Avril Farley on fri 29 jun 01
Janet Kaiser said 'Subject: Barium glaze colour: reduction vs oxidation?
> A potter who has changed from an electric kiln to gas
> recently, came in with some new work today. I was
> amazed at the difference in colour!
This happened to one of my pieces at college. The reduction was too great
and oxide saturation on this thicker areas of glaze (cobalt carbonate
overlaying copper) on buff stoneware, instead of giving me a lovely
turquoise green combination gave a heavy black, and dark mottled blues and
green. By contrast, in the same kiln, different shelf, a porcelain piece
(same glazes) came out pure startling blue and turquoise. Maybe the iron
had something to do with it?. In oxidation at home the colours stayed
true.
Avril in the Forest UK
----- Original Message -----
Janet Kaiser on fri 29 jun 01
A potter who has changed from an electric kiln to gas
recently, came in with some new work today. I was
amazed at the difference in colour!
My question: Is it usual for a reduction fired barium
glaze to turn a dull grey-green (rather than bright
"barium blue") and BLACK where double dipped? I think I
prefer that shocking and infamous barium blue... This
green reminds me of a catastrophic chrome, just matt
rather than gloss, but just as uninteresting
colour-wise.
Janet Kaiser - Sorry for being incommunicado
(especially if I owe you a mail), but Criccieth
Festival took all our energy last week and I have a
newsletter to complete, print and mail this. And to be
honest, these viruses are too close for comfort! The
subject line made it look OK and on-topic. Scary stuff
from Philip P. in Las Vegas!!
Off to the International Potters Festival in
Aberystwyth for a whole day tomorrow... Fred Olsen is
building a kiln, so will ask about the fast firing kiln
if I have the opportunity. Eleven US potters including
Shirley Freed are visiting The Path and The CoA on
their way to Aberystwyth this afternoon... Eleven from
Switzerland due next week... Absolute bliss! Having so
many Path Makers visit in person!
Silently thankful Mel has returned home safe and
well... I bet his doctor thought he was on holiday
resting and relaxing!
The Chapel of Art . Capel Celfyddyd
HOME OF THE INTERNATIONAL POTTERS' PATH
Criccieth LL52 0EA, GB-Wales Tel: (01766) 523570
E-mail: postbox@the-coa.org.uk
WEBSITE: http://www.the-coa.org.uk
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