If you don't want to mess with chemicals, many pros today skip the D2092 methods in favor of a "sweep blast"—a very light abrasive blasting that roughens the zinc without removing it, providing the mechanical "teeth" the paint needs to survive for years. modern primers are the best substitutes for these old ASTM methods?
ASTM D2092: The Standard Guide for Preparing Galvanized Steel Surfaces for Painting astm d2092 pdf
Painting galvanized steel is notoriously difficult because new zinc surfaces are often smooth or chemically treated at the mill with oils or passivates to prevent "wet storage stain". These coatings actively repel most standard paints, leading to rapid peeling and failure. ASTM D2092 provides systematic procedures to remove these inhibitors and create an "anchor pattern" that allows paint to bond chemically and mechanically to the zinc. The Eight Preparation Methods If you don't want to mess with chemicals,