Making Charcoal

Materials and equipment to make the charcoal ‘kiln’

50 Gallon oil drum

Angle Grinder¾ -1″ Cold Chisel.

Metal file

Stout leather gloves

A bucket of sand

Matches

Make sure the oil drum is empty of all liquid before working with it. It helps to set a fire in the oil drum to burn off any waste but this is very smoky, smelly and generally unhealthy and should only be done well aware from residential areas!

Preparing the top

· The base of the oil drum will become the top of the charcoal kiln
· Use the angle grinder to cut off the base of the oil drum. Cut from the top and inside of the metal rim. You need to leave two protruding shelves on the rim. Later these will be used to support the lid.
· Wearing the leather gloves use the file to remove all the ragged edge left from the angle grinding on the drum and the cut section.

Preparing the base

· On the underside of the drum (ie the former top) use the cold chisel to punch five or so holes as shown in addition to the oil drum outlet hole.

Making Charcoal

· Stand the drum on three bricks and seal the base with soil and turf except for an air inlet of 6-9inches diameter.
· Stand a post up the middle of the oil drum and then tightly pack round with 2-5cm thick wood.

· Pull out the vertical post and drop down a lighted firelighter, cover with more sticks and let the wood catch fire.
· Once the fire is established put the cut-off section on as a lid supported by the two shelves left on the oil drum.

· Seal the rim with sand, yes it has to be as this forms a good seal. You will notice that there are two holes left. These are the chimneys to allow the smoke to get out.
· Thick white smoke will appear first but as the water and other material is steamed off the smoke after about three hours will change to a blue haze, which is the charcoal beginning to burn. At this point close all the air inlet/outlets and leave to stand overnight.

Problems to watch out for

More ash than charcoal: Too much air got in during the burn so the wood burnt rather than heated up. Reduce the air inlet next time and pack the turfs around the base more tightly. Did you use sand? If not use it!

Mainly inadequately charred wood (Brown ends) rather than charcoal: The burn did not get hot enough. Make sure the fire has really got established at the start before putting the lid on. Also may be not enough air got in and the air inlet at the base may need to be made larger. Sometime the wood gets suspended in the kiln and gets out of contact with the burn. A few taps on the side helps to avoid this. Save the brown ends for starting the next burn.

 

Historically, production of wood charcoal in districts where there is an abundance of wood dates back to a very ancient period, and generally consists of piling billets of wood on their ends so as to form a conical pile, openings being left at the bottom to admit air, with a central shaft to serve as a flue. The whole pile is covered with turf or moistened clay. The firing is begun at the bottom of the flue, and gradually spreads outwards and upwards. The success of the operation depends upon the rate of the combustion. Under average conditions, 100 parts of wood yield about 60 parts by volume, or 25 parts by weight, of charcoal; small scale production on the spot often yields only about 50%, large scale was efficient to about 90% even by the seventeenth century. The operation is so delicate that it was generally left to colliers (professional charcoal burners).

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