and cured the second layer of epoxy film binding the second layer of polyurethane to the first layer of fiberglass the second polyurethane mold is then removed from around the first layer of fiberglass a third layer of epoxy film is then placed around the second layer of cured polyurethane a second layer of fiberglass is then placed directly onto the third layer of epoxy film the second layer of fiberglass covering the entire second layer of polyurethane the third layer of epoxy film binding the second layer of fiberglass to the second layer of polyurethane a fourth layer of epoxy film is then placed on the surface of the second layer of fiberglass a third polyurethane mold is then placed around the second layer of fiberglass a third layer of polyurethane is then injected into the second polyurethane mold and cured the fourth layer of epoxy film binding the third layer of polyurethane to the second layer of fiberglass the third polyurethane mold is then removed from around the second layer of fiberglass referring now to fig2 there is shown a cross section of an exemplary fan jet engine casing 100 known in the art the outer portion of the fan jet casing 120 comprises an aluminum alloy the portion of the fan jet casing that extends annularly around the fan blade region 130 is.