This specification covers an air drying, ready-mixed, water-borne primer for blast cleaned steel. It is intended for use as a primer coat of a water-borne coating system consisting of two coats of this primer and one or two coats of a water-borne topcoat.
This primer is suitable for exposures in Environmental Zones 1A (interior, normally dry) and 1B (exterior, normally dry), and is intended for brush, spray, or roller application over steel surfaces prepared in accordance with SSPC-SP 6, "Commercial Blast Cleaning." It is suitable as a shop primer, field primer, maintenance primer, or intermediate coat and is to be applied in accordance with SSPC-PA 1, "Shop, Field, and Maintenance Painting of Steel." It is not recommended to expose steel to the weather with less than two coats of water-borne coating; therefore, intermediate and topcoats should be applied as soon as possible.
This primer is based on a latex vehicle produced by emulsion polymerization and appropriate pigments. Details of the composition are given in Table 1.
This primer contains approximately 36% by volume of nonvolatile film-forming solids (pigment and binder). The theoretical spreading rate for a 2.0 mil (51 micrometers) dry film thickness is 290 square feet/U.S. gallon (7.1 square meters/liter). Actual spreading rates can be significantly lower.
