Monica Wright on sun 29 nov 09
so, is Grolleg Kaolin really necessary?=3DA0 It is just so stinking expensi=
ve=3D
.=3DA0 Almost all Porcelin recipes that I have are for Grolleg.=3DA0 There =
is t=3D
he old 25% each of EPK, Ball clay, Feldspar, and Flint but I find it too gr=
=3D
ayish.=3DA0 I don't want to be cheap but geeze... I just can't afford to th=
ro=3D
w out several hundred dollars for only a few bags of the suff.=3D0A=3D0AI k=
now.=3D
.. several of you are going to say "you can't go cheap if you want quality"=
=3D
.=3DA0 Whatever.=3DA0 Aparently you haven't seen my checking account lately=
.=3DA0=3D
Either I go at the very least "cheaper" or I am done with porcelain.=3DA0 =
Th=3D
anks.
Steve Mills on sun 29 nov 09
Just an idea:
How about making up a thin, fine, super-white porcelain slip from a small
quantity of something like Southern Ice, and use that as a finishing "coat"
on your "grayish" Porcelain body. You will have difficulty in achieving
translucency, but you'll get the "Whiteness"you want.
This is a route I've often suggested to people who want a fine (sometimes
coloured) surface on their wares, when firing technique or sheer expense
prohibit a "fine body" route.
Steve M
On Sun, Nov 29, 2009 at 10:33 AM, Monica Wright wr=
ote:
> so, is Grolleg Kaolin really necessary? It is just so stinking expensive=
.
> Almost all Porcelin recipes that I have are for Grolleg. There is the ol=
d
> 25% each of EPK, Ball clay, Feldspar, and Flint but I find it too grayish=
.
> I don't want to be cheap but geeze... I just can't afford to throw out
> several hundred dollars for only a few bags of the suff.
>
> I know... several of you are going to say "you can't go cheap if you want
> quality". Whatever. Aparently you haven't seen my checking account
> lately. Either I go at the very least "cheaper" or I am done with
> porcelain. Thanks.
>
--
Steve
Bath
UK
www.mudslinger.me.uk
Snail Scott on sun 29 nov 09
On Nov 29, 2009, at 4:33 AM, Monica Wright wrote:
> so, is Grolleg Kaolin really necessary?=3DA0
> I know... several of you are going to say "you can't go cheap if you=3D20=
=3D
> want quality"...
It's not a matter of 'quality'. It's a matter of 'qualities'.
One of the qualities of grolleg is the color response
it gives the glazes because its titanium content is
lower than the US domestic equivalents. (I am
guessing that grolleg in Britain is no more pricey
there than domestic kaolins are in the US.) Grolleg
isn't better, just different, and it's only worth the
extra money if the difference matters.
-Snail
Dennis Gerasimov on sun 29 nov 09
Layering porcelain's one on top of another may result in severe cracking
because different porcelains can have amazingly different expansion
rates. I am not saying it will never work, all I am saying it adds
another layer of complexity to your porcelain/glaze system. Now you have
three mixes to match expansion on.
If grolleg seems too expensive, try tile 6 which was engineered to be
grolleg replacement. Anoher one to try is tile 6. Neither is perfect,
but they can be beaten into submission.
Neither one is as transparent as grolleg, so depending on what you are
after, it might not work. Are you throwing or casting? Are you after
whiteness or transparency? You want thin walls or just the "porcelain"
name? What cone are you firing to? Just saying grolleg is too expensive
is not easy to overcome, not enough info.
Dennis
Steve Mills wrote:
> Just an idea:
> How about making up a thin, fine, super-white porcelain slip from a small
> quantity of something like Southern Ice, and use that as a finishing "coa=
t"
> on your "grayish" Porcelain body. You will have difficulty in achieving
> translucency, but you'll get the "Whiteness"you want.
> This is a route I've often suggested to people who want a fine (sometimes
> coloured) surface on their wares, when firing technique or sheer expense
> prohibit a "fine body" route.
>
> Steve M
>
> On Sun, Nov 29, 2009 at 10:33 AM, Monica Wright =
wrote:
>
>
>> so, is Grolleg Kaolin really necessary? It is just so stinking expensiv=
e.
>> Almost all Porcelin recipes that I have are for Grolleg. There is the o=
ld
>> 25% each of EPK, Ball clay, Feldspar, and Flint but I find it too grayis=
h.
>> I don't want to be cheap but geeze... I just can't afford to throw out
>> several hundred dollars for only a few bags of the suff.
>>
>> I know... several of you are going to say "you can't go cheap if you wan=
t
>> quality". Whatever. Aparently you haven't seen my checking account
>> lately. Either I go at the very least "cheaper" or I am done with
>> porcelain. Thanks.
>>
>>
>
>
>
> --
> Steve
> Bath
> UK
> www.mudslinger.me.uk
>
Ron Roy on sun 29 nov 09
Hi Monica,
If you want translucency then you need to use a kaolin with less TiO2 =3D20
- North American Kaolins have too much.
I can convert any grolleg based porcelain to an EPK based one easily - =3D2=
0
all I need is the recipe - you will still have to test it to make sure =3D2=
0
it fires right in your system.
RR
Quoting Monica Wright :
> so, is Grolleg Kaolin really necessary?=3DA0 It is just so stinking =3D20
> expensive.=3DA0 Almost all Porcelin recipes that I have are for =3D20
> Grolleg.=3DA0 There is the old 25% each of EPK, Ball clay, Feldspar, and =
=3D20
> Flint but I find it too grayish.=3DA0 I don't want to be cheap but =3D20
> geeze... I just can't afford to throw out several hundred dollars =3D20
> for only a few bags of the suff.
>
> I know... several of you are going to say "you can't go cheap if you =3D2=
0
> want quality".=3DA0 Whatever.=3DA0 Aparently you haven't seen my checking=
=3D20
> account lately.=3DA0 Either I go at the very least "cheaper" or I am =3D2=
0
> done with porcelain.=3DA0 Thanks.
>
Veena Raghavan on sun 29 nov 09
Hi Steve and Monica,
Steve, your solution really works. I have used it successfully in
reduction. I sometimes use a very nice clay from Highwater called P10, whic=
h tends to
be a bit gray and, therefore, the celadons I use lose their bright clear
quality. So, when I used this clay with a celadon, I coat it, when leather
hard with a sieved slip made from Helios, also from Highwater, but which is=
a
far whiter clay with a highter Grolleg content. As a result, the celadons
come out true.
All the best.
Veena
In a message dated 11/29/2009 9:23:12 PM Eastern Standard Time,
original.mudslinger@GOOGLEMAIL.COM writes:
>
>
> Just an idea:
> How about making up a thin, fine, super-white porcelain slip from a small
> quantity of something like Southern Ice, and use that as a finishing
> "coat"
> on your "grayish" Porcelain body. You will have difficulty in achieving
> translucency, but you'll get the "Whiteness"you want.
> This is a route I've often suggested to people who want a fine (sometimes
> coloured) surface on their wares, when firing technique or sheer expense
> prohibit a "fine body" route.
>
> Steve M
VeenaRaghavan@cs.com
Joseph Bennion on mon 30 nov 09
Ron is right. If translucency is not important to you then grolleg only mak=
=3D
es for expensive whiteware. My observation is that with a few exceptions mo=
=3D
st potters really only want porcelain for a white surface upon witch to pai=
=3D
nt. In fact in a lot of cases a good white stone ware would suffice and be =
=3D
a bit easier to handle. =3DA0In the case of wood fire folks the more "dirty=
" =3D
porcelains may be a better choice any way.
Joe the Potter
Joseph Bennion=3D20
=3D0AHorseshoe Mountain Pottery
=3D0AMom's Stuff Healing Salve=3D20
=3D0APO Box 186 =3D20
=3D0ASpring City, Utah 84662 =
=3D
=3D20
=3D0A435-462-2708=3D20
=3D0Awww.horseshoemountainpottery.com
--- On Sun, 11/29/09, Ron Roy wrote:
From: Ron Roy
Subject: Re: Grolleg?
To: Clayart@LSV.CERAMICS.ORG
Date: Sunday, November 29, 2009, 10:02 AM
Hi Monica,
If you want translucency then you need to use a kaolin with less TiO2 - Nor=
=3D
th American Kaolins have too much.
I can convert any grolleg based porcelain to an EPK based one easily - all =
=3D
I need is the recipe - you will still have to test it to make sure it fires=
=3D
right in your system.
RR
Quoting Monica Wright :
> so, is Grolleg Kaolin really necessary?=3DA0 It is just so stinking expen=
si=3D
ve.=3DA0 Almost all Porcelin recipes that I have are for Grolleg.=3DA0 Ther=
e is=3D
the old 25% each of EPK, Ball clay, Feldspar, and Flint but I find it too =
=3D
grayish.=3DA0 I don't want to be cheap but geeze... I just can't afford to =
th=3D
row out several hundred dollars for only a few bags of the suff.
>=3D20
> I know... several of you are going to say "you can't go cheap if you want=
=3D
quality".=3DA0 Whatever.=3DA0 Aparently you haven't seen my checking accou=
nt l=3D
ately.=3DA0 Either I go at the very least "cheaper" or I am done with porce=
la=3D
in.=3DA0 Thanks.
>=3D20
=3D0A=3D0A=3D0A
John Britt on mon 30 nov 09
Monica,
No, you don't need Grolleg. (It gives translucent porcelain bodies.)
Here is a cone 10 Porcelain Body
27% #6 Tile
27 EPK
13 Silica
13 Pyrax (pyrophillite)
20 Custer Feldspar
2 Bentonite
John Britt
http://ncclayclub.blogspot.com
Craig Martell on mon 30 nov 09
Hello China Clay enthusiasts:
Grolleg is a primary kaolin. US kaolins are secondary clays and contain
more iron and titanium. The TiO2 content of most US kaolins averages about
1.5%. As previously stated the higher titanium content will interfere with
translucency but the bigger deal, as far as I'm concerned, is the color
response with celadon glazes, especially blue celadons. The blues don't
like titanium and will go more towards green.
I don't use grolleg in any of my porcelain bodies, I use Standard and Super
Standard which are also Cornish primary kaolins and are very white. I use
grolleg in slips and glazes though. The whitest US kaolin has been EPK but
I don't know how this is maintaining over time. #6 Tile is a thing of the
past from what I hear. The bags still say 6-tile Clay but it's actually
Sapphire Kaolin according to my supplier. #6-tile has never been real
white but it was a nice throwing clay.
I can send my recipes for the white and off white bodies if anyone is
interested.
regards, Craig Martell Hopewell, Oregon
Sherron & Jim Bowen on mon 30 nov 09
I have a Japanese made bottle that has what appears to be a very white
porcelain slip over a not so white porcelain body. The pot has a sgraffito
decoration that resulted in the designs being a greener celadon on a bluer
ground. Nice effect.
Sherron & Jim Bowen on mon 30 nov 09
Some want a blue celadon which is unlikely to be achieved with a porcelain
body not made from grolleg or a similar low titanium china clay.
JB
----- Original Message -----
From: "Joseph Bennion"
To:
Sent: Monday, November 30, 2009 2:40 AM
Subject: Re: Grolleg?
Ron is right. If translucency is not important to you then grolleg only
makes for expensive whiteware. My observation is that with a few exceptions
most potters really only want porcelain for a white surface upon witch to
paint. In fact in a lot of cases a good white stone ware would suffice and
be a bit easier to handle. In the case of wood fire folks the more "dirty"
porcelains may be a better choice any way.
Joe the Potter
Joseph Bennion
Horseshoe Mountain Pottery
Mom's Stuff Healing Salve
PO Box 186
Spring City, Utah 84662
435-462-2708
www.horseshoemountainpottery.com
--- On Sun, 11/29/09, Ron Roy wrote:
From: Ron Roy
Subject: Re: Grolleg?
To: Clayart@LSV.CERAMICS.ORG
Date: Sunday, November 29, 2009, 10:02 AM
Hi Monica,
If you want translucency then you need to use a kaolin with less TiO2 -
North American Kaolins have too much.
I can convert any grolleg based porcelain to an EPK based one easily - all =
I
need is the recipe - you will still have to test it to make sure it fires
right in your system.
RR
Quoting Monica Wright :
> so, is Grolleg Kaolin really necessary? It is just so stinking expensive.
> Almost all Porcelin recipes that I have are for Grolleg. There is the old
> 25% each of EPK, Ball clay, Feldspar, and Flint but I find it too grayish=
.
> I don't want to be cheap but geeze... I just can't afford to throw out
> several hundred dollars for only a few bags of the suff.
>
> I know... several of you are going to say "you can't go cheap if you want
> quality". Whatever. Aparently you haven't seen my checking account lately=
.
> Either I go at the very least "cheaper" or I am done with porcelain.
> Thanks.
>
Paul Herman on mon 30 nov 09
Hi Craig,
Please do post your clay recipes,
Thanks,
Paul Herman
Great Basin Pottery
Doyle, California US
www.greatbasinpottery.com/
On Nov 30, 2009, at 11:47 AM, Craig Martell wrote:
> Hello China Clay enthusiasts:
>
> Grolleg is a primary kaolin. US kaolins are secondary clays and
> contain
> more iron and titanium. The TiO2 content of most US kaolins
> averages about
> 1.5%. As previously stated the higher titanium content will
> interfere with
> translucency but the bigger deal, as far as I'm concerned, is the
> color
> response with celadon glazes, especially blue celadons. The blues
> don't
> like titanium and will go more towards green.
>
> I don't use grolleg in any of my porcelain bodies, I use Standard
> and Super
> Standard which are also Cornish primary kaolins and are very white.
> I use
> grolleg in slips and glazes though. The whitest US kaolin has been
> EPK but
> I don't know how this is maintaining over time. #6 Tile is a thing
> of the
> past from what I hear. The bags still say 6-tile Clay but it's
> actually
> Sapphire Kaolin according to my supplier. #6-tile has never been real
> white but it was a nice throwing clay.
>
> I can send my recipes for the white and off white bodies if anyone is
> interested.
>
> regards, Craig Martell Hopewell, Oregon
John Britt on mon 30 nov 09
Craig,
I am interested,
John Britt
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