Methods and materials:
above except as noted.
56# of 2 yr. old hardwood (mostly hickory) air dried to about 29% EMC.
1/2" square hardened rod to hold up retort.
80_ F. light wind.
(start) lit fire with newspaper and some burnt motor oil.
(+35 min.) Outgassing starts. Added enough wood during the burn to keep
(+2 hrs 25min.) Outgassing about complete. Pulled rods to allow can bottom
to settle in coals and ashes sealing holes.
(+3 hrs 25 min.) Lifted retort can - feels light indicating a complete
burn. To ensure an oxygen-free condition and to facilitate faster cooling,
I removed the retort from the furnace barrel and placed it on dirt, pulling
dirt up around the bottom.
(+ 5 hrs.) Can cool enough to handle. Opened top and found the results of a
good burn. Volume had decreased by about 1/3 and all of the wood appeared
to have converted to charcoal.
56# of wood yielded 17 1/2# charcoal or 32% by weight. This is very good as
most direct burns result in 25% at the best. I got over 2 1/2 five gallon
buckets of good lump and only one large (4"X6") chunk showed
signs of incomplete conversion with some brown in the center.