How Much Glazed Creosote is Too Much

[mountaineer79]

I am burning an Englander Cat Stove from the early 80s I think it's a NC24 or something. I'm burning hot with seasoned wood. The problem is I've got a 6"flue dumping into an exterior chimney with an 11 x 9 liner. My chimney's only about 14-15 feet tall, and maybe only 10 feet higher than where the flue pipe goes into it. I've lived in and been burning with this set up for about 3 years. I would like to install a 6"s.s. liner, but I don't know if there is a way to connect it to the flue pipe going into the chimney.

Most of the time I've got no smoke coming out of the chimney. I went up to take a look and clean it last weekend. There was no creosote buildup except for about 1/8" or less of the hard shiny black glazed creosote. I've read that it's flammable, so do I need to stop burning or what?

Thanks.

 

[webbie]

Well.......I'm not one to exaggerate such things, but you would be amazed at the amount of fuel that is in that 1/8" coating!

Ideally, you would eventually line the chimney, which should be easy using a TEE with a removable snout, etc.
However, you don't want to line it with that coating in there. I have two pieces of initial advise:

1. Make sure the whole installation is very tight so if you do ignite the creosote, you can cut most of the air back to it. This means no loose cleanout doors, furnace cement between your pipes, etc.
2. Use some of the anti-creosote sprays and powders on a regular basis - they tend to make that tar coating into a brown and softer materials which can more easily be brushed off.

 

[mountaineer79]

Oh yeah. The top of my chimney is not even close to being 2 feet higher than anything within 10 feet of it. Amazingly I still get a pretty good draft with all these design flaws.

 

[billkline]

Mountaineer,
Sounds like you don't have nearly as bad a creosote buildup as you might if you choked that stove down a little bit. A stove with a 6" outlet would work a lot better with a 6" liner in the chimney. If I were to line your chimney with a 6" stainless liner, I'd remove your glazed flue tiles to give me room for a round pipe with 1/2 inch ceramic blanket insulation. Now in my area, the interior dimension of a small rectangle liner is between 6.5" and 7" by 10.5" to 11.5" so getting an insulated round 6 down it is not possible. Removing it also gets rid of that 1/8" of glaze. We would put a Tee at the bottom to connect your stove. We would also recommend investing in an EPA Certified stove.

Your 1/8 inch of creosote glaze would burn, and produce sufficient heat to crack your flue tiles. Would it burn your house down? Probably not, but if there is a defect, it could!

 

[mountaineer79]

So I would hook the tee on the bottom of the liner, then force it down the chimney, ,try to line it up with the 6"flue pipe that's stubbed into the chimney, and then try to push the 6"flue pipe in and connect it to that tee? It seems pretty difficult to do. Why do I want a tee and not a 90. The flue pipe goes into the chimney horizontally. I'm pretty sure that the stove is EPA certified, but I guess there's a big difference between 80s and 00s EPA.

 

[mountaineer79]

Also how do you remove clay tiles that are encased in a brick chimney?

 

[billkline]

I invented the tool that most of the chimney sweeps in America use to break tiles out of a chimney. It is basically a spinning hammer that breaks it up in little pieces and we take them out at the bottom. If your chimney doesn't have a cleanout door, we might have to make one. Or we might have to break out the thimble and make a hole big enough to get the tile pieces out, then put it all back together again. We would raise your brick till it met the 3'2'10' rule. With the tiles out, a 6"insulated flex liner with a removable-snout Tee would go down the chimney a lot easier than an elbow would.
Why else would you want a Tee instead of an elbow? Mainly because an elbow would get plugged with fallen creosote before the season was half done. A Tee will hold 6 times as much stuff before it gets as restricted as a clean elbow.

A stove built anytime before 1990 is not EPA Certified. As a general rule, you can count on a EPA stove to produce about twice as much heat per piece of wood you burn in it. Old stoves were wood gasifiers, but sent most of the wood gas up the chimney unburned. New stoves burn nearly all the wood gas. Depending on the wood, the gas accounts for 60% to 80% of the available fuel.

And Pyro, The last time I read it, which was a while back, the book I read said creosote produced a little more heat per pound than Anthracite Coal, or about 14,000 BTU/lb

 

[mountaineer79]

Does anyone have a recommendation on what kind of creosote spray/powder I should use? I plan on installing a liner this summer. I just wasn't sure if it was possible. I'm still not sure about how to get the tee to connect to the flue pipe with the connection point hidden inside the chimney.

If I am able to install a liner, I guess it would need to be brushed periodically and also pulled up so that the creosote could be removed from the bottom of the tee. Also, is an insulated liner necessary?

CZARCAR - Anthracite coal has a density of 50-58 lb/ft3. I guess that means that I have 230,000 to 270,000 Btu waiting to burn in my chimney.

 

[Shari]

I guess that means that I have 230,000 to 270,000 Btu waiting to burn in my chimney.

That sounds like a pretty good fire!

Shari

 

[Metal]

You need a tee with a long removable snout like in the picture. You fasten the body of the tee to the liner and slide it down the chimney, then from inside the house you can attach the snout (the screw part of the gear clamp is inside the pipe so you can tighten it down from inside). Then just attach your stove or pipe to the tee. I hope this makes sense.

 

[pgmr]

A stove built anytime before 1990 is not EPA Certified. As a general rule, you can count on a EPA stove to produce about twice as much heat per piece of wood you burn in it. Old stoves were wood gasifiers, but sent most of the wood gas up the chimney unburned. New stoves burn nearly all the wood gas. Depending on the wood, the gas accounts for 60% to 80% of the available fuel.

The OP said he has a cat stove, which, if functioning and used properly, should be giving him performance pretty close to a current cat stove.

 

[billkline]

I am not familiar with the model of stove he named. We have mostly Buck-styled fireplace inserts around here. But cat stoves came on the market about '83-'84. I had a Concorde Catalytic, the first production model cat stove. Probably got it in 82. Replaced it with a Consolidated Dutchwest in '85. Replaced that with an Osburn 1600 in '90. Still heat my house with an Osburn 1600.

My first stove was a cabinet model Coal Chief. I bout the coal model so I could burn some of that creosote I was chipping out of people's chimneys, LOTS of FREE Fuel!! I had about half a big grocery bag, (paper back then) filled with sticky creosote. Weighed it on the bathroom scales, and it was about 20 lbs. I stuck the whole thing in on a bed of hot coals, and closed the door. It kept my house warm from 8am till 5pm, on a day when the temp didn't get above freezing. It was great fuel, except for one problem. It was the stinkingest stuff I ever burned. It just smelled AWFUL!! So, we didn't burn any more of it.

The best products I've seen to break down creosote is ACS. Anti-Creo-Soot. Used to be made by Combustion Improvers, Inc, but they sold it to someone recently. I don't remember who. None of them work very well in an exterior oversized chimney. and if you have a properly sized interior or insulated chimney, you won't need them.

 

[mountaineer79]

You need a tee with a long removable snout like in the picture. You fasten the body of the tee to the liner and slide it down the chimney, then from inside the house you can attach the snout (the screw part of the gear clamp is inside the pipe so you can tighten it down from inside). Then just attach your stove or pipe to the tee. I hope this makes sense.

The problem with this fitting is that I only have 6.5" to 7" of space in my chimney. I don't know if I could get this fitting down the chimney even if the snout is removable.

 

[mountaineer79]

I took a look down my chimney Friday afternoon. I actually only have a light glaze of creosote on the 2-2ft sections of tile below the top section. The top section just has a thin layer of flaky creosote. I checked my catalytic element around September, and it looked like it was in good shape.

 

[Shari]

You need a tee with a long removable snout like in the picture. You fasten the body of the tee to the liner and slide it down the chimney, then from inside the house you can attach the snout (the screw part of the gear clamp is inside the pipe so you can tighten it down from inside). Then just attach your stove or pipe to the tee. I hope this makes sense.

The problem with this fitting is that I only have 6.5" to 7" of space in my chimney. I don't know if I could get this fitting down the chimney even if the snout is removable.

Disconnet your liner from the chimney cap, slide the liner down to the firebox, connect the TEE, push liner back up and reconnect with chimney cap.

Shari