Anthracite vs. stoker coal

[bkstabler]

Prior to this evening, I've only used hardwood charcoal in my forge for heat treating. But I just bought 2 bags of coal while on vacation in VA (1 bag of anthracite, and 1 bag of stoker coal). Anyone know which burns hotter? Used stoker for first try, and it took forever to get to non-mag. Even hardwood charcoal gets me to non-mag faster than the stoker did. Anyone know if I'll have better luck with the anthracite? Btw, I'm using a forge I made from a brake drum, black iron pipe, and a hairdryer w/heating element removed

 

[Stacy E. Apelt - Bladesmith]

Stoker coal is just a term for a certain size of lump for the bag. It works with automatic coal stoker furnaces.

Anthracite is "Hard" coal, and has more carbon in it. It burns hot. It is for coal stoves and fire places.

The coal that you really want is Pocahontas #3 blacksmith coal. It is a low volatile bituminous coal with small lump size ( almost like gravel).

You can break up the anthracite into little pieces and try it, but it won't be the same.

Also, your forge may have too small of a blower. Hopefully you have some sort of air control damper. Have you been shown how to build a coal/charcoal fire in it by someone who does this regularly?
It isn't like making the fire for a BBQ.

 

[bkstabler]

Also, your forge may have too small of a blower. Hopefully you have some sort of air control damper. Have you been shown how to build a coal/charcoal fire in it by someone who does this regularly?
It isn't like making the fire for a BBQ.

Thanks Stacy, I have no clue how to build the fire. I basically just got a small bed of hardwood charcoal nice and hot, then covered it with the stoker coal, and then turned the hairdryer on high. Looks like white hot dragons breath when it gets going

 

[elementfe]

BK, it doesn't matter how you start it- I use either a handful of twigs or a plumber's propane torch.
Any coal will build up clinker (unlike charcoal) which is a pasty residue that sinks to the bottom of the firepot.
Shut the draft off for a few minutes when you notice that the air isn't getting through, and the clinker should cake up and be pretty easy to fish out of the bottom of the fire.
And heed Stacy's advice: I've used common coal and there's just nothing about it that's fun once you've used decent smithing coal...it's incredibly stinky (I actually like the smell of good coal), you can't get a good forging or welding heat out of it, and it's full of clinker to the point of taking more time to keep clean than forge.
As far as maintaining a fire, remember that what you're doing is constantly making coke out of coal, and the coke is what you're burning. You keep the hot part surrounded by fresh coal and as the smoke cooks off it you push it into the heat.
Ideal size for coal is walnut or smaller- if your chunks are bigger, smash em. Dust and grains burn fine too.

Andy

 

[bkstabler]

Thanks all, I tried the anthracite today, and got it to non-magnetic in about half the time. Definitely seemed to burn a lot hotter than the stoker coal. May have to look for that Pocahontas #3 sometime.