RITISH
COLUMBIA
a

Combustibles and bombs,
Continued from Page 4

placing them in the saggar and filling spaces
with combustibles and ‘bombs’ took me the
best part of four hours! Then the front wall of
the saggar was finished, and kiln shelves placed
on top as a roof. An 06 cone was placed at a
peep, the kiln door was closed and I was ready
to fire.

The kiln was started on very low, the
damper and peeps out, for four hours. Then
the burners were turned to medium and the
damper pushed in to half way. As the kiln
temperature climbed, the smell of burning
rubbish permeated the kiln shed. The entire
firing took eight hours. I crossed my fingers...
who knew what the results would be?

‘The next day, the kiln was cool enough to
unpack. It was like being at an archaeological
dig! As each revelation or failure emerged,
I learned what to do again, and what not to
do. Masking tape and ‘stick on’ dots were a
mess, as they took off the terra sigillata and
left no appreciable mark. Pieces which had
been sprayed with metallic salts had runs and
obvious splotches. The pots which were not

RECIPES

Basic Terra Sigillata (Cone 04)

1 % cups (205.5 g) ball clay

1% cups (172.5 g) E.PK.

2 tbsp. (30 ml.) sodium silicate

Mix sodium silicate with 1 c. of warm
water to dissolve. Stir the two clays
together, and then add 9 c. of tap water
and the dissolved sodium silicate. Stir
vigorously, shake or blend. Leave at least
24 hours to settle. Most potters siphon
off the top layer, use the middle layer,
and discard the bottom layer. I just give
it a slight stir and brush on as is. If the
brush marks show, or it looks chalky,

throw out and start again.

Ideal Slip (Cone 10)

Ball clay, 60%

Talc, 40%

Use a handheld blender to mix to creamy
consistency. Brush on and smooth when
almost dry with your hands.

Soldner Flashing Slip (Cone 04)
1c. Gerstley Borate

2c. Flint

3c. EPK.

Mix to creamy consistency and brush on.

Packed saggar with 06 cone ready for firing.

wrapped with foil were subtle to the point
of boring. But colour I did have! The wire
lines were green, black, brown and grey. The
blushings from copper were pink, purple,
even lipstick red. Cobalt predictably gave all
sorts of blues. Wire wool and scourers gave
burgundies, oranges, creams and tans. There
were no cracks or breakages. The terra sigillata
offered a soft-to-the-touch satiny surface.

After Christmas, I was ready to have another
go. In March 2011, I rebuile the saggar and
included some larger pieces: hand built tiles
as well as thrown lidded jars and bowls. I'd
been invited to display at the Foyer Gallery in
Squamish, so I decided to show entirely saggar
fired forms. As well as terra sigillata, I used a
flashing slip that I generally used as my trailing
slip to cover the surface. This time, the packing
included a great deal more salt with the
sawdust, as well as more iron and manganese.
‘The firing was sped up to take only six hours.
The results were appreciably different. Terra
sigillata flaked off. The finished surfaces were
dirtier and smokier with lots more grey, brown
and black. Some pieces had salt sticking to
them. There were several breakages, especially
the wide bowls. The flashing slip did not
flake and still took the markings of the firing
beautifully.

The third firing took place on May 1 in
preparation for the Squamish show. This time I
allowed the whole eight hours for the firing, as
there were several large rimmed bowls and tiles
in the saggar and I didnt want to risk breakage.
Some pieces were coated with Paul Soldner’s
flashing slip which he recommends for his low
salt firings. The results: no breakages, lots of
variety in colour and in surface texture. The
Soldner slip was a little dry for my taste, so
some of the pieces were finished with a spray
of Krylon satin clear acrylic.

‘This is a fun way to use a fossil fuel or wood
burning kiln. As far as I know, an electric
the

corrosive damage from the fumes and carbon

kiln’s elements would not withstand

being released during the firing. Because my

Potters Guild of BC Newsletter - August 2011

20-cubic-foot downdraft natural gas kiln
is used for Cone 10 firing, all debris was
vacuumed out before reusing. The kiln shelves
used for saggar firing acquired a layer of salt
glaze and fuming from the saggar firing, so
they are now used exclusively for saggar firing.

Kay Austen will be conducting a saggar firing
workshop for the Whistler Pottery Group in
September. Please phone Laurie MacCallum
604.935.0540, lauriemaccallum@yahoo.ca

for dates and times. See www.kayausten.com
References:

Alternative Kilns and Firing Techniques.
Watkins and Wandless. Lark Books, 2004

"Decorating with Volatile Materials in
Saggars." Allen, Ruth. Ceramics Monthly
article, January 1992

www. pitfire.com - very informative site. Step-
by-step pictures of loading and unloading
the kiln.

www.nelsonmoore.com/art/
SaggarFiring WorkshopHandoutwPicsSm.
pdf

www. natureofclay.com/saggar.html

www.alexmandli.com/techniques/saggar_

firing.html

Adult fall and winter
registration begins July 20.

Crystalline Vases by Li

Classes for all ages and skill levels.

shadboltcentre.com
Call Shadbolt Centre at

604-291-6864 or register
online at: burnaby.ca/webreg.

City of

fey

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