McCoy, Jack Eugene on mon 4 may 98
I have been developing a satin-gloss iron saturated glaze that is amber
where thin and black where it's thick. The problem is that it has large
patches of dry, brown surface areas that hide the amber and black. The
dry areas look almost like rust (like iron).
Can anyone give me any clues as to why this is happening?
Here's my recipe:
Iron Saturated (Cone 9)
Flint 34%
Whiting 20%
Epk 14%
Nepheline Syenite 32%
Add 9% Red Iron Oxide
Thanks in advance for your help,
Jack
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Jack McCoy
Systems Programmer
East Carolina University
Voice: (919) 328-6855
Email: mccoyj@mail.ecu.edu
Vince Pitelka on tue 5 may 98
>I have been developing a satin-gloss iron saturated glaze that is amber
>where thin and black where it's thick. The problem is that it has large
>patches of dry, brown surface areas that hide the amber and black. The
>dry areas look almost like rust (like iron).
>Iron Saturated (Cone 9)
>Flint 34%
>Whiting 20%
>Epk 14%
>Nepheline Syenite 32%
>Add 9% Red Iron Oxide
Jack -
I am curious why you refer to this as an iron saturate glaze. The iron
percentage is right on the borderline where it would in fact be an iron
saturate, but it does not sound like that is what you want. The black is
characteristic of a temmoku, which requires a slightly lower percentage of
iron, and the amber is characteristic of a dark celadon, which requires a
much lower percentage. The red-brown rust you describe is exactly what an
iron saturate glaze is suppose to do, like the famous Japanese kaki glazes.
I have seen glazes which are between a temmoku and a dark celadon, with
perhaps 5% or 6% iron, and which behave much as you describe. So it seems
to me you should just lower the iron content slightly. Try it and see what
happens. Good luck.
- Vince
Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
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