Abstract: A mold assembly includes a collapsible mount for releasably holding an insert within a mold cavity of the assembly in order to integrally form the insert with a molded article such as a tank liner. The collapsible mount includes a number of fingers secured to the mount and capable of being inserted through and expanded to engage the insert. The fingers are expanded after insertion through the insert by a core engageable with the fingers in order to securely hold the insert in position on the fingers of the mount and within the mold cavity. After formation of the article around the insert, the core can be disengaged from the fingers, which then move to a collapsed position such that the mount can be quickly withdrawn from within the insert and the mold cavity.