In early 2008 Webb Mealy began development of a panel cooker, known as the Tennis Ball Cooker. He had seen photos of traditional parabolic style cookers being used in Nepal, and thought he could develop a cooker that would be lighter, less expensive to produce, more easily transported, and with a low profile, so as to be better suited for use in windy areas. The construction of the cooker incorporates the creative reuse of materials. The base panel is made from recycled heavy-weight "gator board" that is 1/2" thick with a tough plastic laminate surface on both sides. Then fifty-six used tennis balls were split and hot-glued onto the panel on approximately 6" centers. Mirrored vinyl film (remnants from a window coating business, available online) was cut into 5" squares and applied to used CD cases. Using a laser, he was able to aim the mirrors at a common focus point (about thirty-two inches above the platform and seven inches in front of the panel's footprint) and then glue them into place using hot glue. The cooking surface, which is thus outside the footprint of the panel, consists of a grill mounted on a recycled african drum stand.
The prototype, working as designed three years later, was stored outdoors (in partial shade, subject to temperatures from 30 degrees F to 90 degrees F and precipitation) for two years to test the weatherworthiness of the design. The mirror material did not degrade or delaminate from any of the CD cases, and the CD cases did not, in nearly all cases, separate from the tennis balls on which they were mounted. The "gator board" platforms failed, however. About half of the hot glue attachments between the tennis ball halves and the gator board failed due to lost adhesion, and another quarter failed due to delamination of the gator board itself. In addition, the gator board warped over time, rendering the orientations of many of the mirrors incorrect. Aluminum sheet or waterproofed and Fiberglas reinforced honeycomb cardboard seems the more durable material for the platforms, and perhaps fast-curing epoxy rather than hotglue for gluing the tennis ball halves to the platform. Storing these cookers indoors, of course, would be ideal, as would storing them in a hanging position, rather than having them stand under their own weight.
Audio and videoEdit
- Tennis Ball Cooker Webb Mealy describes the project in more detail. Two short videos demonstrate its cooking power.