After Ospho comes primer in our Rust Repair Odyssey.
Primer: just like what a normal person (read: non-steel boat owner) uses under any type of paint if they’re doing the job right. We want to do the job right (caveat in this post notwithstanding) so we are applying primer.
It is a fancy-pants two-part primer formulated for metal and costs no more for a pint-sized container than does a good dinner out in Manhattan.
Priming went quickly; much more quickly than chipping, which is the standard by which all further boat projects are measured. Since both the primer and the Ospho’d sections were black I painted on so much primer that it ran off the areas where it was supposed to be sticking. I wanted to make sure I had good coverage but it just made a mess.
I didn’t take photo documentation of the primer. It was a non-photogenic event.