Anyone that has experience painting on aluminum, more specifically sheet metal have any preference to a type of primer? A normal based primer will not effectively work well on aluminum in general especially if it's on anything automotive/racing and gets hit with debris without ripping the paint off easily in my experience using it during my racing days.

Zinc chromate primer worked very well to solve this issue. However I'm having trouble acquiring this lately and finding anyone that supplies it. Anyone else have some experience on what works to stick to aluminum well? 2-part based epoxy primers I've heard also do the job. Let me know your thoughts.