The described embodiments relate to methods and apparatus for increasing rigidity of a metal housing while maintaining or reducing a wall thickness of the metal housing. More particularly a method for embedding a stiffener layer within an aluminum substrate is discussed. In one exemplary embodiment the stiffener layer can be a carbon fiber sheet applied to an inside surface of an unfinished housing and then subsequently covered by depositing a layer of aluminum over the carbon fiber in a solid-state deposition process. The deposited aluminum can adhere to the unfinished housing around or through the carbon fiber layer to bond with the unfinished housing. Deposition parameters can be controlled to prevent damage to the carbon fiber sheet.