What glue to use when glueing balsa to foam? Thinking about using Titebond II. It will require wetting the balsa to conform to the correct shape.
Will that work OK.

I have used three types of glue and prefer the polyurethane wood glue. This glue looks like maple syrup and is sold under two popular brand names: gorilla glue and Elmers probond polyurethane. Walmart sells it in their adhesives section. The other two types of glue that can be used are: epoxy and contact cement. But I prefer the polyurethane. With any method, one trick is to use as much pressure as you can get while the glue is setting up. If you are covering a foam core for a wing, for example, you want a lot of weight on the surface to tightly hold the balsa to the foam. 2 - 5 pounds per square inch. So if you have a 200 square inch wing, you need a few hundred pounds of weight. I use a vacuum pump and put the parts in a bag. The vacuum puts about 3 - 5 pouns of pressure on te part (I have a regulator on the vacuum). A "full" vacuum is about 14 psi and will crush the foam.
Wetting the balsa is OK with any of the gluing methods. And Titebond will work if thats all you have, but there are better choices.