A core assembly for forming a cast component includes a refractory metal core and a ceramic core element. The refractory metal core includes first and second ends and sides extending from the first end to the second end. The ceramic core element includes a slot positioned between first and second lands, each land having an inner surface facing the slot and an adjacent outer surface. The first end of the refractory metal core is secured within the slot with an adhesive, and the refractory metal core extends from the ceramic core element in both a longitudinal and a transverse direction. The slot, lands, and refractory metal core form a core assembly providing access paths to the sides of the refractory metal core. Surplus adhesive is removed from the refractory metal core via the access paths. Investment casting provides the component with an internal passage and an internal cooling circuit.