An integral molten metal casting device comprising: a crossfeeder having an interior surface defining a partial cylinder of a first diameter; a generally cylindrical thimble having an interior surface of a second smaller diameter; and back-up insulation; all formed as a single monolithic structure with the crossfeeder interior surface and the thimble interior surface comprising a continuous, joint free and uninterrupted cylinder insert surface of a thin layer or multiple layers of fiber reinforced low thermal expansion coefficient, high wear resistant material. According to certain preferred embodiments, the thin layer or layers comprise fused silica, alumina or zirconia, and mixtures of these materials with other similar materials such as silicon carbide. Monolithic integrally formed molten metal handling systems of similar structure are also described.