A system and method for insulating an outer surface of a fluid conduit is provided. A portion of the circumference of the outer surface of a conduit is surrounded in a film, thereby forming a generally annular pocket between the outer surface of the conduit and the inner surface of the film. Insulation is deposited into this pocket between the outer surface of the conduit and an inner surface of the film, molded to a substantially uniform radial thickness, and cured to form a cast molded conduit.