A method of making an elastomer lined composite vessel or portion of such vessel is disclosed. The method comprises causing a thin, tacky ribbon comprising an elastomer (preferably curable) to continuously so encircle a center rotational axis of a madrel as to adjacently position and tack together integral segments of the ribbon substantially circumferentially relative to this center rotational axis thereby forming a layer of the elastomer about the mandrel which may be the shell of the pressure vessel in case of internal application of the insulator or may be a workpiece around which the shell is built over the so-layed ribbon.