We are a small paint company and we have a Willys Wheel. It is 2 ft in diameter and holds up to 12 paint cans. You were right in your assessment in the August 2002 issue of what it is and how it is used.
One extra tidbit…We always tested our formulation vs. the competitor’s if the competitor’s was already in the dip tank and proven to be successful, stability-wise. Like many paint tests, this test will not tell you how long your product would remain stable in the dip tank only that it was probably as stable as the known product. P.F.
Boy, am I glad you wrote. I haven’t been able to sleep at night worrying about that device. Thanks for verifying my story. Although I didn’t know it was called a Willys Wheel, with your help I was able to find it in my vast archives of ancient information. It does not appear in Physical and Chemical Examination of Paints, Varnishes, Lacquers and Colors, 9th Ed., H.A. Gardner, 1939. However, it does appear in the 12th Ed., 1962, of the same work.
The official name of the device is “Willys-Overland Aerator.” It is described as “...arrangement for rotating pint cans, simulating dip tanks, at an angle of 45 degrees to the vertical. …Rotation is at a rate of 15 rpm. …Criteria used for evaluating materials may include amount of thinner lost by evaporation, and increase in viscosity, each day.”
It’s funny you should mention testing your paints using competitor’s paints as the standard. Most paint testing such as salt spray, humidity, weathering, etc. is comparative. I remember a question asked during one of my presentations to an operating division at the Westinghouse Research Labs. The Director of Research asked what 350 hr of salt spray meant in real time. My answer was, “350 hr in salt spray is equal to 350 hr in salt spray.”