Sheeting foam cores
Probond is a polyurethane glue that is activated by moisture and expands to several times its original volume. Under pressure, as in the wing cradle, it will expand into the foam and make a very strong bond. It fills gaps well, but do not let it escape, it sands terribly. There are several brands available around here. I remember seeing somewhere else that in the UK it may be sold as Excel glue or Gorilla glue (gorilla is also available in the states.
Try a google search, you should get a few hits.