To the OP:
I owned a
steel yacht for 12 years and I know a wee bit about RUST.
With respect, try thinking out of the box:
1) Any
wood attached to
steel in a wet marine environment is going to eventually cause the steel to RUST. The
wood holds
salt moisture and that will eventually find its way through any
paint system you apply to the steel.
20 How about attaching your wood rub rail to the
hull with a gap of say 6mm? Use purpose-made
SS spacers between the wood and the
hull at the places where the bolts go through the wood and the hull. That way you don't have wood to steel contact. If the rub rail is thick enough and bolts say 700mm apart, the rail should absorb impact without cracking.
3) Again, with respect to all the other posters: nothing beats sandblasting to prep steel for painting. Anything less (grinding, needle
guns, and worst of all "rust converters") is just a stopgap and will leave a residue of rust/salt to continue the rusting process UNDER the new
paint. Good experiences with "rust converters" in automotive situations has no relevance to marine applications in
salt water. Rust converters have their place on a steel boat, but not in this case of wood on steel in a very wet environment.
Just saying; slag me off if you want, but I've been there and done all that for 12 years.