A method of making a solar reflector from a flat rectangular sheet of reflecting material into a substantially a parabolic cross-sectional shape to form a part of a solar heat collecting system wherein the reflector is supported to concentrate the rays of the sun on a pipe through which liquid is circulated including bending permanently the sheet material along its longitudinal center line to give the two half portions thereof a minor angle with respect to a horizontal plane, bending the longitudinal edges back upon themselves to form slotted hook portions along the longitudinal edges of the sheet material and bending the two half portions toward each other below the breaking point of their elasticity to receive the longitudinal edges of a translucent plate in the slots of the hook portions whereby the parts are held in assembly.