If you put fiberglass over foam without first squeegeeing in SOMETHING, the fiberglass will not stay attached to the foam for long...
++++++++++++++++++++++++++++ With respect - I am not convinced the above is correct when it comes to polystyrene (Styrofoam?). This is something I have been trying to understand for months now - what are the salient differences between styrofoam and polyurethane foam in terms of their respective characteristics - strength in shear and surface competence (for adhesion of a skin). Take some duct tape and try to stick it to a sheet of poly-u. The tape will readily come off (fall off) with a thin layer of urethane "dust" coating the adhesive of the tape. I have no difficulty understanding that polyurethane needs something to "bind" and seal the surface in order to achieve any degree of competent surface (suitable for attaching a skin). The same tape attached to a sheet of Styrofoam will take much more effort to remove and will actually tear out individual beads - it has a substantially more competent surface (for sticking things to) - will a slurry mix benefit this in any way? I have built model airplanes up to 40lb (some are now 25 years old) with a variety of wing skins (balsa wood, veneer, glass cloth) attached to styrofoam directly with epoxy. As any modeller will know, these birds are subjected to G loads many times higher than real airplanes - I have never had a failure in the skin attachment. Before I could afford epoxy (1972) I sealed the Styrofoam with a coat of watered down PVC white (wood) glue and used general purpose polyester resin and glass cloth. Very often these wings had no spars so the skin-to-foam bond was critical. Dene (from Gods own country) - your buddy that produces the brilliant Whisper motor glider makes extensive use of white Styrofoam for the wings - maybe ask him what he thinks /recommends !! As I said - with respect. Steve J
