A mandrel and method of making a mandrel for use as a substrate in the manufacture of woven or braided articles. The mandrel may have an inner core of foam at least a first layer of carbon fiber-reinforced resin, and an outer layer of glass fiber-reinforced resin. The foam core may be a high density, closed cell polyurethane foam that is formed of a desired size and shape. The fibers in the first layer and outer layer may be, for example, chopped fibers, continuous longitudinally aligned fibers, circumferentially wound fibers, obliquely aligned fibers, or the fibers may have a woven or braided pattern. Multiple mandrels may be joined together to form complex mandrel shapes such as curves, ovals, and circles.