Look up Crazy Herb's threads on cheapo Big Pink Creations.

Just a hint. Try using the water based polyurethane to soften and adhere newsprint patches where you want local reinforcing. A layer or three of newsprint over foam really strengthens it up against local vibration. I did a couple of control line combat models years ago using thinned carpenter's glue and newsprint over beaded white EPS and could not believe how strong it was. The water based polyurethane would make it a lot lighter and less messy I suspect. And the paper comes to your door for free....