DIANA PANCIOLI, ASSOC. PROF. on mon 27 jul 98
Might know. What atmosphere?
DP
On Mon, 27 Jul 1998, Stephen Mills wrote:
> I'm posting this on behalf of a friend, 'cos I don't know the answer,
> and I'm curious to know what you guys think.
> "I've just had a mid-temperature range Tin Glaze come out Pink! As far
> as I know there hasn't been any contamination by chrome either in the
> glaze or in the Kiln. Does anyone know if there are any other
> explanations for a tin glaze going pink?!"
> --
> Steve Mills
> Bath
> UK
> home e-mail: stevemills@mudslinger.demon.co.uk
> work e-mail: stevemills@bathpotters.demon.co.uk
> own website: http://www.mudslinger.demon.co.uk
> BPS website: http://www.bathpotters.demon.co.uk
>
Andrew Buck on mon 27 jul 98
On Mon, 27 Jul 1998, Stephen Mills wrote:
> "I've just had a mid-temperature range Tin Glaze come out Pink! As far
> as I know there hasn't been any contamination by chrome either in the
> glaze or in the Kiln. Does anyone know if there are any other
> explanations for a tin glaze going pink?!"
In the book "Ceramics Glaze Technology" by J.R. Taylor and A.C. Bull, in
the section on tin, they state "It readily absorbs volatile chromophores
such as vanadium or chromium .....to create undesirable "flashed" areas of
color". Those two elements are all that they mention. In the section on
Vanadium the authors say that vanadium is rarely used as a pigment in
glazes but that it is a very active flux. When vanadium is used in a
glaze, though, it produces yellow or brown. If tin glazes are fired in an
electric kiln, there could be enough chrome released from the ni-chrome
wire to account for some flashing of pink.
What else do you have in the glaze? Someone on the list might be able
to identify another component as being contaminated with chrome without
you being aware.
Andy Buck
Raincreek Pottery
Port Orchard, Washington, USA
Stephen Mills on mon 27 jul 98
I'm posting this on behalf of a friend, 'cos I don't know the answer,
and I'm curious to know what you guys think.
"I've just had a mid-temperature range Tin Glaze come out Pink! As far
as I know there hasn't been any contamination by chrome either in the
glaze or in the Kiln. Does anyone know if there are any other
explanations for a tin glaze going pink?!"
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
John Post on tue 28 jul 98
Steve,
My hunch is that chrome is present in the kiln from previous firings. I
have a kiln that I have fired many times with chrome tin pinks. It now
will turn tin glazes pink even if there is no chrome in the load being
fired. Chrome easily migrates to the surfaces of other pots and to the
kiln itself. I occasionally use this chrome misting as a decorative element.
I also have a tin glaze that turns a light fleshy pink if 1% light rutile
is added. Any rutile in your glaze? I have no explanation of why the
rutile pushes my tin glaze to pink, but it does.
John Post
potter@c3net.net
Sterling Heights, MI USA
>"I've just had a mid-temperature range Tin Glaze come out Pink! As far
>as I know there hasn't been any contamination by chrome either in the
>glaze or in the Kiln. Does anyone know if there are any other
>explanations for a tin glaze going pink?!"
>--
>Steve Mills
stevemills on wed 29 jul 98
----------------------------Original message----------------------------
Dear Diana,
To answer your question and help other interested parties:
Electric fired,
Recipe:
Nepheline Syenite......35
Ball Clay (HVAR).......10
Bentonite.............. 2
Whiting................15
Flint/Quartz...........19
Calcium Borate Fritt... 9
Tin Oxide..............10
Cone: 5/6
TIA
--
Steve Mills
@Bath Potters Supplies
Dorset Close
Bath
BA2 3RF
UK
Tel:(44) (0)1225 337046
Fax:(44) (0)1225 462712
e-mail steve@bathpotters.demon.co.uk
http://www.bathpotters.demon.co.uk
Lyla J. Kaplan on sun 2 aug 98
At 5:59 PM -0400 7/27/98, Stephen Mills wrote:
>I'm posting this on behalf of a friend, 'cos I don't know the answer,
>and I'm curious to know what you guys think.
>"I've just had a mid-temperature range Tin Glaze come out Pink! As far
>as I know there hasn't been any contamination by chrome either in the
>glaze or in the Kiln. Does anyone know if there are any other
>explanations for a tin glaze going pink?!"
i have seen the same thing happen and was told that copper in the reducing
kiln atmosphere can cause this.
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