Bartman1959
Bigger Hammer
I was under the impression that primers were porous and would still allow rust to form if not painted to seal it? Not trying to pretend I know what I'm talking about or say you're wrong as I don't know much about this topic but just trying to learn more.
That's what I thought too, until several videos on Youtube taught me better. Watch this short video to see what I mean.
https://www.youtube.com/watch?v=FKyu3MWuPR8