Phosphate-Free Conversion Coatings Hubbard-Hall's Emerald Paint-Prep line of low temperature and phosphate free conversion coatings offer a cost effective alternative to iron phosphate. Formulated to replace traditional iron phosphates, these coatings can reduce energy usage, environmental concerns, and increase corrosion protection. Features and Benefits include: Increased corrosion resistance with superior salt spray performance Reduced environmental impact with no phosphates or heavy metals Reduced Wastewater Treatment that's easier to neutralize with less sludge Reduced Operating Cost with a room temperature process