Lee Taylor on tue 31 aug 10
I am completing a woodkiln and have heard of and read about people using=3D=
20=3D
water during a firing to obtain certain effects. Some use it during the =
=3D
firing,=3D20
others at the end under embers and then some use it during cooling. I ha=
=3D
ve=3D20
heard some say that it causes reduction atmosphere and others say it caus=
=3D
es=3D20
reduction. I am confused about how it changes the atmosphere at all and=3D=
20=3D
what is actually going on when the water is introduced. Anyone have=3D20
experience with this? Thanks.
Lee
David Beumee on tue 31 aug 10
Gail Nichols book, "Soda, Clay, and Fire," has a Chapter Four, "Painting
with Fire," that presents an excellent understanding of using water to
produce reduction flashing in a soda kiln. Perhaps you could use the info t=
o
adapt to firing your new wood kiln.
David Beumee
Lafayette, CO
On Tue, Aug 31, 2010 at 9:03 AM, Lee Taylor wrote=
:
> I am completing a woodkiln and have heard of and read about people using
> water during a firing to obtain certain effects. Some use it during the
> firing,
> others at the end under embers and then some use it during cooling. I ha=
ve
> heard some say that it causes reduction atmosphere and others say it caus=
es
> reduction. I am confused about how it changes the atmosphere at all and
> what is actually going on when the water is introduced. Anyone have
> experience with this? Thanks.
>
> Lee
>
Hank Murrow on tue 31 aug 10
On Aug 31, 2010, at 8:03 AM, Lee Taylor wrote:
> I am completing a woodkiln and have heard of and read about people =3D
using=3D20
> water during a firing to obtain certain effects. Some use it during =3D
the firing,=3D20
> others at the end under embers and then some use it during cooling. I =
=3D
have=3D20
> heard some say that it causes reduction atmosphere and others say it =3D
causes=3D20
> reduction. I am confused about how it changes the atmosphere at all =3D
and=3D20
> what is actually going on when the water is introduced. Anyone have=3D20=
=3D
> experience with this? =3D20
Dear Lee;
Yes I have. The theory is that at high temperature(above Cone 8) water =3D
disassociates to hydrogen and oxygen. The hydrogen creates reduction =3D
beyond what has been established in the kiln, while the oxygen goes up =3D
the flue along with any un-disassociated water vapor.=3D20
So if you use damp or wet wood at those temperatures, you will have =3D
extra reduction. OR, you could introduce water through a small tunnel or =
=3D
two under the kiln as several in Japan do. In China, pans were built =3D
into the roof of the dragon kilns, which were broken with a rod at high =3D
temperature to introduce the H2O. Kind of scary!
When I soda fire, I introduce the soda as brine(2#'s soda to 2.5 Gallons =
=3D
of hot water). Introducing the brine into the firebox tends to cool the =3D
very hot firebox, while giving up that heat at the cooler chimney end of =
=3D
the kiln...... a splendid result.
Cheers, Hank in Eugene
www. murrow.biz/hank=3D
Lee Love on tue 31 aug 10
I introduce water both from the garden sprayer and also by throwing
ladles of water into the firebox. These both give more dramatic
results than wet or green wood does, simply because there is more
water to make steam.
Also, you get a lot of back pressure. Nothing too
dramatic happens at the water introduction end, but you have steam
pushing out all the blow holes and cracks in the doors.
there was an article in Ceramics Technical. Here is an
article on Chinese water reduciton:
http://books.google.com/books?id=3D3DNGw8DUuNywYC&pg=3D3DPA163&dq=3D3Dwater=
++redu=3D
ction+wood+kiln&hl=3D3Den&ei=3D3DzsV9TPX5E9SjngeDpqydCw&sa=3D3DX&oi=3D3Dboo=
k_result=3D
&ct=3D3Dresult&resnum=3D3D2&ved=3D3D0CDoQ6AEwAQ#v=3D3Donepage&q=3D3Dwater%2=
0%20reduct=3D
ion%20wood%20kiln&f=3D3Dfalse
--=3D20
--
=3DA0Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/
=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi
ivor and olive lewis on wed 1 sep 10
Dear Lee Taylor,
The injection of water into a wood fuelled kiln makes use of what is known
as the "Water Gas Reaction". This is a reaction between Pure Carbon, in the
form of the hot coals generated in the pyrolysis of wood and water, in the
form of superheated steam. Carbon decomposes water to generate Carbon
Monoxide and elemental Hydrogen. These you will recognise as being gases
that have the ability to reduce colorant oxides employed in the production
of pottery. As is usual in many chemical reactions there is a price to pay,
the reaction demands heat energy to drive it and this causes the reaction
zone to cool down unless an adequate draught is maintained.
For an overview see..Greenwood and Earnshaw, "Chemistry of the Elements",
p307. ISBN 0-7506-3365-4
Regards,
Ivor Lewis,
REDHILL,
South Australia
David Beumee on wed 1 sep 10
So, if there is such a price to pay, why are you recommending the protocals
set by John Coulter? Is it really necessary to close the damper, reduce fue=
l
flow to a minimum, close the fire mouths and keep everything sealed for "at
least" fifteen minutes? You must have had a very responsive kiln at the Jan=
e
Hamlyn workshop Ivor. The kiln that I fire is based on natural draft, and i=
f
I break the momentum, I'm dead in the water. I would never be able to reach
temperature.
David Beumee
Lafayette, CO
On Wed, Sep 1, 2010 at 12:15 AM, ivor and olive lewis u
> wrote:
> Dear Lee Taylor,
>
> The injection of water into a wood fuelled kiln makes use of what is know=
n
> as the "Water Gas Reaction". This is a reaction between Pure Carbon, in t=
he
> form of the hot coals generated in the pyrolysis of wood and water, in th=
e
> form of superheated steam. Carbon decomposes water to generate Carbon
> Monoxide and elemental Hydrogen. These you will recognise as being gases
> that have the ability to reduce colorant oxides employed in the productio=
n
> of pottery. As is usual in many chemical reactions there is a price to pa=
y,
> the reaction demands heat energy to drive it and this causes the reaction
> zone to cool down unless an adequate draught is maintained.
>
> For an overview see..Greenwood and Earnshaw, "Chemistry of the Elements",
> p307. ISBN 0-7506-3365-4
>
> Regards,
>
> Ivor Lewis,
> REDHILL,
> South Australia
>
David Woof on thu 2 sep 10
iHi Lee=3D2C
Best wishes and respectfully: you should learn how to fire your kiln effec=
=3D
tively before putting water into it and going for "special effects". =3D20
You will be introducing too many variables all at once to be able to recogn=
=3D
ize and distinguish cause and effect. =3D20
Your questions indicate that a beginning pottery course from a really good =
=3D
instructor would help you very much=3D2C and then go and beg=3D2C crawl=3D2=
C lie=3D
=3D2C cheat=3D2C and/or bribe and lick boots to fire with an established wo=
od f=3D
irer as an apprentice/grunt or whatever. (maybe she/he will let you put in=
=3D
a token pot or two). What matters most is that you get some experience un=
=3D
der your belt=3D2C pay your dues=3D2C and know what is going on in a practi=
cal =3D
sense as well as the chemistry and theoretical.
=3D20
You will no doubt get about twelve quick responders to your posted question=
=3D
=3D2C 3/4 of whom sit with their ass epoxyed in front of a screen Goggling =
up=3D
answers so as to sound like experts in this cyber world they imagine they =
=3D
live in. Hence these folks don't really make pots or fire kilns that often=
=3D
and the pots they do make are just bad copies of a foreign aesthetic they =
=3D
don't understand. So too=3D2C you will get a diluted=3D2C predigested regu=
rgit=3D
ated (read vomited) second hand version at best of what hydrogen reduction =
=3D
is really about. =3D20
=3D20
You will get several posts from those who are actually walking the walk=3D2=
C =3D
but I still stand firm that you need to get a good beginning education befo=
=3D
re venturing into this.=3D20
=3D20
In the meantime go to the archives and read what myself and a number of oth=
=3D
ers have written back from around 1999 and forward. Also anything written =
=3D
by Richard Bresnahan from his research at St Johns in upstate Minnesota=3D2=
C =3D
and his unique discerning of what the gutters in ancient Japanese kilns wer=
=3D
e for while studying there. Ancient kiln constructions that had perplexed =
=3D
many since these kilns were excavated. This information has been published =
=3D
in leading Ceramics publications.
=3D20
( this was back when Clayart had a serious and academic tone uncluttered by=
=3D
the pseudo-intellectual BS we must largely ignore and sift through now to=
=3D
glean the rare gems and pearls of ceramic wisdom and technical/scientific =
=3D
data and support) I think some are deliberately trying to turn Clayart into=
=3D
a Blog site and I find myself falling for it at times too.
=3D20
There are others as well that I am missing to note. The information is ou=
=3D
t there. I think you need to educate yourself in some basics before attemp=
=3D
ting unleashing of this sub atomic process in your new kiln. You are not s=
=3D
plitting atoms but you are splitting molecules. and worst case failing that=
=3D
=3D2C you will be releasing scalding steam and steam of potentially explosi=
ve=3D
character.=3D20
=3D20
For a teaser=3D3B If you have some basic chemistry in your background you w=
il=3D
l know why I say introducing vinegar at the right temp. is more effective t=
=3D
han water.=3D20
Do your home work. =3D20
Come back and tell us your experiences and observations.
=3D20
Do you know=3D2C have you seen=3D2C that in a large anagama=3D2C when the c=
arbon =3D
is forming chains and floating about in web forms in the kiln atmosphere th=
=3D
at you are witnessing the formation of a micro-cosmic of model of cosmic sp=
=3D
ace conditions in which stars are born? Richard published his reasoning's=
=3D
=3D2C Astrophysicists following his papers=3D2C came to his kiln and confi=
rmed=3D
it with spectral analysis.=3D20
=3D20
What we've learned will blow your hair back.. Go after it!!! Don't just po=
=3D
p up out of a rabbit hole with a fresh faced grin seeking enough free advic=
=3D
e to be a danger to your self and misdirection to others. =3D20
Lee I don't say this to be insulting but from an impassioned reverence both=
=3D
for what I do understand and seven lifetimes of what I have yet to learn.
_______________________=3D20
=3D20
Aside here Lee=3D2C I don't know you at all so this is just FYI:
I take issue with the anti-intellectual=3D2C anti-academic=3D2C arrogant do=
it =3D
yourself=3D2C self taught=3D2C spirit so in evidence here on Clayart of lat=
e. =3D
If one really wants to be truly self taught=3D2C go out in the woods and gr=
ub=3D
clay out of a bank and stop asking questions of others. Personally I won'=
=3D
t give anything more to this crowd. They want want want free advice and th=
=3D
en come back and bite the hands that fed them and clutter up this forum wit=
=3D
h their flawed clamoring for expert status about basic things they only hal=
=3D
f understand. Their self elected lee-der(another Lee) is a prime example o=
=3D
f what I speak of here.
Take "defining abstract art" for example: Kids intuitively know how to abs=
=3D
tract forms and ideas until adults come along and impose their ignorant and=
=3D
arrogant self reasoned definitions on what they ignorantly see as childish=
=3D
scribbles and squiggles which are really rich and well defined abstraction=
=3D
s of a magical world as the child apprehends it. One sees the same search=
=3D
ing lines for the abstracted essentials flowing through the drawings of the=
=3D
"great Masters"!!! Look again folks=3D2C and again and again until you Be=
gi=3D
n to learn to see the world as an artist or a child sees=3D3B before you d=
ar=3D
e call yourself a visual arts teacher!!! Grrrrr ach!!!!! =3D20
=3D20
And dust off a Dictionary and start building a personal reasoned comprehens=
=3D
ion and connection between an established definition and the various art fo=
=3D
rms you seek to categorize. Then come and speak your truth=3D2C because you=
n=3D
ow have walked a bit of the walk!!!
=3D20
And so you've dreamed of being a potter all those dreadful years in corpora=
=3D
te or domestic bondage and now that your remaining years are yours to live =
=3D
that dream: jump start it with a few semesters of good pottery classes with=
=3D
established instructors of good reputation=3D20
and Workshops and classes with the likes of Vince Pitelka and Tony Clennell=
=3D
. You will come out way ahead of the do it your self slogging and have re=
=3D
levant things to contribute as well as questions to ask. =3D20
Here at Yavapai College=3D2C Verde Campus=3D2C we have come to love and res=
pect=3D
a gem and a joy to know=3D2C one willing to be open and playful with her l=
if=3D
e=3D2C accomplished in other fields=3D2C and since taking a beginning ceram=
ics =3D
class has returned for several and is now looking ahead to pursuing an MFA.=
=3D
A ways to go and not a necessary goal for everyone to be sure=3D2C but a=
n =3D
example of how our lives can change and be enriched in serendipitous ways b=
=3D
ecause we ventured outside our preconceived comfort zone=3D2C initial goal=
o=3D
r reason for doing.=3D20
=3D20
Newbies=3D2C I love you for your questions and interest=3D2C I just want to=
enc=3D
ourage evidence of some serious commitment like taking some classes as well=
=3D
.
=3D20
Disclaimer for the "over sensitive"=3D2C This is not anger.....it is just =
pa=3D
ssion. Want some? Come get some!!! Passion is free=3D2C sometimes you hav=
e =3D
to pay for the consequences it causes=3D2C but when the big moment comes=
=3D3B =3D
if I have time for regrets I want them to be for things I have done=3D2C no=
t =3D
things I could have and didn't.
=3D20
David Woof.....Clarkdale=3D2C Arizona....an artsy-fartsy open minded "thing=
m=3D
aker"=3D2C a bit "light in the socks" but not gay (just happy) A homo-sap=
ie=3D
ns-sapiens but not phobic=3D2C possibly carrying Neanderthal DNA=3D2C and d=
efin=3D
itely generous squirts from the aboriginals of Ireland and North America (g=
=3D
o Indians=3D2C and wee people!!!) and star dust=3D2C but claiming no affili=
atio=3D
n with Sedona except some of my dear friends are.........and if you have re=
=3D
ad this far you are either my loyal friend or just plain stupid and I love =
=3D
you anyway!!!=3D20
=3D20
=3D20
=3D20
________________________________________________________________________
17. wood/water reduction
Posted by: "Lee Taylor" lee@SPENCERANDTAYLOR.COM=3D20
Date: Tue Aug 31=3D2C 2010 10:15 am ((PDT))
I am completing a woodkiln and have heard of and read about people using=3D=
20
water during a firing to obtain certain effects. Some use it during the fir=
=3D
ing=3D2C=3D20
others at the end under embers and then some use it during cooling. I have=
=3D
=3D20
heard some say that it causes reduction atmosphere and others say it causes=
=3D
=3D20
reduction. I am confused about how it changes the atmosphere at all and=3D2=
0
what is actually going on when the water is introduced. Anyone have=3D20
experience with this? Thanks.
=3D20
=3D20
=3D
David Woof on thu 2 sep 10
Hi Ivor=3D2C I like your post on the role of carbon in hydrogen reduction.=
=3D
=3D20
=3D20
When I was playing around with this I dripped used motor oil as a carbon bo=
=3D
oster to the kiln atmosphere=3D20
prior to introducing the water. =3D20
=3D20
David Woof
=3D20
=3D20
=3D20
15a. wood/water reduction
Posted by: "ivor and olive lewis" iandol@WESTNET.COM.AU=3D20
Date: Wed Sep 1=3D2C 2010 10:42 am ((PDT))
=3D20
Dear Lee Taylor=3D2C
=3D20
The injection of water into a wood fuelled kiln makes use of what is known
as the "Water Gas Reaction". This is a reaction between Pure Carbon=3D2C in=
t=3D
he
form of the hot coals generated in the pyrolysis of wood and water=3D2C in =
th=3D
e
form of superheated steam. Carbon decomposes water to generate Carbon
Monoxide and elemental Hydrogen. These you will recognise as being gases
that have the ability to reduce colorant oxides employed in the production
of pottery. As is usual in many chemical reactions there is a price to pay=
=3D
=3D2C
the reaction demands heat energy to drive it and this causes the reaction
zone to cool down unless an adequate draught is maintained.
=3D20
For an overview see..Greenwood and Earnshaw=3D2C "Chemistry of the Elements=
"=3D
=3D2C
p307. ISBN 0-7506-3365-4
=3D20
=3D20
=3D
ivor and olive lewis on thu 2 sep 10
Dear David,
You seem to be confusing two issues here.
Those salt glaze kilns I have been associated with, the two I built, the =
=3D
two I used with John Coulter and the one at the Jane Hamlyn workshop =3D
were all gas fired. Nothing to do with a wood fired Kiln or with the =3D
injection of water into a kiln to encourage a reducing atmosphere or =3D
converting Charcoal into a combustible gas..
I was under the impression that draught through a kiln was a function of =
=3D
atmospheric density and the difference in this quality between cold air =3D
outside the kiln and the lower density of the kiln atmosphere due to =3D
thermal expansion.
The price to pay during the injection of water is an Endothermic =3D
reaction. If the kiln cools below (from memory) 1050 deg C the reaction =3D
becomes sluggish and may cease.
Regards,
Ivor Lewis,
REDHILL,
South Australia
----- Original Message -----=3D20
From: David Beumee=3D20
To: ivor and olive lewis=3D20
Cc: Clayart@lsv.ceramics.org=3D20
Sent: Thursday, September 02, 2010 3:28 AM
Subject: Re: wood/water reduction
So, if there is such a price to pay, why are you recommending the =3D
protocals set by John Coulter? Is it really necessary to close the =3D
damper, reduce fuel flow to a minimum, close the fire mouths and keep =3D
everything sealed for "at least" fifteen minutes? You must have had a =3D
very responsive kiln at the Jane Hamlyn workshop Ivor. The kiln that I =3D
fire is based on natural draft, and if I break the momentum, I'm dead in =
=3D
the water. I would never be able to reach temperature.
David Beumee
Lafayette, CO
On Wed, Sep 1, 2010 at 12:15 AM, ivor and olive lewis =3D
wrote:
Dear Lee Taylor,
The injection of water into a wood fuelled kiln makes use of what is =
=3D
known
as the "Water Gas Reaction". This is a reaction between Pure Carbon, =
=3D
in the
form of the hot coals generated in the pyrolysis of wood and water, =3D
in the
form of superheated steam. Carbon decomposes water to generate =3D
Carbon
Monoxide and elemental Hydrogen. These you will recognise as being =3D
gases
that have the ability to reduce colorant oxides employed in the =3D
production
of pottery. As is usual in many chemical reactions there is a price =3D
to pay,
the reaction demands heat energy to drive it and this causes the =3D
reaction
zone to cool down unless an adequate draught is maintained.
For an overview see..Greenwood and Earnshaw, "Chemistry of the =3D
Elements",
p307. ISBN 0-7506-3365-4
Regards,
Ivor Lewis,
REDHILL,
South Australia
Lee Love on thu 2 sep 10
On Tue, Aug 31, 2010 at 4:17 PM, Hank Murrow wrote:
> Yes I have. The theory is that at high temperature(above Cone 8) water >d=
=3D
isassociates to hydrogen and oxygen. The hydrogen creates reduction beyond
> what has been established in the kiln, while the oxygen goes up the flue =
=3D
along
>with any un-disassociated water vapor.
Lee, I sent you an article that explains how water early on
causes oxidation. The Chinese brick kilns use this technique to make
very red bricks. This is trickier, especially if your kiln is
temperamental.
Reduction with water occurs at higher temps. If you are
used to soda spraying, there is nothing to it. You add water at
the same time you would add solution.
It'd be good to do a few firings without water first, so
you know how the kiln behaves without it. How your kiln handles it
depends on your kiln.
--
=3DA0Lee, a Mashiko potter in Minneapolis
http://mingeisota.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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