[TheForge] Pocahontas Coal

Sat Apr 20 12:26:11 2002

Dave -

I wish I had my figures with me, but I've misplaced them, at least for the time
being. A recent move still has things quite disorganized.

I know I didn't have figures for Pocahontas, but I had figures for others which
I've used. Although I am a big believer in knowing the figures of what I'm
using, I've also found out that they don't necessarily mean one type of coal is
particularly better than the other when it comes to using it.
I picked up some coal from a coal yard that was different than anything I'd
used before, but it was still very useable. I could easily get to a welding
heat, but it produced more ash and less clinker than typical "blacksmithing"
coal.
Had I only looked at the figures, though, I'd have totally dismissed this coal.
Another thing I've found out is to weigh every person's opinion carefully (mine
included) when listening to recommendations of coal
Everyone has a particular way (or two) of how they like to work with coal, and
I think a lot of that comes from either their first experience with coal or
their most common experience. This is one of the reasons one guy will never use
water around his fire and another uses water almost constantly.
One coal may have a high fusibility rating, another a very low one.
One makes a clinker which is easy to pull out without it falling to pieces,
another makes clinker that falls apart very easily.

From what I've experienced, every type of coal has its own peculiarities and
its own preference for how it wants to be worked, and although two types of
coal may have totally different working characteristics, neither is really
better or worse than the other, just different.

Having said that, my experience with Cumberland Elkhorn and Pocahontas had
nothing to do with the numbers. As I said, Cumberland Elkhorn makes more smoke
(when adding green coal) than does Pocahontas. Everything else being equal, I
would definitely prefer Pocahontas over CE for that single reason.
The actual working characteristics I found virtually identical.
If they were the same price and could be purchased with equal ease, then I too
would buy Pocahontas. (Otherwise Cumberland Elkhorn wins out for price and
location in my case.)

Interestingly, neither of these is my favorite coal.
Unfortunately my favorite I have no figures for, and I'm not even sure where it
comes from, though I'm pretty sure it's a West Virginia coal.
Wherever it comes from, in my opinion it easily beats both Pocahontas and CE.
Only problem with it, though, is that it cokes up into such a solid mass, I
have to remember to keep up with breaking coke off the walls. Otherwise I end
up with two solid walls that are so tight, trying to break pieces off the walls
does nothing more than completely destroying the fire.
I like to use some water on my fire, but I don't want to be constantly reaching
for the dipper either, so I look for a coal that works best with a certain
amount of water. I also have a preference for a clinker that stays together, so
those are the things I look for more than anything else.
Yes, the numbers are important, but they only tell part of the story.

I wish I had my numbers handy, because I could swear the figures given to me
make a little more sense when it comes to adding up to, or close to, 100%. I
know your figures differ from mine, because mine always include a figure for
ash content and yours don't. I'm also pretty sure my figures have the Carbon
rated as free Carbon, and the amount of free carbon measured is separate from
any carbon tied up in volatiles.
I'm not positive about that, and without my notes, I'm depending upon a
less-than-reliable memory.

Bob

-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Dave Brown
Sent: Saturday, April 20, 2002 9:53 AM
To: [email protected]
Subject: RE: [TheForge] Pocahontas Coal

<snip>
Bob,

The most significant difference between the two can be seen in their levels
of fixed carbon and volatiles between Pocahontas #3 and the Cumberland
Elkhorn.  There's about twice as much volatile matter in CE than in the P3
and that makes a big difference.  "Volatile matter" are the oils and tars
(hydrocarbons) that boil off and burn rapidly and make the flame and
smoke.  What is left is essentially the coke/breeze or fixed carbon
component.  If all you are comparing is the ability to heat a piece of
steel, then burning carbon is burning carbon and heat is heat and you won't
necessarily see the difference.  It's what you don't see that also matters.

A comparison below of the two for carbon, hydrogen, volatile matter, and
Btu content points out where most the difference lies.

         P3      CE

%VM     18.7    38.1
%C      90.7    83.2
%H       4.1     5.4
BTU/#   15,730  14,820

Yes, I know that the % above add up to more than 100%, but that's because
much of the hydrogen is tied to some of the carbon and makes up much of the
volatile matter and is sent up the flue as smoke (soot/carbon) and unburned
hydrocarbons.  The CE has less carbon overall and twice as much carbon
contained in the volatile hydrocarbons.  The result is less coke/breeze
formation per pound of coal burned, and it's the coke/breeze that we want
in the heart of the fire.

The P3 also has a Free Swell Index (aka Coke Button) of 8-9 where the CE
has a FSI of only 3, which relates to coke formation.  This means more
carbon burning in the heart of the fire where you want it and less up the
chimney as fire and smoke where it doesn't do you any good.

There's a lot more in the differences in composition of these two coals
that contribute, but it's probably much more than you want to know and more
than I feel like writing.  But the above stuff is the critical stuff.

Don't get me wrong, CE is good blacksmithing coal and beats the snot out of
a lot of other coal sources.  But it is still a ways short of P3 in my
book.  Given the choice, the P3 is well worth the difference in price ...
when you can get it bulk that is.  P3 is also a much better buy in bags
from Skei at $400/ton than is the CE from Centaur Forge at $880/ton (plus
shipping on both).  A truckload of P3 to Wisconsin is about $150/ton <give
or take a little>, CE is not much less.  (shipping/freight cost is at least
half of this delivered cost)

Dave Brown

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