The idea is to put the strips I female frames and glass them together whit a layer of BX on the inside. The two halves are then glued together and reinforced from the outside with glass or carbon. The inside of the spar will be filled with a light weight foam (20 kg/m3)
I have considered the method of building a box in the middle, making the both ends in solid wood and bend the ply over it. The problem is that for a spar with small cross section you would get a lot of solid wood and very little ply.
I definitely hope to end up under the weight of a alu superwing (19kg, the weight of the Sydväst superwing!!!)
Don’t start to build one yet, this is only an experiment. But if it works all right it could definitely be a cheap way for the homebuilders.
I like female builders…