[72K10]

I agree with ccsrcr; pitting is usually filled with automotive glazing putty. That's exactly what it's for. Sand it to bare metal, primer it, then putty. Primering and sanding over and over again would do it, but if you were using regular primer, it would take probably 25 coats or more. Don't know about the high build primer, but sounds like it would work as well.