PostBy: DOUG On: Sat Jul 19, 2008 7:05 pm

I have experimented burning a variety of hard woods, bituminous "Pittsburgh Lump Coal," and anthracite in "Stove, Nut, and Buckwheat" from both Blackshack and Reading Coal. The Clayton 1600 has a 6 inch flue that I hooked up to a 7 inch 37 foot stainless steel lined chimney located in the center of the house. I set the barometric draft regulator fairly high at .07 inches of water. The reason is I like to be able to throttle back the stove when burning wood and have the capability to burn my favorite Reading Anthracite Buckwheat Coal, which needs a strong draft to get the air through that small coal. The Clayton burns for about 4 to 10 hours on a full load of wood depending on the demand for heat. It burns down to a fine powdery ash and I have to empty the ash drawer every 3 to 5 days. When burning bituminous coal, the Clayton burns for about 8 to 16 hours on a full load depending on the demand for heat. It burns down to fine ash and small broken up gravel sized coke and I have to empty the ash drawer 1 or 2 times a day. The Clayton burns for 12 to 20 hours on a full load of anthracite depending on the demand for heat. It burns down to fine ash and small hard sharp clinkers. I need to empty the ash drawer 1 to 2 times a day. The only problem that I have when burning coal hard with a high heat demand, especially with the buckwheat anthracite, is that after about 7 days it burns into one big clinker. I have to let the fire go out and shovel it out the feed door. I could keep it burning but I would have to load it over the fire bricks, because I can't shake it down enough. Maybe I'm pushing it too hard. All I know is that the Clayton heats the house beautifully and there insn't that big gas bill every month. If it means I have to spend an hour or so once a week to empty it out and to fire it back up, it is a good trade off to me. I'm home with the family, not working overtime to pay for the gas bill. If anyone has any suggestions on how to light a fire once a year, I'm all ears. Keep the coal fires burning!
Stove/Furnace Model: CLAYTON 1600

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PostBy: LsFarm On: Sat Jul 19, 2008 8:25 pm

Hi Doug, what you are experiencing with your Clayton with the formation of a big sheet of clinker is the result of your firebox design.. The sloped firebrick sides act like a funnel.. and as the coal burns down and the ash drops through the grate into the ashpan, the very hot pieces of burning coal and ash get funneled together, jammed together while they are HOT, near the temperature where the ash is molten [ash fusion temperature, or AFT] and the pieces of ash fuse togther into a big clinker.. have you noticed that some parts of the clinker look like molten glass?

There is nothing that can be done except maybe redesign the firebrick mounting on the sides so that the bricks are vertical or near vertical.. There is another Clayton owner that found some specialzed firebrick and reshaped his firebox for better antracite burning.

If you look at any of the made-to-burn-coal stoves, like the Harman Mark series, or the Harman SF250, A Harman TLC2000, a handfired Alaska or Keystoker, or a Harman SF 160-260-360, or a Hitzer stove, you will find that the firebrick are vertical.. and the entire floor of the firebox is composed of several grates to grind up any small clnkers.

The Clayton is the best at burning coal of all of the US Stove Co. wood/coal appliances,, but all of them are really meant to burn wood, which doesn't need the square sided firebox,, and then 'also burn coal'.. the word coal was added to the name/description for marketing,, but unfortunately it does have some quirks and problems when buring coal.. You have discovered some of these quirks..

You may have better luck with burning nut size coal, and shaking it less, let the powdery ash around the hot coals insulate them from each other,, keeping them from fusing together. And try burning the stove at a lower heat level, this may keep the clinkers smaller, less of a problem..

As for lighting a single fire for the whole season,, I really do't think you can with that firebox design, unless you can cure your clinker problem. I had to shut down my 'Big Bertha' stove which has a similar fiebox design every week to remove the clinker that blocked the grates..

It's good to hear that your Clayton burns well, often the US Stove products have problems with the fire going out, or poor heat output.. At least you have the best of the US Stove products.. the 'hot blast' and a few others are pretty problematic for the owners.

Greg L.
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland