While our forges work well with raw wood, some people like to use charcoal as a fuel as well. Charcoal is lighter for transporting. It gets hotter faster than waiting for wood to burn down to coals and is especially handy for forge welding and casting. It's also great for cooking over!
Many methods of charcoal making have been used over the years, ranging from burying wood in pits to complex retort arrangements. We've tried many of these and found them cumbersome. Having to commit to pile for a long period of time, or drag fuel to a central burner is inconvenient.
We found our solution in an easy adaptation to the typical 55 gallon drum burn barrel.
Normally a burn barrel has holes drilled near the bottom to allow air in to feed the fire. In the Whitlox Charcoal Maker design, the barrel is left solid so all air is supplied from the top and instead the barrel is tipped to 60 degrees. This creates a natural draft, as hot air rushes along the upper surface, pulling fresh air in the lower lip of the barrel.
Begin by getting a hot fire going in the bottom of the barrel. We have made a removeable ledge to make this easier, but it is possible without this tool also.
When the starter fire has burned down to coals, add a moderate layer of wood. The right amount to add will vary by the size and water content of your fuel, but you will be able to gauge the amount by watching for smoke. If the fire smokes, that's too much fuel at once. The burning of the new fuel creates a flame cap that preserves the charcoal below it by consuming the supply of oxygen before it can go down and completely oxidize the charcoal accumulating on the bottom of the barrel.
If you need to interrupt your charcoal making session, stand the barrel up and put a lid on it. This will stop the burning and preserve the charcoal. Otherwise, continue adding fuel until the barrel is about 60% full of charcoal before standing up and putting a lid on it.
You can make charcoal with hard or soft woods. You'll find it is useful not just as forge fuel, but can also be great for the BBQ and as a garden amendment.