I need to use a larger mesh pattern or no mesh at all? This bituminus coal has been secured for free from local sources. Not sure of origin, but most is nut size and not very shiny. If I have to use a large mesh, then what about bats and birds; my whole reason for the mesh. Thank you for your help. I love getting, handling, working with and burning coal - especially when it's free. Dan (I can't understand how to post my photo)

Dont worry about bats and birds, they tend to move out once you establish a decent fire. I would lose the mesh as there is just to much junk in Bituminous smoke.
I would shop around for coal as Bituminous has a very extreme quality variance, a little change may make a big differance.

lose the cap/mesh, it's nothing but a soot catcher. why did you reline your chimney with a 6" liner for burning bituminous, that is quite small, you will likely clog it up quickly as well as experience poor drafts. even if the clay tiles were cracked or deteriorating, for burning coal, that is not much concern, providing the structure of the chimney itself was sound, in all liklyness you may have caused yourself more problems by relining.

Hello Dan, welcome to the forum. I would get rid of the mesh in the cap, if you are concerned about rain getting down the chimney, then keep a cap on the liner.

The liner you used.... is it a smooth pipe or a corrugated, expandable tube?? If you used the corrugated tube, I believe you will have lots of soot build-up inside the liner. The smooth pipe will be better, but bituminous soot will stick to just about anything.

To reduce the soot as much as possible, you may need to add heated secondary air to your firebox. Take a look at Berlin's plans on the how-to thread here in the forum. He has air passageways going through or over the firebox, heating the air in the tubes, then the hot air is exhausted just above the coal fire.

Bituminous coal creates it's soot during the intial burn of fresh coal when the volitiles are being burnt off. There is rarely enough air to burn up the large volume of volitiles and the result is soot, which is just unburnt carbon.

At Berlin's suggestion I created a heated secondary air pipe for my firebox. I was amazed at the huge blowtorch effect I saw when fresh bituminous coal was added, the hot air out of the secondary pipe lit off the smoke above the coal in a spectacular way!! This reduced the soot in my boiler and flue.

My secondary air pipe had a short life, I had made it out of regular steel tube, and it couldn't stand up to the intense heat of the coal fire. I'm planning on making another one out of stainless steel and see if it will last longer.

Can you post a photo of the firebox so we can see it's design?? Maybe we can offer a suggestion or two. I'm not familiar with that particular stove.

Hope this helps. Greg L

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Greg, I don't know what your secondary air piping looks like but cast iron would have the longest life. Where do you get cast iron piping? Since you are also a car collector how about an engine exhaust manifold? Might be just the thing.

Yanche

Thanks Yanche, that 's not a bad idea. Do you think my boiler would appreciate having a 1927 Pierce Arrow exhaust manifold adapted to this job???

That is the closest to a simple tube that I can think of. I'd have to block-off several cylinder ports..... Hmmm.

I think I'll try the SS tube first.

But a very good idea, Maybe I can find a source for cast iron tube, I do have a few sources for casting new parts from old.

Merry Christmas!

Greg L

Gentlemen; thank you all for the replies. The deeper I go into this forum, the more valuable it becomes. A great group of guys, mature postings and lost of good information. I see I am not alone in my love for buring coal; the validation was consoling! Please allow me to respond to the questions/comments that were posed to me. I have cut out the mesh on my chimney cap and just keft the "roof" portion to keep rain out; no more soot catching. I lined my 7"x11" clay flue with a 6" stainless for three reasons; one, the exit on my stove is 6" so I thought I should keep it uniform all the way up. Two, I also burn wood in my combination stove, and my 80 year old flue did have cracks. Three, I got the pipe for free from a sheetmetal contractor I befriended. My liner is not flexible, but straight, 3' sections of heavy stainless screwed together. Your secondary air supply to the firebox sounds very interesting; I will pursue.
I am getting my coal free from a shipping terminal on Lake Erie. An operator "spills" some for me. The only coal dealer anywhere near me is charging $140/ton for Kentucky lump, and $210/ton for anthracite. At these prices, it is worth it for me and my young sons to go get a perhaps lesser quality soft Ohio coal free for the hauling. The big drawback is that this free coal is also full of small particles and dust (must be for a certain kind of furnaces?). So, I have built some large, 1/4" mesh shakers, and my boys go at it like little vibrating machines! What we are left with is coal from about 1/4" to golfball size. There are some stones too, and they are a pain in the neck in our shaker grates, so we have to pick them out as well. I will try and post some pictures. Thanks for all the thoughts and courtesy, Guys! Dan.

Two of my boys sifting coal. Dan

My 6" stainless liner. Dan

Our Lopi stove installed in front of the fireplace. Dan

Hi Dan, do you want to 'loan' me your coal sifters?? I have to sift out the fines from my bituminous too. They stick together and make a sheet of gooey-soft coal.

I burn a mix of anthracite and bituminous coal. The anthracite is much easier to work with, cleaner, less ash. Powdery ash instead of crusty, and no soot or smell.

BUT anthracite comes from the east end of Pennslyvania. And costs more than Bituminous.

If you are willing to work with the bituminous, it makes a very good heat source, just isn't as easy as anthracite.

Let us know how the chimney works with the screen removed.

Do you get your coal sticking together and 'bridging' over the fire?? Do you get stuck together ash know as Clinkers??

Take care, we are virtually neighbors, I'm about 1.5 hours north of Toledo.

Greg L

Dear Greg L.,

You certainly know a lot about burning coal; I can see myself tapping into you as a resource from time to time. Let me first answer your questions: Yes, I do get some bridging, but it has never been an issue. Sometimes I break it up and sometimes I don't. Either way, adding coal on top of it in about an hour or so, and it all burns away. Same with my clinkers; they always seem to burn away. I add wood every once in a while and that seems to help make the clinkers go away. I also have a boiler and the old 1920's radiators in my house, but I would love to add on a coal unit someday. Had a chance to buy a nice Kodiak boiler for $500 from a man I know in Marblehead, but I let it get away. My house is about 80 years old and I must be the only guy around who actually uses his coal bin for coal; most neighbors have had the doors replaced with glass blocks. I live in a great neighborhood and my buddies all tell me they can smell my coal. It aggrivates a few liberals, but that is a good thing. I was raised in the country and really miss farm life, but I just couldn't afford a place with a barn and a few acres. For now, this place is fine and we are close to school, church, pediatrician, grocery, etc. This coal I am getting comes in on freighters on Lake Erie, and then loaded onto rail cars. It is like burm stone; ranges from dust size to golf ball. It also has stones in it. Might you know what kind of plants have furnaces that handle this grade of coal? It is a pain in the neck, but hey, it's been free. Thanks, and talk to you soon. Dan

Hi Dan, I suspect that coal is used at an electricity generation plant. Most coal burning generating plants burn Bituminous. The coal is ground to a fine dust and blown into the burner area into an existing oil or natural gas flame. The mixture of powdered coal and air burns like a blowtorch with little but ash left over. That is why it is supplied in an unsized, unwashed mix, it is going to be ground to dust anyway. Anthracite is sized, washed and sold in various sizes with virtually no dust.

It sounds like you have a good method going to deal with the Bituminous coal. Since you are able to break the bridge or add wood or more coal to your firebox, the bridged coal is not an issue for you. In my firebox, it is loaded and left alone for 10-12 hours, and a strong bridge of coal will not collapse. The fire burns away under the bridge and the fire is not as hot as it should be. Anthracite coal burns as separate pieces of coal, like a pot full of red hot marbles. They don't stick together.

Is your heat system in your house a hot water or steam system??

I only know what I know about burning coal from an interesting path I took to heating my house, I had to learn a lot very quickly. I had a great deal of help from this forum.

I really enjoy learning and then sharing what I've learned. I strive to help others figure out how to burn the different coals in less-than-optimum stove designs like I had to. Hopefully I can make the path not as steep or difficult as mine was.


Take care, Greg L

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Greg,

My boiler is hot water and works very nicely. It must be about 15 years old; was the first replacement for the original coal boiler. This old unit was converted to gas in the 60's but gone before we bought the house. I am posting a few pics of a boiler that was probably identical to the old one that was in my house. The boiler in the pics is just a few blocks from me, and it also is converted to natural gas. If the owner decides to replace it, I asked him to let me know. Have you ever heard of anyone putting an 80 year old boiler back into service as a coal burner? It seems to be in very good shape. Do you think I should take it if I can get it? The shroud of insulation is that plaster/asbestos mix, just like what is on all the pipes throughout my house. Of course, one needs to be careful with such material, but I'm not one to get hysterical over it. Thanks, Dan.

I would seriously consider putting it into service in your house, but probably it would be best if it ran as a supplement to your existing boiler. This way you would still have the natural gas fired newer unit as the backup, and for when you are away from the house for several days.

You will have to find a creative heating contractor or do it yourself. Most plumbing/heating guys wouldn't be willing to work with an old boiler.

Working with the asbestos requires a few precautions. Most are very 'common-sense'. But the main caution would be to be extra carefull with all your kids around, it seems that exposure to asbestos is more dangerous to children than to adults. I don't remember where I read that.

Was that old boiler a hand feed unit or was it a stoker feed?? If it was a hand feed, you probably would have only minor modifications to put it back into service. Maybe the shaker grates are still around?? If it was stoker fed, is the stoker hiding in a corner somewhere??? That would be a real find!!

Take care, Greg L

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