Back in 1991 I started a similar repair on my Passport 45 (it had teak
decks). I found that it was originally constructed with small (maybe 3"x3") pieces of bolsa wood. The small pieces were put together like a jig-saw puzzle, then filled with polyester resin. I guess this is a typical Tawain deck
Anyway, I cut off the top layer, in the place that I suspected some problem. It took me about 30 minutes to realize that the problem was much worse that I suspected. Water
had made channels all through the deck and the bolsa absorbed it like a sponge.
I ended up taking a small circular saw and cutting the entire top layer of FG off (teak deck & all) and removing the entire core. Every single
piece of bolsa was entirely soaked. The deck weighed a ton.
I replaced the core with 3/4" marine plywood
(cut to fit) in about 4' sections (1' wide to maintain a small amount of curvature on fore & aft decks), laying each section in epoxy
resin. I faired out the deck with epoxy
filler, glassed it (with epoxy), faired it again and that deck is strong as can be and one heck of a lot lighter than the wet Bolsa that was in there. The entire project
only took me about a week (with an assistant).
I would NEVER own another boat
decks. Why anyone would take a perfectly sealed FG deck and drill 2000 holes in it is beyond my comprehension.