A method and apparatus for reinforcing an end portion of a deformable tool configured for use in forming a composite object. An insert may be placed within a hollow portion of the end portion of the deformable tool in which the insert substantially conforms to a cross-sectional shape and a size of the hollow portion of the end portion of the deformable tool. A side of the end portion of the deformable tool may be reinforced by the insert located within the hollow portion of the end portion of the deformable tool during a curing process used to form the composite object.