coldcoal wrote:Titleist, ok so that picture is a big help, here's why and maybe where some over firing comes into play for me. I see no red at all there, or space with flames coming up so I'm now confused. I read here by our fellow folks to do a layer at a time in filling and make sure u leave fire coming through. Now they might have meant from scratch fire, but I'm still doing this always. This makes for at least a 1 hour process with the ash door open as the layers slowly build, and a fiery finale once fully loaded. Your pic negates all this, looks like you put 5 inches on top of red instead of slow building. So there's that.
Coalbed (notice how I changed your handle
), I think you may be confusing two different reasons to layer. Layering is especially important as you're trying to build a healthy coalbed, but is less critical once you have established a good bed. A healthy coalbed, in my opinion, is one where, even after shakedown, you still have at least several inches of healthy red coals throughout the entire firebox
, not just in the center. At that point, you can load as many inches of fresh coal on as you'd like. You won't smother the fire--remember, the coalbed really burns from below, where the fresh air from the ashpan door/vents enters the stove and first meets the coalbed, not from the top. As long as you give it plenty of air, it doesn't matter how many inches of new coal are piled on top of the burn zone, that fire will eventually spread all the way to the top coals. Another way to say this is that your stove can still produce good heat even with many inches of green coal still on the top of the coalbed.
So, why do some people still layer upon reloading, even with a healthy coalbed? And why do others say to just leave some red coals uncovered while reloading until the new coal starts to burn? There is no discepancy here--just different styles/techniques/habits. The purpose of layering a reload, or of maintaining a small patch of active fire uncovered with fresh coal, both have the same purpose: to prevent the collection, and subsequent explosion, of volatile coal gases being released from the new coal as it is heated. This is known as a puffback and is to be avoided if possible--if it happens, you will
be changing your underwear, but the cat will beat you to your bedroom and will be under the bed. The cat will go nowhere near the stove, and possibly remain completely hidden from view, for a week or more. Both techniques-- layering during reload and maintaining an area of open fire on reload--prevent the sudden coming-together of all the necessary and sufficient conditions for an explosion: an enclosed or concentrated collection of flammable gas, oxygen, and ignition. Preventing any of the three condtions prevents the explosion (although obviously it defeats the purpose to completely prevent ignition, since the object is to get the coal to burn).
Since he filled up completely at once and didn't layer or leave open an area of active fire, Titleist's technique of filling the stove completely sets up some
of the "right" pre-conditions for a puffback. However, he likely does something else in his technique to prevent actual explosions. This might involve a very high drafting chimney and leaving a manual damper open that prevents accumulation/concentration of volatile gases; or maybe he leaves the fill door open or an over-the-fire vent open to burn the gases as they are released. The point is that his technique works for him in his setup; but the general rule about layering reloads, or maintaining a small area of active fire, is a good one to minimize puffback risk. I generally load full except for a 3-4 inch diameter open area, and fill that area when I have flames in most of the firebox. Enough oxygen comes thru that opening to ensure that the volatile gases can burn as they are released. In addition, there is a constant source of ignition, rather than the sudden emergence of one.
Whatever your technique with reloading, you will find something that will be effectively free of puffback risk that won't take an hour of your time to accomplish. Most people's stove tending time here is probably about 10 minutes twice daily, as is mine.
Happy New Year!