Abstract: Method of making a cylindrically shaped, partially collapsible, foam mandrel to be used for the manufacture of hollow resin impregnated fiber tubes. The mandrel is made of a substantially rigid foam cylindrical member, an extractable bar, and a means for aiding in collapsing the cylindrical member such as a groove. Both the extraction bar and the means for aiding in collapsing the cylindrical member are disposed in and along the entire length of the cylindrical member such that the longitudinal axis of the bar, the means for collapsing the cylindrical member, and the axis of the cylindrical member preferably lie on the same plane.The method of manufacturing the aforementioned mandrel comprises the steps of first providing a circular mold having upper and lower sections. A groove-forming member is placed in the lower section and the extraction bar is placed on the upper section. Foam forming material is poured into the lower section which is then covered with the upper section.

Abstract: A reusable cylindrically shaped, pivotally collapsible, foam mandrel used for the manufacture of hollow resin impregnated fiber tubes. The mandrel includes a substantially rigid foam cylindrical member, an extractable bar, and a means on the outer surface of the foam member for aiding in collapsing the cylindrical member, such as a groove. In one embodiment a hinge member is employed to further aid in the pivotal collapsibility of the foam cylindrical member.