If you have your heart set on electric drill options, you probably should start with a visit to your local home improvement center or hardware store and look at mixers designed for mixing paint or drywall mud.  These devices are readily available and cost effective.  As for clamp mounting you might consider a low-cost drill stand or create a clamp mount of your own.  To avoid excess foaming, you may need a variable speed drill or just exercise care to be sure that the mixer is sufficiently submerged to avoid drawing air from the surface.  You may need a heavy duty drill to be able to handle you high viscosity.

Another option is to investigate is small mixers found in laboratory equipment catalogs or those offered by mixer catalog companies found on the Internet.  These sources offer low-cost options that are actually designed for mixing in small containers, include support stands, and have multiple impeller options.  Some of the same sources offer more specific information about mixer application.  You may benefit by reading an article in Food Processing about portable mixers.  Dickey, D. S., "Tip Portable Mixers in Your Favor," Food Processing, August 2006.

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