Garth Warner writes: >I'm laying up 1/32 C grain balsa with .58 oz glass >cloth on both sides for a long boom HLG. Something to consider for the next project: A-grain balsa considerably better as a core material in a sandwich, since it has greater through-the-thickness stiffness than C-grain. The "mother-of-pearl" fibers which make C-grain stiff to bending forces also make A-grain stiff to crushing forces. Endgrain is of course vastly better still as a core material, but this is rather impractical in a 1/32" sandwich (unless you're REAL GOOD with a razor saw!) FWIW, these are the relative stiffnesses for balsa along the three directions (taken from Crandall, Dahl, Lardner): 100.0 along grain 5.0 perpendicular to C-grain, into A-grain face 1.4 perpendicular to A-grain, into C-grain face I don't know about the relative strengths, but for holding the face sheets against buckling, stiffness is what matters. - Mark Drela RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
