thepotter on thu 18 dec 03
We have been firing a phoenix fast fire kiln with wood for several years.
In the latest firing, we had significant issues with a gold shino crawling
consisitently on each pot it was on. In the last firing, this particular
glaze was awesome on every pot. The last firing went to cone12 in 23 hours
with the last 2 for soaking. It did stall between 9-10. This firing also
went to cone 12 but only in 17 hours with a 2 hour soak. I don't think
speed was an issue since it was very smooth transition and was fairly
consistent rise of temp. throughout the firing. It was very cold but we
were quite careful to preheat and it was almost 10 hours til cone 010.
Can anyone help with suggesting other variables that may have created this
situation of crawling, especially under the lip of bowls but sometimes even
in the middle of a plate? Could it have anything to do with this glaze in
particular? I am pretty sure we mixed it quite well.
the recipe is as follows:
f-4 feldspar 48.00
Spodumene 36.00
Soda Ash 10.00
Kaolin 6.00
Rutile 4.00
Is it possible that it was just applied to thickly? We applied it the same
way, dipping, for the last firing.
Thank you for your help.
Bev in RI where it was 10 degrees during the firing sat. nite.
clennell on thu 18 dec 03
Sour Cherry Pottery
> Can anyone help with suggesting other variables that may have created this
> situation of crawling, especially under the lip of bowls but sometimes even
> in the middle of a plate? Could it have anything to do with this glaze in
> particular? I am pretty sure we mixed it quite well.
>
> the recipe is as follows:
> f-4 feldspar 48.00
> Spodumene 36.00
> Soda Ash 10.00
> Kaolin 6.00
>
> Rutile 4.00
>
> Is it possible that it was just applied to thickly? We applied it the same
> way, dipping, for the last firing.
>
> Thank you for your help
> Bev in RI where it was 10 degrees during the firing sat. nit
Bev: I've had excessive crawling with shino and it is almost always
attributed to thickness. I reseive the glaze every time i use it. If i
don't it appears really thick and i go ahead and add more water which in
the end makes it too thin. Seiving it gives me a better reading of the
proper thickness. A weenie will know why this happens.
Also I usually line jugs and teapots the day before or the clay body is
saturated and when you dunk it in glaze for the outside it seems to crawl
quite badly. Overlapping of the shino can also cause severe crawling that
looks like brain, which I don't like.
Welcome to the shino torture chamber.
Cheers,
Tony
P>S Hank that damn finger is going to mkae me neurotic. Up and down like a
toilet seat at a party.
Tony Ferguson on thu 18 dec 03
My guess is you put it on too thick. Also, dust could have be issue on
bisque if you are bisquing. Shinos like to evaporate water more quickly I've
noticed than other glazes--this even means during a glazing session from the
beginning to the end of the session the glaze can lose water.
This it down a bit and refire.
Thank you.
Tony Ferguson
On Lake Superior, where the sky meets the Lake
Custom & Manufactured Kiln Design
Stoneware, Porcelain, Raku and more
by Coleman, Ferguson, Winchester...
http://www.aquariusartgallery.com
218-727-6339
315 N. Lake Ave
Apt 312
Duluth, MN 55806
----- Original Message -----
From: "thepotter"
To:
Sent: Thursday, December 18, 2003 9:57 AM
Subject: help with crawling shino
> We have been firing a phoenix fast fire kiln with wood for several years.
> In the latest firing, we had significant issues with a gold shino crawling
> consisitently on each pot it was on. In the last firing, this particular
> glaze was awesome on every pot. The last firing went to cone12 in 23
hours
> with the last 2 for soaking. It did stall between 9-10. This firing also
> went to cone 12 but only in 17 hours with a 2 hour soak. I don't think
> speed was an issue since it was very smooth transition and was fairly
> consistent rise of temp. throughout the firing. It was very cold but we
> were quite careful to preheat and it was almost 10 hours til cone 010.
> Can anyone help with suggesting other variables that may have created this
> situation of crawling, especially under the lip of bowls but sometimes
even
> in the middle of a plate? Could it have anything to do with this glaze in
> particular? I am pretty sure we mixed it quite well.
>
> the recipe is as follows:
> f-4 feldspar 48.00
> Spodumene 36.00
> Soda Ash 10.00
> Kaolin 6.00
>
> Rutile 4.00
>
> Is it possible that it was just applied to thickly? We applied it the
same
> way, dipping, for the last firing.
>
> Thank you for your help.
> Bev in RI where it was 10 degrees during the firing sat. nite.
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
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>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
Paul Herman on thu 18 dec 03
Bev,
It sounds like you may have just gotten it on a bit thick. Does it seem
that way? The recipe certainly isn't too clayey. I use some shinos with
up to 40% clay.
Was the ware put into the kiln while it was still wet from glazing?
best wishes,
Paul Herman
Great Basin Pottery
423-725 Scott Road
Doyle, California 96109 US
potter@psln.com
----------
>From: thepotter
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: help with crawling shino
>Date: Thu, Dec 18, 2003, 7:57 AM
>
> We have been firing a phoenix fast fire kiln with wood for several years.
> In the latest firing, we had significant issues with a gold shino crawling
> consisitently on each pot it was on. In the last firing, this particular
> glaze was awesome on every pot. The last firing went to cone12 in 23 hours
> with the last 2 for soaking. It did stall between 9-10. This firing also
> went to cone 12 but only in 17 hours with a 2 hour soak. I don't think
> speed was an issue since it was very smooth transition and was fairly
> consistent rise of temp. throughout the firing. It was very cold but we
> were quite careful to preheat and it was almost 10 hours til cone 010.
> Can anyone help with suggesting other variables that may have created this
> situation of crawling, especially under the lip of bowls but sometimes even
> in the middle of a plate? Could it have anything to do with this glaze in
> particular? I am pretty sure we mixed it quite well.
>
> the recipe is as follows:
> f-4 feldspar 48.00
> Spodumene 36.00
> Soda Ash 10.00
> Kaolin 6.00
>
> Rutile 4.00
>
> Is it possible that it was just applied to thickly? We applied it the same
> way, dipping, for the last firing.
>
> Thank you for your help.
> Bev in RI where it was 10 degrees during the firing sat. nite.
thepotter on thu 18 dec 03
Thank you to all who answered my calls of distress. Most came up with the
same conclusion as far as thickness. The pots were glazed at least a day
ahead, some of them more so I don't think it was the drying. I also didn't
think that the time sequence had anything to do with it since it was only
the gold shino and not the other shinos or other glazes. Thanks. We will
let you know how the next one goes when we thin it out a bit. Have a great
holiday all!
Bev in RI
where there are actually lots
of potters for such a little state!
Donald G. Goldsobel on fri 19 dec 03
One of the beauties of using the same glaze over and over is knowing its
idiosyncrasies. Every shino Iv'e tried has a thickness tolerance. If your
glaze is particularly sensitive, anywhere the glaze accumulates on dipping,
as with the underside of a bowl lip, will tend to crawl. I use a Gustin
shino, that is a horror if dipped and wonderful if sparayed. Dipped the
inside of a bowl crawls like mad, but if sprayed, it is fine and even.
Control the thickness and you control the color as well as the surface
character.
Happy shinoing.
Donald
> 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.
Lee Love on fri 19 dec 03
----- Original Message -----
From: "thepotter"
> Is it possible that it was just applied to thickly? We applied it the
same
> way, dipping, for the last firing.
In my experience, the most common cause of crawling (and ugly color)
is applying the shino too thick.
--
Lee In Mashiko, Japan
http://Mashiko.org
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