it's fairly rigid. If you were to hold a 1.5" x 1.5" x 8 foot from one end, it probably wouldn't flex 2 inches on the extreme end. It machines like butter.
Jake, which foam? There are sooo many different types of foam available it can be overwhelming...right now I have 7 different types of extruded polystyrene in my shop, along with Rohacell and Nomex for use as cores in molds. All the polystyrenes act differently and most wouldn't be suitable for a boat building project but they exist!
