Hello all. Just new to this forum & could use some advice. Last summer we aquired a 32' houseboat. Needed some work. I repaired the front & back top decks with bondo,primer & paint. This was over plywood. Worked good but it has cracked. Would like to fiberglass over this when it warms up. Don't have any idea what kind of fiberglass to use or  how to prepare surface now that I have it painted.  The boat now sets alongside our pond in the back yard. A nice little get away & I want it to last. Any advice would be helpful. Thanks very much,Mike & Barb