Just badply. On one laywer let loose and I couldn't see any evidence of residual glue. THe skin layer is only about 0.010" thick, No strength at all. The skins probably accounted for a bout 15% to 20% of the total thickness, All the strength is across the surface grain. This is one of my pet peves about ARF's. Even the Sig 4*60 had fuselage sides that had little strength in the ply. At least it was full 1/8" though, this stuff is probably 2mm. It's lite all right, but no strength.

Don