Eloise VanderBilt on sun 9 apr 00
-------------------
I unloaded a cone 6 firing from an electric kiln and was surprised to see =
that
the usually-good-clear-glazed pots and a white glaze test tile had a =
decidedly
pink hue. Other than glaze contamination, could there be another reason for
this happening? thanks for any clues. I hate to throw out good glazes.
June Perry on mon 10 apr 00
If the glaze batch itself didn't get contaminated, you may have had glaze
containing chrome in that firing that affected your clear glaze.
Regards,
June
Debby Grant on mon 10 apr 00
If you had some pots in the kiln with a glaze colored with chrome
oxide, that would account for your white glazes turning pink. Chrome
tends to migrate and will often turn other glazes pink.
NakedClay@aol.com on mon 10 apr 00
Hi Eloise!
It appears there's not enough information (glaze and clay ingredients aren't
included here), to make other than a superficial guess, about your problem.
Here are my thoughts:
Perhaps your firing temperature isn't high enough. Clay and glazes sometimes
remain pink (the color of most bisqueware), if there's either a heat
distrubution problem, or some other malfunction of the kiln, which would
cause the wares to get insufficient heat.
Ingredient conflict in either the clay itself, or the glaze, or both. This
may not be a concern, if you're using a clay and glaze combo that has worked
well in the past.
A coloring ingredient, such as copper carbonate, or manganese, may have been
a contaminant. Either one of these are used (in combination with other
ingredients) to make pink glazes, for cone 6.
If you post your glaze recipe, and clay recipe, the ClayArt glaze and clay
gurus might be able to help you solve the problem. If either your glaze or
clay are commercially made, post it here, and contact the manufacturer, too.
Best wishes!
Milton NakedClay@AOL.COM
Not quite ready to be a prime time clay and glaze guru!
Kat Berger on mon 10 apr 00
Did you have any copper glazed pieces sitting next to the pots in the
kiln? The copper fumes can turn other glazes in the kiln colors.
Especially when Tin Oxide is also present.
Kat
in Maryland where it decide to snow in April!!!!
Wade Blocker on mon 10 apr 00
----------
From: Eloise VanderBilt
To: CLAYART@LSV.UKY.EDU
Subject: white and clear glazes turning pinkish
Date: Sunday, April 09, 2000 7:08 PM
----------------------------Original message----------------------------
-------------------
I unloaded a cone 6 firing from an electric kiln and was surprised to see
that
the usually-good-clear-glazed pots and a white glaze test tile had a
decidedly
pink hue. Other than glaze contamination, could there be another reason
for
this happening? thanks for any clues. I hate to throw out good glazes.
----------
Eloise,
If you had chrome oxide as part of a glaze recipe, any glaze
containing tin oxide as an opacifier will take on a pinkish hue. That is
why I avoid using chrome because of the way it migrates to other glazes.
Mia in ABQ
gwalker on tue 11 apr 00
Something not commonly known is that titatnium dioxide will also be
blushed by chrome. I have never in thirty years read of this, but have
used the information to produce various ranges of pottery. If you are
interested in the effects, you might like to take a look at the sandrift
range on our web site. The background glaze is very high in titaniuim
whilst one of the splashed glazes (not the bluish one) on top contains
chrome. You will notice the somewhat random blushing around this glaze.
If ever I can allocate the time, I will attempt a treatise on this
phenomenon. ;-)
Bestest,
Geoff
http://www.cronulla-pot.com.au/
(still not updated ... I bought a pottery supply business last month ...
what a dill! lol!)
Wade Blocker wrote:
> ----------------------------Original
> message----------------------------
>
> ----------
> From: Eloise VanderBilt
> To: CLAYART@LSV.UKY.EDU
> Subject: white and clear glazes turning pinkish
> Date: Sunday, April 09, 2000 7:08 PM
>
> ----------------------------Original
> message----------------------------
> -------------------
> I unloaded a cone 6 firing from an electric kiln and was surprised to
> see
> that
> the usually-good-clear-glazed pots and a white glaze test tile had a
> decidedly
> pink hue. Other than glaze contamination, could there be another
> reason
> for
> this happening? thanks for any clues. I hate to throw out good
> glazes.
> ----------
> Eloise,
> If you had chrome oxide as part of a glaze recipe, any glaze
> containing tin oxide as an opacifier will take on a pinkish hue. That
> is
> why I avoid using chrome because of the way it migrates to other
> glazes.
> Mia in ABQ
Smart on tue 11 apr 00
Dear Eloise,
I think you use a tin glase, and sometime it gives a pink hue when parts of
chromium are present during the firing (pink stains are composed with Tin,
Calcium and Chromium : Cr-Sn-Ca). Chromium can be given by your kiln
resistances (if they are Iron-Chromium-Aluminium alloy), but it can be also
given by stains containing chromium.Calcium is certainly present in your
glaze.
In all the case you have to fire tin glaze alone in you kiln (without
chromium compounds).
I hope to help you,
Best regards
See my French ceramic site : http://perso.wanadoo.fr/smart2000/
You can ask me questions about glazes and firing conditions.
----- Original Message -----
From: Eloise VanderBilt
To:
Sent: Monday, April 10, 2000 3:08 AM
Subject: white and clear glazes turning pinkish
----------------------------Original message----------------------------
-------------------
I unloaded a cone 6 firing from an electric kiln and was surprised to see
that
the usually-good-clear-glazed pots and a white glaze test tile had a
decidedly
pink hue. Other than glaze contamination, could there be another reason for
this happening? thanks for any clues. I hate to throw out good glazes.
Paul Taylor on tue 11 apr 00
Dear Eloise
My bet would be that these pots and tiles suffered some reduction in your
kiln, which can happen in a crowded air tight electric kiln. The chrome or
copper oxide that floats around your kiln unnoticed in Oxidation becomes a
red/pink blush Reduced.
Regards Paul T
----------
>From: Eloise VanderBilt
>To: CLAYART@LSV.UKY.EDU
>Subject: white and clear glazes turning pinkish
>Date: Mon, Apr 10, 2000, 2:08 am
>
>----------------------------Original message----------------------------
>-------------------
>I unloaded a cone 6 firing from an electric kiln and was surprised to see that
>the usually-good-clear-glazed pots and a white glaze test tile had a decidedly
>pink hue. Other than glaze contamination, could there be another reason for
>this happening? thanks for any clues. I hate to throw out good glazes.
Smart on thu 13 apr 00
OK You 're the best, I answer the same message to Eloise.
You can visit my french ceramic site : http://perso.wanadoo.fr/smart2000/
Care : It's a french site only written in french, I hope you remember high
school with your french lessons...
Cordialement,
Smart
----- Original Message -----
From: Debby Grant
To:
Sent: Monday, April 10, 2000 9:13 PM
Subject: Re: white and clear glazes turning pinkish
> ----------------------------Original message----------------------------
> If you had some pots in the kiln with a glaze colored with chrome
> oxide, that would account for your white glazes turning pink. Chrome
> tends to migrate and will often turn other glazes pink.
Carenza Hayhoe on fri 14 apr 00
I've never had a clear glaze turn pink but I have had it with a tin glaze
and couldn't identify any source of chrome anywhere. One friend whose tin
white glaze turned pink found an old chrome kitchen teaspoon at the bottom
of her glaze bucket. After months of asking every glaze guru I know I found
the only clue to my problem in the Hamers' Dictionary. Sometimes whiting is
obtained from chalk beds containing fossilised mussel shells and mussel
shells contain trace elements of chrome. Potters have to play many roles
including Sherlock Holmes!
Carenza
http://www.mochaware.com
----- Original Message -----
From: June Perry
To:
Sent: Monday, April 10, 2000 8:04 PM
Subject: Re: white and clear glazes turning pinkish
> ----------------------------Original message----------------------------
> If the glaze batch itself didn't get contaminated, you may have had
glaze
> containing chrome in that firing that affected your clear glaze.
>
> Regards,
> June
>
>
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