Barbara Skelton on fri 2 nov 01
Me too, Me too-----both ideas. What can I do w ith a wood stove and what can
I Do with the ashes.
Thanks
Barb Skelton in Oregon
Cathi Newlin on fri 2 nov 01
I just got a big (4' high wood stove for the barn/studio and got it all
hooked and fired it up. Its a big ol' cast iron potbellied stove, not one
of the modern types. It heats the barn very nicely!
How can I use this stove for pottery???? What sort of firing can I do in it
(as hubby groans that I have turned yet *another* household item into an
art supply...)?
Also, can I use the stove's ashes as a glaze? Can someone tell me how?
Sometimes I'm not sure which I like more...the clay or the fire!
C Newlin, typicalgirl@stinkbalm.com
StinkBalm!
Midwest Boxer Rescues
Kurt Wild on sat 3 nov 01
>Low temperature, polished blackware firing - primitive or pit fire-like
>techniques. Did it years ago. Too busy today to write more but will do
>so a bit more next week. Will be off Clayart starting now til then.
Kurt Wild
1000 E. Cascade
River Falls, WI 54022
phone: 715-425-5715
email: kurt.l.wild@uwrf.edu
web site main page: http://wwwpp.uwrf.edu/~kw77/
current (available) work: http://wwwpp.uwrf.edu/~kw77/Available.html
John Baymore on sat 3 nov 01
Also, can I use the stove's ashes as a glaze? Can someone tell me how?
Hi. Yup...... you can.
Depends a lot on your firing range as to how useful they'll be and how mu=
ch
wood ash you can use in your glaze. If you are firing to cone 8-10 or so=
they can be very useful. To really understand this stuff...... you
probably should start doing some more "formal" study of glaze chemistry. =
And a good book on ash glazes will be a big help on the specifics. =
Wood ashes chemical composition depends on the type of wood burned and th=
e
exact place it was grown. It can and does vary all over the place. That=
is the beauty of ash glazes.......... chemically unique. Lots of trace
materials that often give them their character. Hard to duplicate....ver=
y
complex. Basically...... wood ash supplies a lot of CaO (calcium oxide) =
in
the fired glaze. It also supplies some Na2O (sodium oxide) and K2O
(potassium oxide)......... particularly if you do not "wash" the ash
(rinsing in water to get the solubles out .... watch it..... CAUSTIC!! =
Lye!). So wood ashes can be thought of as supplying fluxes into the glaz=
e
batch.
CaO (calcium oxide) acts as a flux on SiO2 (silica), the main glass forme=
r
in ceramics. It lowers the high melting point of pure silica into the
range of the potters firing. The exact ratio of CaO to SiO2 in the fired=
glass is important. There is also Al2O3 (alumina) involved in this stuff=
. =
Glaze chemistry, in this case, involves looking at the relationships of
...... CaO+Na2O+K2O to Al2O to Si2O. =
Even with a good understanding of molecular glaze chemistry, unless you
have a good analysis of the particular ash you are using....... you have =
a
lot of room for error in your calculations. And the ash varies batch to
batch. So ash glazes are great places to use more "historical" approache=
s
to formulating glazes..... kinda' like the "founding mudders" of ceramics=
have done for generations . =
SO......... in the more immediate "seat-of-the-pants" department......
.............
For one cone 9-ish test try a blend of wood ash and potash feldspar. It=
is called a "line blend". One test is 90% ash and 10% feldspar. The nex=
t
is 80% ash and 20% feldspar. The next is 70% ash and 30 % feldspar. wat=
ch
out for runs! You'll learn a bit from that. Then try the same thing wi=
th
Cedar Heights Redart clay instead of the feldspar. Then try the same thi=
ng
with "dirt" from your backyard (not humus type soil) that has been seived=
thru a 100 m screen.
If you find an interesting area in a blend... like the three tests betwee=
n
80% ash to 60% ash look good......... try making the "steps" you then tes=
t
between them smaller. Increment in 2% changes and do a new run of tests
for that smaller range of values between 80% and 60%. =
If you are firing lower....like maybe cone 6-ish, try using nepheline
syenite instead of the potash feldspar above. And probably skip the gard=
en
dirt one .
Another test is to do what is called a "triaxial blend". Hard to explain=
the setup of this in a verbal only medium . See a book like Daniel
Rhodes / Robin Hoppers "Clay and Glazes for the Potter" for an explanatio=
n
of how you set that up. It is like a "line blend" but is for combining
THREE materials. Put Potash feldspar on one point, your ashes on another=
,
and any kind of ball clay on the third. For cone 6-ish....again sub neph=
.
sy. for the spar. That one triaxial test will likely generate a LOT of
possibilities for you to explore more fully.
Another experiment is to take a glaze that calls for a moderate amount of=
Whiting as a glaze ingredient and substitute wood ashes for the whiting. =
Not scientific....but CAN result in some nice effects sometimes.
Won't get into the "durable / food safe" issue for these "glazes" here. =
But from purely a visual standpoint........ you'll get some interesting
possibilities for at least sculptural work or maybe the outsides of
functional forms. Luckily wood ashes don't typically have a lot of reall=
y
toxic oxides present to possibly leach out of the fired glazes...... so
unless they come from some other raw material in the batch...... the
quality of the "glass" that you produce is not all that critical.
ALWAYS plan on the possibility of the glaze running when testing any
glaze........ but PARTICULARLY wood ash glazes .
Sometimes I'm not sure which I like more...the clay or the fire!
AHA!!!!!!!!! Another potential woodfirer. Pyros of the world....UNITE! =
With that comment in your post ....may I STRONGLY reccommend that you ava=
il
yourself of a woodfiring workshop at the first possible time .
Best,
..............................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JohnBaymore.com
JBaymore@compuserve.com
John.Baymore@GSD-CO.com
"Earth, Water, and Fire Noborigama Woodfiring Workshop 2002 Dates TBA"=
Tim Lynch on sat 3 nov 01
In a house I lived in a few years back, we heated with a wood burner in the
living room. I used to take trimmings while still wet and wad them into a
ball 1" to 2". Then I poke a small hole through the middle of it to make a
giant bead. Then I stuck them in a corner of the wood burner and left them
there for a few days. Take them out and make wall hangings. I also did
small plaques.
Tim
--
Tim Lynch
The Clay Man
1117 Tedford St SE
East Wenatchee, WA 98802
hifired@earthlink.net
On 11/2/01 9:01 PM, "Barbara Skelton" wrote:
> Me too, Me too-----both ideas. What can I do w ith a wood stove and what can
> I Do with the ashes.
> Thanks
> Barb Skelton in Oregon
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
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Snail Scott on sat 3 nov 01
At 09:03 PM 11/2/01 -0600, you wrote:
>I just got a big (4' high wood stove...
>How can I use this stove for pottery?
I had a wood stove in my old studio- did
some 'pit firing' in it. Used burnished
pots, pre-heated on top of the stove.
(Burnished the clay; no terra sig.) Did
a Mata Ortiz-style firing by putting
the pot on a stilt, spreading rabbit poop
around, and covering it with a coffee can.
(The Mata Ortiz folks use cow pies, but
I figured rabbits could serve as 'scaled-
down' herbivores. Since the can was inside
the stove, I didn't put any poop banked
up around the can. I got some great solid-
black pots - gorgeous. My roommate did
about 30 tiny dollhouse-scale pots this
way, all in one can, 'tumble-stacked'.)
I bet you could do raku, too; those
stoves get mighty hot.
-Snail
Cathi Newlin on sat 3 nov 01
At 10:38 AM 11/3/01, you wrote:
>If you are firing lower....like maybe cone 6-ish, try using nepheline
>syenite instead of the potash feldspar above. And probably skip the garden
>dirt one .
Perfect...my kiln is ^6
Lots of great info from everyone!
Won't get into the "durable / food safe" issue for these "glazes" here.
>But from purely a visual standpoint........ you'll get some interesting
>possibilities for at least sculptural work or maybe the outsides of
>functional forms.
I do alot of non functional stuff, so that's cool
>
>Sometimes I'm not sure which I like more...the clay or the fire!
>
>
>AHA!!!!!!!!! Another potential woodfirer.
We just had 200 tons of gravel spread in the barn, up the drive etc, and
had some dirt work done too. I had the dirt guy dig me a nice pit in back
of the studio with his backhoe.
I live on 15 acres and own another 20 wooded, and have livestock, so
there's plenty of wood, hay, leaves and manure around to burn...
C Newlin, typicalgirl@stinkbalm.com
StinkBalm!
Midwest Boxer Rescues
Wade Blocker on sat 3 nov 01
You can use the ashes,properly prepared by screening, washed or not, from a
wood stove to make ash glazes for your pottery. The stove will keep you
warm while potting. Mia in ABq
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