Rebar coating?

[Sarpedon]

I have a pond drain that has rebar for the grille. The rebar is not protected and open to the elements, so it is rusting. Is there anything I can coat it with to seal it? Most things I have found are meant to be used when the rebar is inside concrete.

Spar urethane has been reccommened, but this seems to be aimed for wood. Can it be used on steel as well?

Thanks

 

[Square Eye]

It can be used on steel, fiberglass and wood.
BUT
You need an epoxy coating in a constant, water contact situation. Spar varnish is good for weather resistance but it's still a maintenance issue. A 2 part epoxy finish will bond and seal and last like nothing else. The old boat builders abandoned spar varnish on hulls a long time ago when they saw the advantages of the epoxy resins