Bruce Bowers on fri 23 apr 10
Hi Folks,
Has anyone out there ever tried burying a pot under charcoal in a place
where no shelf damage could be done, to see if the carbon has any effect on
flashing.
I am taking only about pure, 100% hardwood lump charcoal with no impurities
like most commercially available charcoal has (like "Kingston")
My understanding is that pure charcoal produces very little ash and is
almost 90% carbon.
The wood kiln that I am going to use for a rather large firing next week
has no side stoke holes and, therefore, no good way to bury pots under
charcoal and embers that naturally occur in the firing.
My only source of stoking is from below the grate or through the main stoke
hole at the front of the kiln.
I am trying for some blacks with a high ball clay content, very smooth clay
that I have used with success in the past. I use this stuff in the
cooler, cone 7-9 areas of the kiln, because I get good flashing with this =
body at
that range. This is where I am thinking about the inclusion of pure
hardwood charcoal.
Any opinions.......or is this just goofy?
Thanks,
Bruce Bowers
_www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
David Woof on sat 24 apr 10
Hi Bruce=3D2C
"Goofy" is good!!!=3D20
What an opportunity you have here to experiment and discover. Pile on the =
=3D
charcoal and top off the pile by dumping on a generous coating of ash to f=
=3D
orm an insulating "sagger" condition. Do another without the ash. do anot=
=3D
her with charcoal=3D2C potato chips and vitamin pills....... doggie doo... =
yo=3D
ur underpants=3D2C get the idea?
Look up Korean charcoal kilns.=3D20
=3D20
At beginning of each semester I tell my students that A's in my class are r=
=3D
eserved for failures. Jaws drop=3D2C I have their attention. That the richn=
es=3D
s of truly creative work is brought about by ventures into the unknown. To =
=3D
push to the next level of success we must risk the almost certainty of fail=
=3D
ure along the path. And if we are not inventing technique to bring our ide=
=3D
a to fruition we are probably not pushing past the outer edge of our presen=
=3D
tly acquired experience and success. I'm happy to say that I give out a go=
=3D
od many A's.
=3D20
This is also the formula for living large and full within the life choices =
=3D
we make or un-make to move ahead or on.
=3D20
David Woof........Clarkdale=3D2C Az
__________________________________-
9. Charcoal and Wood Firing
Posted by: "Bruce Bowers" Sailoor47@AOL.COM=3D20
Date: Fri Apr 23=3D2C 2010 9:15 am ((PDT))
Hi Folks=3D2C
Has anyone out there ever tried burying a pot under charcoal in a place
where no shelf damage could be done=3D2C to see if the carbon has any effec=
t =3D
on
flashing.
I am taking only about pure=3D2C 100% hardwood lump charcoal with no impuri=
ti=3D
es
like most commercially available charcoal has (like "Kingston")
My understanding is that pure charcoal produces very little ash and is
almost 90% carbon.
The wood kiln that I am going to use for a rather large firing next week
has no side stoke holes and=3D2C therefore=3D2C no good way to bury pots un=
der
charcoal and embers that naturally occur in the firing.
My only source of stoking is from below the grate or through the main stoke
hole at the front of the kiln.
I am trying for some blacks with a high ball clay content=3D2C very smooth =
cl=3D
ay
that I have used with success in the past. I use this stuff in the
cooler=3D2C cone 7-9 areas of the kiln=3D2C because I get good flashing wit=
h th=3D
is body at
that range. This is where I am thinking about the inclusion of pure
hardwood charcoal.
Any opinions.......or is this just goofy?
Thanks=3D2C
Bruce Bowers
=3D20
=3D20
_________________________________________________________________
Hotmail is redefining busy with tools for the New Busy. Get more from your =
=3D
inbox.
http://www.windowslive.com/campaign/thenewbusy?ocid=3D3DPID28326::T:WLMTAGL=
:O=3D
N:WL:en-US:WM_HMP:042010_2=3D
Johanna DeMaine on sun 25 apr 10
Hi Bruce
Although this is not the area I work in, I am aware that Phillip Corneliu=
=3D
s
and the late Byron Temple both worked in this area using the kiln as a bi=
=3D
g
saggar. They have been well documented for their work with charcoal. Hav=
=3D
e a
look at Peter Lane's book "Studio Ceramics" p 230 in Chapter 6, Individua=
=3D
l
Kiln Techniques, where he discusses Phillip's technique. Look up the old=
=3D
er
archives of Clayart as well under saggars.=3D20=3D20
Johanna DeMaine
http://johanna.demaine.org
http://overglaze.info
Lee Love on sun 25 apr 10
Bruce, use real wood charcoal and not composite briquettes.
In my teacher's yohen chamber behind the main stoke chamber, pine
charcoal is poured in at the end of the firing to cover the pots in
this narrow chamber.
Amazingly, no ash is deposited on the pots from the charcoal.
None on shelves either. There is heavy reduction and you get a dull
layer of oxides on the surface of the pots that requires sanding and
buffing to bring out the color.
They look very different compared to the pots in the firebox that
get flyash. There is absolutely no gloss or runs on them. It is
similar to post reduction in raku, but at high fire.
Funny thing is, at the unloading, you sometimes find unburnt
charcoal inside the open jars.
I plan on building a sort of coffin kiln that I can fill with
charcoal at the end of the firing.
You can see some examples of pots I put in my firebox so they got
buried in coals here, making them look similar to Yohen pots:
This one was unglaze:
http://picasaweb.google.com/togeika/55TeaBowls#5332937653217334434
This one had a thin coat of shino:
http://picasaweb.google.com/togeika/55TeaBowls#5332937642159274338
a couple more shots here:
http://mashikopots.blogspot.com/search?q=3D3Dyohen
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
Carl Cravens on sun 25 apr 10
Lee Love wrote:
> Funny thing is, at the unloading, you sometimes find unburnt
> charcoal inside the open jars.
That's the weird thing about charcoal... it's made by heating wood in an ox=
ygen-starved environment to drive off water and volatiles, leaving behind, =
in good charcoal, mostly carbon. If your kiln is in heavy reduction, you'r=
e reproducing the kind of environment the charcoal is made in, albeit signi=
ficantly hotter. Shielded in a pot from direct flame, the strongest of the=
radiant heat, and starved of oxygen, I can see charcoal surviving a firing=
. Neat, when you're kind of in the mind-set that anything that isn't ceram=
ic or glass is going to be "cleansed" from the kiln during firing.
(I once read up on how to make charcoal because I was interested in making =
my own. Decided that was too much work when I found I could stock up on re=
al charcoal during the right (outdoor grilling) season.)
--
Carl D Cravens (raven@phoenyx.net)
If I want your opinion, I'll take you out of my killfile.
James Freeman on sun 25 apr 10
On Sun, Apr 25, 2010 at 10:22 AM, Lee Love wrote:
> This one was unglaze:
>
> http://picasaweb.google.com/togeika/55TeaBowls#5332937653217334434
>
> This one had a thin coat of shino:
>
> http://picasaweb.google.com/togeika/55TeaBowls#5332937642159274338
>
Beautiful pots, Lee. Excellent work.
One of my favorite pots in my collection is a Mark Goertzen piece that
fell off the shelf into the ash pit half way through a firing, and was
completely buried in ash and cinder. I put a snapshot of it on my
flickr page (http://www.flickr.com/photos/jamesfreemanstudio). The
surface is completely crusty, and displays every color of the rainbow
(well, at least in a subtle wood-fired sort of way). I found it
languishing forlornly, unloved and unwanted, on a bottom shelf in Mark
and Dick Lehman's studio. I gave it a good home.
All the best.
...James
James Freeman
"All I say is by way of discourse, and nothing by way of advice. I
should not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/resources
James Freeman on sun 25 apr 10
On Sun, Apr 25, 2010 at 11:19 AM, Carl Cravens wrote:
>>
>> Funny thing is, at the unloading, you sometimes find unburnt
>> charcoal inside the open jars.
>
> That's the weird thing about charcoal... it's made by heating wood in an
> oxygen-starved environment to drive off water and volatiles, leaving behi=
nd,
> in good charcoal, mostly carbon. If your kiln is in heavy reduction, you=
're
> reproducing the kind of environment the charcoal is made in, albeit
> significantly hotter. Shielded in a pot from direct flame, the strongest=
of
> the radiant heat, and starved of oxygen, I can see charcoal surviving a
> firing. Neat, when you're kind of in the mind-set that anything that isn=
't
> ceramic or glass is going to be "cleansed" from the kiln during firing.
A young friend spent a semester saggar firing a bunch of tiles, using
all sorts of combustibles and at all sorts of temperatures. I was
eating an apple (yes, in the studio; naughty me!) while she was
loading some saggars, and I tossed the apple core into one. It came
through the firing completely intact, but transformed to carbon. I
still have it in my studio after all these years. You can even see
the bite marks in it.
She also loaded some saggars with Cheerios. They survived a cone 10 firing=
!
...James
James Freeman
"All I say is by way of discourse, and nothing by way of advice. I
should not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/resources
Lee Love on sun 25 apr 10
>
> (I once read up on how to make charcoal because I was interested in makin=
=3D
g
> my own. =3DA0Decided that was too much work when I found I could stock up=
o=3D
n
> real charcoal during the right (outdoor grilling) season.)
There were several charcoal kilns around Mashiko. They are basically
low temp anagamas that are oxygen starved during the firing.
This is a "back to the old ways" program called Dash Mura, hosted by
the members of the rock group Tokio. They built a charcoal kiln:
http://www.ntv.co.jp/dash/
Here is a how to page including steel drum plans for a charcoal kiln:
http://homepage2.nifty.com/sumiyaki/eindex.htm
--
Lee, a Mashiko potter in Minneapolis
http://mashikopots.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
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