Ball Milling Glazes
I’ve been ball milling all of my glazes for the last four or five years. For those of you unfamiliar with the process, it is a method of pulvarization of the raw glaze to enhance the melt and consistency of the glaze. It also can eliminate speckling of color in many glazes including celadons. One of my primary reasons for ball milling is to achieve glazes that are easily sprayed and airbrushed. I simply have not been able to airbrush a glaze that has only been sieved. Numerous raw materials are sold with particle sizes too large to pass through an airbrush, and ball milling solves this problem. Many glazes will settle when stored into rock hard deposits at the bottom of the storage container, a side benefit of ball milling is to significantly reduce or eliminate this problem ( a major time saver for me). It also makes it easier to glaze trail, again due to the even consistency of the raw glaze. Finally, I believe that the glazes look better when ball milled, perhaps due to the more even distribution of materials.
For more info take a look at http://digitalfire.us/4sight/education/ball_milling_glazes_204.html on the Digital Fire website.
Ball mill that my son Jeff and I built.
The porcelain jars turn on the ball mill pictured above. I usually mill each glaze for two hours. I’ve had problems with crawling when milling for longer times, and two hours seems to work just fine.