I have successfully drawn out 16 foot jon boat plans and will be constructing the core today and tommorrow. My question is regarding fiberglass and gelcoat.      

Fiberglass: what weight should I use? If I use a 12 oz biaxial can I get away with only one layer on the hull's exterior? Should I glass the interior or just waterproof it?

Gelcoat:  Is it neccessary?

Also, I plan on decking this boat and would like to install 2 bildge pumps. If anyone knows how I can set these up to keep the compartments dry I'd be happy to hear. My original thoughts were to let all water flow to rear of boat with one bildge but if water accumulates in underneath the front deck how could it flow out? Ha. I was then thinking of two pump locations with long hoses on each that I could extend and pump water out like a shop vac. Suggestions?

Longer the hose,...less suction.

As for gelcoat, it is the "looks" part of it.  If you don't care how it looks, just paint it.

Even with Biax, I would do a layer on each side.

Good luck, take lots of pics for us!!

So I should glass the exterior and the interior? More less for strength? I'll try to upload my design here in a few. Thanks. I'm going to go with two stationary pumps. Maybe 3 - stern compartments, bow compartments, console.

I would say that depends on what you plan to use it for (type of water, size of impoundments, etc)

For this particular project, might I suggest, (Glenn, pls dont kill me) that you look for a wood boat building site.  You need very specific info.

I'm afraid most of us would just be guessing or answering "to our best ability" which may not be the best for you.  You need exact answers and techniques.

I do ask, that if you can find good info, to inlcude it in your thread as you go along.  Many of us will be very curious to learn more about this project and hopefully we'll have the correct answers for the next member who takes on such a project.

I would like to include this build thread in the sticky section above regarding boat rebuild tutorials. (should you decide to post a "build" thread )

Good luck, keep us posted.