Abstract: In a method of making a fluted core radome from resin impregnated glass cloth, an outer skin, a fluted core, an inner skin, an edge band and a drain cap are individually fabricated from plies of resin impregnated glass cloth which are laid up on a mold and then subjected to pressure using a vacuum bag and to resin curing heat using an autoclave. The fluted core is formed on a mold having recesses in the surface thereof by placing silicone rubber mandrels within the recesses and on top of the plies of glass cloth, the mandrels tending to expand in response to the application of heat thereto and at the same time tending to contract in response to the application of pressure thereto so that an equilibrium is reached which provides a tight fit of the glass plies over the mold and a relatively even flow of resin within the glass cloth.