The primer layer acts as the specialized, chemical anti-corrosion barrier, a non-negotiable step in the humid, corrosive Singaporean environment. For ferrous (iron-containing) metal, a rust-inhibiting primer is mandatory. On new or pre-existing galvanized steel (zinc-coated), a specialized etching primer or a dedicated DTM (Direct-to-Metal) adhesion-promoting primer, such as a water-b... https://kkroofspecialist.com.sg/painting-metal-roofing-singapore/