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re underglaze

updated mon 26 feb 01

 

Wade Blocker on sat 24 feb 01


Dear Judi and Martin,
This is a rather belated answer to Martin and to the recipe that Judi
had been using. It is Conrad's E l0
white engobe which can be applied to dry greenware or bisque. The firing
range is from cone 04 to cone 4 and should be applied thick.Here is the
recipe as published in John Conrad's Ceramic Formulas:
Flint 25
China Clay (Kaolin) 20
KY Ball #4 20
Potash Felspar 15
Nepheline syenite 10
Borax 5
Whiting 5

I have used this engobe to cone 6 successfully. With 10% black stain it
makes an excellent black engobe. This engobe works with other stains as
well.
The only reason I use Amaco's underglazes is that they come premixed. I
have used Amaco's underglazes and the above engobe colored with stains, on
the same piece of stoneware I was decorating. After the bisque firing it
was covered with a tranparent glaze. I was unable to distinguish the
commercial underglaze from Conrad's engobe. Mia in chilly ABQ