Thanks Dave ... good thoughts there. What do you mean by "A/C's"? Sorry I'm a bit slow, not enough sleep.
There is a lot more to add to this Scratcho thread that's gone into other threads now! Especially the stuff on making a foam filled PU wing, expanded in the moulds: http://www.rcgroups.com/forums/showthread.php?t=1721451
I made up a light fuse last night to go with the light wing and tails. This will be the lightest one yet. Painted white in the mould. I am finding the whole process easier since I made templates for the various sections I wet up into the mould. I am really chuffed because I pressurized the inflation bladder to 25psi and it didn't leak at all!