Concerned with the anticorrosive properties of acidified Mimosa tannin when used as a wash primer, either to provide added protection under a conventional air-drying maintenance paint system for mild steel, or as a short term protection in its own right. Based on observations from about nine hundred test-panels, draws on three related fields of investigation: corrosion chemistry, tannin chemistry and thirdly, a fundamental investigation into the formation of iron tannate on rusted mild steel. -- AATA