I just replaced my Beneteau First 345 Keel Bolts
Well, this thread is more than a year old, but I thought I'd add some recently acquired wisdom.
I just finished replacing the keel bolts in my recently-purchased First 345.
The heads looked *much* worse than in Fodder's pictures. MUCH worse.
The bolts were fine and they came out stubbornly, but they came out. The toughest part was breaking them loose, both because of sealant under them and also because I had to grind the heads back into a hex shape - they were puddles of rust.
But the shanks of the bolts were perfect, with only one slight exception; a bolt next to the mast step that must have leaked around the sealant.
After replacing five of them (one at a time) with brute strength and a 30" breaker bar, I switched to a rented 3/4" impact wrench driven by compressor. It was a great move. Every one came out easily with the impact wrench.
Beneteau has instructions. They are good - follow them!
The project is entirely doable. Don't be scared off by the gloom and doomers who have replied to this thread.