Fuel

I use almost exclusively coal, though sometimes I’ll burn some charcoal.

I’m not an expert on coal, but I have learned that there are 3 basic grades of coal: Lignite, Bituminous ands Anthracite. Lignite is the dirtiest and has the lowest energy content. Bituminous is mid-grade and Anthracite is the hardest, cleanest burning and most energy dense.

Most blacksmithing is done with bituminous coal. I had worked with anthracite that I picked up on the roadside in West Virginia and it burned wonderfully in my forge so I wondered why it isn’t used more often for blacksmithing. So I finally, after years of wondering, ask Mr and Mrs Google and found out that it’s more expensive. That seems to be the main reason. I wasn’t aware of that because I never buy coal.

Most of the coal that I scavenge is bituminous and every batch of bituminous coal that I get burns a little differently. It cokes up differently and produces different amounts and types of clinker.

When you blacksmith with bituminous coal, the fire is actually a coke fire and you’re turning coal into coke as you work. Coke is to coal as charcoal is to wood. Charcoal is wood that’s burned without flames and oxygen – just heat. If flames and oxygen get to the wood, you have ashes instead of charcoal. Coal that is piled up around the coke fire, out of the air blast from the blower, will turn to coke from the heat. If it gets air, it turns to ashes and cinders instead of coke.

Clinker is a glassy substance formed from impurities in the coal. I once got about 4 tons of coal from a coal cellar in an old house. The cellar was partitioned with a plywood wall. All the coal looked the same but the coal from one section produced probably 3 times as much clinker as that from the other section. I can tell which section I’m using coal from by the amount of clinker that forms.