Manufacture of solar reflectors

Claim 1

A method of making a reflector specular to infra-red solar radiation for a solar energy collector system using a female mold having therein a longitudinally extending parabolic recess with a structurally reinforced mirror finished surface, and constructing a male mold from said female mold, the steps comprising (a) spraying a thin, tough, epoxy polyamid gelcoat onto said mirror finished surface; (b) applying fiberglass resin mixed with chopped roving onto said coated mirror finished surface in thin layers to prevent exotherm warpage; (c) structurally supporting said applied layers to stabilize a convex parabolic configuration on the convex surface thereof; (d) applying a fiberglass retainer layer over said structurally supported layers of fiberglass resin mixed with chopped roving; (e) at least partially curing said structure and removing it from said female mold; (f) attaching transversely extending adjustable spacing means between opposing portions of said convex parabolic configuration at locations remote from the directrix thereof; (g) adjusting said spacing means to correct for minor distortions in said parabolic configuration; (h) bending a smooth, mirror finished planar film free of surface irregularities across said parabolic configuration and securing it thereto to form a longitudinally extending smooth rigid convex surface of precise parabolic cross section throughout, thereby completing said male mold, and thereafter: (i) spraying said rigid convex surface with a resin release agent; (j) spraying thereover in an uncured state and in a plurality of different operations a plurality of layers of thermosetting resin to form a reflector support structure; (k) removing the longitudinally extending parabolic trough reflector support structure so formed from said convex surface; (l) vacuum depositing aluminum onto the exposed concave surface of said reflector support structure to a thickness opaque to infra-red solar radiation and no greater than 0.001 inches; and (m) closing the ends of said reflector support structure with structure utilizing planar end pieces oriented normal to the concave surface formed in the reflector support structure.

Claim 2

A method of making a reflector specular to infra-red solar radiation for a solar energy collector system using a female mold having therein a longitudinally extending parabolic recess with a structurally reinforced mirror finished surface, and constructing a male mold from said female mold, the steps comprising (a) spraying a thin, tough, epoxy polyamid gelcoat onto said mirror finished surface; (b) applying fiberglass resin mixed with chopped roving onto said coated mirror finished surface in thin layers to prevent exotherm warpage; (c) structurally supporting said applied layers to stabilize a convex parabolic configuration on the convex surface thereof; (d) applying a fiberglass retainer layer over said structurally supported layers of fiberglass resin mixed with chopped roving; (e) at least partially curing said structure and removing it from said female mold; (f) attaching transversely extending adjustable spacing means between opposing portions of said convex parabolic configuration at locations remote from the directrix thereof; (g) adjusting said spacing means to correct for minor distortions in said parabolic configuration; (h) bending a smooth, mirror finished planar film free of surface irregularities across said parabolic configuration and securing it thereto to form a longitudinally extending smooth rigid convex surface of precise parabolic cross section throughout, thereby completing said male mold, and thereafter: (i) spraying said rigid convex surface with a resin release agent; (j) spraying thereover in an uncured state and in a plurality of different operations a plurality of layers of thermosetting resin to form a reflector support structure; (k) removing the longitudinally extending parabolic trough reflector support structure so formed from said convex surface; (l) vacuum depositing aluminum onto the exposed concave surface of said reflector support structure to a thickness opaque to infra-red solar radiation and no greater than 0.001 inches; and (m) closing the ends of said reflector support structure with structure utilizing planar end pieces oriented normal to the concave surface formed in the reflector support structure.