Cornelius Shino Redux

I’m a bit cloudy on the source of this glaze, but I seem to remember receiving it from Karen Sullivan who taught ceramics at Cal Poly Pamona College in California (I think) when I attended a firing there with Phil Cornelius. I know I wrote the recipe down wrong as the %’s were way off, so I played around and made a few adjustments and this is what I got, which I really like. If anyone has Phil’s email address I would love to send him this image and see if he would help me get back to the original.

  • Nyph Sy    62.00
  • EPK    10.00
  • Tin Oxide    8.00
  • Kosher Salt    8.00
  • Red Art    8.00
  • Dolomite    4.00

Notes: This is a ∆10 Reduction glaze that loves a 30 minute soak at the end of the firing with the kiln being closed in reduction. This glaze is more of  a specialty shino type glaze, that depending on clay body and thickness of glaze application will range from a golden almost metallic to a light yellow with an unctuous soft finish. Really looks good over high iron clays. This glaze will carbon trap. For carbon trapping start your reduction at 1560-1570F. Please test this glaze for your firing conditions.

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3 Responses to Cornelius Shino Redux

  1. Zygote says:

    Kosher Salt?
    What effect on a glaze does this contribute when added to the glaze rather than the atmosphere?

    • shyrabbit says:

      Adding Kosher Salt to a glaze is similar to adding Soda Ash (particularly for Shino type glazes), both being soluble salts that will migrate to the surface of the glaze while drying. This surface coating of salt will lower the fluxing point of the shino which aids in the carbon trapping effect. Sodium in its various forms begins to melt at about 1560F, this is the reason for early reduction for carbon trapping glazes. Adding Sodium (in various forms) to a shino glaze is primarily to promote carbon trapping. Due to all the variables in how the salts might migrate to the surface, Carbon Trapping glaze results can be allusive and often frustrating.

      Salt added to the environment of the kiln, at temperature, combines with the alumina and silica in the clay to form a simple glaze on unglazed clay as well as effecting the glazed surfaces by contribution.

      I would think of salt added to the glaze as localizing its effect and adding salt to the kiln environment as generalizing its impact.

      I hope this makes sense.

  2. Zygote says:

    Gold… pure gold… Thank you Michael. That totally made sense.

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