Abstract: An article, such as an airfoil, is cast by a lost wax investment casting process. The process includes providing a core having a configuration corresponding to the configuration of a space to be formed in the airfoil. The core is at least partially enclosed with a layer of wax. A portion of the layer of wax is removed from the core. The step of removing a portion of the layer of wax from the core includes heating a tubular member and melting a portion of the wax layer by engaging the wax layer with the heated tubular member. Molten wax is conducted away from the core through the heated tubular member. A mold is formed by at least partially coating the wax layer with mold material which extends across the core at the locations where the melted wax was conducted away from the core. The wax layer is removed to form a mold cavity which is filled with molten metal to cast the airfoil.