Installing Deck in 28 foot diesel fishing boat

I gutted the last 9 feet of my 28 foot fishing boat in order to repower to a single Cummins diesel 6BT 210HP v-drive. Questions about install the deck. The boat will be used for offshore recreational fishing. Using poly/vinylester resin, what's a good way to glass the deck to the walls of the hull and transom? Do I have to have a backer along the entire bottom edge or can I just mix up some some very thick resin, squirt it in the crack from the top side, then glass just the top side?

My plan was to shape two 4x8 panels of pre-glassed divinycell, then I was thinking of doing 1 unit of 4" tabbing around the outer edge using 3/4 mat | 1208 nytex | 3/4 mat, then covering the whole deck with 2 units of 3/4 mat | 18 oz roving | 3/4 mat and having it all overlap 8-10 inches up the sides of the hull and transom

The bulkheads offer support along the sides of the hull every 18 inches, but there is currently no deck support along the transom. I was thinking of adding some vertical supports along the transom.

All the bulkheads are 1/2" divinycell and I have been using poly/vinyl esther for this whole project. I want to use divinycell for the deck so it never rots. I was planning on sizing a couple 4 x 8 sheets of pre-glassed divinycell panels and laying it overtop of my bulkheads (bulkheads are already cut with a 2-degree slant towards the side of the boat. Planning to cut the holes for the hatches later once the first deck panels are in. Battery storage will go above the strut backing plate.

 

Tabbing a small ledge will keep the edge level and straight. You can simply use a foam strip and mat.

 

This is a good plan. The triangular gunnel can be a strip of foam with a thin layer of glass to help with uniform fairing. Glue in place with clamps, and then complete layup and deck fixing.

 

OK. I am planning to make a 3" ledge of 1/2" pre-glassed divinycell foam strips. How much 3/4 mat should I use on the bottom side? Is this ledge for real strength or does it just align the deck and make a form for the thickened resin?

On the topside, I plan to use two 6" strips of 1208 nytex with 3/4 oz mat in between to connect the deck to the wall. Then then go over everything with 2 units of 3/4 oz mat | 18 oz roving | 3/4 oz mat

Does this sound good?

 

Hard to say without being there .
Rovings is only there to provide a good connection to the woven FG and the Foam.
It doesn't come into the strength calculations very much.

It should be applied at the same time you put the first woven layer onto the foam, and when you first apply the foam strip up against the old hull. It just fills in the surface imperfections.

The ledge foam itself IS important structurally, but it only provides compression strength ( eg side impacts, deck loads) IF it has sufficient woven layers on every side.