Joe, I was given a new gal. can of "Zink Enriched Primer" that came from a Railroad Car restoration shop that was used on all new chassis castings. It has excellent filling quality's as the consistently is heavier that most primers. When you sand blast that axle you'll find its full of pin size holes if its like my 1910 Mitchell.It brushes out like satin and drys very fast!! In warm climate its dry to the touch in 20 mins or less! It sands well if you get a sag. I loved it for chassis parts like springs, axles, ect as its drys fast and applies smooth .Of coarse its claim to fame is excellant rust protection and filling qualities. Google it! Mike