As a GC I always thought that pvc trim boards and sheets we use would make for good hard points in composite structures. It's heavier than you are looking for but fairly cheap considering how little is needed. I did some googling and found this:I looked and looked, no joy. For several scratchbuilt composite airplanes, the method of attaching control surfaces is including a high density foam block (20 pcf foam, Wicks stocked it) in the massive cores, glass the surface, then imbed hinges in the clock of high density foam.
Trouble is I can not find 20 pcf foam anywhere and mine is used up. I did find companies that list that density and others near it, but none of their distributors have any of it, and the maker is only interested if you want a semi-trailer full of it. Anybody know what the currently used options are for this sort of construction?
I can make syntactic foam using simple molds and dry micro at about 32-35 pcf (about 0.51-0.55 g/cm^3) but using a previously engineered material is always a better option in my mind...
I would test machined cuts since it would expose the cells.