Finally, after months of experimenting with different formulations on this Cassius Basalt slip - SUCCESS! No bloating, no bumps, no lumps. I was throwing this clay body, bisque firing really slow and everything looked good out of the bisque but once it came out of the glaze firing, a bad case of the mumps is and understatment. At the New member gathering at the Nelson's we all discussed this and talked about the possibilities of using a slip over my porcelain thrown piece. And voila, success. Now it is time to produce more, as this piece sold at the Corvallis Fall Festival.