I forged with coal for nearly four years.
Fun - but dirty.
Traditionally, blade smithing should be done with Pocohontas #3 bituminous coal. The amount of btus and sulfur content are well balanced.
I'm not sure what coal power plants use, but it may either be anthracite, which burns MUCH! hotter than bituminous, or they may be using coke, which is coal with all of the impurities burned out, which you will do during your regular forging process.
When forging with coal, and you will need a blower to keep it going, the heat can skyrocket!!
There's an old saying in blacksmithing which states that "the best thing a blacksmith can hope for is to end up with as good a piece of steel as he started out with".
Not only with coal, but propane as well, we have FAAAAAAAAAAAAAAAAAAAAAAAr more opportunities to ruin a decent piece of steel than we do to improve it.
When you use coal, those opportunities to ruin it magnify.
There is a definite learning process to using it, but it can be very rewarding.
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