soft, spongy cored decks - repair method and costs?
\It really depends on how much is good and how much is soft in any
amount. If there are any more than isolated soft spots be prepaired to
pay out some bucks or spend a year in hell. Otherwise, I would look for
another boat.
Soft decks means moisture in the core. Real soft decks means rot. You
will need to rip down to the lower skin back to solid core and then
another foot or so of top skin only. Let the edges dry out, recore and
reskin and then fair out to the original deck. You could core with
plywood but the added weight will raise the COG and make the boat a
little more tender.
Also if the rot is extensive you better make sure how the cabin top is
supported. On many production boats the side decks provide most of the
support for the cabin. When you remove that support the cabin top must
be held in place by temprary bracing and tied carefully into the recored
side decks.