we used to core our dinghy hulls with that stuff. it's supposed to be non absorbant, but I have seen it smashed up and it will hold water once compressed. it has some amazing strength when sandwiched between a couple thin layups
How do you plan on using it? It can be very good, or very bad, it just depends on what you want it to do. Give us some details of your project, it sounds you have a big one in mind.
