Valspar 21850 Galvanized Metal Primer Enamel, 1 GallonA professional industrial grade metal oil based primer formulated to provide longlasting finish on old or new metal surfaces including railings, flashings, gutters, and fencing. Etching new galvanized metal is not necessary. Aluminum surfaces must be fully sanded prior to application. Special high hiding characteristic of this primer permits use as a 1 coat, low sheen finish or as a primer under other coatings. Apply with roller or brush. coverage: