Abstract: Fluoroelastomers, particularly ultra high temperature thermally stable fluoroelastomers are bonded to a metal substrate by forming a roughened bonding surface on one side of the substrate, controllably oxidizing the substrate at a temperature sufficient to cause the formation of an oxide coat on said bonding surface but below the tempering temperature of the substrate, adjusting the substrate to a temperature above the softening temperature of the fluoroelastomer, adhering the fluoroelastomer which includes a minor amount of an alkaline earth oxide dispersed therein, heated to a temperature sufficient to initiate curing thereof, directly onto said bonding surface, and expeditiously compressing said fluoroelastomer between said bonding surface and a mold face maintained at a temperature closely adjacent to the temperature of the substrate.