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green slip disaster

updated sun 29 jul 01

 

becky schroeder on fri 27 jul 01


horrors abound when i opened the kiln this morning. the beautiful soft
green slip i put around the outside of my plates in a 2 inch band had turned
into the most putrid color of poop brown you can imagine. this was the
glaze firing. after being bisqued the color was wonderful. i used white
stoneware slip (same body as my plate) colored with chromium oxide as i have
done frequently in the past with no problem. fired ^5 oxidation. covered
with a clear gloss glaze. all the rest of the colors on the plate came out
as expected and non colored parts came out white as expeceted. the four
that are already glaze fired will be going into the circular file but is the
any hope for the 8 others that are awaiting the glaze firing. can't take
the slip off but could i do anything else cover it up with a nice green
glaze maybe, or will the poop color just come on through.

of course i know i'll have to experiment but any suggestions on what went
wrong and ways to fix it would be greatly appreciated. i have many hours
invested in these puppies. one lesson learned already (amoung many) is that
from now on i think i'll use stains instead of oxides.

tia,
becky

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Avril Farley on sat 28 jul 01


Becky, it is highly likely that one of your glaze/slip ingredients included
some zinc oxide which always turns chrome green into sludge brown. I don't
think putting another glaze over will help. Perhaps an overglaze or enamel
might be ok.

Avril in the Forest UK
----- Original Message -----
From: "becky schroeder"
To:
Sent: Friday, July 27, 2001 11:38 PM
Subject: green slip disaster


> horrors abound when i opened the kiln this morning. the beautiful soft
> green slip i put around the outside of my plates in a 2 inch band had
turned
> into the most putrid color of poop brown you can imagine. this was the
> glaze firing. after being bisqued the color was wonderful. i used white
> stoneware slip (same body as my plate) colored with chromium oxide as i
have
> done frequently in the past with no problem. fired ^5 oxidation. covered
> with a clear gloss glaze. all the rest of the colors on the plate came
out
> as expected and non colored parts came out white as expeceted. the four
> that are already glaze fired will be going into the circular file but is
the
> any hope for the 8 others that are awaiting the glaze firing. can't take
> the slip off but could i do anything else cover it up with a nice green
> glaze maybe, or will the poop color just come on through.
>
> of course i know i'll have to experiment but any suggestions on what went
> wrong and ways to fix it would be greatly appreciated. i have many hours
> invested in these puppies. one lesson learned already (amoung many) is
that
> from now on i think i'll use stains instead of oxides.
>
> tia,
> becky
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
>
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Jean Cochran on sat 28 jul 01


Dear Becky,

It seems to me that, over the years, the only thing I can ever count on is that I
can't count on anything to emerge like I planned it. What works eleventy-dozen
times, fails to work the next time.

I was in helpless tears of laughter and of empathy reading your post about the
green. Green has done that to me more times than I can count, and I've used
different materials to have it repeat its' little trick.

I have a beautiful wind chime, which has 64 chimes on it. Each chime's design was
painstakingly outlined, defined and re-defined, painted with three coats of a green
underglaze (that had always been a beautiful green); hours and hours and hours of
work. Yuk brown are the leaves. It hangs in my bedroom/showroom in my 200 year
old log cabin. The fan blows on these chimes and lulls me to sleep at night.
Customers say, "Oh what a beautiful chime!". I refrain from saying "Oh, that old
thing with the yuk brown leaves that are supposed to be beautiful green."

Keep your chin up. Try re-firing if you wish. Anyway, happy potting.

Jean Wadsworth Cochran
Fox Hollow Pottery (in a real hollow in the woods of Kentucky)

becky schroeder wrote:

> horrors abound when i opened the kiln this morning. the beautiful soft
> green slip i put around the outside of my plates in a 2 inch band had turned
> into the most putrid color of poop brown you can imagine. this was the
> glaze firing. after being bisqued the color was wonderful. i used white
> stoneware slip (same body as my plate) colored with chromium oxide as i have
> done frequently in the past with no problem. fired ^5 oxidation. covered
> with a clear gloss glaze. all the rest of the colors on the plate came out
> as expected and non colored parts came out white as expeceted. the four
> that are already glaze fired will be going into the circular file but is the
> any hope for the 8 others that are awaiting the glaze firing. can't take
> the slip off but could i do anything else cover it up with a nice green
> glaze maybe, or will the poop color just come on through.
>
> of course i know i'll have to experiment but any suggestions on what went
> wrong and ways to fix it would be greatly appreciated. i have many hours
> invested in these puppies. one lesson learned already (amoung many) is that
> from now on i think i'll use stains instead of oxides.
>
> tia,
> becky
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.