Has anyone tried working with composite materials for a pack frame? The idea came to me to build my own small composite pack boat, but I do not want to spend a whole lot of money on Carbon fiber, that and carbon fiber is not the best in the outdoor world (very sensitive to stress fractures and UV). The idea came to me to try Tyvek and the filler material that is typically used with carbon fiber to try make a rigid pack frame (or possibly even a canoe if its rigid enough). Has anyone here experimented with this or any composites?

The only concern I might have in trying it is that carbon fiber tends to absorb the resin, where as I fear that tyvek will just layer it instead of absorbing it and becoming hard. Maybe kite tyvek since it is softer? I don't know, it has been a long time since I have played with Tyvek...