If I were to use foam or honeycomb core for my pilothouse roof would veneer be suitable for sealing the end grain. Design calls for 3 layers of 1/4 inch ply which would then be glassed and epoxied. I am planning on goin increasing cabin/pilothouse length one to two feet so want to keep topside wieght down. Am using the boxkeel option so that should help compansate for the extra windage and reduce leeway. Thanks.