If the bolts are galvanized steel, the coating might be a good idea.

Agreed that they should be uncovered if stainless. OTOH, that's why
stainless steel isn't the best keelbolt material. Most of the bolt,
the part you can't see, is sealed from that protecting oxygen. Hence,
you never know whether you'll be getting crevice corrosion down where
you can't see it. So, a better material is Monel or Bronze, assuming
lead ballast. (If the ballast is iron, galvanized steel will be
better.)

Capt. JG wrote:
You shouldn't have any coating on them... same goes for lifelines, stays,
etc.... that PVC deprives the metal of oxygen, promotes rust.

--
"j" ganz @@
www.sailnow.com