A method and apparatus for forming a fiber reinforced composite structure comprising at least two components, a hard base tool presenting a first tool face, a second tooling element presenting a second tool face to locate the second component against the first component. Components are of a dry fibrous form and are to be injected with a liquid resin. A flexible bagging blanket forms with the tools a sealed enclosure into which the resin is injected to form the structure by resin transfer infusion. To maintain the relative dispositions of the components without the need for elaborate mandrel plates, control rods are inserted at least partially through the two components to act as fasteners and to maintain the relative disposition of the components during resin injection. After injection the assembly is cured and the control rods may remain in situ or be removed from the structure.