RE: peel-ply ????
My experiance is with 35% aerobatic planes. Contest balsa seems to really suck up resin even after it has been sealed, so I came up with this process.
The process I use is I set the core in the saddle and sand lightly with 80 grit, then with 150grit. I position the skin on the core and mark a centerline on the core and on the bottom of the sheeting. Once I a positive that the wing is sitting square, I spray the core and sheeting, I bend the sheeting so that the center is bowed down (you really need two people for this) and then lower the skin on to the core at the center marks, then just follow with the same motion down until the sheeting is all the way down.
I always throw the top cradle on and weight it down but I cannot say if it realy helps anything. I guess just for a piece of mind.
The thick epoxy/cabosil works too, but its not as lite. That darn porus balsa!