Gary Jackson: Fire When Ready Pottery
A Chicago potter’s somewhat slanted view of clay & play
Pottery Process

There’s a lot of work that goes into every piece of pottery.
Most people have that glorified image of throwing clay on a wheel
thanks to Demi Moore & Patrick Swayze in “Ghost.”
But there’s a lot more to it than that.

One of the most frequent questions I get at an art fair is
“How long does it take to make this piece?”
I try to explain that it is a process and there might be several pieces
all in different stages of the process – so it’s hard to determine
the amount of time for each individual piece.

Hopefully the following overview will give you some idea of the steps
that each piece of handmade, soda-fired pottery goes through.
It’s a labor of love – we don’t do it because it’s easy.

Wedging
Before you can throw clay on the wheel, you need to get out any excess air pockets
by wedging the clay. Basically it’s a process like kneading bread dough. Being careful
to press out the air bubbles instead of folding in new ones!

Wheelthrowing
The wedged ball of clay is placed on the center of the wheel. Once secured, the clay
is wet and spun fast on the wheel. The first step is to center the clay and smooth out
all of the edges. Once the ball is smooth & centered, you can open it up, compress
the bottom and start to raise the walls. As the walls get taller they also get thinner
and less stable. Once the clay is raised to the desired height and the walls are a
good thickness, the shaping can begin. Carefully refining the curves, the shapes
and the rim. When finished, the piece can be wired off the bat and moved off
to start drying.

Drying to Leather-hard
The thrown pieces are set aside and allowed to dry slowly to a soft, leather-hard stage.
At this point, the clay is still malleable, yet no longer sticky or squishy. The pot holds its form
and can now be altered & decorated.

Trimming
Once the pots are stiff enough to work with, they can be flipped over and the bottom trimmed.
The excess clay is trimmed away by scraping with a metal loop tool while spinning quickly -
kind of like a wood lathe. The ribbons of shavings come off and reveal a finished “foot”
for the pot to stand on.

Stamping
While still leather-hard, I use my handmade stamps to create the repetitive patterns
on my work. It is always a challenge to get the stamps to look consistent and line-up
when you get around to the other side. The stamp is pressed in one-at-a-time,
over & over again. I have created hundreds of stamps to choose from… and yet,
there are definitely some favorites that show up more frequently then others!

Attachments… such as handles!
After my pots have been stamped & trimmed, it is now time to start finishing
them with attachments & handles. To add a handle, I “pull” them all
from a lump of clay forming the strap handle. I allow the strap to set up
for awhile – at least until they are no longer wet, mushy & sticky. Once deciding
where to place the handle, I “score & slip” the attachment points,
cut off the necessary portion of the strap handle and press it into place.
A few refining touches and the pot now has a handle.
A basic cylinder is instantly transformed into a mug!!!

gary-jackson-pulled-handles

gary-jackson-attaching-handles

Slip Painting
As if the stamping process weren’t labor-intensive enough… I also like to apply
colored slip to the stamps & top rim of the vases. Around the top of each vase,
I paint colored slip to give the top section. In the center raised section of each stamp,
I apply some slip to help accent the stamp and draw the color down throughout the pot.

Drying to Greenware
Once all of the pieces are trimmed, stamped and slip painted, they are set aside to dry.
As they dry, they become more and more fragile. All pots need to be dry before they
can be placed into the kiln.

Bisque Firing
Once the work is completely dry, it needs to be fired to cone 06,
which is approximately 1850 degrees. This is the point where the clay
becomes solid & less fragile. It is still porous and will readily accept the glaze.

Glaze Inlay
To accentuate the stamping, I take time to inlay glaze into the stamped impressions.
Without the contrasting glaze color, the stamps don’ always show-up
as much as I would like them to.

Glaze Inlay Reveal
Once the stamps are filled with glaze, I gently wipe off the top surface
to reveal the pattern now filled with the contrasting glaze.

Glazing
Once all of the stamps are inlaid with glaze, the interiors need to be glazed as well.
In a soda firing, the exterior of the pots don’t need to be glazed as the soda residue
left from the flame flashing will create the “glaze” surface. If specific colors are wanted,
the choices are colored slip at the leather-hard stage or glaze at this point. Frequently,
I spray some accent colors on the sides of the pots.

Wadding
Another labor-intensive step… every piece that goes into the soda kiln needs to be
raised off the shelf so that the soda build-up doesn’t adhere the pot to the shelf.
Typically, three small balls of wadding are attached to the bottom to raise the piece
on a “tripod of wad.” Wadding is a soda-resistant clay mixture made with alumina hydrate.
And when we say every piece needs to be wadded… that includes every tile!

Glazed & Wadded – ready to go!
As each piece is finished, they are put onto the cart waiting to go downstairs
to the kiln. It’s a great feeling to see the cart filling up with pots that are all done
and waiting to be fired for the final time!

Kiln Loading
Once everything is glazed & wadded it is time for the kiln loading.
Each shelf is supported by three bricks, then another shelf, then more bricks!
Think of it as a three-dimensional jigsaw puzzle. Trying to fit in as many pieces
as possible while leaving enough space above & between the pieces to allow for
good air flow and flame flashing throughout the kiln.

Closing The Kiln
Once the kiln is loaded, the door needs to be closed…. one brick at a time!
From bottom to top, the bricks are placed allowing for the peeps and temperature sensors.
Specially shaped (shaved) bricks finish off the top arch.

Glaze Firing
The soda kiln is a gas reduction kiln. Meaning the flames enter through the back
of the kiln and heat the kiln to cone 10 around 2350 degrees. The reduction atmosphere
is created by altering the balanced ratio of gas-to-air by reducing the amount of air.
The flames “search” the kiln for the needed air and pull it from the porous clay body
thus sealing the clay and making it solid & vitreous.

As the kiln gets hotter throughout the day, the pyrometric cones each melt
at a different temperature. To see the cones inside the kiln, you carefully remove
two of the bricks in the door – peek inside to see which cones have melted.
When the last cone goes down… you know you are at cone 10 and the kiln
is done. It’s a long day… but well worth the wait.

Kiln Cooling
After a full day of firing, the kiln takes another full day to cool.
At certain points through the cooling, the peeps can be removed and the damper opened
to help speed along the process. If the kiln is cooled to rapidly, there is a chance of cracking
the pots inside through thermal shock.

Kiln Unloading
Once the kiln is cooled, the door can be unbricked. The sequence needs to remain intact
so that the next person who will be firing can put the bricks back in in the same sequence.
If the pieces are cooled enough to touch, they can be taken out of the kiln. The wadding
typically pops right off and can be thrown away. All of the shelves and posts are taken out
layer by layer along with the pots. Every shelf needs to be scraped to remove any excess
soda build-up that may have adhered during the firing. Shelves are also recoated with
kiln wash which helps protect the shelf from the soda. The fire box on each side of the kiln
needs to be cleaned out as well – any leftover residue from the soda mixture needs to be
swept out before the next firing.

And Now For The Fun Part
Once all of that dirty work is done… you can sit back and enjoy the new pots.
Unloading a kiln is kind of like a little treasure hunt. Some of the pieces are immediate
favorites, while others may not be what you expected and may take a few minutes
to grow on you. Luckily, they are always a few hidden surprises along the way!

4 Comments

Kelly

February 24th, 2009

Merryn wonders if that oven gets so hot that it would melt clay?

Shanae

March 24th, 2009

I LOVE YOUR WORK. Beautiful

Johnny

June 30th, 2009

Your ceramics are very nice. I use an electric kiln and like gas kiln results better. You have gorgious results.

Johnny

June 30th, 2009

too bad I can’t spell! Gorgeous work!

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