Wade Blocker on wed 11 apr 01
I read Alisa's glaze tests with Behren's glazes. Decades ago CM
published articles and glazes submitted by Mr Behrens. I tested a lot of
the glazes, and sad to say there was not one that found its way into my
collection of glazes.
Alisa's testing of glazes with slips reminded me of the following:.
Any slip clay which matures at cone 9 to 10 can be used,eg, Albany, Sadler,
Michigan or your local slip clay. The slip clay which on its own fires to a
brown glaze,should be colored with one of the following additions:
5% cobalt oxide for blue
15% copper oxide for Green
15% red Fe oxide for brown
15% nickel for grey
Method: Brush three coats of colored slip clay to which some CMC has
been added,unto your greenware. Bisque, then glaze with either a matt
white glaze, a semi matt or a transparent glaze.To the transparent glaze an
opacifier has to be added eg 2 to 3% Sn oxide or zirconium.
Fire to cone 8-10 in oxidation or reduction.Carlton Ball's glazes worked
very well as the cover glazes. eg. G Matt 3 or Mg2 Matt, Transparent 16
with tin addition. Each of these cover glazes will produce a different but
For cone 5 to 6 firing you will have to add 10% frit or 10% nepheline
syenite to the slip glaze to make it melt at a lower temperature. Then
proceed as above except use cover glazes which mature at cone 5 or 6.
The resulting glazes are mottled glazes with a lot of surface interest.
Mia in windy and chilly ABQ