Abstract: A composite pressure vessel and method of manufacture. A composite pressure vessel comprises a multi-component mandrel that is integrated into the vessel, thereby becoming a permanent part of the pressure vessel, and comprises a cylinder and dome ends. Dome ends are made from custom molds with a fiber reinforced polymer. Components of the mandrel may be pieced together with a joining resin. The mandrel comprises a permeation barrier coated on the inside by spraying with elastomer resin, for example. Filaments are wound onto the mandrel, allowing any length of cylinder section to be made for the pressure vessel.