Ceramic Arts Daily

Pugmills blend and homogenize clays. A de-airing vacuum pump removes air from the clay, which, in most cases, eliminates the need for further wedging. (Photo courtesy Axner Pottery)

Clay Mixer, or Pugmill, or Both?

An example of a horizontal mixer. The hopper on this model from Bluebird Mfg. tilts forward to aid in emptying the machine once the batch has been mixed.

Function
What do you need? If all you want to do is mix your own clay, you need a mixer at a minimum. If you want a mixer that empties itself, go for the mixer/pugmill or a mixer with a tilting hopper. If you need clay that’s ready to throw without any further wedging, you’ll need a de-airing pugmill either as a standalone machine or as part of a mixer/pugmill. If your concern is just recycling, a pugmill or a mixer/pugmill can do the job but you’ll need to ask the dealer about what condition the clay has to be in before it can be processed, for example, stiff, bone dry, slurry, etc.

Capacity
You don’t want to overestimate your needs and purchase a machine you’ll only use once or twice a year, or one that won’t keep up with your requirements. Manufacturers make machines of varying capacities and rate them by batch-mixing sizes (in pounds), mixing rates (pounds/hour), and pugging rates (pounds/hour). In addition to these rates, you’ll need to consider times for batching, unloading and wedging to get an idea of total clay throughput.

Ventilation
If you’re planning to mix clay, you’ll need a ventilation system to control dust even if the clay mixer has a tight fitting lid on the hopper. There are dust collection systems available or you may have an existing system to tie into. Caution: Even with a ventilation system, you’ll still need to wear a respirator when working with dry materials.