The Physics of the
Pinewood Derby Book

The Virtual Racing CD


Select Individual Items
Axle Polish Compound
Bore Polish

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The bore polish compound is a very fine talcum or pumice-like compound made from decomposed siliceous limestone. It has been found to be very effective for smoothing the surfaces of the polystyrene pinewood derby wheels. The wheel bores on new wheels may be contaminated with mold release agent, an oily material that coats the plastic wheel surfaces during manufacture. Liquid polishing compounds may lay down a shiny wax-like layer, but such a layer is much softer than the polystyrene itself and will not support a monomolecular graphite film. It will take a material like the bore polish compound to actually remove the oily layers and a very tiny amount of the plastic surface itself.

The polishing theory is exactly as it is for harder compounds like steel but we are applying it to the rather soft by comparison wheel plastic. The cardboard rods are just the right size to snugly fit into the wheel bore. The cardboard is not as hard as the wheel plastic and will not damage the surface as would a metal rod. The polishing compound is mixed with water and applied at a certain rotation speed to the cardboard rod. An instruction sheet is included with this item.


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