iandol on sat 4 mar 00
------------------
Llewellyn Kouba asks
----------------------------Original message-------------------------
=3Cthis client wants an all black porcelain tea set. Any suggestions out =
there ?
cone 9 black tea for two=3E
Will someone please explain for me why a clay which has been compounded so =
that
it is as white and transluscent as possible has to be covered with an black
glaze, which, because of the stain or oxides it contains, will be in all
probability be opaque. What are the advantages?
Ivor Lewis. Who has an interest in porcelain
Iveragh Ceramics on mon 6 mar 00
Obviously it is because llewellyn's client thinks it will be nice.All
llewellyn asked for was a recipe for a black glaze,not your or anyone else's
hangs.
Bob Hollis
----- Original Message -----
From: "iandol"
To:
Sent: Sunday, March 05, 2000 12:11 AM
Subject: Black Glaze for Porcelain
----------------------------Original message----------------------------
------------------
Llewellyn Kouba asks
----------------------------Original message-------------------------
?
cone 9 black tea for two>
Will someone please explain for me why a clay which has been compounded so
that
it is as white and transluscent as possible has to be covered with an black
glaze, which, because of the stain or oxides it contains, will be in all
probability be opaque. What are the advantages?
Ivor Lewis. Who has an interest in porcelain
Ron Roy on mon 6 mar 00
Hi Ivor - I am not sure I can explain this in a way that makes sense to you but:
There is something that happens to many glazes when on porcelain. You must
understand that not all porcelains are translucent - think of them as white
(grey) fine grained clays - easy to carve and provide a light background
for many glazes.
It is the way glazes look on porcelain - better from my point of view - and
well worth the extra hassle of working with a clay that is only 50% plastic
material.
The glazes have a better finish - look richer and - I am struggling to
describe this - more luminescent. It has to do with all that body flux
adding to the melt and forming a union that is quite different from the
interaction of stoneware and glaze.
My Tenmoku glaze owes most of it's quality to the porcelain underneath.
It also occurs to me that you might not think of the clay I use as
porcelain - it is ballclay, kaolin, feldspar and silica with some bentonite
- not translucent but vitrified at cone 10. Never the less - when you
compare a glaze on this type of body with the same one on stoneware - you
might not even think it is the same glaze.
Need more - don't think I have more on this but will try if I have to -
wish you were here to see the difference.
RR
>----------------------------Original message----------------------------
>Llewellyn Kouba asks
>
>----------------------------Original message-------------------------
>
>>cone 9 black tea for two>
>
>Will someone please explain for me why a clay which has been compounded so that
>it is as white and transluscent as possible has to be covered with an black
>glaze, which, because of the stain or oxides it contains, will be in all
>probability be opaque. What are the advantages?
>
>Ivor Lewis. Who has an interest in porcelain
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
Antoinette Badenhorst on mon 6 mar 00
Ivor, I think sometimes a person will like all the other advantages that
porcelain give, like weight,sound,marble feel and so forth, but sometimes
they just want to call it porcelain for it `s status.
Antoinette.
Marcia Selsor on tue 7 mar 00
I agree with Ron. Porcelain can make a stoneware glaze be much more
jewel-like. There is something about the sleakness and refined finish of
the surface.
Marcia in Montana
Ron Roy wrote:
>
> ----------------------------Original message----------------------------
> Hi Ivor - I am not sure I can explain this in a way that makes sense to you bu
>
> There is something that happens to many glazes when on porcelain. You must
> understand that not all porcelains are translucent - think of them as white
> (grey) fine grained clays - easy to carve and provide a light background
> for many glazes.
>
> It is the way glazes look on porcelain - better from my point of view - and
> well worth the extra hassle of working with a clay that is only 50% plastic
> material.
>
> The glazes have a better finish - look richer and - I am struggling to
> describe this - more luminescent. It has to do with all that body flux
> adding to the melt and forming a union that is quite different from the
> interaction of stoneware and glaze.
>
> My Tenmoku glaze owes most of it's quality to the porcelain underneath.
>
> It also occurs to me that you might not think of the clay I use as
> porcelain - it is ballclay, kaolin, feldspar and silica with some bentonite
> - not translucent but vitrified at cone 10. Never the less - when you
> compare a glaze on this type of body with the same one on stoneware - you
> might not even think it is the same glaze.
>
> Need more - don't think I have more on this but will try if I have to -
> wish you were here to see the difference.
>
> RR
>
> >----------------------------Original message----------------------------
> >Llewellyn Kouba asks
> >
> >----------------------------Original message-------------------------
> >
> >> >cone 9 black tea for two>
> >
> >Will someone please explain for me why a clay which has been compounded so th
> >it is as white and transluscent as possible has to be covered with an black
> >glaze, which, because of the stain or oxides it contains, will be in all
> >probability be opaque. What are the advantages?
> >
> >Ivor Lewis. Who has an interest in porcelain
>
> Ron Roy
> 93 Pegasus Trail
> Scarborough
> Ontario, Canada
> M1G 3N8
> Evenings 416-439-2621
> Fax 416-438-7849
--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/spain99.html
http://www.silverhawk.com/ex99/selsor/welcome.html
Llewellyn Kouba on tue 7 mar 00
Ivor & Bob,
yes, I agree that black would probably have been my last choice for a glaze
over porcelain. As we all know the beauty of porcelain is the way it will
refract light and show off a glaze to best advantage. As the client wants
black I am very limited...though I have also seen where one uses an opaque
color on porcelain, even here the glaze can have a richness and clarity of
color that cannot be duplicated on anything else but porcelain. I have the
tea loaded now and hope to fire latter in the week. It may well be that the
glaze will be opaque but it could still be more refined, or a different
depth of color. I thank you all for your input and that is what makes
Clayart so wonderful...the defined right of choices, the broad spectrum of
people and a way to refine our talents.
Llewellyn
ABBEY POTTERY
http://www.assumptionabbey.com/Pottery
----- Original Message -----
From: "Iveragh Ceramics"
To:
Sent: March 06, 2000 10:44 AM
Subject: Re: Black Glaze for Porcelain
> ----------------------------Original message----------------------------
> Obviously it is because llewellyn's client thinks it will be nice.All
> llewellyn asked for was a recipe for a black glaze,not your or anyone
else's
> hangs.
> Bob Hollis
> ----- Original Message -----
> From: "iandol"
> To:
> Sent: Sunday, March 05, 2000 12:11 AM
> Subject: Black Glaze for Porcelain
>
>
> ----------------------------Original message----------------------------
> ------------------
> Llewellyn Kouba asks
>
> ----------------------------Original message-------------------------
>
> there
> ?
> cone 9 black tea for two>
>
> Will someone please explain for me why a clay which has been compounded so
> that
> it is as white and transluscent as possible has to be covered with an
black
> glaze, which, because of the stain or oxides it contains, will be in all
> probability be opaque. What are the advantages?
>
> Ivor Lewis. Who has an interest in porcelain
Barry and Toni Martens on wed 8 mar 00
------------------
Must admit I think Ivor has a point, and having it, also the right to hang =
it
out there,
But then it could be heat craze that's on me or the desire to jump back =
into
Clayart with both feet. Could be worse, the client could have asked for a =
blue
one?? =3CG=3E
Toni Martens in Durban South Africa damn tired of humidity and looking for
things to bite
----------------------------Original message----------------------------
Obviously it is because llewellyn's client thinks it will be nice.All
llewellyn asked for was a recipe for a black glaze,not your or anyone else's
hangs.
Bob Hollis
----------------------------Original message----------------------------
------------------
Llewellyn Kouba asks
----------------------------Original message-------------------------
=3Cthis client wants an all black porcelain tea set. Any suggestions out =
there
?
cone 9 black tea for two=3E
Will someone please explain for me why a clay which has been compounded so
that
it is as white and transluscent as possible has to be covered with an black
glaze, which, because of the stain or oxides it contains, will be in all
probability be opaque. What are the advantages?
Ivor Lewis. Who has an interest in porcelain
David Hendley on wed 8 mar 00
I was hoping that Ron Roy would respond to this, since
his work illustrates exactly why a black glaze on porcelain
can be so rich and alive.
In fact, like a celadon glaze, the claybody under a tenmoku
is very important, more important than for many other types
of glazes.
To re-phrase what Ron says, the glaze and clay become more
intimate; the glaze melts into the clay, rather than just
covering it.
On lips and edges, when the black goes to brown, it can become
a spectacular luminescent almost gold that's just not the same
on stoneware.
Finally, on porcelain the glaze can appear even smoother and
more glossy, for a denser feeling.
That said, there is another class of 'black glazes' that does not
particularly benefit from a porcelain claybody. Typically, these
glazes are based on an iron bearing clay that is made black
through the addition of manganese dioxide, cobalt oxide, and
iron oxide. Whereas a tenmoku is subtle, and varies according
to clay color and thickness of application, there is nothing
subtle about these glazes; they are *black* no matter what,
and don't give much clue as to what kind of clay they are covering.
I consider such glazes as 'suspicious as far as safety for use on a
tea set, since the saturation of metallic oxides could leach out
of the glaze. Formulating and firing a good tenmoku is more
difficult than using a cobalt oxide saturated black, but for both
practical and aesthetic reasons it would be the superior choice
for the tea set.
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
----- Original Message -----
From: Ron Roy
To:
Sent: Monday, March 06, 2000 1:18 PM
Subject: Re: Black Glaze for Porcelain
| ----------------------------Original message----------------------------
| Hi Ivor - I am not sure I can explain this in a way that makes sense to
you but:
|
| There is something that happens to many glazes when on porcelain. You must
| understand that not all porcelains are translucent - think of them as
white
| (grey) fine grained clays - easy to carve and provide a light background
| for many glazes.
|
| It is the way glazes look on porcelain - better from my point of view -
and
| well worth the extra hassle of working with a clay that is only 50%
plastic
| material.
|
| The glazes have a better finish - look richer and - I am struggling to
| describe this - more luminescent. It has to do with all that body flux
| adding to the melt and forming a union that is quite different from the
| interaction of stoneware and glaze.
|
| My Tenmoku glaze owes most of it's quality to the porcelain underneath.
|
| It also occurs to me that you might not think of the clay I use as
| porcelain - it is ballclay, kaolin, feldspar and silica with some
bentonite
| - not translucent but vitrified at cone 10. Never the less - when you
| compare a glaze on this type of body with the same one on stoneware - you
| might not even think it is the same glaze.
|
| Need more - don't think I have more on this but will try if I have to -
| wish you were here to see the difference.
|
| RR
|
| >----------------------------Original message----------------------------
| >Llewellyn Kouba asks
| >
| >----------------------------Original message-------------------------
| >
| >there ?
| >cone 9 black tea for two>
| >
| >Will someone please explain for me why a clay which has been compounded
so that
| >it is as white and transluscent as possible has to be covered with an
black
| >glaze, which, because of the stain or oxides it contains, will be in all
| >probability be opaque. What are the advantages?
| >
| >Ivor Lewis. Who has an interest in porcelain
|
Earl Brunner on thu 9 mar 00
Hi Toni! Glad to see you back on this list!
There are a few of my glazes that need the colorants from
the clay or the reaction of the colorants in the clay to
reduction in order to look good.
In other words I don't think they look good on a light or
white clay body.
However, there is something about porcelain with other
glazes, that just
makes them stand out over the same glaze on darker clay.
If you look at the porcelain mugs on my website, the inside
of the first
one, and the top, outside of the second one both show the
throwing marks through the glaze. The pots are perfectly
smooth, but non porcelain clay
just doesn't show up detail like for me in the same way.
Barry and Toni Martens wrote:
>
> ----------------------------Original message----------------------------
> ------------------
> Must admit I think Ivor has a point, and having it, also the right to hang it
> out there,
> But then it could be heat craze that's on me or the desire to jump back into
> Clayart with both feet. Could be worse, the client could have asked for a blue
> one??
> Toni Martens in Durban South Africa damn tired of humidity and looking for
> things to bite
> ----------------------------Original message----------------------------
> Obviously it is because llewellyn's client thinks it will be nice.All
> llewellyn asked for was a recipe for a black glaze,not your or anyone else's
> hangs.
> Bob Hollis
>
> ----------------------------Original message----------------------------
> ------------------
> Llewellyn Kouba asks
>
> ----------------------------Original message-------------------------
>
> > ?
> cone 9 black tea for two>
>
> Will someone please explain for me why a clay which has been compounded so
> that
> it is as white and transluscent as possible has to be covered with an black
> glaze, which, because of the stain or oxides it contains, will be in all
> probability be opaque. What are the advantages?
>
> Ivor Lewis. Who has an interest in porcelain
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
Paul Taylor on fri 10 mar 00
Dear All
I also think Ivor has a point and I do not see that it matters what
prompted his question.
Above all I think "hangs" are the life blood of this group. It is also very
difficult to contradict or question in writing with out a directness that
can so easily be misunderstood as aggressive
( misconstrewed is a better word by I can not spell it).
Ivors question touches on some fundamentals in the look of body and
glazes
A porcelainious stone ware should give the same surface quality to a
temocue as a porcelain, but does it? .
Stoneware has cheaper ingredients and can be thrown bigger and easier
than porcelain.
Would a porcelainious stone ware ie a stoneware that fully vitrfyed give
the same results.
For a start it is difficult to construct a stoneware with the same
analysis as a porcelain made with bentonite. The finer particle size of the
ballclay lowers the meeting points so a slightly different analyses will
result in a successful stoneware. There will also be a difference in the
physical quality of the body. This may lead to a difference in the glaze
body layer which could make a big change to a temocue that shows this layer
when it breaks.
All this is purely speculative of course. I have never done the
tests. I would like myself to know more about the effects of a glaze body
layers especially with regard to the opalescent effects and color effects of
the crystals this layer seems to form.
The reason most of us would use a porcelain body for mirror blacks etc is
a little simpler ;in that we all have the odd bag of porcelain hanging
about, and unless temocuse and blacks were going to form the significant
part of the range, you might as well use the body you have and know. I do
not think ballclay based fully vitrfyable bodies are available or any
cheaper pre prepared, you may have to make them up your self . However if
you are using dark glazes a lot and you like the smooth surface. You may
save a few quid and have an easier time of the throwing by asking yourself
Ivors question.
Regards Paul T
----------
>From: Earl Brunner
>To: CLAYART@LSV.UKY.EDU
>Subject: Re: Black Glaze for Porcelain
>Date: Thu, Mar 9, 2000, 9:07 pm
>
>
>----------------------------Original message----------------------------
>Hi Toni! Glad to see you back on this list!
>There are a few of my glazes that need the colorants from
>the clay or the reaction of the colorants in the clay to
>reduction in order to look good.
>In other words I don't think they look good on a light or
>white clay body.
>However, there is something about porcelain with other
>glazes, that just
>makes them stand out over the same glaze on darker clay.
>If you look at the porcelain mugs on my website, the inside
>of the first
>one, and the top, outside of the second one both show the
>throwing marks through the glaze. The pots are perfectly
>smooth, but non porcelain clay
>just doesn't show up detail like for me in the same way.
>
>Barry and Toni Martens wrote:
>>
>> ----------------------------Original message----------------------------
>> ------------------
>> Must admit I think Ivor has a point, and having it, also the right to hang it
>> out there,
>> But then it could be heat craze that's on me or the desire to jump back into
>> Clayart with both feet. Could be worse, the client could have asked for a blu
>> one??
>> Toni Martens in Durban South Africa damn tired of humidity and looking for
>> things to bite
>> ----------------------------Original message----------------------------
>> Obviously it is because llewellyn's client thinks it will be nice.All
>> llewellyn asked for was a recipe for a black glaze,not your or anyone else's
>> hangs.
>> Bob Hollis
>>
>> ----------------------------Original message----------------------------
>> ------------------
>> Llewellyn Kouba asks
>>
>> ----------------------------Original message-------------------------
>>
>> >> ?
>> cone 9 black tea for two>
>>
>> Will someone please explain for me why a clay which has been compounded so
>> that
>> it is as white and transluscent as possible has to be covered with an black
>> glaze, which, because of the stain or oxides it contains, will be in all
>> probability be opaque. What are the advantages?
>>
>> Ivor Lewis. Who has an interest in porcelain
>
>--
>Earl Brunner
>http://coyote.accessnv.com/bruec
>mailto:bruec@anv.net
| |
|
