Re: sealing the deck
Well, you are going to hear that you should replace the stringers ( that's what the deck gets screwed into generally ) and while this is usually the case, we all know there are plenty of boats out there where all that was replaced was the deck.
Here's what I would do. First, it would be nice to see what we are dealing with, but I'm going to work based on assumptions, because that's what we have to work with.
Since your stringers are seemingly too thin to drive a screw into, the solution that comes to mind is to run strips of wood along the length of your stringers and use that to hold your decking to the boat structure. Get a few 1x4's and sandwich the original stringer with one on each side. Get some PL premium adhesive and some coated deck screws of the right length and build a platform on which the deck can be glued and screwed to.
But before you do all that, coat that wood thoroughly with a good exterior paint or poly to seal it up to avoid rot. Make sure you do the same to the deck you are installing.
Once you've gotten the deck installed, you'll want to join the edges of the deck to the sides of the hull. This is where you should do at least some fiberglassing. One, to seal the edges from water intrusion, and two, to keep your hull integrity.
Before anyone else flames me for this, this is the MINIMUM I would suggest be done to replace the deck on old stringers of questionable integrity.
If you want to do it the PREFERRED way, let us know and we'll be happy to outline everything you need, including references, picture tutorials, etc.
If you want to do it the cheapest, yet safest way, consider what I posted as a suggestion on where to start...I value the opinion of the others on the board that may disagree with anything I suggested, so weigh all the options we present to you before jumping in to the pool without looking
