jackpine said:
Ah, Yes! - an extended burn... that is an art that hand fired stove owners aspire to. I typically obtain 6 to 7 hours burn... burn being wood fuel with visible flame and another 2 hours of coal output with stovepipe temperature at about 250 - 300 degrees.
Here, the 'usable heat' burn times are anywhere from 2-5 hours with (internal) flue temps of 400*-500*... depending on outdoor temperatures and indoor demand.
The overall volume of my D-16 has been reduced considerably by the addition of a ring of firebrick splits lining the cast (lower) firebox. (Sometime, I should try to make a meaningful estimate of the actual firebox volume now in use.)
I'm guessing that the burn time you quote as typical is on a (chock) full load, a good bed of coals, large, close packed hardwood splits and draft controls fairly 'tight'.
Elsewise, I'd simply have to marvel that you're able to achieve anything close to that.
I often have 'light off' coals after 10 or more hours, but a cold stove otherwise.
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Yes, my burn time average is with a fully loaded stove, high and tight on a good bed of coals. Interestingly, I read in one of the threads here that you stated the cylinder stove was designed to burn the wood vertically. I have discussed this point with other cylinder stove owners in the past and there does not seem to be a definitive conclusion... vertical or horizontal fuel placement. If interested, I can tell you what I do know and researched on the subject.
But, anyway I achieve my burn times by burning chunk wood cut no longer than 16 inches and laid in the stove horizontally and vertically. In addition, selection of wood species and fuel moisture is critical. This is the burn setup I strive for:
First of all I do not want a grate top free from ashes. One to one and one-half inch depth of ashes is about right and on top of that I want a good bed of coals. The first layer of fuel is chunk wood laid in firebox horizontal and smaller pieces of fuel are tucked in here and there. Depending on the diameter of the first layer of chunk wood, I may lay in another horizontal layer of chunk wood to bring the fuel height half way up the first door. Then open both doors and insert fuel wood vertically. This maximizes the fuel load. If you continue to layer the fuel horizontally, fuel depth in the stove is limited to height of the top door opening.
Second, fuel species is considered. Horizontal pieces are most generally Red or White oak and elm. The vertical fuel is Black locust, Pignut or Shagbark hickory. Shagbark is preferred because of the high volume of coal that it produces. At times I will insert high moisture fuel (not green) as the top layer.
Stovepipe damper is open, ash pit draft is closed and hot blast draft in the lower feed door is open to ignite the lower fuel. When stovepipe thermometer reaches 450 to 500 degrees, feed door draft is closed and stovepipe damper is closed to two-thirds or completely shut.
Jackpine
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