I have started to refinish a 1967 16' Lone Star fiberglass boat. I removed the deck and underneath is foam (almost like styrofoam) The deck was rotting and this foam is waterlogged. After I remove the foam I will have to replace it with a few stringers as the foam sandwiched between the botton of the boat and the deck is what gave the hull additional support. Does anyone have experience with a product called SEACAST? Seems like I should be able build some forms and pour this stuff in, like pouring mini concrete forms? Any help would be great.