Fiberglass can be molded into shapes or forms that are not practical in metals and the molds for fiberglass cost 1/10th as much as for aluminum. However, aluminum will not develop cracks with age and will not deteriorate when exposed to the elements without a protective finish. Electric Time Street Clocks are completely cast in aluminum for longevity. We do not use fiberglass to save money.
Photograph of inside of fiberglass post clock with crack.
