Thanks guys. And JeffL the link was very helpful. I done bought it....so guess I will see what the FINE does. Only got 200# I will use it up and may see that I need COARSE. I do have a few spots that are serious thick rust, probably will just cut them out anyway.
That Zink Phospate sounds like the etching primer that we spray a light coat of, until we can get around to serious priming and blocking.
Wayne.