Jean Eiers-Page on wed 10 aug 11
Hello,
What amount of oxides or stains and combinations of oxides such as RIO, =
=3D
cobalt, manganese, rutile, zinc, etc. could I add to this clear recipe? =
=3D
Can I use this as a base recipe?
cone 6 ox. clear glaze recipe:
Silica 25 %
Kaolin 15
Talc 10
Gerstley Borite 25
Nepheline Syenite 25
_____
100%
Thank you for any help.=3D20
Jean=3D
Steve Slatin on wed 10 aug 11
Jean --
It has a rather low CTE, so there may be some problems with
glaze fit , depending on your clay body. Other than that,
I imagine it's a respectable glaze, fairly rich in boron,
and should give fairly predictable color effects.
Zircon and tin will make it white, iron will turn it
towards brown, cobalt will push it to blue, copper will
go towards green (probably not enough calcium in that
glaze to give reds in reduction). =3D20
Zinc will tend to lower your melting temperature, possibly
making the glaze runny, and will likely make the colors rather
muddy. Rutile gives tans and browns, maybe some green depending
on clay body and reduction.
Steve Slatin --=3D20
N48.0886450
W123.1420482
--- On Wed, 8/10/11, Jean Eiers-Page wrote:
> From: Jean Eiers-Page
> Subject: Adding glaze colourants
> To: Clayart@LSV.CERAMICS.ORG
> Date: Wednesday, August 10, 2011, 9:29 AM
> Hello,
>=3D20
> What amount of oxides or stains and combinations of oxides
> such as RIO, cobalt, manganese, rutile, zinc, etc. could I
> add to this clear recipe?=3DA0 Can I use this as a base
> recipe?
>=3D20
> cone 6 ox. clear glaze recipe:
>=3D20
> Silica=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 25 %
> Kaolin=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 15
> Talc=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 10
> Gerstley Borite=3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0=3DA0=3DA025
> Nepheline Syenite=3DA0 =3DA0 =3DA0 =3DA0 25
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 _____
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0 =3DA0
> =3DA0 =3DA0 =3DA0 =3DA0 100%
>=3D20
> Thank you for any help.=3D20
>=3D20
> Jean
Ron Roy on thu 11 aug 11
Hi Jean,
I calculated this out with different talcs and it looks like a stable
glaze - I am assuming for cone 6?
You included zinc as an addition along with the others which give
colour - zinc is not for colour but a flux - I assume you did not mean
to include that.
The real answer about how much to add depends on which oxide and how
much - in the end you need to have the glaze tested with colourants
added to see if you have added too much.
Rutile has a good effect on durability - 5 to 6% is fine - iron up to
10% cobalt is very strong so 1% can be too much.
If you want a white try 10% zircopax, superpax opax or any of the many
zirconium silicates.
Let me know if you have questions.
RR
Quoting Jean Eiers-Page :
> Hello,
>
> What amount of oxides or stains and combinations of oxides such as
> RIO, cobalt, manganese, rutile, zinc, etc. could I add to this clear
> recipe? Can I use this as a base recipe?
>
> cone 6 ox. clear glaze recipe:
>
> Silica 25 %
> Kaolin 15
> Talc 10
> Gerstley Borite 25
> Nepheline Syenite 25
> _____
> 100%
>
> Thank you for any help.
>
> Jean
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