Lisa on mon 16 sep 96
Hi y'all. I am interested in doing a pit firing, but the only
information I have on how to do it is in a small box in McKee's book,
_Ceramics Handbook_.
My questions (as of now.):
1. Is pit fired ware vitrified or is it like raku?
2. Do you bisque the ware first, and if so, is ^06 ok?
3. Are there glazes to use with pit firing?
4. How long does it take?
5. McKee's book says to sprinkle things like cobalt or copper carb over
the ware in the pit for "effects". Does that mean I'll get nice
colors?
6. How deep/wide should the pit be?
7. If one uses dung, should it be dry? (Ok, I know that sounded stupid
but I have no idea, and I wanna know!)
8. I have some lowfire clay (earthenware), is this best for pit firing?
TIA!
Katherine Villyard on tue 17 sep 96
On Mon, 16 Sep 1996, Lisa wrote:
> ----------------------------Original message----------------------------
> Hi y'all. I am interested in doing a pit firing, but the only
> information I have on how to do it is in a small box in McKee's book,
> _Ceramics Handbook_.
> My questions (as of now.):
>
> 1. Is pit fired ware vitrified or is it like raku?
It's like raku. The pit tends to reach LOWER temperatures than the
average raku.
> 2. Do you bisque the ware first, and if so, is ^06 ok?
I do. ^06 tipped is USUALLY okay for burnished ware, any higher (like ^06
flat) burns the burnish off. I usually bisque to ^012.
> 3. Are there glazes to use with pit firing?
You will likely get icky bits of fuel stuck to the glaze if you try. I've
heard of people pit-firing vitrified, glazed ware but have never tried it.
> 4. How long does it take?
Depends. If you don't bisque first you want to fire REALLY slowly.
Anyware from several hours to a few days.
> 5. McKee's book says to sprinkle things like cobalt or copper carb over
> the ware in the pit for "effects". Does that mean I'll get nice
> colors?
Maybe. Maybe not. Experiment. :) A hint--it seems to relate to the
temperature the pit reaches and the amount of oxygen it gets. Black
carbon covers color effects.
> 6. How deep/wide should the pit be?
How much do you feel like digging? :) (I usually end up building mine
out of loosely-stacked bricks 'cause I don't feel like digging.)
> 7. If one uses dung, should it be dry? (Ok, I know that sounded stupid
> but I have no idea, and I wanna know!)
Yes, it should. And prepare yourself for everyone and their dog to walk
up to your pit, inhale deeply, and say, "Mmmmm, mmmmm, smells good, what's
cooking?" :) While if you use sawdust you will get, "My God what IS that
foul smell? Are you burning cow dung or something?" :)
> 8. I have some lowfire clay (earthenware), is this best for pit firing?
It'll work. Anything fairly open or with good thermal shock will work
well. I prefer fine-bodied clay so I can burnish. Make some small pieces
with different clays and combustibles and chemicals and see what you like.
--Katherine
Dannon Rhudy on tue 17 sep 96
>----------------------------Original message----------------------------
>Hi y'all. I am interested in doing a pit firing, but the only
>information I have on how to do it is in a small box in McKee's book,
>_Ceramics Handbook_.
>My questions (as of now.):
>
>1. Is pit fired ware vitrified or is it like raku?
> It is not vitrified, it is more like raku.
Do you bisque the ware first, and if so, is ^06 ok?
It is best to bisque the ware first, otherwise you will
lose most of it in the firing. Cone 06 is ok; I usually us
cone 010; some bisque to an even lower temp.
>3. Are there glazes to use with pit firing?
> Pitfired wares are unglazed, usually burnished wares.
4. How long does it take?
> Depends on what and how much fuel used.. it takes
until the fuel burns up and the ware has cooled.
McKee's book says to sprinkle things like cobalt or copper carb over
> the ware in the pit for "effects". Does that mean I'll get nice colors?
> Means it might, but there are other means of achieving
color. Some of it depends upon the combustibles you
use to fire (wood, dung, seaweed, etc)
How deep/wide should the pit be?
deep enough and wide enough to hold the wares and the
combustible material. You need enough combustible
material to make a hot fire that lasts more than a few
minutes.
7. If one uses dung, should it be dry? YES
>
>8. I have some lowfire clay (earthenware), is this best for pit firing?
> Its ok; so is stoneware, so is porcelain, I've used each
from time to time.
>TIA!
>
>Dannon Rhudy
dannon@koyote.com where it is one in the morning and why am I not asleep?
Michelle H. Lowe on tue 17 sep 96
There is a great article on the ceramicsweb about Primitive Firing. It
goes into detail about many of the variations possible in firing methods
and procedures.
That magic URL is:
http://apple.sdsu.edu/ceramicsweb/articles/primitivesurface.html
Michelle Lowe, potter in the Phoenix desert \|/ |
mishlowe@indirect.com -O- | |
mishlowe@aztec.asu.edu /|\ | | |
|_|_|
http://www.amug.org/~mishlowe ____ |
-\ /-----|-----
( )
<__>
Mary Hays on tue 17 sep 96
I've done quite a bit of experimenting with pit-firing. Your questions were
actually good ones. I'll share my method with you, hope it helps. First, i
bought a metal trash can with lid. Next, i punctured holes all over it for
good ventilation. I've found pitfiring on a windy days gives my best firings.
Then I layer sawdust and pots till i've filled it to 3/4 full. Mix in leaves,
dung, straw, or whatever throughout. Takes about 8 hours. The pots are made
of white earthenware, burnished 2 times in leather hard stage, 1 time in bone
dry stage. Firing at 950 degrees keeps your burnish, any hotter and
burnishing is lost. (ocassionally, if i don't feel like burnishing, i'll
bisque fire, pit-fire and spray with a glossy sealer for that tiring burnish
look.)(o.k., i do this more than occasionally). I also pit-fire some of my
sculpture. It really gives it a nice deep rich look. It's my preference till
i get rich and famous and can work in bronze. Good Luck! Oh, i forgot the
most important step, Have Fun.
Jonathan Kirkendall on tue 17 sep 96
Tips on pit-firing:
- Robert Piepenburg has a great how to in his book The Spirit of Clay
-I use cone 10 white stonware burnished and bisqued to ^06. Bisqued any
lower, and I find my wares more black than I like.
-I sometimes spray my pots with saltwater with a little copper carb thrown
in.
-I sprinkle salt as well as oxides over my pots, as well as a medium grade
dog food (look at the ingredients! They usually include both copper and
cobalt!). My firings are more varied when I use the dog food.
- Copper wire (#22 or thinner, which is hard to find) wrapped around a piece
will leave its mark.
-I've recently discovered (by accident) that pit fired ware can be washed
when it comes out, just like raku, without losing any of the markings.
-And finally, I have also just discovered tung oil as a finish. Turned my
pots into glowing, ivory colored vessels. Rumour has it that it also seals
for water, but I haven't tried that yet. If you use this stuff, don't follow
the directions on the can meant for wood. Apply, then immediately begin to
wipe it with a soft, lint free cloth.
Have fun and experiment!
Jonathan in Yonkers, where I'm trying to learn how to throw with a cast on my
left foot.
Matt Benacquista and Marci Selsor on tue 17 sep 96
There is a difference between pit firing and sawdust-saggar firing.
I am not sure the original question came from someone aware of the
difference. A pitfiring would not happen in a construction of
loose bricks. will explain later . . .gotta
run!
--
Marci Selsor
Matt Benacquista
http://www.imt.net/~mjbmls/
mjbmls@imt.net
Matt Benacquista and Marci Selsor on wed 18 sep 96
Pit firings versus sawdust saggar firings
I think pit firings occur in a pit and sawdust/saggar firings
occur in perforated cans, loosely stacked chambers of soft brick,
etc. Piepenburg's "smoke fired" techniques are excellent for
instructions of how to do a "smoke firing". Pit firing, on the
other hand, is an historical method of primitive firing without
bisque, with cow dung in (must I say) a PIT, i.e. below the ground
level. I have fired both methods often. When firing with cow dung,
select "frisbie quality" dried pies. Avoid collecting dung in May or
June when fresh green grass gives cows the runs (crepe quality pies).
The directions were posted about a month or so ago.
--
Marci Selsor
http://www.imt.net/~mjbmls/
mjbmls@imt.net
Katherine Villyard on wed 18 sep 96
On Wed, 18 Sep 1996, Matt Benacquista and Marci Selsor wrote:
> ----------------------------Original message----------------------------
> Pit firings versus sawdust saggar firings
> I think pit firings occur in a pit and sawdust/saggar firings
> occur in perforated cans, loosely stacked chambers of soft brick,
> etc. Piepenburg's "smoke fired" techniques are excellent for
> instructions of how to do a "smoke firing". Pit firing, on the
> other hand, is an historical method of primitive firing without
> bisque, with cow dung in (must I say) a PIT, i.e. below the ground
> level.
I prefer to reserve the term "saggar firing" for a firing involving a
saggar built inside a kiln which is then fired. Firing in a trash can is
more like firing in a hole in the ground than like firing in a saggar
built inside a kiln. The saggar inside a kiln achieves higher temperature
and is in general a more controlled process. Technically, the difference
between unbisqued ware fired in a hole in the ground with dung and a
bisqued pot fired in a perforated trash can with sawdust and a pot fired
in a kiln in a saggar full of combustables and reactants is not a sharp
line but instead a fuzzy continuum of vitrification level and amount of
flashing. The differences appear to ME to be instead philosophical
("authenticity," etc.) and therefore somewhat arbitrary. If the use of
the term "pit firing" for a perforated trash can or loose brick stack
filled with sawdust bugs you, we can always call it "smoke firing" instead
(not that I see much difference), but I must disagree with the descriptor
"saggar firing."
Semantically yours,
Katherine
from Denton, Texas
Matt Benacquista on thu 19 sep 96
To Katherine Villyard of Denton, Tx.
I fully agree with your definition of a true saggar as being that inside
a kiln. True saggars were use to protect tin-glazed ware
from the contaminents of a fire. Also used historically in
Stoke-on-Trent to protect the ware from coal clinkers. Using a saggar to
"reduce" with flashing of organic bits packed in the saggar is yet
another innovation of contemporary potters.
"Ceramics; the world's most fascinating hobby"
(that's why I like it)
Marci Selsor
Matt Benacquista
http://www.imt.net/~mjbmls/
mjbmls@imt.net
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