Don't blame the tools for a poor workman.
There's nothing wrong with balsa coring, when someone has taken the time and expense to properly
bed it in
epoxy, which makes it impossible to saturate the coring with moisture since each piece is then separately surrounded and entombed in
epoxy and the
water simply can't migrate anywhere.
Similarly, if the penetrations in the
deck are properly constructed and sealed, water won't get in in the first place.
Plywood and hardwoods
rot too. If you've never chased rotted
wood all the way down a bulkhead in the
bilge because someone didn't maintain the chainplates properly and now you've got six feet of
rot, no balsa needed...It isn't the wood's fault. One could also argue that most chainplates are a lousy excuse for a good design, because they make these
leaks so easy.
Now you've got the chance to build a proper cockpit sole, from honeycombed frp. Light, waterproof, strong...And of yeah, its gonna cost you. (G)