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pit firing pics australia

updated fri 22 aug 03

 

Sam Kelly on sat 16 aug 03


Hi here are a few pics of our last pit-fire day/night last year. We are all
potted up for this years firing on the 30th of this month.
http://www.users.bigpond.com/sdkelly9/pottery/pitfire/index.htm

Sam

Eric B on sat 16 aug 03


great firing! the orange blushes are killer. just curious, were any/all of
the orangey pots burnished? i've done burnished/pit-fired pieces that get
good color but have always heard that "one must burnish to get colors in a pit
fire." true or false?

thanks for sharing the pics

Sam Kelly on sat 16 aug 03


Have had quite a few emails on some of the process so I thought I would add
some info:

Glad you all liked the pics. On the bottom is saw dust and around the pots
is sea weed(there was a lot more added than in the photo). Pick it up off
the beach but do not wash it, its ok to shake the excess sand off but its
the salt content on the dry weed that is needed to react with the fire to
produce colour. See here
http://www.users.bigpond.com/sdkelly9/pottery/pitfire/pages/pic-6.htm

The pots are sprayed with copper sulphate and water and I think Iron Oxide
(will have to check my notes)and water. Sprayed individually with a small
air brush spray gun, this has to be done before the bisque firing and you
have to be very carefull loading the bisque kiln or the the above sprayed
on will wipe off on your hands(see
http://www.users.bigpond.com/sdkelly9/pottery/pitfire/pages/pic-2.htm )

One hour after the fire is lit we use a long piece of house rain water pipe
(tin) and roll a few hand fulls of salt up in newspaper and use a prodder
and position the pipe between the sheets of roofing iron you see in the
pics and push the wraped salt into the middle of the fire. If you look at
this pic you will see the orange colour in the middle of the pit where the
salt landed, this is also the hottest part of the pit
http://www.users.bigpond.com/sdkelly9/pottery/pitfire/pages/pics-14.htm

lela martens on sat 16 aug 03


Thank you Sam for sending the pictures. Beautiful pots. The way the pictures
are displayed loaded fast on my poor old PC. For thoses who missed it, here
is the address again. Worth looking at. Best wishes from Lela . Surrounded
by a fine smoke brought by the breeze from terrible wild forest fires to the
west.

>
>Hi here are a few pics of our last pit-fire day/night last year. We are all
>potted up for this years firing on the 30th of this month.
>http://www.users.bigpond.com/sdkelly9/pottery/pitfire/index.htm
>
>Sam
>
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Sam Kelly on sun 17 aug 03


Hi, yes most of the pots were burnished, but not to a mirror shine, just
smoothed off. They do not have to be burnished as you can use raku clay to
get the rugged look. The pots can be sprayed with a compound to make them
shiny after the firing or I like to use clear boot polish rubbed on with a
hankerchief.

Sam

William Lucius on mon 18 aug 03


I found the pictures of your pit kiln interesting, especially the vertical
wood slabs around the perimeter. Imagine being an archaeologist who has
found more than a few prehistoric Pueblo (American Southwest) trench kilns
that have vertical slabs of sandstone (perhaps to support such wood). He
wants to know what led you to this fuel setting and what are its benefits?
From the post-firing picture the kiln atmosphere was strongly oxidizing
(orange color). Have you ever tried to do reduction (or at least a neutral
atmosphere)?

By the way, nice pots too. Unfortunately, not too much seaweed here in
Colorado.


William A. Lucius, Board President
Institute for Archaeological Ceramic Research
845 Hartford Drive
Boulder, CO 80305
iacr@msn.com

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Joe Coniglio on mon 18 aug 03


Arrr--the scorched earth always brings a tear of joy to my eyes.

A rather professionally formed cadre of pots. Looked like a very happy
outing.

JoeC
http://www.myfonts.com/foundry/coniglio/

Joe Coniglio on wed 20 aug 03


The Dr's Lucius's comment on vertical slabs. My guess you were firing on
land that was mostly sand. The vertical slabs kept the walls from filling the
hole with dry falling sand. I lived on a piece of dry shoreline one time and
the asphalt roads; even with an underbase of gravel there was nothing to hold
back the sand when there was a wash out. The road bed literally sat on over
a dozens feet of sand. That's what some sink holes over coastal highways are
all about. There are some tongue-in-groove steel supports like those used in
retaining walls that can be used.

Sam Kelly on wed 20 aug 03


The wood around the perimeter is to help keep as much heat in as possible,
did not work and has now been replaced with common house bricks wich will
be tested at the next fire, 30th of this month.
Orange colour comes from a fine mist of red iron oxide sprayed onto the
pots prior to bisque, the heat is also a mojor factor as you can see the
centre of the fire gives the best results

William Lucius on thu 21 aug 03


Your suggestion that the upright slabs are a response to loose sand is
interesting, but in general these kilns are shallow excavations into a dense
red loess (a windblown silt-sized soil horizon). I have always suspected
that the upright slabs have something to do fuel placement, so when I saw
the almost vertical wood slabs in the Australian pit kiln I thought perhaps
someone else had figured out the problem for me. I do not think that the
primary reason for the slabs (wood or stone) is to keep the heat in the pit,
but I need to design a scientific test to verify this assumption. Most of
the heat of pit firing goes up into the air, and our most recent replication
firings suggest that a proper mix of wind fuel type and fuel amount is the
key to bringing the pots up to a red heat. If it is calm, too humid, or if
insufficient fuel is used, then it is unlikely that enough heat will be
generated.

Just some thoughts, and thanks for the reply.

William A. Lucius, Board President
Institute for Archaeological Ceramic Research
845 Hartford Drive
Boulder, CO 80305
iacr@msn.com

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Joe Coniglio on thu 21 aug 03


Can't go against the experts. I reexamined the photos and it is the red soil
describe. What I saw was a base of woodchips or some other homogenous base in
one of the photos. Most fire pits I've seen in photos are indeed shallow.
The australian example seemed waist-to chest deep. At any rate the vertical
materials still make a nice clean frame surrounding the fire. Maybe they are
a moisture barrier.

IN A PIT FIRING I KNOW THAT WOOD CAN BE HEAPED HIGHER THAN GROUND LEVEL BUT
ARE THERE ANY PITFIRED POTS POSITIONED (STACKED) ABOVE GROUND LEVEL SINCE THE
WOODEN MASS WILL END UP IN THE PIT ANYWAY??

Heaps of broken shards surrounded old southwestern pits too didn't they?
Sort of creating some form of insular protection from initial thermal shock
and maybe keeping the pots clean.

What if all of todays lovely fire licks/flashings that make a woodfired pot
so sought after and interesting were frowned upon by old makers who sought
uniformity as a quality trait? I wonder what they liked and didn't like.

There's a lot of lost stuff out there and no one alive to ask.

Thanks! Joe Coniglio