Abstract: A fiberglass-binder insert is made by fabricating a shape-constant, cured fiberglass-binder mixture, into a shape-constant insert core, and shrink-wrapping the core while leaving exposed any bore which extends into the core. The core is fabricated by mixing fiberglass and uncured binder in a mixer, dropping the mixture into a conforming guide such as a funnel, and moving the mixture through the conforming guide and into a mold. A tamper can tamp the mixture to move the mixture from the conforming guide into the mold, and to distribute portions of the mixture vertically in the mold. Rotation of the mold effects circumferential distribution of the mixture in the mold. The mixture in the mold is heated to cure the binder, thus to establish a fixed shape of the resultant core product. A shrink film is shrunk about the core, providing apertures in the shrunk film at bore openings in the core.

Abstract: A fiberglass-binder insert is made by fabricating a shape-constant, cured fiberglass-binder mixture, into a shape-constant insert core, and shrink-wrapping the core while leaving exposed any bore which extends into the core. The core is fabricated by mixing fiberglass and uncured binder in a mixer, dropping the mixture into a conforming guide such as a funnel, and moving the mixture through the conforming guide and into a mold. A tamper can tamp the mixture to move the mixture from the conforming guide into the mold, and to distribute portions of the mixture vertically in the mold. Rotation of the mold effects circumferential distribution of the mixture in the mold. The mixture in the mold is heated to cure the binder, thus to establish a fixed shape of the resultant core product. A shrink film is shrunk about the core, providing apertures in the shrunk film at bore openings in the core.