Abstract: Vibration and shock protection is provided for circuit cards by means of a sealed compliant bag which holds a supply of catalyst and resin which when mixed together form a foam which expands and becomes rigid upon curing. Initially, the catalyst and resin are maintained separated within the bag. Upon assembly, the catalyst and resin are mixed within the bag and the bag is placed within a housing. The circuit card is then installed in the housing. Formation and expansion of the foam causes the bag to conform to the top surface of the components mounted on the circuit card.