A method of making a lightweight thermal shield that includes obtaining a mold having a shaped support screen with a molding surface configured to allow the passage of air and moisture therethrough, and with the mold being adapted for drawing a vacuum from behind the support screen. The method also includes applying a wet insulation material onto the molding surface of the support screen and drawing a vacuum to withdraw moisture through the support screen and consolidate a layer of insulation material on top the molding surface. The method further includes removing the consolidated layer of insulation material from off the molding surface, installing the consolidated layer of insulation material into an outer shell layer, and drying the consolidated layer of insulation material within the outer shell layer to form a lightweight core insulation layer.