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: shino with a soda ash "wash" disaster. please help me

updated wed 1 oct 03


iandol on mon 29 sep 03

Dear Sandi Finney,

I know nothing about Shino Glazes (must get onto that deficit in my =
education!!) But I do know about Sodium Carbonate.

At Cone 012 Sodium Carbonate will be molten and react vigorously with =
any free silica which is available, creating a highly corrosive fluid =
fluxing situation. Since this fluid would seal the clay against the =
ingress of elemental carbon you would not have the anticipated staining =
effect. Further heating causes additional melting as the ingredients of =
your true Shino begin to fuse and alloy with the Sodium silicate. On =
cooling you have a green soda glass.

May I suggest a lighter hand with the soda brush.

Hope you have eventual success.

Best regards,
Ivor Lewis. Redhill, South Australia=20