Lesley Anton on fri 4 may 07
Hi all,
I have a question about a shino I use regularly.
Most of the time I get a great splotchy black/gray/brown perfect
carbon trap shino (cone 10, redux recipe)
Every once in a while I don't though - no good redux for whatever
ineptness I happen to be carrying
around with me that day. So when that happens, is there a way to
refire the darn pot to get a good result.
I have tried to just refire with no change - I am guessing that the
reason for this is that the carbon trapping happens around the lower
temps? So if I get some more glaze on there - heating up the pot and
dipping it back in the shino, then refiriing it - what are my chances
of getting some of that good carbon on there?
any ideas would be much appreciated.
Thanks
Lesley Anton
Lesley Anton Handmade Ceramic Lighting
www.lesleyanton.com
Lee Love on sat 5 may 07
Solubles in the glaze (soda ash) leaves faster than the
non-solubles. When ever you have to add water to your glaze, you
should add soda ash. I have pre-dipped pots in soda ash water
before glazing. Also, drying will effect howmuch soda ash is
deposited on the surface of the glaze. I have found that fast
drying helps create carbon trapping.
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://potters.blogspot.com/
"To affect the quality of the day, that is the highest of arts." -
Henry David Thoreau
"Let the beauty we love be what we do." - Rumi
Dannon Rhudy on sat 5 may 07
It would take so much time to do that -
why not just make some new pieces? Also, you can
refire to bisque temp and get some very nice orange
colors. Or, you can brush the surface with a saturated
solution of soda ash, and refire. Sometimes that will get
the carbon trap you are looking for, and it is a lot easier
than re-glazing.
regards
Dannon Rhudy
John Fulwood on sat 5 may 07
Hi Lesley,
I would just appreciate the pot for the qualities it has and make another one. What part of the process do you enjoy the most? Why bother trying to force the pot to be what you want it to be when the next one may please you even more.
Good luck,
John Fulwood
-----Original Message-----
>From: Lesley Anton
>Sent: May 4, 2007 10:40 PM
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: good carbon trap
>
>Hi all,
>I have a question about a shino I use regularly.
>
>Most of the time I get a great splotchy black/gray/brown perfect
>carbon trap shino (cone 10, redux recipe)
>Every once in a while I don't though - no good redux for whatever
>ineptness I happen to be carrying
>around with me that day. So when that happens, is there a way to
>refire the darn pot to get a good result.
>
>I have tried to just refire with no change - I am guessing that the
>reason for this is that the carbon trapping happens around the lower
>temps? So if I get some more glaze on there - heating up the pot and
>dipping it back in the shino, then refiriing it - what are my chances
>of getting some of that good carbon on there?
>
>any ideas would be much appreciated.
>
>Thanks
>Lesley Anton
>
>
>Lesley Anton Handmade Ceramic Lighting
>www.lesleyanton.com
>
>______________________________________________________________________________
>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.
John Fulwood
Kissimmee River Pottery
One 8th St. #11
Frenchtown, NJ. 08825
www.kissimmeeriverpottery.com
Diane Palmquist on sun 6 may 07
Hi,
I was hoping the experts could shed some light on a recent Shino
problem. I am in a co-op and we had a Shino firing. We used a few different
shino glazes(one being Makotos which NEVER has any issues) We had some good
results but had some REALLY bad ones too. Some of glazes came out very dry.
Even on the same pot we had areas of glossy melted glaze and areas of crusty
glaze. It was not a crawling issue at all. Jusy very dry and crusty in some
areas. The kiln was definatley fired hot enough- cone 10. We have had
firings in this kiln before and have had wonderful results with lots of
carbon trapping and good melt. We are going to give it another go but want
to know if anyone has experienced this before.
Thanks for your input,
Diane
Vince Pitelka on sun 6 may 07
Diane Palmquist wrote:
> I was hoping the experts could shed some light on a recent Shino
> problem. I am in a co-op and we had a Shino firing. We used a few
> different
> shino glazes(one being Makotos which NEVER has any issues) We had some
> good
> results but had some REALLY bad ones too. Some of glazes came out very
> dry.
> Even on the same pot we had areas of glossy melted glaze and areas of
> crusty
> glaze. It was not a crawling issue at all. Jusy very dry and crusty in
> some
> areas. The kiln was definatley fired hot enough- cone 10.
Diane -
If these shinos contained soda ash, then of course the thorough drying of
the pieces is critical. The soda ash is disolved in the water, so it soaks
into the claybody when you glaze the piece, and then migrates back to the
surface as the moisture evaporates. There are some conditional
circumstances which greatly effect the outcome dependant on the way the
moisture evaporates. For example, when any form with a rim opening equal to
or smaller than it's depth, such as a teabowl, mug, pitcher, or jar is
glazed inside and out with the same shino, the moisture humidifies the
inside of the pot, and thus most of the evaporation takes place on the
outside, which receives a much higher concentration of soda ash and comes
out completely differently from the inside. Similarly, if you glaze pots
with shino and then place them close together on a ware cart, the spaces
between the pots will be humidified, while surfaces of pots exposed on the
outside of the cart or wherever there are larger spaces between pots will
dry more effectively and thus draw more soda ash to those surfaces. This
can make a huge difference in how the glazes turn out. To get the most even
shino effect (which certainly is not always the objective), the pot should
be dried standing alone for at least 24 hours before loading into the glaze
firing.
Hope that helps -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Elizabeth Priddy on mon 7 may 07
Is this the same process as with Egyptian paste?
E
Elizabeth Priddy
Beaufort, NC - USA
http://www.elizabethpriddy.com
http://www.flickr.com/photos/7973282@N03/
Diane -
If these shinos contained soda ash, then of course the thorough drying of
the pieces is critical. The soda ash is disolved in the water, so it soaks
into the claybody when you glaze the piece, and then migrates back to the
surface as the moisture evaporates. ...vince
____________________________________________________________________________________
We won't tell. Get more on shows you hate to love
(and love to hate): Yahoo! TV's Guilty Pleasures list.
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Vince Pitelka on tue 8 may 07
Elizabeth Priddy wrote:
Is this the same process as with Egyptian paste?
Elizabeth -
There's certainly a parallel. In the case of Egyptian paste, the soluble
flux is mixed with the clay, and migrates to the surface as the clay dries,
forming a crust that melts to create the characteristic glaze, dependent on
the amount of dissolved flux. Of course with a shino the soda ash is just a
part of the flux in the glaze, and is carried into the claybody by
absorption during glazing, and then migrates back to the surface during
drying.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Diane Palmquist on tue 8 may 07
Hi Vince,
Thanks for the response. I do know all about the soda ash and drying the
pieces as we had a workshop with Malcolm Davis. We have had some pieces get
no carbon trap-just and orange color and we have had some major crawling
also. But what we never experienced before was the dry crusty appearance on
some pieces. On the inside and outside and also some melt on the pieces
which also had this bad surface. This has never happened before. Don't want
it to happen again! Any thoughts? Could it have something to do with uneven
temp.? Or a cool spot in the kiln?
Thanks,
Diane
----- Original Message -----
From: "Vince Pitelka"
To:
Sent: Sunday, May 06, 2007 9:38 PM
Subject: Re: good carbon trap
> Diane Palmquist wrote:
>> I was hoping the experts could shed some light on a recent Shino
>> problem. I am in a co-op and we had a Shino firing. We used a few
>> different
>> shino glazes(one being Makotos which NEVER has any issues) We had some
>> good
>> results but had some REALLY bad ones too. Some of glazes came out very
>> dry.
>> Even on the same pot we had areas of glossy melted glaze and areas of
>> crusty
>> glaze. It was not a crawling issue at all. Jusy very dry and crusty in
>> some
>> areas. The kiln was definatley fired hot enough- cone 10.
>
> Diane -
> If these shinos contained soda ash, then of course the thorough drying of
> the pieces is critical. The soda ash is disolved in the water, so it
> soaks
> into the claybody when you glaze the piece, and then migrates back to the
> surface as the moisture evaporates. There are some conditional
> circumstances which greatly effect the outcome dependant on the way the
> moisture evaporates. For example, when any form with a rim opening equal
> to
> or smaller than it's depth, such as a teabowl, mug, pitcher, or jar is
> glazed inside and out with the same shino, the moisture humidifies the
> inside of the pot, and thus most of the evaporation takes place on the
> outside, which receives a much higher concentration of soda ash and comes
> out completely differently from the inside. Similarly, if you glaze pots
> with shino and then place them close together on a ware cart, the spaces
> between the pots will be humidified, while surfaces of pots exposed on the
> outside of the cart or wherever there are larger spaces between pots will
> dry more effectively and thus draw more soda ash to those surfaces. This
> can make a huge difference in how the glazes turn out. To get the most
> even
> shino effect (which certainly is not always the objective), the pot should
> be dried standing alone for at least 24 hours before loading into the
> glaze
> firing.
>
> Hope that helps -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft, Tennessee Technological University
> Smithville TN 37166, 615/597-6801 x111
> vpitelka@dtccom.net, wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka/
> http://www.tntech.edu/craftcenter/
>
> ______________________________________________________________________________
> 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.
Eva Gallagher on tue 8 may 07
Hi Lee - can you use the dip on the foot as well or will it stick to the
shelf ? I hate the white of porcelain even in reduction as it's just too
cold for me and really clashes with shinos.
Regards,
Eva Gallagher
Deep River, Ontario
----- Original Message -----
From: "Lee Love"
To:
Sent: Monday, May 07, 2007 7:55 PM
Subject: Re: good carbon trap
>>
> Yes, especially in the case when you use the soda dip technique. I
> have also used the old type calgon as a dip, to get the unglazed part
> of the pot, like on bean pots, to get some wamth.
>
> the soda ash dip only looks good on porcelain. My
> experiments with iron bearing stoneware end up looking burnt and
> crusty.
>
>
> --
> Lee in Mashiko, Japan
> Minneapolis, Minnesota USA
> http://mashikopots.blogspot.com/
>
> "To affect the quality of the day, that is the highest of arts." -
> Henry David Thoreau
>
> "Let the beauty we love be what we do." - Rumi
>
> ______________________________________________________________________________
> >
Lee Love on tue 8 may 07
On 5/7/07, Elizabeth Priddy wrote:
> Is this the same process as with Egyptian paste?
>
>
Yes, especially in the case when you use the soda dip technique. I
have also used the old type calgon as a dip, to get the unglazed part
of the pot, like on bean pots, to get some wamth.
the soda ash dip only looks good on porcelain. My
experiments with iron bearing stoneware end up looking burnt and
crusty.
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://mashikopots.blogspot.com/
"To affect the quality of the day, that is the highest of arts." -
Henry David Thoreau
"Let the beauty we love be what we do." - Rumi
Vince Pitelka on tue 8 may 07
Diane Palmquist wrote:
> Thanks for the response. I do know all about the soda ash and drying the
> pieces as we had a workshop with Malcolm Davis. We have had some pieces
> get
> no carbon trap-just and orange color and we have had some major crawling
> also. But what we never experienced before was the dry crusty appearance
> on
> some pieces. On the inside and outside and also some melt on the pieces
> which also had this bad surface. This has never happened before. Don't
> want
> it to happen again! Any thoughts? Could it have something to do with
> uneven
> temp.? Or a cool spot in the kiln?
Diane -
That is sounding like uneven temperatures. All you can do is fire again and
give the kiln a little more time to equalize, and make sure that there is
always some back pressure to hold the heat in the kiln. You probably know
all about that, but it's one thing that potters so often overlook when
firing fuel kilns. From the start of the firing, it is a simple matter to
check the back pressure at the spy holes. At lower temperatures you can
just wave your hand in front of the spy hole to see if there are hot gases
coming out. If there are, open the damper a bit until you can detect no
back pressure, and then re-close it to ensure the slightest amount of back
pressure. And of course you will need more back pressure when you get up
around cone 012 if you want to promote carbon trapping.
Based on your comments above you seem to have good sound experience in
firing, so I am probably not telling you anything new. Any chance of a bad
glaze batch? I guess you did say that the pieces that showed dry places
also showed some gloss, so it doesn't sound like a bad glaze batch.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Diane Palmquist on wed 9 may 07
Thanks again for the help Vince. We will do another firing and try to
even things out and check the back pressure. These shinos are just too good
when they are good to give up!
Best,
Diane
----- Original Message -----
From: "Vince Pitelka"
To:
Sent: Tuesday, May 08, 2007 3:51 PM
Subject: Re: good carbon trap
> Diane Palmquist wrote:
>> Thanks for the response. I do know all about the soda ash and drying the
>> pieces as we had a workshop with Malcolm Davis. We have had some pieces
>> get
>> no carbon trap-just and orange color and we have had some major crawling
>> also. But what we never experienced before was the dry crusty appearance
>> on
>> some pieces. On the inside and outside and also some melt on the pieces
>> which also had this bad surface. This has never happened before. Don't
>> want
>> it to happen again! Any thoughts? Could it have something to do with
>> uneven
>> temp.? Or a cool spot in the kiln?
>
> Diane -
> That is sounding like uneven temperatures. All you can do is fire again
> and
> give the kiln a little more time to equalize, and make sure that there is
> always some back pressure to hold the heat in the kiln. You probably know
> all about that, but it's one thing that potters so often overlook when
> firing fuel kilns. From the start of the firing, it is a simple matter to
> check the back pressure at the spy holes. At lower temperatures you can
> just wave your hand in front of the spy hole to see if there are hot gases
> coming out. If there are, open the damper a bit until you can detect no
> back pressure, and then re-close it to ensure the slightest amount of back
> pressure. And of course you will need more back pressure when you get up
> around cone 012 if you want to promote carbon trapping.
>
> Based on your comments above you seem to have good sound experience in
> firing, so I am probably not telling you anything new. Any chance of a
> bad
> glaze batch? I guess you did say that the pieces that showed dry places
> also showed some gloss, so it doesn't sound like a bad glaze batch.
>
> Good luck -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Craft, Tennessee Technological University
> Smithville TN 37166, 615/597-6801 x111
> vpitelka@dtccom.net, wpitelka@tntech.edu
> http://iweb.tntech.edu/wpitelka/
> http://www.tntech.edu/craftcenter/
>
> ______________________________________________________________________________
> 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 thu 10 may 07
On 5/9/07, Eva Gallagher wrote:
> Hi Lee - can you use the dip on the foot as well or will it stick to the
> shelf ? I hate the white of porcelain even in reduction as it's just too
> cold for me and really clashes with shinos.
Yes, you can dip it on the foot. That is how I started: I used
to dip in the top water of a shino bucket, but that was using up the
shino soluables. So I mixed up soda ash water that would be
equivalant to 6% in a glaze. THat is much weaker than the saturated
dip. I have also used old calgon on the outside of bean pots to
create warmth.
I would wad, especially porcelain. Wad filled shells are the best.
The saturated dip blushes bare porcelain
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://mashikopots.blogspot.com/
"To affect the quality of the day, that is the highest of arts." -
Henry David Thoreau
"Let the beauty we love be what we do." - Rumi
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