The wood for these two batches was completely dry and the process was correspondingly successful and efficient. The first batch was mixed split cedar and spruce from shop projects, and the second was mainly split spruce construction scraps. The burns were so efficient that there was time to complete two in one day, including the required cooling down time between the first and second batch.
Even softwood charcoal has a nice clear ring to it when properly cooked. Dropping or tapping it is one way to evaluate the quality and burn properties. Once the charcoal is completely cool, it must be chopped by hand into smaller uniform pieces for use in the forge.
For the sake of research, we added a couple of scraps of different wood to the retort this time. The wood is relatively easy to identify as it retains its original appearance and grain pattern. The hardwoods didn’t seem to take any longer to undergo pyrolysis and we are considering experimenting with the production of some artists’ charcoal in future batches.
Right to left, softest to hardest; cedar, spruce, cottonwood, and oak:
The heat shield has served well, but already after six batches it has almost burnt out and the bottom of the inner retort chamber is also oxidizing heavily. We will likely need to change the inner 16 or 20 gal. drums every few months at this rate and the shield every month or two.
Bottom of retort chamber with heat shield removed:
Oxide flakes from the heat shield collecting in the bottom of the combustion chamber:
< Some of the cedar was from recent driftwood projects here and thanks to Jim from around the corner for the spruce wood scraps for today's runs.
Read more about the charcoal making process and why we do it: How Charcoal is Made
Read some background information on fuel alternatives: Sustainable ‘Smithing?
Find out about the construction and operation of our new and improved charcoal kiln: Charcoal Kiln V.3
Follow the charcoal making progress: All posts tagged Charcoal