I’m working on restoring a 13ft whaler and found some old repairs while sanding off some really cracked gel coat. Little investigating showed that water got inside and started rotting/eating at the foam inside the hull. Not sure where to go from here, do I cut out a square section around where I think the extent of the damage is? I know I need to get all the old foam out but not exactly sure how. Any help or direction on where to go from here would be greatly appreciated!