Hi Wynn,A composite is created when 2 layers of carbon,fiberglass,Kevlar or similar are epoxied on both sides of a core material.It can be foam,balsa,flat carbon strips laminated to the top and bottom of a spar.The seperation of the 2 E-glass/carbon layers by the core(whatever it is)determines the strength.Example:If you take 3 pieces of foam 1/8,1/4,and1/2 and laminate both sides of each piece with the same amount of material,the thinner the core is the weaker the piece will be structurally.All 3 will be way stronger than just the foam itself but the 1/2 wil be strongest of all.I just did a wet layup on mine but the sheets could be vaccum bagged for additional weight savings.Wet layup on foam was how the homebuilt composite movement got started.The Vari Eze,KR-! and 2,War Aircraft Replicas,and more were carved foam and wet layup E-glass.It does not have to be popped from a mold to be composite but it sure is easier that way.I am working on some molds for this winters main project.We're gonna try that next.
Jeff