Dianne Kirwin on tue 23 oct 01
have just started experimenting with pit firing. sooooo much fun! have
done a lot of research on the archives and think i am going in the right
direction but have a few (very elementary) questions.
used a much thicker bed of sawdust to set my pots on this time and the
result was much more black smoke marking. i want some, but ended up
with mostly black pots. ( i plan to actually fire completely black at
some future date but right now i want only black smoke patterns here and
there.) i am thinking that if i reduce the amount of sawdust i will get
the effect i want. right? does one use no sawdust in order to get no
black at all? do i need to use a grate in the bottom of the pit instead
of setting pots on sawdust? any advice will be appreciated. TIA
Dianne
(who spent HOURS searching for car keys dropped while collecting cow
pies in the vastness of a cattle ranch in new mexico. what a day!)
Lajos Kamocsay on tue 23 oct 01
Hello,
I've done some "pit firing" in my smokey joe barbecue. I've put a layer of
charcoal on the bottom, pots wrapped in shredded LA Times for protection on
top, and then filled the whole thing with more charcoal. I've lit 4 pieces
of charcoal on my gas kitchen stove, put it on top, covered the bbq with the
lid... in an hour the whole thing was glowing red... and glowing red for 2
more days.
I wanted to do some color effects, so I got some manganese dioxide, but had
no idea how to get it to the pots. So I melted a candle (in a little jar on
top of the bbq on day #2) and dissolved the manganese dioxide in the hot
wax. Then I poured the wax over the burning charcoal... and got thick black
smoke... not exactly what I wanted...
There was a small pot I was firing inside a bowl. The small pot ended up
totally black, because the bowl held some of the wax I was pouring onto the
fire, acting kind of like a saggar. But the black I got is as black as black
gets. No purple from the manganese dioxide as I intended... a happy accident
I would call it.
So now I'm trying to create a "saggar" with a funnnel so I can get my wax in
there during firing. Wax is just easier to come by in North Hollywood than
cow pies...
In my previous attempt I didn't use wax, it was just the pots wrapped in
shredded newspaper, and charcoal around. The pots came out really "clean".
I've never tried sawdust so I can't compare, but the shredded newspaper
works really well for me and easier to obtain.
Lajos
----- Original Message -----
From: "Dianne Kirwin"
To:
Sent: Tuesday, October 23, 2001 10:07 AM
Subject: primitive firing
> have just started experimenting with pit firing. sooooo much fun! have
> done a lot of research on the archives and think i am going in the right
> direction but have a few (very elementary) questions.
>
> used a much thicker bed of sawdust to set my pots on this time and the
> result was much more black smoke marking. i want some, but ended up
> with mostly black pots. ( i plan to actually fire completely black at
> some future date but right now i want only black smoke patterns here and
> there.) i am thinking that if i reduce the amount of sawdust i will get
> the effect i want. right? does one use no sawdust in order to get no
> black at all? do i need to use a grate in the bottom of the pit instead
> of setting pots on sawdust? any advice will be appreciated. TIA
>
> Dianne
> (who spent HOURS searching for car keys dropped while collecting cow
> pies in the vastness of a cattle ranch in new mexico. what a day!)
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
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> You may look at the archives for the list or change your subscription
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> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Cindy Strnad on tue 23 oct 01
Dear Dianne,
The black color comes from the pots' exposure to
smoke in the absence of oxygen. So, to get less
black, add more oxygen. You can do this by setting
a metal pipe in the fire so the end is open to the
air (be aware that new galvanized will emit toxic
fumes, so don't breathe them). If you're using a
trash can, etc., you can drill more holes. A grate
would also introduce more air. If you don't like
the way your pots turned out this time, just
refire them.
Best wishes,
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
Jeff Tsai on wed 24 oct 01
Hi,
Yeah, you're getting the black from the sawdust, but anywhere you
tightly pack a combustible that smolders like hay too, you'll get
black.
If you want, reduce the sawdust or take it out completely. don't dig
your pots into the saw dust, just lay them atop the sawdust.
Sawdust is useful because it gives you a place to put the copper
carbonate and rocksalt around the piece almost touching the piece so
it has the most effect. If you take all the sawdust out and use a
grate, that is fine too, sawdust is just traditional, but not like a
required part of the process.
Here's what i'd do. reduce the amount of saw dust to just a little,
and don't pack it down, let it lay loosely in the pit. then place
your pot down there.
prior to placing the pot down there, decorate it. take a paper
grocery bag and throw in some hay, copper carbonate, and rock salt.
lots of rock salt. Wrap that bag up as tightly to the piece as you
can and put it in the pit. then sprinkle more copper carb and more
rock salt around the bags. Carefully put a layer of wood up in the
pit. you might build teepees of wood around your pieces first and
then start throwing in the rest until (depending on the pit size) you
get a layer of wood a couple feet high. light it and let it go.
other things to throw in might include dog food (dry), banana peels,
seaweed, and kinds of trash or copper wire. Then just let the pit
burn down. you want a nice layer of coals over the pieces so add wood
as is necessary until what is left after the fire is almost all
coals, is a nice layer of coals almost completely covering your
pieces.
this should help you get more color, which is mostly an affect of
using a lot of copper and a lot of rock salt.
-jeff
tomsawyer on wed 24 oct 01
Dianne,
I went to a workshop about 2 yrs ago given by Russel Fonts that promoted the
production of smoke fired pottery in an electric kiln! The idea was to
bisque fire a pot to 05 using terra sigillata if available then taking that
pot and wrapping it very tightly in tin foil inside of which and on the pot
various combustables were placed. I did a nice bowl fired to 05 before the
workshop with a light colored terra sig. We fired the pieces shortly after
lunch and as I had some salad left over I put it in the bowl - what the
heck - a salad bowl. We fired to 1000 F. The end product was really nice.
I'm in the process, as I write, to make two large lidded pots using this
method. When cool I've used floor wax to spruce up the shine. What is nice
is that most of us have access to an electric kiln. I've tried pushing the
firing limits to 1300-1400 F but the tin foil disintegrates and the
reduction effects are lost. I've contemplated rolling out thin slabs of clay
that I could break off without damaging the underlying pot and firing to
higher temperatures. See no reason why this wouldn't work but one would need
to be very careful in breaking off the shell covering so as not to damage
the underlying pot.
Tom Sawyer
tsawyer@cfl.rr.com
Belton, Christine on wed 24 oct 01
Dear Dianne,
We've done an interesting primitive fire/sagaar fire process: =20
=20
* Place your burnished/bisqued or greenware pot in a paper bag with
sawdust, copper carb, copper wire, salt, etc.=20
* Fold the bag down and tape well. =20
* The bag will hold all of the materials in place if it is packed
well. =20
* Coat strips of newspaper with thick slip (like paper mache). =20
* Wrap the paper bag with the strips until you have several layers all
around the bag....it's a big, soggy mess.=20
* Let it dry thoroughly. We set the sagaar on stilts to let air
circulate underneath.
* Place in a trash can that has holes punched in the sides. We have a
beat up lid that keeps the ash inside and still lets air in the can.
* Surround with sawdust, newspaper and wood...make sure some
combustibles are underneath the sagaar.
* Torch it.
* The fire will die but the sagaar will still be hot until the next
day!
* Do not pop open until completely cool!!!!!!!!!!!!!!!!!!!
* When cool, break it open (it's kinda like a clay pi=F1ata) gently.
* Rinse your pot..................it will have fired in a reduced
oxygen environment.....
We have had beautiful results! Lovely colors (reds/purples) and =
beautiful
blacks and greys.
Christine
> -----Original Message-----
> From: Cindy Strnad [SMTP:earthenv@GWTC.NET]
> Sent: Tuesday, October 23, 2001 6:46 PM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: primitive firing
>=20
> Dear Dianne,
>=20
> The black color comes from the pots' exposure to
> smoke in the absence of oxygen. So, to get less
> black, add more oxygen. You can do this by setting
> a metal pipe in the fire so the end is open to the
> air (be aware that new galvanized will emit toxic
> fumes, so don't breathe them). If you're using a
> trash can, etc., you can drill more holes. A grate
> would also introduce more air. If you don't like
> the way your pots turned out this time, just
> refire them.
>=20
> Best wishes,
>=20
> Cindy Strnad
> Earthen Vessels Pottery
> RR 1, Box 51
> Custer, SD 57730
> USA
> cindy@earthen-vessels-pottery.com
> http://www.earthen-vessels-pottery.com
>=20
> =
________________________________________________________________________=
__
> ____
> Send postings to clayart@lsv.ceramics.org
>=20
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>=20
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
Dannon Rhudy on wed 24 oct 01
At 02:11 PM 10/24/01 -0400, you wrote:
>Dear Dianne,
>
>We've done an interesting primitive fire/sagaar fire process:
>
>* Place your burnished/bisqued or greenware pot in a paper bag with
>sawdust, copper carb, copper wire, salt, etc.
>* Fold the bag down and tape well.
>* The bag will hold all of the materials in place if it is packed
>well.
>* Coat strips of newspaper with thick slip (like paper mache).
>*
This is an easy technique, and it is detailed in Pottery Making
Illustrated, Winter 2000.
HOWEVER: This technique was really designed to protect a
kiln from the effects of the combustibles in a saggar firing.
It was designed for use IN A KILN. You can of course use it
WITHOUT a kiln, but it isn't necessary. You could stop at the point of
just putting the work and combustiblesl in a paper bag, if
you're firing in a garbage can. The slip covered strips of
paper aren't really needed in this situation, and they are
quite a bit more work.
regards
Dannon Rhudy
GlassyClass on thu 25 oct 01
Was reading in Pottery Making (old copies a friend gave me) about putting a
piece in a "sagger" made of newspaper coated with slip, like paper mache.
Might be what you are looking for.
Bud
----- Original Message -----
From: "tomsawyer"
Sent: Wednesday, October 24, 2001 5:52 PM
Subject: Re: Primitive firing
> Dianne,
> I went to a workshop about 2 yrs ago given by Russel Fonts that promoted
the
> production of smoke fired pottery in an electric kiln! The idea was to
> bisque fire a pot to 05 using terra sigillata if available then taking
that
> pot and wrapping it very tightly in tin foil inside of which and on the
pot
> various combustables were placed. I did a nice bowl fired to 05 before the
> workshop with a light colored terra sig. We fired the pieces shortly after
> lunch and as I had some salad left over I put it in the bowl - what the
> heck - a salad bowl. We fired to 1000 F. The end product was really nice.
> I'm in the process, as I write, to make two large lidded pots using this
> method. When cool I've used floor wax to spruce up the shine. What is
nice
> is that most of us have access to an electric kiln. I've tried pushing the
> firing limits to 1300-1400 F but the tin foil disintegrates and the
> reduction effects are lost. I've contemplated rolling out thin slabs of
clay
> that I could break off without damaging the underlying pot and firing to
> higher temperatures. See no reason why this wouldn't work but one would
need
> to be very careful in breaking off the shell covering so as not to damage
> the underlying pot.
> Tom Sawyer
> tsawyer@cfl.rr.com
>
Dianne Kirwin on thu 25 oct 01
thanks for the responses to my questions on pit firing.
i did have one interesting result.....i dipped several pieces in a solution of
copper sulphate and water prior to firing. what i got was a solid burgundy red
(on buff clay)....in the places that were not completely black from smoke. plan
to try more of this....maybe splashing random patterns. i didn't come across this
in the archives so i thought i'd pass it on.
dianne in denver
(thrilled to have a remote place to go where i can build an open fire and have an
unlimited source of fuel..cow pies)
tomsawyer on fri 26 oct 01
tom,
yikes, tin foil in my electric kiln! now there's an idea! you do mean
"tin" and
not "aluminum", right?
dianne in denver
Dianne - U right Me wrong
mudslingers@ATT.NET on fri 26 oct 01
diane kirwin wrote:
>i did have one interesting result.....i dipped several
>pieces in a solution of copper sulphate and water prior
>to firing. what i got was a solid burgundy red
>(on buff clay)....in the places that were not completely
>black from smoke. plan to try more of this....maybe
>splashing random patterns. i didn't come across
>this in the archives so i thought i'd pass it on.
diane,
i tried this too with completely different results!
the saturated copper sulphate solution acted as a
resist! (to see an example, go to:
http://mudslingers.home.att.net/690pitrc.jpg
i never would have expected THAT as a result.
maybe it was your use of cow pies as the fuel source.
i know they increase the temp.
i also used some cow pies but maybe not enough?
does anyone have other theories on the different
behavior of this solution?
thanks,
lauren
mudslingers pottery
http://mudslingers.home.att.net
Dianne Kirwin on fri 26 oct 01
tom,
yikes, tin foil in my electric kiln! now there's an idea! you do mean "tin" and
not "aluminum", right?
dianne in denver
tomsawyer wrote:
> Dianne,
> I went to a workshop about 2 yrs ago given by Russel Fonts that promoted the
> production of smoke fired pottery in an electric kiln! The idea was to
> bisque fire a pot to 05 using terra sigillata if available then taking that
> pot and wrapping it very tightly in tin foil inside of which and on the pot
> various combustables were placed. I did a nice bowl fired to 05 before the
> workshop with a light colored terra sig. We fired the pieces shortly after
> lunch and as I had some salad left over I put it in the bowl - what the
> heck - a salad bowl. We fired to 1000 F. The end product was really nice.
> I'm in the process, as I write, to make two large lidded pots using this
> method. When cool I've used floor wax to spruce up the shine. What is nice
> is that most of us have access to an electric kiln. I've tried pushing the
> firing limits to 1300-1400 F but the tin foil disintegrates and the
> reduction effects are lost. I've contemplated rolling out thin slabs of clay
> that I could break off without damaging the underlying pot and firing to
> higher temperatures. See no reason why this wouldn't work but one would need
> to be very careful in breaking off the shell covering so as not to damage
> the underlying pot.
> Tom Sawyer
> tsawyer@cfl.rr.com
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
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