This may be a silly question, but has anyone found 20 yds of fiberglass insufficient for the Rowcruiser? I'm just getting to the exterior glassing, which I understand will take 42 ft of glass. The interior used about 11 ft. Am I crazy, or does that leave only 7 feet to cover all the deck? I'm sure I'm missing something here, but I'd like to know what it is before I make any more exciting mistakes. Thanks.