hull reconstruction

I am not an experienced boat builder, however I have an 18', 1989, center console fiberglass fishing boat I am working over. I found rotten wood on the deck and in the stringers. I like the boat and plan on keeping it for a while so I want to do a good job reparing it. I was planning on replacing all of the stringers and deck. The boat does not have a composite floor (balsa or poly). The boat bottom is flat. Should I go this route? Also, has anyone tried to make a composite hull using the product Gator foam or Gator board.

Thanks

 

Gator Foam

I would guard against using Gator Foam (low density urethane, I believe), as it is mainly used for non-structural applications such as signs and display pieces. Urethane foam, espically low density (< 15 lb) is very friable and your bondlines will deteriorate rapidly. Strictly go with a structural core material such as end grain balsa, or any structural plastic foams especially in the hull.

 

hull repair

I'm replacing the floor in a 18.5 jet boat. The area under the floor has a single stringer, but where it goes into the engine bay, there is a hole(it had a plug in it, cheesy) is this hole supposed to be there, and if so does it need a plug? also, do I fiberglass under the floor to keep it water tight, and why cant I use fiberglass as the bonder between the deck and hull? Thanks for your consideration. C holder