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celedon for soda/salt

updated thu 5 aug 10

 

Bruce Bowers on tue 3 aug 10


Hi All,
I am looking for a good celedon for use in the chamber of a noborigama that
we lightly salt/soda.
The one I have used for years contains a small bit of bariem carb. and,
although I have had it tested for toxicity and it is fine, I would prefer n=
ot
to use this chemical anymore.
A lot of pots will only have a liner, with the exterior slipped and
stained. That is where most of the celedon would go....but a little on the
exteriors in some cases; in small areas.
Any suggestions would be appreciated.
Thanks,
Bruce Bowers
_www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)

Eva Gallagher on tue 3 aug 10


Hi Bruce -
One that we have had a lot of success with just in regular reduction is the
Fraser Blue Celadon from John Britt's book. Ron Roy revised it for me to
lower the expansion to reduce crazing. Below is the revised version. It is
about 64 versus 68 expansion of the original.
I also like to add about .6% of a blue stain as suggested by the Coleman's
for their Celadons - though they use more like 1.5% of a stain. It also is =
a
good clear without any iron - get nice little bubbles to give it depth if
applied more thickly. Don't know how it will perform in salt/soda but I am
planning to use it in my wood/soda firing which I hope will finally be next
week or so.

Eva Gallagher
http://newfoundoutpotter.blogspot.com/
http://www.valleyartisans.com/gallagher/Gallagher.htm

----- Original Message -----
From: "Bruce Bowers"
To:
Sent: Tuesday, August 03, 2010 9:07 AM
Subject: Celedon for Soda/Salt


> Hi All,
> I am looking for a good celedon for use in the chamber of a noborigama
> that
> we lightly salt/soda.
> The one I have used for years contains a small bit of bariem carb. and,
> although I have had it tested for toxicity and it is fine, I would prefer
> not
> to use this chemical anymore.
> A lot of pots will only have a liner, with the exterior slipped and
> stained. That is where most of the celedon would go....but a little on
> the
> exteriors in some cases; in small areas.
> Any suggestions would be appreciated.
> Thanks,
> Bruce Bowers
> _www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
>
>

Eva Gallagher on tue 3 aug 10


Hi Bruce - Sorry but forgot to paste in the reicpe for the revised Frase
Blue Celadon here it is:

Recipe Name: Fraser Blue Celadon RR Revised Jan 07

Cone: 10 Color: blue
Firing: Reduction Surface: Glossy

Amount Ingredient
23.2 Feldspar--G-200
4 Spodumene--Foote
28.3 Wollastonite
3 Talc
17.2 Kaolin--Grolleg
24.2 Silica

99.9 Total

Additives
.5 Iron Oxide--Red

Unity Oxide
.025 Li2O
.044 Na2O
.099 K2O
.111 MgO
.721 CaO
1.000 Total

.391 Al2O3
.007 Fe2O3

3.635 SiO2
0 TiO2

9.3 Ratio
64.8 Exp

Comments: May ball mill FeO for better colour. revised to reduce crazing.
-----------------------------------
Calculations by GlazeMasterT
www.masteringglazes.com

Eva
------------------------------------

----- Original Message -----
From: "Eva Gallagher"
To: ;
Sent: Tuesday, August 03, 2010 10:28 AM
Subject: Re: Celedon for Soda/Salt


> Hi Bruce -
> One that we have had a lot of success with just in regular reduction is
> the Fraser Blue Celadon from John Britt's book. Ron Roy revised it for me
> to lower the expansion to reduce crazing. Below is the revised version. I=
t
> is about 64 versus 68 expansion of the original.
> I also like to add about .6% of a blue stain as suggested by the Coleman'=
s
> for their Celadons - though they use more like 1.5% of a stain. It also i=
s
> a good clear without any iron - get nice little bubbles to give it depth
> if applied more thickly. Don't know how it will perform in salt/soda but =
I
> am planning to use it in my wood/soda firing which I hope will finally be
> next week or so.
>
> Eva Gallagher
> http://newfoundoutpotter.blogspot.com/
> http://www.valleyartisans.com/gallagher/Gallagher.htm
>
> ----- Original Message -----
> From: "Bruce Bowers"
> To:
> Sent: Tuesday, August 03, 2010 9:07 AM
> Subject: Celedon for Soda/Salt
>
>
>> Hi All,
>> I am looking for a good celedon for use in the chamber of a noborigama
>> that
>> we lightly salt/soda.
>> The one I have used for years contains a small bit of bariem carb. and,
>> although I have had it tested for toxicity and it is fine, I would prefe=
r
>> not
>> to use this chemical anymore.
>> A lot of pots will only have a liner, with the exterior slipped and
>> stained. That is where most of the celedon would go....but a little on
>> the
>> exteriors in some cases; in small areas.
>> Any suggestions would be appreciated.
>> Thanks,
>> Bruce Bowers
>> _www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
>>
>>
>

May Luk on tue 3 aug 10


Isn't celadon glaze just a transparent base with a pinch of iron oxide?

Just curious..

May

On Tue, Aug 3, 2010 at 9:07 AM, Bruce Bowers wrote:
> Hi All,
> I am looking for a good celedon for use in the chamber of a noborigama th=
=3D
at
> =3DA0we lightly salt/soda.
> The one I have used for years contains a small bit of bariem carb. and,
> although I have had it tested for toxicity and it is fine, I would prefer=
=3D
not
> to =3DA0use this chemical anymore.
> A lot of pots will only have a liner, with the exterior slipped and
> stained. =3DA0That is where most of the celedon would go....but a little =
on=3D
the
> exteriors in some cases; in small areas.
> Any suggestions would be appreciated.
> Thanks,
> Bruce Bowers
> _www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
>



--=3D20
http://twitter.com/MayLuk

Ron Roy on tue 3 aug 10


Hi Bruce,

Send me the recipe and I'll reformulate it with calcium replacing the
barium - you won't see the difference if the barium amount is small.

RR


Quoting Bruce Bowers :

> Hi All,
> I am looking for a good celedon for use in the chamber of a noborigama th=
at
> we lightly salt/soda.
> The one I have used for years contains a small bit of bariem carb. and,
> although I have had it tested for toxicity and it is fine, I would prefer=
not
> to use this chemical anymore.
> A lot of pots will only have a liner, with the exterior slipped and
> stained. That is where most of the celedon would go....but a little on t=
he
> exteriors in some cases; in small areas.
> Any suggestions would be appreciated.
> Thanks,
> Bruce Bowers
> _www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
>

Marcia Selsor on tue 3 aug 10


I had an ^10 iron saturate red that would go celedon green in Soda. =3D
Maybe if you try and iron red and reduce the iron content from being a =3D
saturate to maybe 1.5% you'll have what you want.
Stoneware glazes can do some nice things in Soda. They can also changed =3D
drastically.
Marcia

On Aug 3, 2010, at 9:28 AM, Eva Gallagher wrote:

> Hi Bruce -
> One that we have had a lot of success with just in regular reduction =3D
is the
> Fraser Blue Celadon from John Britt's book. Ron Roy revised it for me =3D
to
> lower the expansion to reduce crazing. Below is the revised version. =3D
It is
> about 64 versus 68 expansion of the original.
> I also like to add about .6% of a blue stain as suggested by the =3D
Coleman's
> for their Celadons - though they use more like 1.5% of a stain. It =3D
also is a
> good clear without any iron - get nice little bubbles to give it depth =
=3D
if
> applied more thickly. Don't know how it will perform in salt/soda but =3D
I am
> planning to use it in my wood/soda firing which I hope will finally be =
=3D
next
> week or so.
>=3D20
> Eva Gallagher
> http://newfoundoutpotter.blogspot.com/
> http://www.valleyartisans.com/gallagher/Gallagher.htm
>=3D20
> ----- Original Message -----
> From: "Bruce Bowers"
> To:
> Sent: Tuesday, August 03, 2010 9:07 AM
> Subject: Celedon for Soda/Salt
>=3D20
>=3D20
>> Hi All,
>> I am looking for a good celedon for use in the chamber of a =3D
noborigama
>> that
>> we lightly salt/soda.
>> The one I have used for years contains a small bit of bariem carb. =3D
and,
>> although I have had it tested for toxicity and it is fine, I would =3D
prefer
>> not
>> to use this chemical anymore.
>> A lot of pots will only have a liner, with the exterior slipped and
>> stained. That is where most of the celedon would go....but a little =3D
on
>> the
>> exteriors in some cases; in small areas.
>> Any suggestions would be appreciated.
>> Thanks,
>> Bruce Bowers
>> _www.bowerswoodfireandpics.com_ =3D
(http://www.bowerswoodfireandpics.com)
>>=3D20
>>=3D20
>=3D20

Marcia Selsor
http://www.marciaselsor.com

May Luk on tue 3 aug 10


Hi Ron and friends;

Celadons are traditionally fired in saggers, if it were fired without
a sagger at a kiln location where ash / soda is flying around, how
would that change the nature of the glaze? Should the base be on the
low expansion side to begin with?

More idle curiosity

May


On Tue, Aug 3, 2010 at 11:46 AM, Ron Roy wrote:
> Hi Bruce,
>
> Send me the recipe and I'll reformulate it with calcium replacing the
> barium - you won't see the difference if the barium amount is small.
>
> RR
>
>
> Quoting Bruce Bowers :
>
>> Hi All,
>> I am looking for a good celedon for use in the chamber of a noborigama
>> that
>> =3DA0we lightly salt/soda.
>> The one I have used for years contains a small bit of bariem carb. and,
>> although I have had it tested for toxicity and it is fine, I would prefe=
=3D
r
>> not
>> to =3DA0use this chemical anymore.
>> A lot of pots will only have a liner, with the exterior slipped and
>> stained. =3DA0That is where most of the celedon would go....but a little=
o=3D
n
>> the
>> exteriors in some cases; in small areas.
>> Any suggestions would be appreciated.
>> Thanks,
>> Bruce Bowers
>> _www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
>>
>



--=3D20
http://twitter.com/MayLuk

ivor and olive lewis on wed 4 aug 10


Dear May Luk,

The beauty of Celadon style glazes is determined by their optical
properties. They should be translucent not transparent, see illustrations i=
n
Nigel Wood, "Chinese Glazes" ISBN 90-5703-23-25

Photomicrographs published by Robert Tichane suggest that translucency in
this style of glaze is due to bubbles which evolve and are retained in a
felspathic glass.



Regards,

Ivor Lewis,
REDHILL,
South Australia

Eric Hansen on wed 4 aug 10


May: I have an otherwise celadon-type blue-green translucent glaze,
fired in wood, reduction, but where fly ash accumulates I got spots of
opaque iron-calcium yellow-tan. Fly ash has a tendency to produce that
color wherever it accumulates. I think the glaze was 85 old cornish
stone (purple-ish with fluorspar) and 15 whiting. Fired to at least
cone 10. I'll send you a new image later today.
H A N S E N

On Tue, Aug 3, 2010 at 8:10 PM, May Luk wrote:
> Hi Ron and friends;
>
> Celadons are traditionally fired in saggers, if it were fired without
> a sagger at a kiln location where ash / soda is flying around, how
> would that change the nature of the glaze? Should the base be on the
> low expansion side to begin with?
>
> More idle curiosity
>
> May
>
>
> On Tue, Aug 3, 2010 at 11:46 AM, Ron Roy wrote:
>> Hi Bruce,
>>
>> Send me the recipe and I'll reformulate it with calcium replacing the
>> barium - you won't see the difference if the barium amount is small.
>>
>> RR
>>
>>
>> Quoting Bruce Bowers :
>>
>>> Hi All,
>>> I am looking for a good celedon for use in the chamber of a noborigama
>>> that
>>> =3DA0we lightly salt/soda.
>>> The one I have used for years contains a small bit of bariem carb. and,
>>> although I have had it tested for toxicity and it is fine, I would pref=
=3D
er
>>> not
>>> to =3DA0use this chemical anymore.
>>> A lot of pots will only have a liner, with the exterior slipped and
>>> stained. =3DA0That is where most of the celedon would go....but a littl=
e =3D
on
>>> the
>>> exteriors in some cases; in small areas.
>>> Any suggestions would be appreciated.
>>> Thanks,
>>> Bruce Bowers
>>> _www.bowerswoodfireandpics.com_ (http://www.bowerswoodfireandpics.com)
>>>
>>
>
>
>
> --
> http://twitter.com/MayLuk
>



--=3D20
Eric Alan Hansen
Stonehouse Studio Pottery
Alexandria, Virginia
americanpotter.blogspot.com
thesuddenschool.blogspot.com
hansencookbook.blogspot.com
"To me, human life in all its forms, individual and aggregate, is a
perpetual wonder: the flora of the earth and sea is full of beauty and
of mystery which seeks science to understand; the fauna of land and
ocean is not less wonderful; the world which holds them both, and the
great universe that folds it in on everyside, are still more
wonderful, complex, and attractive to the contemplating mind." -
Theodore Parker, minister, transcendentalist, abolitionist (1810-1860)

Lee Love on wed 4 aug 10


On Tue, Aug 3, 2010 at 7:10 PM, May Luk wrote:
> Hi Ron and friends;
>
> Celadons are traditionally fired in saggers, if it were fired without
> a sagger at a kiln location where ash / soda is flying around, how
> would that change the nature of the glaze? Should the base be on the
> low expansion side to begin with?

May, especially salt, bleaches iron. Typically in iron glazes in
salt/soda, you need more iron and less flux to stand up to the
bleaching action of the vapor glazing.

Great article on the effect by my Mashiko friend Euan Craig. The
unnamed friend that asks him the question about black in soda was me,
years ago:

http://euancraig.blogspot.com/2010/03/black-is-black.html
--
=3DA0Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/

=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi