What's that Lassie? You say that stryped fell down the old
rec.crafts.metalworking mine and will die if we don't mount a rescue
by Tue, 13 Jul 2010 07:49:03 -0700 (PDT):

I am taking apart my trailer to replace the wood bed. I took a wire
cup brush to the metal. I wanted to coat it before putting the treated
wood back on. WOuld spray undercoating or oil based rustomleum work
better?

See if you can find a source for a product called
POR-15. You can apply it to rusty post wire brushed metal.
Very strong, very hard coating. Moisture/rust cure.
It can't take UV so you might have to put a topcoat on.

--

Dan H.
northshore MA.