pit firing

updated sat 15 jul 06

Jo on tue 18 jun 96

Hi Everyone:

I know this has been covered but at the time I wasn't considering it. Now
my circumstances have changed and I'm thinking of trying this. I would
appreciate it if someone (or all) could send me specific directions on how
to pit fire. All I know is that you dig a pit, put in your pots and then
build a fire on the pit. I need to know a lot more such as:
Do I bisque the pots first?
What do I line the pit with or do I line the pit?
What sort of fuel do I put in the pit?
Do I need a sagger and how do I make one?

As you can see I'm a real novice and this will be my first firing. I know
of no one near me to help me with the particulars but I know you all can get
me through it. I look forward to reading every post.

Thanks ever so much in advance.

Jo Fellows
Currently of Algonac, Michigan

Claudia O Driscoll on tue 18 jun 96

Jo,
This could be a lot of fun! I can give you a few hints, but I do not actually
fire in a pit...I have a small brick kiln and fire with sawdust. Still, I would
suggest that you bisque first as pots fired in this way are not very
strong if fired raw. I usually bisque to cone 06, which allows strength
and still accepts a nice smoking.
Choose a clay that is not too tight as well. I use raku clay as it can
withstand the temperature changes better than say, earthenware clay.
I hope this gets you started. Feel free to email any questions directly if
you like.
claudia (claudiao@clackamas.cc.or.us)

Michael Henderson on tue 18 jun 96

For Jo, in Michigan.... RE Pitfiring. This is my sixth season (i.e. when it
might not rain for a little while) of pitfiring. I just read Claudia's
suggestions which are sorta like a "barrel-burn" technique. I suggest you
get a copy of Karin Hessenberg's book Sawdust Firing ISBN 0-8122-3301-8 It
is a volume in The Complete Potter and may be listed by that series title.
I fire at the beach and am constantly dealing with issues peculiar to that
environment. I agree with Claudia. You will need a clay that will handle
thermal shock well. Often that means ones that are well-grogged. But,
should you decide to burnish your pots (i.e. polish the near leatherhard
pots with a smooth object such as a stone, bone, back of spoon etc.,), you
will need to consider whether the grog will mar the finish. You may also
decide to slip your pots. (This I am lousy at and suggest you e-mail Vince
Pitelka for best advice) and then burnish the slip. The other concern for
me, since my pots are wheel-thrown is enough structure to the clay to let me
make something reasonably large. I find it a careful balancing act. 1.
Can take thermal shock 2. Burnishes well 3. Enough structure to let me
make something reasonably large My objective is also to achieve color
without chemicals and I have discovered that certain clay bodies will do
different things in different wood bases (i.e. cedar vs. fir, fruit woods
etc.) My pits look rather haphazard but are actually really thought out for
my peculiar firing cionditions. Here in Oregon I have a wide variety of
weights and types of sawdust to choose from in my immediate area. WOOD WE
GOT. I do use a thick layer of sawdust to line my pits and have discovered
that different weights and densitys make a difference in the firing as well
as dampness and wood type. I also bisc my pots to ^010 and have discovered
that it is important that the pots be carefully made and the walls be
uniform in thickness as well as the base. My survival rate is better. My
technique is basically bon-firing with dung as an insulator. But here is a
method that might work for you: Dig pit 3feet deep, 3 feet wide, 3 feet
long (or longer for a trench kiln works fine) Put down a rug of wwod
shavings or (sawdus) (about 6 inches) put pots in separated from each other,
cover with a layer of construction cutoffs mixed with some light weight
kindling (This stuff burns longer than kindling alone and will keep th
sawdust burning (you can spread the sawdust between the pots too) and cover
with a piece of corregated tin roofing material. This will burn about three
hours maybe, but watch it, as the fire burns down you can then add more wood
as needed to keep it going about 8 more. Finally cover it up and let it
cool for a day or so. Have fun Emily, in Astoria where the SUN is FINALLY
OUT! And I just finished trimming a pot made of a great clay for color but
rips up like all get out when even trimmed on the wheel. Maybe I'll find
the ideal one soon. I've fired true red earthenwares all the way to
porcelain looking for the right stuff.

dannon@ns1.koyote.com on tue 18 jun 96

>----------------------------Original message----------------------------
>Hi Everyone:
>
> Do I bisque the pots first?
> What do I line the pit with or do I line the pit?
> What sort of fuel do I put in the pit?
> Do I need a sagger and how do I make one?
>
>
>Jo,

Bisque the pots first; losses are extremely high if you do not. You may
line the pit or not. I used to line the bottom with brick and put a couple
courses of brick around the top (I was firing in essentially a sand-dune,
and needed some stability). Some line the whole thing, some not at all.
You can use a variety of fuels: wood, sawdust, a combination of those
things, straw soaked in salt water (if you wish to use salt). Pine needles.
Dried dung (any kind). Scrap wood (except pressure treated wood). You
don't have to use saggars, and your pots will get hotter if you don't. Use
something to cover the top of the pit once you get the fire going, you'll
achieve greater heat and better reduction if you do.

Anne Yagoda on mon 4 nov 96

I thought you all might be interested in my experience this weekend. I
participated in a pit fire this weekend and I love the entire process.
There were about 20 potters. Each of us are allowed 10 pieces with no
restrictions on size. A large pit was dug many years ago on private
property. We all gathered on Saturday and prepared to make the pit ready.
We then did some enhancements to our pots with yellow ocre and copper
carbonate. Are there any other chemicals that are used to create
interesting color flashes? We stacked it tightly, put loads of wood
(carefully) lit the fire and soon after covered it up. We stayed together,
had some dinner and drank some wine.
We all were anxious to open it up and see our treasures this afternoon.
It was wonderful. Of course, not everybody was thrilled with their pots
but I thought the entire process was enlightening. The sense of community
and cooperation abounded.
Soon, I hope you will be able to read a detailed article about the event
in Claytimes Magazine.
I thought I would share this with you all for over time how generous you
have been to me.
Thank you,
Anne Yagoda

Jennifer Rhinesmith on tue 4 mar 97

Dear Clayarters: I have a friend who is not on clayart that does pit
firing all the time. She has been having some problems getting the results
that she wants. She is using either low fire terra cotta, white
earthenware, or high fire stoneware. She has been firing in a firebrick
pit built above ground. She would like to put in greenware (like the
Indians did) and busique it. She can't seem to get the pit hot enough to
reach bisque temp.. Also, she can't seem to get the colors that she wants.
She wants to be able to do things very primative like and is very
frusterated because she can't get them to work. She either uses wood,
sawdust, or cow dung. If anyone out there can be of some help, please let
me know and I'll foward it on to her. Thank You Jennifer in Alpine,TX.

Michael Karpowich on tue 6 may 97

Is there anyone in the metro Detroit area who does pit firing? I'm dying
to "break away" from ^6 ox., but I live in an area that prohibits an
outdoor firing. I would love to help with the preparation and learn what I
can from someone with some experience in that area. Please post me
privately if you wouldn't mind helping out a pit fire beginner!!

Deni Karpowich
karpowic@tir.com

Deborah Zinn on wed 5 nov 97

Hi,

Interested in info on pit firing (coloring agents and techniques). Any
suggestions as to where to begin? Info sources on the web?

Thanks,
Deborah

Patsy Catsos on fri 7 nov 97

Try http://www.lib.uconn.edu/NativeTech/pottery/pottery.htm

Its a cool website with lots of info on traditional native american methods.

Patsy

Cheryl L Litman on sun 9 nov 97

I've begun firing in a garbage can recently so I'm not any kind of
expert. I was just invited to a pit fire done by someone who does pit
firing exclusively.

The pit firing was with Olivia Gabriel and some of her friends and some
of their friends. She's the middle school art teacher in my town and all
her work is pit fired. She had a bottom course of cinder blocks on their
side so air could enter the pit which was about 5'x5'. Then there were
bricks on top about 2.5' high. We put down about 5" of sawdust, then a
layer of barley and oats which she says gives blacker blacks, then a
heavy sprinkling of copper carbonate, then the pots with the tallest in
the center and the smallest ringing them. We stuck quite a bit of pine
wood scraps from the school's wood shop upright in between the pots,
sprinkled another heavy dusting of copper carbonate. Next came lots of
crumpled newspaper tossed in until we couldn't see the pots any longer.
Then we took long broken branches and wood scraps and stood them in a
teepee shape over the pots (the ends were against the bricks on the outer
edges and they leaned into the center towering over the pots. Then we
took a minute and made "kiln gods", lit the bonfire and had the
obligatory potluck lunch while the fire burned down. She also lit a few
garbage cans which were stacked the same way as the pit - no lids.

Most everyone had terra sig on their pots and we decorated with a Bennet
bean recipe before putting them in the pit. We could also used a mix of
70% kosher salt, 30% copper carbonate misted with water till damp and
"glued" onto the pots with a quick spray of Krylon clear gloss to make
the pot sticky. Some tied wires onto the pots and stuck leaves or hay
underneath.

The pit fired pieces I made, I'm not thrilled with, but some others got
great stuff. My terra sig didn't cover the grainy raku clay very well so
it looked dull. Those who used a low fire clay had better coverage with
the terra sig, either that or they made better terra sig! The Bennet
Bean "glaze" is

1 heaping Tbsp of borax (20 mule team)
1 heaping Tbsp of any kind of stain or oxide (optional)
1 heaping Tbsp of ferro frit 3819 which Olivia said isn't made any longer
so she uses
ferro frit 3269 instead (I don't know the difference)
1/2 tsp of gum solution which she buys premixed from Ceramic Supply in NJ
(liquid)
about 1/2 cup of water

Stir often.

She had a blue, green, yellow, maroon, copper carb, iron oxide and clear
made up for us to use. I think the mason stain ones were too "fake". I
liked the look of the oxides better. The clear picked up the smoke
differently and looked good as well - kind of a resist.

The best markings came from the 70%kosher salt/30% copper carb mixture
she "glued" on with Krylon spray. Nice maroon flashing when in the right
place in the fire - but isn't that true with everything.

We took a few pots out of the pit early with tongs and she used
horsehair, one strand at a time to add lines to the pot. You hold the
hair across the pot and it sizzles and burns in. Got a lot of zigzag
lines if the hair is held loosely.

She leaves the pit open, no lid. Although she also did a few pieces in
garbage pails, loaded it the same way but after the bulk of the wood had
burned down, she put the lid on and left it till the can was cool.


At a local community college this summer we also did pit fires. Laid
concrete blocks down on their sides and built up a brick wall around it
about 2'x3'. Laid down about 5" of sawdust then a layer of pots,
sprinkled with copper carb and then kept layering till we got to the top
or ran out of pots. Crumpled some newspaper on top, lit it and then
immediately covered with a loose metal cover. Pretty much left it alone
until it burned down.

In my garbage can I'm not getting the color flashing I want and I think
you need terra sig for that along with the copper carb. Also now that
I've done a few other firings, I feel that I need to poke a lot more
holes in my can, I'm not getting enough air into it.

A good book is by Karen Hessenberg and it's part of the Complete Potter
series of books.

Good luck.

Cheryl Litman
Somerset, NJ
email: cheryllitman@juno.com

On Wed, 5 Nov 1997 10:39:50 EST Deborah Zinn
writes:
>----------------------------Original
>message----------------------------
>Hi,
>
>Interested in info on pit firing (coloring agents and techniques).
>Any
>suggestions as to where to begin? Info sources on the web?
>
>Thanks,
>Deborah
>

Evaroot on tue 5 may 98

Thanks for responding Claudia!

Where do I start with all that I want to know! Let me tell you what I have
done, and then maybe you can elaborate on what I may be missing. Through
class I have participated in a few firings, sometimes using chemicals,
sometimes using banana peels, oranges, seaweed. What I'm looking for here are
answers to clay bodies that work best, I love working with MAC but it doesn't
seem to hold up well. I would also like to know if anyone has found a way
that raises the odds on flat pieces surviving the fire. That may be enough
questions for now!

corey

Beth and Matt Stichter on wed 6 may 98

Pit Firing and smoking-

I have been doing some experimentation with smoking, mostly, and I am also
having trouble getting the tiles and platters to survive the uneven heating
and cooling process. I am also bewildered with the problem of getting the
atmosphere hot enough. I am using a double trash can with two 'rings' of
holes punched though, layering with sawdust, hay, and large wood chips,
pine cones, and newspaper. The smoking tends to smother itself after the
first few hours, and even after a day long smoke firing, I still have most
of the finish washing off. Suggestions please!



Beth Stichter

Columbus, OH

Claudia O Driscoll on wed 6 may 98

Hi Corey,
Well, let me tell you what clay body I use for starters. I picked a standard
Raku clay supplied here locally. I assume that any supplier can get you
that type of body. It is ready to take the temperature variations and is
more open than earthenware or terra cotta clays.
My work is handbuilt, and sometimes I think that does better in the
pits...sort of primitive to primitive, I guess. I bisque to cone 06, but for
darker blacks, will bisque to cone 010. The lower the bisque, the more
intense the blacks.
As for effects from added organics, I am still learning after all these
years! And what works in one firing, does not work in another. That is
part of the magic of this kind of fire. If you place a leaf beneath your
piece, you sometimes get a nice 'shadow'...try different types of leaves. I
put fir cones up next to the pots for a flashing.

As for flat pieces, yes, those are a challenge. I have had luck with
pieces about as big as a pie plate, but find that they need to have a slight
curve to them. Totally flat pieces really struggle in there!

Tell me a little about your work. And I am sure you saw the posting from
Justin Smith. I am going to ask him a bit about the color too!
claudia

Cindy on thu 7 may 98

Beth,

To increase the survival of your ware, I suggest you bisque first in an
electric or fuel kiln to around ^010.

I don't know why your smoke finish isn't staying--I've never had this
problem, but I pit-fire in a pit and don't use sawdust, so maybe that's the
difference.

Possibly your problem is that your fire isn't burning hot enough. Try
wadding up some chicken wire at the bottom of the barrel. You might also
consider mixing some other combustibles with your sawdust and/or using wood
chips--something that leaves a little more air space for better combustion.
Of course, this will also increase the oxidation of your firing, so you
have to strike a balance somewhere. Too much oxidation, and you won't get
the blackening most pit-firers adore.

Once your ware has fired good and hot, but not expended all fuel (it should
be possible, if perhaps not necessarily expedient, to get that drum to a
softly glowing cherry red heat), try plugging up your air vents
(experiment--wet clay might work . . . ceramic fiber would probably do the
trick, too). This will give you some increased reduction/smoking at the end
of your firing.

Hope this inspires your experimental side, Beth. Happy firing. :)

Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm

Evaroot on thu 7 may 98

Hi Claudia,

Your ideas for shading are a great idea, I'm going to send my son out on an
expedition for interesting pinecones and leaves!

I am strictly a handbuilder, tried the wheel but just wasn't satisfied with
the experience. I've been experimenting with a figure of a woman, impressed
from below a flat surface. As I mentioned, this flat surface is giving me
problems. I also have been making larger (for me this means approaching two
feet) vases, with handcarving. My biggest influence would be from the native
american tradition.

I have an aversion to high fire glazes, I'm just not happy with the perfection
of them, which is what led me to Raku and pitfire. I am like a kid at
Christmas when it's time to take the pieces out. We have used various
chemicals, I can't think of them off the top of my head, but they enhance the
flashings in the pit, often leaving a beautiful alabaster sheen...

Tell me about your work, what is your current passion?

Corey

Olivia T Cavy on thu 7 may 98

Beth,

Apparently your pit firings are not getting hot enough. I use a brick
"pit" which is a box shaped container made of house bricks, with a sheet
metal cover. I use horse manure and sawdust as my combustibles, but find
that I need to at least start the fire with logs on top to ignite the
manure/sawdust. I put a layer of sawdust/manure at the bottom of the pit,
rest my pots on that layer, and sprinkle another layer of sawdust/manure
all around the pots, plus on top. Then I add the logs and kindling and
start the fire. When the logs are burning well, I put my cover on the
pit. (I understand that dry cow pies are better than horse apples, but
the cows are further away, so horses it is!)

My smokings go all the way through the pots. I couldn't wash them off if
I wanted to. Also, they smell like an old fireplace or extinguished
campfire for a while.

Note that you should only be bisquing your pots before pit firing them.
You want the pots to be porous, to absorb the smokings. I've used a wide
variety of clays with success-raku clay, earthenware, ^6 stoneware and
porcelain. I haven't smoked plates or platters. (BTW I bisque to cone
06.) I have been told that large flat pieces are more at risk.

I believe that because you start your pots IN the pit from the beginning,
they are less likely to crack, since they are not subject to sudden heat.

I try to keep my pit firings smoking for at least 4 hours, because it
takes that long for my sawdust/manure mixture to burn all the way down to
the bottom. The first time I did it it worked well, so I never changed my
method.

Bonnie

Bonnie D. Hellman
Pittsburgh, PA
work email: oliviatcavy@juno.com
home email: mou10man@sgi.net

On Wed, 6 May 1998 07:54:08 EDT Beth and Matt Stichter
writes:
>----------------------------Original
>message----------------------------
>Pit Firing and smoking-
>
> I have been doing some experimentation with smoking, mostly,
>and I am also
>having trouble getting the tiles and platters to survive the uneven
>heating
>and cooling process. I am also bewildered with the problem of getting
>the
>atmosphere hot enough. I am using a double trash can with two 'rings'
>of
>holes punched though, layering with sawdust, hay, and large wood
>chips,
>pine cones, and newspaper. The smoking tends to smother itself after
>the
>first few hours, and even after a day long smoke firing, I still have
>most
>of the finish washing off. Suggestions please!
>
>
>
> Beth Stichter
>
> Columbus, OH
>

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Beth and Matt Stichter on thu 7 may 98

Thanks so much for the info!
If I may, let me explain a little further
what I am trying to accomplish. My primary difficulty is that I am smoking
largish sculpture pieces, about 1/2 an inch to 1 inch in
thickness...handbuilt, score and slip. Since these pieces are already
unweildy and delicate (lots of appendages), I don't feel comfortable
leaving them at bisque...I fire them up to cone 6 (on a cone 10 clay
body...Soldate), and *then* smoke them. I realize that the clay body is
not nearly as porous as one would like, so I have tried spraying on iron
oxide and copper carbonate to augment the coloration. However, as I said,
the color is mostly washing off, or at least, I am getting really wildly
varied results. (ie: sometimes the carbon and coloration soaks in....for no
reason I can determine).

So I guess I will have to keep experimenting around, but I appreciate
_every little_ tidbit of advice or experience that anyone could lend me.

I am primarily interested in

1. How do you keep the smoking hot?

2.How do you obtain coloration?


Thanks to All..


Beth

Justin M. Smtih on fri 8 may 98

Because There is so much interest sparked by my first posting about our pit fire
there are so many questions I am going to post the whole procidure and tips that
used and what we have learnd over ther last three years. Look for the posting o
clayart on Sunday.
If you have any futher questions feel free to email me. ibpede@hotmail.com
Justin M. Smith

Azclockdoc on fri 8 may 98

In a message dated 5/7/98 8:44:26 AM PST, stichtbm@netwalk.com writes:

<< I have tried spraying on iron
oxide and copper carbonate to augment the coloration. However, as I said,
the color is mostly washing off, or at least, I am getting really wildly
varied results. (i.e.: sometimes the carbon and coloration soaks in....for no
reason I can determine). >>


In addition to spraying on the red iron oxide and copper carbonate solution,
you can add dry chemicals right next to the pots prior to firing. Chemicals
such as copper carbonate, ironite, rock salt and vermiculite will add flashes
of blues and yellows. The coloring although unpredictable, can be beautiful
at times.

John Guerin
Tucson, AZ

Myrrhia Rae Resneck-Sannes on sat 9 may 98

For the issue of the cracking platters in pit firings, (which I have
never done) your guy's problems might be from having the plates resting
on an uneven surface. I know that in my kiln, an even slightly warped
shelf will ruin a plate or platter. Maybe placeing a flat, level, heat
resistent platform in your pit will enable the plates to survive. Just a
random idea. Good luck!
Myrrhia

Cindy on sat 9 may 98

Beth,

Once the clay has fired to ^6, it is vitrified and will not take smoke
well. It is possible, since your pieces are large, that uneven heating in
your kiln accounts for the areas which do take smoke. Those areas may not
have reached ^6 and thus may be more porous. If you don't want to risk
pit-firing ^010 to ^06 bisque, you could try firing at least a little bit
lower--say ^1-^4. Vitrified ware cannot take smoke consistently. Try
smoke-firing a glass paper-weight. The smoke *will* wash off, as will any
colored fuming effects.

If you want color, try copper carb or sulfate, iron chromate, pet food,
organics--yarrow, marigolds, banana peels, sea weed, etc. To increase the
fuming effects, isolate your piece in some sort of saggar. With large ware,
this may be difficult. You might try heavy-duty aluminum foil (with the
fuming materials inside, of course).

Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm

BobWicks on sun 10 may 98

Beth: I think if you add some nepheline syenite to your iron oxide wash that
it will flux enough to hold it in place. Peter Pinnel offered this suggestion
for me when I had a similar problem. I believe he said about 9% would do it.

Bob

MRS SANDRA L BURKE on sun 10 may 98

Cindy,
I was reading your message to Beth and I have a question about the
aluminum foil fuming. Do you completly enclose the fuming materials
in the foil or do you leave the packet parially open. Also what cone
do you fire to?

Jenny Lewis on fri 18 sep 98

I took part in my first pit-firing recently - wow!!! I knew it
would be a Good Thing to do, but I never expected it to be that good.
I just have to enthuse to the clay world at large!

I did a 4-day thing at the workshop I go to, which consisted of pit,
sawdust, newspaper and raku firings. Unfortunately, the technician
at the workshop is not a terrific teacher - nice person, good sense
of humour, but not great on imparting information. So we all sort of
bumbled around a bit without knowing what we were supposed to be
doing. Credit to Clayart though - I remembered so many bits of
information that I had read, it helped enormously! Incredible
really, considering I have a sieve-like memory.

It was such fun, and now I look at my little pots, plus one fat-belly
coiled larger one, and feel quite amazed to think that I had anything
to do with them. I may have pinched and prodded some bits of clay
around, but the results are as good as they are simply because of the
fire. The kiln goddess was exceptionally good to us and there were
hardly any breakages.

I know what Joyce means (hi Joyce, welcome back) about keeping her
wood-fired pots to herself. If anyone dares to suggest taking one
of my pit-pots away there will be trouble. Unless it's a close
relative or friend I can trust....

Or someone fabulously rich....

Can't wait to play with fire like that again, although I don't often
get the opportunity, but I'll keep a lookout.

Anyone still reading this far, thank you for letting me drivel on!

jl
overlooking regents park
and thinking pits

Grace Epstein on sat 19 sep 98

jl
can you share some of the details of techniques and results ?
grace

Alford Wayman on sun 27 sep 98

HEy!
I am doing a pit firing and since this is the first one I have no idea of
what I am doing. I have the pots and the big hole in the ground and
plenty of sawdust.
I was wondering if anyone out there could give me some suggestions on how
to go about doing this.
I would like to know how I should prepare the pots for the firing.
How to make engobes or slips to put on them, and also the high tec. stuff
like air flow and all. So if a few of you potters could give me some
pointers I would feel more confident and safe doing this! thanks
From al in P.A.

Chris Leake on tue 29 sep 98

My husband and I have had a lot of fun pit firing. We got a lot of
information from the following books:
Burnished Clay by Miriam Licht
Sawdust Firing by Karin Hessenberg (Part of the Complete Potter series)
Smoke-fired Pottery by Jane Perryman
Santa Clara Pottery Today by Betty LeFree
The LIving Tradition of Maria Martinez by Susan Peterson
Also, if you have access to a 1991 June/July/August Ceramics Monthly,
there is a great article:
Woody Hughes at Peters Valley by Susan Evans. It has information on
terra sigillatas.
Good luck! Hope you have as much fun as we have had!

> ----------------------------Original
> message----------------------------
> HEy!
> I am doing a pit firing and since this is the first one I have no idea
> of
> what I am doing. I have the pots and the big hole in the ground and
> plenty of sawdust.
> I was wondering if anyone out there could give me some suggestions on
> how
> to go about doing this.
> I would like to know how I should prepare the pots for the firing.
> How to make engobes or slips to put on them, and also the high tec.
> stuff
> like air flow and all. So if a few of you potters could give me some
> pointers I would feel more confident and safe doing this! thanks
> >From al in P.A.

Louis Ballard on tue 29 sep 98

Get some Peat Moss and mix it in with your sawdust. How much? Try 2
to 1 Sawdust to Peat Mix and adjust according to your experience which
you will soon have.
Get some Copper Carbonate and mix it with Borax 50-50 more or less in
a wash solution and drip, drizzle or brush over your pots which are
preferably made of white earthenware or covered in some way with
white slip and either bisque-fired or unfired or a mix of both? load the kiln
spacing about a fist width of sawdust/peat mix in between the pieces
making sure to fill up the interiors of the pots setting the pots on a good
bed of fuel and be sure to throw in some TREATS such as orange and
banana peels, compost, etc.....and allow about a shoe length of fuel
above the pots so the smolder can set itself before engaging the pots
and light the entire mixture with Ronson lighter fluid making sure that
there is not a big flame or build a small wood fire on top of the sawdust
and extinguish the flame to establish the smolder then cover with scrap
sheet metal to lessen the air flow to a slight draft and then GO AWAY
AFTER you have made sure that the mix will not reignite into a brushfire;
SMOLDER, you want SMOLDER. Come back the next day after making
and drying the next load of pots and unload the previous load and RINSE
DO NOT SCRUB the surfaces of the fired pots; ALLOW TO DRY
THOROUGHLY; then spray sensibly(read the directions!!!) with Duncan
SS332 Matte Ceramic Sealer; take a few slides and head for the nearest
craft show or gallery. Did you remember the KILN GOD? Don't do this in a
BIG CITY or even some of the smaller ones for that matter. You can also
use metal trash bins with holes punched in them fior air-flow which can
be adjusted by plugging the holes with clay or common household
loose-brick kiln. Happy Pitting!! LB

Alford Wayman on wed 30 sep 98

Chris Leake wrote:
>
> ----------------------------Original message----------------------------
> My husband and I have had a lot of fun pit firing. We got a lot of
> information from the following books:
> Burnished Clay by Miriam Licht
> Sawdust Firing by Karin Hessenberg (Part of the Complete Potter series)
> Smoke-fired Pottery by Jane Perryman
> Santa Clara Pottery Today by Betty LeFree
> The LIving Tradition of Maria Martinez by Susan Peterson
> Also, if you have access to a 1991 June/July/August Ceramics Monthly,
> there is a great article:
> Woody Hughes at Peters Valley by Susan Evans. It has information on
> terra sigillatas.
> Good luck! Hope you have as much fun as we have had!
>
> > ----------------------------Original
> > message----------------------------
> > HEy!
> > I am doing a pit firing and since this is the first one I have no idea
> > of
> > what I am doing. I have the pots and the big hole in the ground and
> > plenty of sawdust.
> > I was wondering if anyone out there could give me some suggestions on
> > how
> > to go about doing this.
> > I would like to know how I should prepare the pots for the firing.
> > How to make engobes or slips to put on them, and also the high tec.
> > stuff
> > like air flow and all. So if a few of you potters could give me some
> > pointers I would feel more confident and safe doing this! thanks
> > >From al in P.A.Thanks Chris Leake!
I just got some good books yesterday .
I am building up a good libuary of books that have become very useful.
Right now I have about 15 pots I am going to try out in a pit fire . All
I have to do is get them ready. Thanks for the material references.
Al.p.s The latest issue of Ceramics monthy has an artical called "women
who fire wood". I found that I like raw and earthy, primative pots and
texture on clay so that is what led me to try a pit fire. Thanks again!

elle and md on thu 21 jan 99

Most of my work is pit fired so here is my take on it. With everything
in clay you'll probably find a bunch of different opinions.
I use a high temp white stoneware clay. I have used lofw fire before but
didn't like it as much. You may want to try a few diffrent ones to see
which one you like the best.
As far as temp, I hae never really checked the temp but once I did but a
piece of unbisqued ware in and by the end it had been bisqued but it was
at a low temp.
I have done a couple different types of pit/sawdust firing(ie in a pit,
a makeshift kiln and sagger). While I think they are all great I tend to
go back to the pit in the ground.
You can put terra sigellata. It is not a glaze more like slip than
glaze but it can be burnished so it has a shine to it. I have done this
before and I know others who do this to waterproof it and/or make it
shinier. You can use polyurethane.You can buy it glossy, satin etc. I
have heard of people using Thompsons water seal before but have never
used it.
Two books I can suggest are Smoke fired pottery by Jane Perryman and
Sawdust firing which is part of the Complete potters series. Also if you
can find any last year in a magazine called ceramic review(out of
london) there was an article on Magdelene Odundo. She I believe does
hers in a gas kiln but you might be able to pick up some good info. In
the Jan? edition of Ceramics monthly was an article on a woman who does
pit firing. If I come up with any more I'l let you know.
Good luck

Michelle

FUSION:The Ontario Clay & Glass Association on wed 17 nov 99

------------------
Hi Lisa,

I solved this problem with my pit firing by digging a vent. Dig a small =
tunnel
on a vertical angle that starts a few feet beside the pit and comes out on =
the
inside wall of your pit, near the bottom. A long metal rod is the best tool=
for
this but a stick will do. It's hard work but worth it. You can block the =
vent
with a rock when you need to get reduction. If it's a big pit, a couple of
vents on opposite sides could be good.

I wish I could show you a drawing. Feel free to e mail me personally if you
need clarification.

-Rebecca pothead=40interlog.com

----------------------------Original message----------------------------
Hey y'all. We dug a hole in the ground to replace the brick =22pit=22 we
had been using to do our pit firing. The bricks had gaps, where air
could get through, and draw the fire down to the pots. The hole in the
ground doesn't have this feature, and we're wondering how this could be
achieved with an in-ground actual pit. Haven't unloaded yet, so don't
know if it's actually necessary, but we're wondering ahead of time. Any
suggestions?
--
Lisa Skeen

Dana Henson on sun 6 feb 00

Looked through the archives and found only a brief reference to my
dilemma---how can you pit fire without getting the black residue on the pieces?
The post that I found said that this never happened if they used leaves instead
of sawdust.
I keep seeing pictures of beautiful pit-fired work that is smooth all over,
without the residue. How are the experts doing it? Is the answer using leaves
instead of sawdust? Would greatly appreciate input!

Dana Henson
Denton, TX

Carolyn Nygren Curran on mon 7 feb 00

what kind of wood is used in making the sawdust? I'm no expert, but it
seems to me that I've read caveats about not using pine because of the
resin. Someone correct me if I'm wrong. CNC

Kent / Pat on tue 8 feb 00

Carolyn

> what kind of wood is used in making the sawdust? I'm no expert, but it
> seems to me that I've read caveats about not using pine because of the
> resin. Someone correct me if I'm wrong

In my pit firing, low salt firing, wood fuming and raku, I have used both
hard wood and soft wood without a problem. The only thing I would stay away
from is pine needles, because, I am told that the creosote may be
significantly higher. Pine, spruce etc., also contain that, but at a lower
level, hence the need to clean your chimney more often.


The thought just occurred to me, I wonder if that is what turned Maria
Martinez's pots so beautifully black. Anyone have an idea?

Pat Porter
pporter@4dv.net
Aurora CO USA
----- Original Message -----
From: "Carolyn Nygren Curran"
To:
Sent: Monday, February 07, 2000 12:20 PM
Subject: Re: Pit firing


> ----------------------------Original message----------------------------
>
> what kind of wood is used in making the sawdust? I'm no expert, but it
> seems to me that I've read caveats about not using pine because of the
> resin. Someone correct me if I'm wrong. CNC

Sheron Roberts on wed 9 feb 00

------------------
When I pit fired my little
millennium pots on New Year's
Eve, I used cedar shavings,
sold for dog and hamster bedding,
because I could not find sawdust.
I also used yellow pine lumber
scraps, not treated, and hardwood
debris, (complements of Hurricane
Floyd). The clay I used was
a white stoneware, and I had
burnished the pieces. I wanted
the pots to turn out black and shiny
and they did, well most of them
anyway. I do not know if it
had anything to do with the
shavings or wood, or
reduction.
I have never pit fired before and
I more or less did this on my
own. The person I was supposed
to have fired with came down with
the flu and couldn't do anything.
Maybe some of you could
enlighten me. :)
Sheron in NC

By the way, when I pulled them
out of the fire I washed them
and scrubbed them with a
soft bristled brush and the
residue came off.

Vince Pitelka on wed 9 feb 00

> The thought just occurred to me, I wonder if that is what turned Maria
>Martinez's pots so beautifully black. Anyone have an idea?

Maria's pots were fired on a low grate, with kindling under the grate, and
dry cow-pies all around and on top. Such a fire is very low-key, but quite
hot. It never flares up at all, and in fact Maria and Julian did their
bonfiring under the roof of an open-sided wooden shed. When the fire
reached maximum temperature, it was smothered with large amounts of crushed
dry manure, and then immediately buried in ashes. The smoke from the
crushed manure, trapped within the fire by the ash cover, turns the pots
jet-black.
Best wishes -
- Vince

Vince Pitelka
Home - vpitelka@DeKalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166

P.Bjerkan on wed 5 apr 00

Hi, I'm in the Napa Valley and I'm interested in pit firing (never done it
before). Where and when are you going to do it???
Peggy Bjerkan
peggy@maskwoman.com
http://maskwoman.com
----- Original Message -----
From: SAM YANCY
To:
Sent: Tuesday, April 04, 2000 11:00 AM
Subject: Re: weird economics


> ----------------------------Original message----------------------------
> Hi Jean,
> How I agree with you on the expectations of folks who want what they
> want, and usually for a price that makes my neck twist. It isn't just in
> pottery though, least I don't think so. Last week I went to Mail Boxes
> Etc. to buy stamps. The guy charges an extra buck something, for one
> book! When I asked him 'why' he just looked at me....Woos (SP?) that I
> am I bought one book, (was gonna buy more), and walked away thinking it
> is true: If the buck isn't in my pocket then it's in yours! So what?
> don't no. Maybe I'll stay a woos, I don't have much time for people so
> into making that almighty buck.
> Mary Jean....in the sunny bay area of San Francisco....Pit fire
> anyone?

SAM YANCY on fri 7 apr 00

Hi Peggy,
We haven't set aside any dates for pitfiring yet. Normally we fire
at the ocean, but I would rather fire on land where their isn't so much
sand, as at the ocean. And I haven't found a spot yet. Do you have work
ready to fire?

Patrice Murtha on wed 21 jun 00

For those of you in the Chicago area there will be a pit firing on July 15
from 10-4pm lead by Joe Pintz at the Evanston Art Center. Price of the
workshop is $25.00, you can call the Center at 847-475-5300.

Jim and Marge Wade on wed 25 apr 01

Check out "Sawdust Firing" by Karin Hessenberg and "Smoke Fired Pottery" =
by
Jane Perryman. Great references. Steve Branfman's "Raku: A Practical
Approach" also has a chapter on the subject. Bisquing the pots first will
help alot to reduce breakage. I've used a low fire white clay with good
results and it's easy to work with. Some use a raku body. Let me know if =
you
need more specifics.

Marge

> From: Chris Clarke
> Organization: chrisclarkepottery
> Reply-To: Ceramic Arts Discussion List
> Date: Thu, 26 Apr 2001 11:46:59 -0700
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: pit firing
>
> Help, I've some how been sucked into doing a pit fire with a bunch of g=
irl
> scouts, any basic books out there, tricks, tips you guys know. Nothing=
fancy,
> just basic stuff. chris
>
>
> temecula, california
> chris@ccpots.com
> www.ccpots.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.

Jim and Marge Wade on thu 4 oct 01

There have been lots of suggestions given as to types of waxes to use after
pit firing, but does any one use something more orgainc such as beeswax? I
have not been able to find a chunk of pure beeswax so have been using a
product called Sno Seal sold at outdoor stores for sealing boots (a sample
usually comes with Sorrel boots). It has a strong scent of beeswax. I would
like to use something non petroleum based knowing I will probably not have
the same amount of shine, but at least it would be a more natural finish.

Marge

> From: Cindy Strnad
> Reply-To: Ceramic Arts Discussion List
> Date: Thu, 4 Oct 2001 10:21:56 -0600
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Re: pit firing - acrylic wax?
>
> Dear Lajos,
>
> Many kinds of wax or oil will work to finish your
> pit fired pieces. If you wax the inside with
> acrylic wax, they will even be somewhat watertight
> so they can hold flowers, etc. (Not food), though
> you should still set the vase on a saucer or
> something. As Jonathan says, they will smell a bit
> sweet if you use acrylic wax. This wax is
> available at your grocery store--a popular brand
> is Future floor wax. The aroma goes away after
> several days, and if you don't apply the wax
> thickly, you don't end up with super shiny pots.
> Works well for me. However, try several things and
> find out which you like best.
>
> Cindy Strnad
> Earthen Vessels Pottery
> RR 1, Box 51
> Custer, SD 57730
> USA
> cindy@earthen-vessels-pottery.com
> http://www.earthen-vessels-pottery.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.

Martin Howard on fri 5 oct 01

Marge, I use beeswax, but I don't do pit firing. I use it with vegetable oil
as a wax resist. I melt it on the boiler, when it is cold enough to need to
light the boiler.
Or I put it on top of the kiln. When it is not hot I use if by just rubbing
the bottom of pots on the flat surface. When it is hot I just touch the
bottom of pots onto the surface so as to cover the footring, but not the
raised inside bottom area within the footring. That is quite a knack, but
worthwhile.

You can get the raw beeswax, unrefined (you don't need to pay the price of
the refined stuff) from any bee-keeper. It is slightly grey and has all
sorts of interesting bits in it from dead bees:-o

Makes the pottery smell wonderful, when warming.

Martin Howard
Webb's Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
England

martin@webbscottage.co.uk
http://www.webbscottage.co.uk
This web-site is about to be updated.

emily ivey on fri 5 oct 01

Nasco an Dick Blick and any art school supply dealer sells chunks for
Batik. A pound of it is around $8 and all these places are on-line at
their respecive dot coms.


On Thu, Oct 04, 2001 at 07:56:38PM -0500, Jim and Marge Wade wrote:
> There have been lots of suggestions given as to types of waxes to use after
> pit firing, but does any one use something more orgainc such as beeswax? I
> have not been able to find a chunk of pure beeswax so have been using a
> product called Sno Seal sold at outdoor stores for sealing boots (a sample
> usually comes with Sorrel boots). It has a strong scent of beeswax. I would
> like to use something non petroleum based knowing I will probably not have
> the same amount of shine, but at least it would be a more natural finish.
>
> Marge
>
> > From: Cindy Strnad
> > Reply-To: Ceramic Arts Discussion List
> > Date: Thu, 4 Oct 2001 10:21:56 -0600
> > To: CLAYART@LSV.CERAMICS.ORG
> > Subject: Re: pit firing - acrylic wax?
> >
> > Dear Lajos,
> >
> > Many kinds of wax or oil will work to finish your
> > pit fired pieces. If you wax the inside with
> > acrylic wax, they will even be somewhat watertight
> > so they can hold flowers, etc. (Not food), though
> > you should still set the vase on a saucer or
> > something. As Jonathan says, they will smell a bit
> > sweet if you use acrylic wax. This wax is
> > available at your grocery store--a popular brand
> > is Future floor wax. The aroma goes away after
> > several days, and if you don't apply the wax
> > thickly, you don't end up with super shiny pots.
> > Works well for me. However, try several things and
> > find out which you like best.
> >
> > Cindy Strnad
> > Earthen Vessels Pottery
> > RR 1, Box 51
> > Custer, SD 57730
> > USA
> > cindy@earthen-vessels-pottery.com
> > http://www.earthen-vessels-pottery.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.
>
> ______________________________________________________________________________
> 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.

--
Support the arts: buy Tupperware!
http://my.tupperware.com/ivey

emily ivey
artist in residence, gweezle bur poetry manufacturing
http://www.earthandfire.com

Craig Clark on sat 19 jan 02

I've only done a pit firing once, and that was about fifteen years ago. =
Could any of you pit firing gurus on the list give me a crash coarse? =
I'd like to give it a try.
Thankyou
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org

Jeff Tsai on sat 19 jan 02

It's pretty easy really.

Dig a pit, size doesn't really matter, but lets say three 3' x 3' x 3' If
you have more ware, you can make it wider or longer, but 3' is deep enough.

Spread about 6 inches of sawdust (a mixture of fine and big particles is
good, but whatever is available) and compact it down as much as you can.
Lay the pots atop the sawdust, bury them if you live in more sawdust. Where
the sawdust touches the pot should go black, and if you place the piece
upside down so the moutn of a pot is under sawdust, the inside will go black.

Spread copper carbonate and rocksalt around the pots. Inside the pots is nice
too, I usually put down more sawdust in the pots and throw in some copper and
salt.

Build up a layer of wood carefully over your pieces. Smaller stuff first,
thicker stuff last. I've seen people put pot shards over their pieces after
about a foot of wood to "protect the ware" but I find this unnecessary.

Use lighter fluid to soak the wood and light the pit. (it's important to have
bisqued work and to try and get the pit going all at once to avoid shock from
different temperatures in the pit.

I also use things like red copper oxide and copper sulfate and too a lesser
extent cobalt and iron. Seaweed works great, as do some kinds of leaves. The
initial wood pile on top should become a mound just above ground level. I
usually throw more wood on as the wood burns down to build up a good layer of
coal and then cover the pit with corrugated steel after the flames have died
down significantly.

-jeff

Martin Rice on sat 19 jan 02

Jeff wrote:

it's important to have bisqued work and to try and get the pit going all at
once to avoid shock from different temperatures in the pit.

For the last few days I've been reading as much as I can find online about
pit firing, including the clayart archives.

I want to start pit firing because it's almost impossible for me to get an
electric or gas kiln where I am. So this question of having bisqued work to
pit fire is kind of a bugger. My understanding from what I've read is that
the chief reason for this is that non-bisqued work tends to break because of
what the shock that Jeff refers to.

I'm certainly willing to experience higher breakage if the alternative is
not to fire, but my question is: does anyone on the list have any
suggestions as to how to pit fire in a way that would reduce the incidence
of breakage?

Thanks,
Martin
Lagunas de Barú, Costa Rica
www.rice-family.org

L. P. Skeen on tue 20 may 03

> << I'd appreciate any suggestions from those who pit fire as to types of
> white, smooth, clay they've had success with.

Laguna Bmix and Aardvark BEE mix, both ^6 and 10. Excellent stuff.

L

Naomi Rieder on tue 20 may 03

I'd appreciate any suggestions from those who pit fire as to types of white,
smooth, clay they've had success with. I've been using a 50/50 ball/talc
and love it to work with, but the breakage rate is high: 50-70%, which is
not exacly encouraging. I'd be more interested in knowing about a
commercially prepared clay than a special mix, since I use only small
amounts. Also, has anyone tried using molochite with a Grolleg porcelain
clay fro pit firing?

MTIA,
Naomi

Marta Matray Gloviczki on tue 20 may 03

naomi,
i use raku clay (tan claybody color) with white terra sig or porcelain
clayslip. you can use your own white claybody`s slip or make terra sig out
of it.
any commercial raku clay body should be strong enough for pitfire.
marta
ps: ooops, i used the 'body' word too many times...should i go for time-out?


>I'd appreciate any suggestions from those who pit fire as to types of
white,
>smooth, clay they've had success with. I've been using a 50/50 ball/talc
>and love it to work with, but the breakage rate is high: 50-70%, which is
>not exacly encouraging. I'd be more interested in knowing about a
>commercially prepared clay than a special mix, since I use only small
>amounts. Also, has anyone tried using molochite with a Grolleg porcelain
>clay fro pit firing?

John Guerin on tue 20 may 03

In a message dated 5/20/03 3:23:53 PM Central Daylight Time, naomirdr@AOL.COM
writes:

<< I'd appreciate any suggestions from those who pit fire as to types of
white,
smooth, clay they've had success with. I've been using a 50/50 ball/talc
and love it to work with, but the breakage rate is high: 50-70%, which is
not exacly encouraging. I'd be more interested in knowing about a
commercially prepared clay than a special mix, since I use only small
amounts. Also, has anyone tried using molochite with a Grolleg porcelain
clay fro pit firing?

MTIA,
Naomi >>

Hi Naomi,
I have used Laguna's EM212 for Pit Firing. It is a pure white with talc
added. It is the same as EM210 but has a medium temper added which acts as a
good thermal shock. You can also reduce breakage by prefiring in an electric
kiln. I prefire at cone 018. The low prefire allows the pitfiring to still
absorb the pitfire colors.

Good luck
John Guerin
Tucson, AZ

Elizabeth Herod on wed 21 may 03

Lisa--

Is there an East coast supplier for the Aardvark BEE mix, or do you have
that shipped from CA?

Beth

> << I'd appreciate any suggestions from those who pit fire as to types of
> white, smooth, clay they've had success with.

Laguna Bmix and Aardvark BEE mix, both ^6 and 10. Excellent stuff.

Ilene Mahler on wed 21 may 03

Cambell pottery in Va and Md carry Aardvark clays even Colemen Porcelain
thats where I get mine from...Ilene in Conn
----- Original Message -----
From: "Elizabeth Herod"
To:
Sent: Wednesday, May 21, 2003 8:25 AM
Subject: Re: Pit firing


> Lisa--
>
> Is there an East coast supplier for the Aardvark BEE mix, or do you have
> that shipped from CA?
>
> Beth
>
> > << I'd appreciate any suggestions from those who pit fire as to types of
> > white, smooth, clay they've had success with.
>
> Laguna Bmix and Aardvark BEE mix, both ^6 and 10. Excellent stuff.
>
>
____________________________________________________________________________
__
> 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.

claybair on wed 21 may 03

Lisa,

Is that B-Mix with or without sand?

Gayle Bair
Bainbridge Island, WA
http://claybair.com

-----Original Message-----
From: L. P. Skeen

> << I'd appreciate any suggestions from those who pit fire as to types of
> white, smooth, clay they've had success with.

Laguna Bmix and Aardvark BEE mix, both ^6 and 10. Excellent stuff.

L

____________________________________________________________________________
__
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.

L. P. Skeen on wed 21 may 03

I've used both, with excellent results.

> Lisa,
>
> Is that B-Mix with or without sand?

L. P. Skeen on wed 21 may 03

Campbell Ceramic Supply has it. The closer one to you is in Richmond but I
don't have their number.

L
----- Original Message -----
From: "Elizabeth Herod" > Lisa--
>
> Is there an East coast supplier for the Aardvark BEE mix, or do you have
> that shipped from CA?

Gerald O'Sullivan on thu 22 may 03

Pit firing losses are lowest if the clay-body is very open, like raku clay.
So in theory, you should be able to use any white clay as long as you open
it with lots of grog or clean river sand. This will allow the clay to cope
with the uneven thermal stresses produced by the pit fire.

Traditional earthernware clay is coarse so that the pots can stand directly
in the fire without breaking when used for cooking. My clay bodies are 50/50
clay/river sand - which makes surface decoration tedious - but they survive
my firings with no bisque and no breakages.

If you don't bisque, then besides thermal stresses, you will have heavy
losses if the temperature increases too quickly, so pre-heat the pots gently
and thoroughly, and then fire immediately. This will drive off the water
(which is always present even in bone-dry clay) without bursting the
claybody.

(I wish I had known this when I started - my first firings were like a
shooting range, with pots bursting with a bang, flinging shards around the
place. Not to mention the spalling of the house bricks I used. Definite
hard-hat area, until I learnt)

Gerald

----- Original Message -----
From: "Elizabeth Herod"
To:
Sent: Wednesday, May 21, 2003 2:25 PM
Subject: Re: Pit firing


> Lisa--
>
> Is there an East coast supplier for the Aardvark BEE mix, or do you have
> that shipped from CA?
>
> Beth
>
> > << I'd appreciate any suggestions from those who pit fire as to types of
> > white, smooth, clay they've had success with.
>
> Laguna Bmix and Aardvark BEE mix, both ^6 and 10. Excellent stuff.
>
>
____________________________________________________________________________
__
> 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.
>

Bonnie Staffel on sun 24 aug 03

Hi Clayarters,

I am planning to create a pit or a trench for pit firing. If I decide to
make the trench type, I have read that wind direction creates a draft.
Would it be better to create the trench towards the prevailing winds or
crosswise? I don't believe this question was ever discussed in the trench
firing information so am looking to you who are gurus of this process. I
will be making it in a very high windy area where the winds are coming from
southwest towards the northeast.

Thank you,
http://pws.chartermi.net/~bstaffel/kiln.htm
This kiln is for sale. I am looking at $2000 or best offer. Great kiln for
sculpture, large pot firing and production.

Bonnie Staffel of Charlevoix.

Naomi Rieder on fri 17 oct 03

My surface pit is built on ground with a high water table and now, with all
the rain we've had in this area, the bottom is quite wet. I'd like to make
some kind of steel grating to place inside, then put bricks on top, then the
sawdust, etc. I have no idea what thickness or shape the steel should be so
that it won't buckle. Has anyone done this? Any suggestions?

MTIA,

Naomi Rieder
In the very soggy Catsk

logan johnson on fri 17 oct 03

Hi Naomi,

my husband recomends that you use 1/2 " expanded sheet metal. this will allow it to breathe so it wont capture moisture. don't know how this will work but, it might be worth a try.

good luck!!
Logan in soggy seattle
Carpe Argilla!!

Naomi Rieder wrote:
My surface pit is built on ground with a high water table and now, with all
the rain we've had in this area, the bottom is quite wet. I'd like to make
some kind of steel grating to place inside, then put bricks on top, then the
sawdust, etc. I have no idea what thickness or shape the steel should be so
that it won't buckle. Has anyone done this? Any suggestions?

MTIA,

Naomi Rieder
In the very soggy Catsk

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terry sullivan on sat 18 oct 03

Naomi,

We have found that some moisture wicking into the sawdust bedding for
pots in the pit fire produced some very dark and shiny blacks. We
actually wet some of the sawdust intentionaly to get these great blacks.
Or, if that isn't desired, one can put the pieces in metal can sagars
for great results.

Terry Sullivan
Nottingham Arts

Les on sat 18 oct 03

Naomi -

Mayor Mel suggested to us a while back, when building a kiln, to put a piece
of expanded metal between the base and the floor of the kiln.

I am wondering if you put a sheet of expanded metal under your pit floor if
it would stop the moisture problem.

Les Crimp in very rainy, very wet Nanoose Bay on Vancouver Island.
lcrimp@shaw.ca

----- Original Message -----
From: "Naomi Rieder"
To:
Sent: Saturday, October 18, 2003 3:20 PM
Subject: Pit firing


> Dear Clayarters,
>
> I"d appreciate hearing from anyone who has solved this kind of problem:
> how to prevent ground moisture from wicking-up in my surface pit and
wetting
> the sawdust layer. The area is 48" x 55" with concrete bricks on the
> bottom, laid over gravel. Because this area, when put in, was divided
into
> 4 sections, with the dividing bricks set so they are higher than the rest,
> I've levelled the area with more gravel. So far, I've found a metal
> supplier who has what they call "bar grating" (some call it "subway of
steel
> welded in a grid, either 1" or 1-1/2" h. & spaced 1" apart. I'd have 4
> sections cut 24" x 27" (they'd each way 40-!/2lb. - my max schlep
ability).
> On top of that I've planned on putting hard firebricks--the kind used in
> fireplaces. Do you think these would insulate enough to keep the grating
> from buckling? They can be heated up to 2000 deg F., and the heat from the
> pit fire isn't that high.
>
> Do you think the above set-up will work? Or is there a better set-up?
>
> MTIA!!!
>
> Naomi Rieder
> In the very, very, wet Catski
>
>
____________________________________________________________________________
__
> 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.

Naomi Rieder on sat 18 oct 03

Dear Clayarters,

I"d appreciate hearing from anyone who has solved this kind of problem:
how to prevent ground moisture from wicking-up in my surface pit and wetting
the sawdust layer. The area is 48" x 55" with concrete bricks on the
bottom, laid over gravel. Because this area, when put in, was divided into
4 sections, with the dividing bricks set so they are higher than the rest,
I've levelled the area with more gravel. So far, I've found a metal
supplier who has what they call "bar grating" (some call it "subway of steel
welded in a grid, either 1" or 1-1/2" h. & spaced 1" apart. I'd have 4
sections cut 24" x 27" (they'd each way 40-!/2lb. - my max schlep ability).
On top of that I've planned on putting hard firebricks--the kind used in
fireplaces. Do you think these would insulate enough to keep the grating
from buckling? They can be heated up to 2000 deg F., and the heat from the
pit fire isn't that high.

Do you think the above set-up will work? Or is there a better set-up?

MTIA!!!

Naomi Rieder
In the very, very, wet Catski

Logan Oplinger on mon 20 oct 03

On Fri, 17 Oct 2003 09:41:47 -0400, Naomi Rieder wrote:

>My surface pit is built on ground with a high water table and now, with all
>the rain we've had in this area, the bottom is quite wet. I'd like to make
>some kind of steel grating to place inside, then put bricks on top, then
>the sawdust, etc. I have no idea what thickness or shape the steel should
>be so that it won't buckle. Has anyone done this? Any suggestions?
>
>MTIA,
>
>Naomi Rieder
>In the very soggy Catsk


Hello Naomi,

Recently some friends and I built a small 27 in. x 45 in. fire pit in and
area that is constantly flodded with rainwater. We placed a sheet of
galvanized corrugated roofing metal directly on the ground in the bottom of
the fire pit to keep moisture out of the sawdust. The sawdust is placed
directly on top of the roofing metal. Works fine, relatively inexpensive,
should last for a few firings.

Logan Oplinger
Another Pacific Island
(Over 8 in. of rain in 48 hours this weekend past!)

Naomi Rieder on mon 20 oct 03

Hi, Logan,

Does the corrugated sheeting buckle from the heat?

Naomi

Logan Oplinger on tue 21 oct 03

On Mon, 20 Oct 2003 08:59:59 EDT, Naomi Rieder wrote:

>Hi, Logan,
>
>Does the corrugated sheeting buckle from the heat?
>
>Naomi


Hello Naomi,

Umm, good question. It is possible that longer sheets of metal may warp if
heating is uneven.

In our firepit two short length sheets were overlapped to completely cover
the bottom of the pit. I have not noticed any warping. Short lengths were
not intentional, but were used because they were salvaged from scrap. The
corrugation, and the short lengths should help to relieve heat stress and
avoid warping. Also, since the burning wood and pots completely filled our
firepit, the metal was subjected to fairly even heating overall.

Logan Oplinger

Richard G. Ramirez on sat 9 apr 05

Hello,
Just enjoying the morning, reading your post on pit firing.
I remembered, when I use to go from greenware to finish product.
Enjoyed the process, hand or wheel-thrown, took the time in decorating them nicely. Wonder why few came out undamged and shinny-black. Changed the tightness of the pit, above ground or below. Fuel, loose higher temp, fine it smloders! I believe the key would be, bone-dry, slower fire, and fine sawdust. Richard Ramirez

Kate Johnson wrote:
> Wendy,
> I have had success by using the following in the pit. My "pit" is above
> ground created by stacking bricks about 8 layers high with some air holes
> between the bricks --mostly at the 1st or 2nd layer of bricks.



> Oh , I should say that after about 20 minutes of leaving the "pit"
> uncovered I cover it with sheet metal to create the smoke necessary to
> create the colors.
> There are many other methods --this one works for me. Breakage is usually
> less than 20% --you must accept some loss in this method as the temp rises
> quickly and (in my pit ) can approach 1800 degrees Far.


Fred, Wendy, etc.--I'm curious. We mostly seem to talk about pit firing as
a final step, glazing or smoke-glazing, with bisquing done in a more modern
kiln. Our forebears did ALL their firing that way (OK, so I'm trying to say
Native/Aboriginal/Indian/Primitive/First People, but I can't keep up with
what word to use...) Anybody going from raw greenware to finished
product, pit-firing?

Percentage-wise, I'm assuming you lose more than 20% that way. (Truthfully,
I pretty much lost 95% when I tried it.) Anyone have thoughts on this?
Experiences to share?

Best--
Kate Johnson
http://www.cathyjohnson.info/

Art, History, Nature and More at Cathy Johnson's Cafepress--
http://www.cafepress.com/cathy_johnson/

Graphics/Fine Arts Press--
http://www.epsi.net/graphic/

______________________________________________________________________________
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settings from http://www.ceramics.org/clayart/

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Wendy on sat 9 apr 05

Ive never done a pit firing before and wondering if anyone has any great tips on getting some
interesting colours... much appreciate hearing your experiences.

thanks wendy in australia

Fred Hagen on sat 9 apr 05

Wendy,
I have had success by using the following in the pit. My "pit" is above ground created by stacking bricks about 8 layers high with some air holes between the bricks --mostly at the 1st or 2nd layer of bricks.

For colorants I layer the following :1st a line of salt, then on top of that a line of Copper Sulfate (small crystals that can usually be found at feed and grain companies or from flower and landscape retail outlets) then on top a layer of Copper Carb. The layers are placed around all the pots --in my case I have a layer of sawdust on the floor about 3-4 inches thick so the pots sit on the sawdust and the fumigants are trailed around the pots. Don't put the ingredients on the pots or they will make nasty blotches on your pots. Oh, prior to putting the pots in the pit I use terra sig so they are polished --when they come out I clean them up and put on some polish i.e. bees wax (or Johnson Table Wax) both seem to work, then buff with a soft cloth like flannel.
Oh , I should say that after about 20 minutes of leaving the "pit" uncovered I cover it with sheet metal to create the smoke necessary to create the colors.
There are many other methods --this one works for me. Breakage is usually less than 20% --you must accept some loss in this method as the temp rises quickly and (in my pit ) can approach 1800 degrees Far.
Good Luck!
Fred Hagen


Wendy wrote:
Ive never done a pit firing before and wondering if anyone has any great tips on getting some
interesting colours... much appreciate hearing your experiences.

thanks wendy in australia

______________________________________________________________________________
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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.

Vicki Hardin on sat 9 apr 05

Wendy,

Eduardo Lazo has written an excellent article on advanced techniques of pit firing which is posted on at

To the advice that Fred gave you I would add that it is very important that the fire become hot enough to cause these materials to fume and give you the results that you want. Many times, people will stoke their pits with too much sawdust, almost to the brim and not reach the temps that are needed. I am now using aluminum saggars with some sawdust in them rather than placing sawdust in the pit. On average, I burn two truck loads of brush (my neighbors love me) per firing. Stoking usually lasts about two hours. I have found that quick cooling leads to the fuming being more intense. So, I do not cover the pit at all, letting it cool to the point at which the saggars can be removed. I have considered removing them while hot, but my pots are large and I feel likely to be damaged.

Good Luck
Vicki Hardin
http://VickiHardin.com
>

Vicki Hardin on sat 9 apr 05

Wendy,
I second every thing that Fred said and add that one of the biggest problems with pitfiring is not getting the pit high enough in temperature to cause your chemicals to fume. I used to fill the pit with sawdust, build a small fire on the top, light it, and hope for the best. I came out with gray black smoke fired pots. So then I went to firing the pots in saggars filled with sawdust in my raku kiln. Now I am using aluminum saggars with a very small amount of sawdust which I burn in a pit with no sawdust at all. I usually burn two truck loads of brush in firing which takes about two hours to complete. After this, the pit is left to cool without covering as I have found that coveing extends the heat and causes the effects I want to in some cases burn off. I have considered taking them out while hot, but my pots are large and I am concerned I may break them.

In terms of chemicals, Eduardo Lazo has written an excellent article on Techniques of Advanced Pitfiring which you can find at

Good Luck! and let us know how this turns out.

Vicki Hardin
http://VickiHardin.com

Kate Johnson on sat 9 apr 05

> Wendy,
> I have had success by using the following in the pit. My "pit" is above
> ground created by stacking bricks about 8 layers high with some air holes
> between the bricks --mostly at the 1st or 2nd layer of bricks.



> Oh , I should say that after about 20 minutes of leaving the "pit"
> uncovered I cover it with sheet metal to create the smoke necessary to
> create the colors.
> There are many other methods --this one works for me. Breakage is usually
> less than 20% --you must accept some loss in this method as the temp rises
> quickly and (in my pit ) can approach 1800 degrees Far.


Fred, Wendy, etc.--I'm curious. We mostly seem to talk about pit firing as
a final step, glazing or smoke-glazing, with bisquing done in a more modern
kiln. Our forebears did ALL their firing that way (OK, so I'm trying to say
Native/Aboriginal/Indian/Primitive/First People, but I can't keep up with
what word to use...) Anybody going from raw greenware to finished
product, pit-firing?

Percentage-wise, I'm assuming you lose more than 20% that way. (Truthfully,
I pretty much lost 95% when I tried it.) Anyone have thoughts on this?
Experiences to share?

Best--
Kate Johnson
http://www.cathyjohnson.info/

Art, History, Nature and More at Cathy Johnson's Cafepress--
http://www.cafepress.com/cathy_johnson/

Graphics/Fine Arts Press--
http://www.epsi.net/graphic/

Vince Pitelka on sat 9 apr 05

> Fred, Wendy, etc.--I'm curious. We mostly seem to talk about pit firing
> as
> a final step, glazing or smoke-glazing, with bisquing done in a more
> modern
> kiln. Our forebears did ALL their firing that way (OK, so I'm trying to
> say
> Native/Aboriginal/Indian/Primitive/First People, but I can't keep up with
> what word to use...) Anybody going from raw greenware to finished
> product, pit-firing. Percentage-wise, I'm assuming you lose more than 20%
> that way. (Truthfully,
> I pretty much lost 95% when I tried it.) Anyone have thoughts on this?
> Experiences to share?

Kate -
Part of the confusion here has to do with terminology. Smoke firing or
sawdust firing usually cannot be considered true firing processes, because
the wares do not get to even minimal sintering temperature, and must be
pre-bisqued. Pitfiring means that the wares are fired in a pit among the
coals, and this process is capable of fairly high temperatures. Bonfiring
means above-ground firing in an open fire (sometimes with the wares on a
grate or in a cage within the fire), and the heating and cooling tends to be
abrupt and uneven.

I have been interested in ancient and tribal firing processes for several
decades, and around 1988 at U-Mass I started teaching a workshop called
"Primitive Ceramics." I quickly realized that the term "primitive" was
appropriate only for the techniques, not for the ancient and tribal wares,
and now I call the workshop "Ancient Clay." The first time I tried
bonfiring, most of the wares were not pre-bisqued, and the losses were very
high. We still had a wonderful time - digging through all those shards was
like an archaeological dig. People really loved the fragments, and the few
intact pieces were like treasures.

Most of the claybodies we use in studio ceramics would not stand up to
bonfiring without a bisque, because they are too tight and do not release
water vapor and chemically-combined water easily, and because it is too
difficult to control the heat. And in the fired state most claybodies have
relatively low thermal-shock-resistance and risk breakage during the
cooldown. Maintaining slow, even heat in a bonfiring is difficult. If you
had no other option, you could certainly do it.

Many of the claybodies traditionally used for bonfiring contain over 50%
tempering materials - sand, grog, crushed seashell, volcanic ash, etc., thus
they are able to release water vapor very quickly, and have very high
thermal-shock-resistance. They are fired to a very low temperature -
usually the equivalent of low red heat, about 1200 Fahrenheit - and thus in
the cool-down have even higher thermal-shock-resistance. That is why they
subsequently work so well as cooking pots over an open fire.

In my Ancient Clay workshop
() we always do
a blackware bonfiring at the end of the week, and after coating the wares
with terra sigillata and polishing them, we do a very low bisque-firing -
usually to cone 018. After that, the loss in bonfiring is extremely low,
and it also allows us to bonfire in a timely fashion. We can start the
bonfire at 8:30 AM and smother and bury it an hour and a half later, and
then dig it up mid-afternoon. The claybody we use contains equal parts
extra fine grog, Goldart stoneware clay, OM-4 ball clay, and fire clay.
Best wishes -
- Vince

Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/

Vicki Hardin on sat 9 apr 05

Kate Johnson Wrote
Fred, Wendy, etc.--I'm curious. We mostly seem to talk about pit firing as a final step, glazing or smoke-glazing, with bisquing done in a more modern kiln. Our forebears did ALL their firing that way (OK, so I'm trying to say
Native/Aboriginal/Indian/Primitive/First People, but I can't keep up with what word to use...) Anybody going from raw greenware to finished
product, pit-firing?

Percentage-wise, I'm assuming you lose more than 20% that way. (Truthfully,
I pretty much lost 95% when I tried it.) Anyone have thoughts on this?
Experiences to share?


Okay, I didn't do this, but did get to see it done by a group of Hopi Native Americans. It was tricky. They spent a considerable amount of time waiting for the right weather conditions and seemed almost as concerned for the amount of wind as possible rain. First they started a small fire in a circle of stones around which their handbuilt painted greenware pots were placed. That was allowed to burn for about an hour or so..(bear with, this was 15 years ago) Then a metal grate went over the coals. This was something that looked like it had been reclaimed from an old barbeque pit. The pots were shifted onto this following which came shards. It took about another hour to place the shards and there was much consideration of this. This was not to be a black firing but rather a firing which would produce those golden ochre pots that had been very meticulously painted. After the shard placement, came cow chips they brought all the way from Arizona to Texas! They were very particular abo
ut their fuel. Once these were stategically placed over the shards, the fire was lit on two sides and allowed to burn. Once the fire had burned down to some extent, sheets of tin were placed over the f
iring. Their were only 5 or 6 pots that were fired. One I remember broke and the other had a black carbon mark on it which meant it would have to be refired. Although I thought it was beautiful to them it was totally unacceptable. Having lost one pot and with the other marked, they did not consider this a successful firing, but a good one under the circumstances. One thing about their pots is that they were thicker than what you normally find and I think this allowed for more strength.

The process they went through to burnish was also interesting. After the pot was bone dry, it was thoroughly sanded following which a wet sponge was rubbed over the outside to work up a wet slip. Then a rock was used and their rocks were handed down from several generations.

The whole process was very exciting and underscored how meticulous one would have to be to take a piece of work from bone dry to finished work using the primitive process.

Best Regards,
Vicki Hardin
http://VickiHardin.com

Chris Leake on sat 9 apr 05

There are two books that I would reccomend to you, Smoke Fired Pottery by Jane Perryman and Alternative Kilns & Firing Techniques by James Watkins & Paul Wandless.

You can see pictures of the firing technique that Jim (my husband and flame man) and I use in the pit-fire gallery on my site.

http://www.leakeart.com

Sally McLeod on sun 10 apr 05

Wendy,

We do pit firing in bonfire rings (concrete) at the beach. The first step is to dig out all the stuff people have thrown into the fire pit. . . . . lots of broken glass (some of it has melted), nails, nuts and bolts, even a set of keys! Usually there are large rocks in the pit as well as charcoal from the wood of previous fires. What seems to work best for us is to use a screen (1" squares) that I attached to two pieces of 2X4's. Two handles have been attached to each board. Two "worker bees" grab hold of the handles and sift the contents of the ring by rocking
the stuff back and forth. All of the junk is put into large trash barrels and the clean sand and rocks are returned to the ring when we've finished firing.

As to the firing process, we bring bisque fired pots (cone 018) to the beach that were burnished prior to the bisque firing. We start early in the day and get the work done while it's still cool.
The pits have been dug out to approximately 30 inches deep. First comes a 4-6 inch layer of sawdust from the local lumberyard. Next, the pots are positioned on the sawdust knowing that where the pieces touch the sawdust, they will turn black. I should mention that I use Quyle's Sandstone Buff. It has a significant amount of iron in it and I love the orangey color of the finished pots. Next we drape pieces of sea grass, seaweed, banana peels, orange peels, eucalyptus leaves over the pots. Oh, some of pots have been wrapped with a thin guage copper wire or have a piece of a copper "choreboy" on them. I have done the process when some copper carbonate has been sprinkled onto the sawdust, but actually, I prefer using the organic materials. The next step is to cover the draped pots with "cow paddies". They are dry, light and don't really have any odor. The paddies are a good fuel, but also serve as an insulator from the fire that is built on top of them. We use a propane torch
for a quick start to burning the kindling. We actively feed the fire for two hours and then the waiting game begins. We prepare for the waiting game by bringing chairs, umbrellas, and food to share. It's always a pleasure to sit and share with other potters and friends.

When the first pots emerge from the embers, we cover them with other embers to prevent as much thermal shock as possible. It's a slow process, and eventually we are poking with sticks to uncover pots. We can't leave pieces in the pits and so have to get them out by late afternoon. The marks on the pieces seem to develop as the pots are pulled to cool. We dump ashes out of the pots, but some always manages to stay. The next day, we empty pots again and then vacuum them out. This seems to be the easiest solution.

Hope this helps. . . along with all the other posts.

Happy firing! (If you were at the Clay Times booth at NCECA; perhaps, you bought a "Mudslinging Pyromaniac" sweatshirt to wear.)

Marvin Klotz on mon 11 apr 05

I have been to two above ground "Pit Firings" in San Marcos Tlapazola,
Oaxaca with Eric Mindling. Potters in San Marcos fire their beautiful ware
just once, it is quite thin and burnished with a stone after coating with
two coats of red slip - sort of terra sigillata but not quite since
burnishing has to be fairly vigorous. As Vicki describes, there is much
care taken with noting wind conditions, placement of fuel and pots (and the
broken pots used around the outer edge) etc. for the firing. In addition
the ladies of San Marcos fire their pots a little late in the afternoon
after thoroughly warming the pots in the sun beforehand. The first firing
I attended went very well, I don't think a single pot was lost. The second
time, our group was delayed and got there rather late in the day. It was
clear that the coolness of the pots was a concern and indeed, as the firing
got underway, noises from the pile indicated that pots were "blowing
up". Macrena and Alberta, our teachers, were philosophical about losing
what must have been hours of work, they smiled gently and said "we will
just make more" (in Spanish). The clay used in San Marcos is dug from the
fields close to the village, by the potters themselves, cleaned of stones
and twigs, slaked in water etc. and then at the end mixed with quite a bit
of sand, which probably also contributes to their usual firing success.

Regards,

Joan Klotz.

Our forebears did ALL their firing that way (OK, so I'm trying to say
>Native/Aboriginal/Indian/Primitive/First People, but I can't keep up with
>what word to use...) Anybody going from raw greenware to finished
>product, pit-firing?
>
>Percentage-wise, I'm assuming you lose more than 20% that way. (Truthfully,
>I pretty much lost 95% when I tried it.) Anyone have thoughts on this?
>Experiences to share?
>

>Vicki Hardin said

>Okay, I didn't do this, but did get to see it done by a group of Hopi
>Native Americans. It was tricky. They spent a considerable amount of time
>waiting for the right weather conditions and seemed almost as concerned
>for the amount of wind as possible rain. First they started a small fire
>in a circle of stones around which their handbuilt painted greenware pots
>were placed. l

snip

> The pots were shifted onto this following which came shards. It took
> about another hour to place the shards and there was much consideration
> of this.
>
>The whole process was very exciting and underscored how meticulous one
>would have to be to take a piece of work from bone dry to finished work
>using the primitive process.

Chris Leake on mon 11 apr 05

It is great reading all these posts on pit-firing. The beach fire really struck home for Jim and I. A few years ago we combined a family reunion with a pit-fire at Whiskey Creek Beach in Washington.

We went out with the kids and collected cow pats from the family pasture and gathered drift wood from the beach. Everyone helped dig the pit. Since I am the only potter in the family, I brought enough pieces so each person could pick one and pack it in a saggar with their chosen materials. I had made clay saggars with holes to protect from the settling wood and beach rocks. The fire was a very respectable beach bonfire which we enjoyed for sometime before letting it burn down and covering it. As we enjoyed the beach, the food, and family we also experienced the one thing we had miscalculated, the height of the tide! The odd snake-like hissing gradually demanded our attention. We had planned on a few more hours before opening the pit, but mother nature had her own plans. That is when we got our first experience with fast cooling a pit-fire. We only lost two pieces! One "worry ball" floated out with a wave and the other we dug up a year later when digging a new pit.

The colors were great! Family members went home with treasures they had helped to create. Ever since we have pulled them out hot and fast cooled them. Of course, here in the sunny California Delta we can't match that icy Washington sea water for cooling fast.

I use either Laguna Sculpture Raku Clay or a recycled mix that is mostly Sculpture Raku. I fire to ^09.

If any clayarters out there would like to meet near beautiful Port Angeles Washington sometime for a pit-fire email me and maybe we can get together.

Also, if you are really into the Danish foods, check out Ballard in the Seattle area. I have my sister checking for Gammel Dansk for NCECA.

Happy Claying everyone!
Chris



http://www.leakeart.com

Kurt Raynor on tue 20 dec 05

Does anyone have ideas about clay bodies for pit firing? I am planning on
using a bisqued ^10 clay. Any information about maximum thickness? Has
anyone tried filling their fuel fired kiln with sawdust rather than building
a barrel kiln?

BTW natural gas and methane from any source are the same thing.

Kurt

Taylor, in Rockport TX on tue 20 dec 05

Kurt:

I am currently pit firing with a comercial raku clay with good results. I
coat with slip and burnish. Have not had any breakage with the raku clay.
I have also used a cone 6 stoneware with grog and had only one pot break
probably due to a firing mistake. I will be trying a cone 10 clay soon. I
have pieces with 1/4 inch come through no problem. I do thin that major
differences in thickness will be a problem, so better to be consistant with
wall thickness rather than worry too much about what thickness. Check
archives for some great books on pit firing. The Watkins book is a
fantastic source for all types of alternative firings. Be sure to post some
pics on the clayart blog when you have some sucessful firings.

Later,

Taylor, in Rockport TX
http://wirerabbitpots.blogspot.com

On Tue, 20 Dec 2005 17:45:28 -0500, Kurt Raynor wrote:

>Does anyone have ideas about clay bodies for pit firing? I am planning on
>using a bisqued ^10 clay. Any information about maximum thickness? Has
>anyone tried filling their fuel fired kiln with sawdust rather than building
>a barrel kiln?

steve graber on tue 20 dec 05

i did "can red" firing a few times. i put metal cans in my gas kiln, with saw dust in the cans, and bisque pots. i coated the bisque pots with salad oil & graphite. i was after american indian style black pots & got that result. i fired the cans until they turned "red". i saw this in ceramics monthly some 8 years ago.

i suspect that had i used other clays, burnished, and no graphite, i'd get pots more like a pit fire.

see ya

steve





Kurt Raynor wrote: Does anyone have ideas about clay bodies for pit firing? I am planning on
using a bisqued ^10 clay. Any information about maximum thickness? Has
anyone tried filling their fuel fired kiln with sawdust rather than building
a barrel kiln?

BTW natural gas and methane from any source are the same thing.

Kurt

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Marcia Selsor on wed 21 dec 05

I did 42 press molded book forms/images in earthenware paperclay
with terra sig, on them. I saw-dust fired some in a barrel, some in
a Bailey fiber kiln filled with sawdust and some in a train kiln
filled with sawdust, sticks and charcoal bricquets. Than one took 2
days to fire up at the Bray. I know you can get interesting effects
of firing stonware fired pieces (^10) and then smoking them in a
sawdust firing. A pit firing, actually in the ground could get hotter
than a sawdust burning in a barrel. I have seen some go for a day,
overnight. I would worry about dunting a piece fired to ^10.
Marcia Selsor in Montana
On Dec 20, 2005, at 3:45 PM, Kurt Raynor wrote:

> Does anyone have ideas about clay bodies for pit firing? I am
> planning on
> using a bisqued ^10 clay. Any information about maximum thickness? Has
> anyone tried filling their fuel fired kiln with sawdust rather than
> building
> a barrel kiln?
>
> BTW natural gas and methane from any source are the same thing.
>
> Kurt

Joe Cooper on wed 21 dec 05

Kurt,
You might consider an earthenware clay body, which matures at ^06. That
way, your product will be closer to vitrification with a low-temperature
firing. Thinner is better, within reason, and uniformity of thickness is
vital. Time and Patience are your friends in making the pots, drying them,
and firing them. Thermal shock at firing is obviously a big enemy
regardless of what firing technique you use, unless you are using a raku
clay body.
Happy potting.
Joe

----Original Message Follows----
From: Kurt Raynor
Subject: pit firing

Does anyone have ideas about clay bodies for pit firing? I am planning on
using a bisqued ^10 clay. Any information about maximum thickness? Has
anyone tried filling their fuel fired kiln with sawdust rather than building
a barrel kiln?

______________________________________________________________________________
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.

Lauren Bellero on thu 22 dec 05

kurt raynor asked:
> Does anyone have ideas about clay bodies for pit firing?

you can really pit fire with any kind of clay, i think the
trick is a low bisque to keep the body open. having said that:
i've tried a few clays and now use 2 kinds of cone 6 stoneware
bisqued to cone 010. my assumption is (and ivor, or anyone,
please correct me if you know the science!) a higher fire
clay will stay porous at the lower pit fire temps and therefore
remain open and be able to accept color better.
i use: a white stoneware (standard's #245) good for a nice burnished
sheen when using terra sig (i use vince pitelka's method), and a
salmon colored clay (#14z from ceramic supply, nj), which provides a
different color canvas (comes out peachy-ish).

regarding raku clay: i tried standard's #239 (great stuff to throw with!)
which, of course, holds up to thermal shock the best. it provides a
gray canvas and rough surface. but i find it does not take the color
flashes as well as the others.

also, i have a large pit, so i believe i get a hotter firing.

all the best,
lauren
--
Mudslingers Pottery, Lauren Bellero
http://mudslingerspottery.net
39 Leroy Place, Red Bank, NJ 07701
732.747.4853

Taylor, in Rockport TX on thu 22 dec 05

Hey Lauren:

I have loved your stuff for a few years. I'm sure I found your website
soon after beginning my involvement with clayart. Well, I have just now
started experimenting with pit firing. I offered to have a pit firing on
my property in February in conjuncion with a pottery fair benefiting our
county senior center. I figured I ought to have fired a few pits before
people came. I'm having mixed results, but it sure is fun.

I think your current pictures are new as I don't remember the steel
retaining wall on your pit before. Anyway, I don't have the quantity of
pots that you have, but I wanted to ask you about how yo stack your pit.
You seem to have quite a few pieces stacked next to or on others. I see
plates stacked with straw between and those nice squared off vases leaning
on each other. How has that been working for you as far as breakage and
color responses? Perhaps that is something I need to try because I am not
getting the variation in color I want. On the good pots I get reds or
blacks but not much in between. I must also be too stingy with my pit
chemicals because this last firing of mine was a flop. I have pics on my
blogs and on flickr.com where I keep my pit pictures for reference. If you
have time take a look at my last pit loading. I'm pretty sure it's too
light on both pots and chemicals. I will be lengthening my pit soon to fit
larger and more numerous work. Let's keep our fingers crossed on that.

I'm hoping by Feb I'll have some nice pots and a better understanding of
things. Right after christmas though, I have to pull out the glazes that
have been sitting unused for a year and start chipping away at all the hard
pans. UGH! Pit firing is looking so much better.

Happy holidays, Lauren.

Taylor, in Rockport TX
http://www.wirerabbitpots.blogspot.com

Lauren Bellero on fri 23 dec 05

taylor in rockport wrote:

> I wanted to ask you about how yo stack your pit.
> You seem to have quite a few pieces stacked next to or on others. I see
> plates stacked with straw between and those nice squared off vases leaning
> on each other. How has that been working for you as far as breakage and
> color responses? Perhaps that is something I need to try because I am not
> getting the variation in color I want. On the good pots I get reds or
> blacks but not much in between. I must also be too stingy with my pit
> chemicals because this last firing of mine was a flop.

hey taylor in rockport!

i had checked out your pics when you wrote about trying it out
and thought you did great! nice contrasts with the black, white and
red. but you're right, the latest is disappointing.

my first 3 large pit fires were great. then i had 2 lousy ones (talk
about disappointing! try it with 100+ pots and not be happy!). but the
cool thing is you can try again with the same pots. so even with
more experience, i couldn't seem to get it on the mark every time.
the last lousy time, i realized i did not have enough air at the far
end of my pit. not enough air means not enough heat. none of the
chemicals volatized at that end of the pit. so you need SOME air.

my most recent one was pretty good. but i still got several that i'll have
to do over. i'm still getting surprised by what does and doesn't happen
in the pit. and sometimes i have to believe that even if we did have all
the information, we can't control it all, all of the time. gotta take
the good with the bad, i suppose. just the nature of the beast -- true
with glazing too.

anyway... to get to some of your issues: don't be afraid to add
some more chemicals. but you don't have to go too crazy. you don't need
a ton. great, what's that really mean, right? let's see if i can put
it in perspective. for my 8' pit i'm sure i used no more than 1/2 pound
of copper carb and probably less. i sift it on using a plastic
kitchen sifter/strainer thingy with a handle and a metal screen.
i see you use copper sulfate. yep, definitely not enough of it there.
sprinkle it liberally. and do you use any salt? salt gives the
yellow to peach to orange colors. i also use ferric chloride sprayed
on (nasty stuff, where proper protection). it gives some oranges.

as far as loading... yep, i put them up against and on top of each
other. i had only 2 out of 16 masks and one other pot crack out of 120+.
so i think that's pretty good, and i think it helps with the color
flashing (or maybe it's just the high heat). i let the copper carb go
on top of the pots, but i try to keep the rock salt off and just sprinkle
that in the sawdust so it (hopefully) won't be touching pots too
much. sometimes the salt can make unattractive marks when touching.
also, what do you bisque to? keep it low: 010.

best of luck! and i hope you'll be reporting
on your future experiments -- and your big
february gig! any questions, just give a yell.

merry happy,
lauren

--
Mudslingers Pottery, Lauren Bellero
http://mudslingerspottery.net
39 Leroy Place, Red Bank, NJ 07701
732.747.4853

j e motzkin on fri 23 dec 05

Taylor,
Lauren's pit fire is a good example to follow. I read
your blog description of your firing and recommend that
you get your fire a bit hotter, adding fuel for longer
before covering for the night. Excessive chemicals will
do little if the pit is too cool. I also think that pots
that kiss make for interesting markings, confusing and
altering the flow of the fire and the balance of the
atmosphere. If you stack large pots beneath smaller ones
you will not get breakage from the touching. A denser
packing will retain the heat longer as well.
If you make your pit larger, try to make it bigger all
around to avoid hot center, cool ends that might result
from making it longer, though I think Lauren has a
rectangular pit.
Have fun, experiment, and be safe. Wet the grass around
the pit thoroughly. Stay alert for serendipity. Try
everything twice.
judy




taylor wrote... I wanted to ask you about how yo
stack your pit.
You seem to have quite a few pieces stacked next to or on

others. I see
plates stacked with straw between and those nice squared
off vases leaning
on each other. How has that been working for you as far
as breakage and
color responses? Perhaps that is something I need to try
because I am not
getting the variation in color I want. On the good pots
I get reds or
blacks but not much in between. I must also be too
stingy with my pit
chemicals because this last firing of mine was a flop. I

have pics on my
blogs and on flickr.com where I keep my pit pictures for
reference. If you
have time take a look at my last pit loading. I'm pretty

sure it's too
light on both pots and chemicals.

/motzkin/studio/7 TUFTS Street/Cambridge, MA 02139/
617-547-5513/jmotzkin@yahoo.com/
http://www.motzkin.com/
http://spiritkeeper-urns.com



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Sam Kelly on sat 24 dec 05

Hi, here is a few pics of our pit firing in 2002, we do one each year

http://home.exetel.com.au/pottery/pottery/pitfire/pitfire/index.htm

Sam
Australia

Donna Kat on tue 27 dec 05

I did my first pit firing this fall with great success (that is - I really
like the results). I am fairly certain that we used #105
http://www.creativeclaypottery.com/storeclay.htm . It is a low fire, very
plastic clay (I really liked throwing this). The way we (it was a
workshop) burnished was to dry the piece to bone dry and then paint a slip
on it with a soft brush over a small area at a time and rub shiny with a
soft cloth. I was very dubious about this method but the pots I did this
way looked indistinguishable from those I spent hours on burnishing with a
smooth stone except that they did not have dents in them. You can do two
or three layers of this but one will work as well. The slip is made from
the same clay as the body and it must be relatively thin (you don=92t want
to see edges from where you have brushed it on). You bush it on, let it
almost dry and then rub. Go to the next spot and continue until you have
covered the pot. Do this on your lap or on a large piece of foam so that
you don=92t break to piece. If you want to be fancy, you can add some
colorant to the slip. It is important to bisque fire this at cone 010 not
cone 06 to keep the burnish. For my pots I dripped iron and copper oxides
on paper and then when dried wrapped the pots in the paper. The group
sprinkled a lot of table salt over the sawdust. We also threw in seaweed,
banana skins and other odds and ends that you really don=92t want to breath
in.

We used a cement dumpster to do our pit fire (filed the bottom with about
a foot of sawdust, placed the pots with about a foot between rows for
walking, built teepees out of twigs and then stacked wood on top to about
5 feet. This was set a fire and unloaded the next day. I have seen
pictures of kilns for pit fires made out of stacked house bricks (with
gaps between the bricks for air circulation) and old oil drums with holes
drilled in them. You need the air holes for the saw dust to burn.

Search the archives. There are those here that do this for real and have
given great advice.

Donna Kat on tue 27 dec 05

Sorry! I meant a terra sig not slip!!! (I do not live in the world of
verbal communication).

Marcia Selsor on tue 27 dec 05

I did 42 press molded book forms/images in earthenware paperclay
with terra sig, on them. I saw-dust fired some in a barrel, some in
a Bailey fiber kiln filled with sawdust and some in a train kiln
filled with sawdust, sticks and charcoal bricquets. Than one took 2
days to fire up at the Bray. I know you can get interesting effects
of firing stonware fired pieces (^10) and then smoking them in a
sawdust firing. A pit firing, actually in the ground could get hotter
than a sawdust burning in a barrel. I have seen some go for a day,
overnight. I would worry about dunting a piece that was bisque-fired
to ^10.
Marcia Selsor in Montana

Liz Urse on thu 12 jan 06

Pit firing is new to me and I was wondering if anyone had experimented
with any stains or colored slips in a pit firing to achieve color on the
surface of pots. Also I was wondering what other dry materials could be
used to produce color in the firing other than copper carb, iron and
copper sulfates, and rock and sea salt. I have experimented with
combustibles such as brass, copper, and steel wool, seaweed, berries,
leaves, copper soaked twine and banana peelings. Any other suggestions
for combustibles? I always see these pit fired pieces with beautiful reds
and I wonder how that color is produced. Any information would be
helpful.

Leland Hall on sun 15 jan 06

Liz,

I started my clay carreer as a "Potters Assistant" for a potter whos
specialty was pit fired pottery. He mixed copper carb directly into his
clay body, used sheep or llama dung as fuel, and the pots were usually very
multi-coloured. Reds, salom, magenta, green, blue, purple, just
beautiful. Burnishing accentuated the colour too.


I realize this doesn't directly address your question, but if it's food for
thought, that's good.

Best,


Leland Hall
Before The Wheel
La Pine, OR, USA

Liz Urse on tue 17 jan 06

Leland,

Any information is helpful in the beginning stages. Mixing the copper carb in with the clay is an interesting idea. Varying percentages could be experimented with and I guess the copper carb could also be wedged into the clay. Thank You!! This will be something to try out.

Liz Urse

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Leland Hall on tue 17 jan 06

Liz,

When I left that job as potters assistant, that is how I did my pit fired
masks. I had no clay mixer, so wedged the copper carb right into boxed
clay. I found it was easyest to pound out a thick slab, spead out the C.
Carb, then moisten it with a sprayer before begining wedging. It was a lot
of work, but it worked out fine.

One thing I always wondered back when I was doing this, was skin absorbtion
of the copper. Kind of had me worried. On the other hand, my employer had
thrown pots with this claybody for an entire carreer, and his health seemed
fine. But come to think of it, I don't know what became of him.

Good luck,
Leland Hall,
Before The Wheel
La Pine, OR, USA
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Leland,

Any information is helpful in the beginning stages. Mixing the copper
carb in with the clay is an interesting idea. Varying percentages could be
experimented with and I guess the copper carb could also be wedged into the
clay. Thank You!! This will be something to try out.

Liz Urse

Bonnie Staffel on thu 19 jan 06

Dear Claybuds,

When I mixed up a batch of paper clay, I had heard that adding a little
copper carb or sulfate to the mix would retard mold formation. Imagine
my surprise when I fired my first pot to stoneware temperature with my
white glaze to have the pot turn a light green color. It really was
beautiful. I am looking forward to trying this clay in my Trash Can
firing next spring when the weather is more congenial for this kind of
firing. I will report the results then.

Warm regards,

Bonnie Staffel


http://webpages.charter.net/bstaffel/
DVD Throwing with Coils and Slabs
DVD Beginning Processes
Charter Member Potters Council

Marcia Selsor on sat 29 apr 06

I like what terra sig does on the surface but it isn't required. try
putting salt in the pit with everything else.
You can wax the surface after you clean it. Burnishing and /or terra
sig enhance the flashing imho.
Look at my saggar pots in Gallery on my website. They have terra sig
on them, steel wool and copper of various types, with salt.


Marcia Selsor
http://marciaselsor.com

Fadra Hepner on wed 12 jul 06

Thanks to all who answered my silly questions. You have confirmed my initi=
al thoughts, but sometimes there are interesting surprises so it is worth l=
aying it out there for others to digest. (Like the fact that Vince's terra =
sig has been fired to 04 without loss of shine-neat!) I think I'll only tr=
y this on one pot first though!

Thanks to all and happy firing
FAdra Hepner
Mommy and teacher in MO

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jmotzkin on thu 13 jul 06

Date: Wed, 12 Jul 2006 05:37:20 -0800
From: Fadra Hepner
Subject: pit firing

Fadra,
I don't know who told you that terra sig fired to ^04 will not lose it's shine.
Vince says it won't happen, I say it won't happen, others have said it.
I hear you looking for the answer you hope for and latching onto it
despite that fact that most say otherwise.

If shine is a primary consideration, fire low. ^012-09

If strength is your primary consideration, fire a bit hotter.^08-06
You will then compromise the sheen.
Fire too high and you decrease the clay's ability to absorb the effects of the fire.

There is a trade off between color receptivity, shine and strength. You choose.
The clays you use are a variable.
Then of course there is the temperature of the pit fire itself...

Fire and learn,
Jude
www.motzkin.com




Thanks to all who answered my silly questions. You have confirmed my initi=
al thoughts, but sometimes there are interesting surprises so it is worth l=
aying it out there for others to digest. (Like the fact that Vince's terra =
sig has been fired to 04 without loss of shine-neat!) I think I'll only tr=
y this on one pot first though!

Thanks to all and happy firing
FAdra Hepner
Mommy and teacher in MO