This specification covers a French process zinc oxide, raw linseed oil and alkyd primer suitable for use over blast cleaned steel.
This is an alkyd/linseed oil primer containing 30% more alkyd resin than SSPC Paint 25. It is not recommended for hand cleaned steel.
This primer is suitable for exposures in Environmental Zones 1A (interior, normally dry) and 1B (exterior, normally dry), and is intended for brush, roller, or spray application over steel surfaces prepared in accordance with SSPC-SP 6/NACE No. 3, “Commercial Blast Cleaning,” or SSPC-SP 11, “Power Tool Cleaning to Bare Metal,” or better. (See Note 9.6.) 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.” If the primed part of the structure is to be exposed to the weather, it should be topcoated as soon as practical.
This specification contains requirements to ensure performance that is comparable to that customarily expected from paints containing lead and chromate pigments. It has fair wetting ability, about 18 hours drying time and good resistance to weathering before field coating. The wetting ability of this primer is the result of one third of the binder being raw linseed oil. Type II has a lower percentage of volatile organic compounds (VOC) than Type I. The reduced VOC content of Type II was achieved by replacing some of the mineral spirits with high flash naphtha and by making other minor composition changes. Details of the compositions are given in Table 1 for Type I and in Table 2 for Type II.
The Type I primer contains approximately 65% by volume of nonvolatile film forming solids (pigment and binder). The theoretical spreading rate for a 50 micrometer (2.0 mil) dry film thickness is 12.8 m2/L (520 ft2/U.S. Gallon). Actual spreading rates can be significantly lower. On a calculated basis, the VOC content is 270 grams per liter(2.3 lb/gal).
The Type II primer contains approximately 72% by volume of nonvolatile film forming solids (pigment and binder). The theoretical spreading rate for a 50 micrometer (2.0 mil) dry film thickness is 14.2 m2/L (580 ft2/U.S. gallon). Actual spreading rates can be significantly lower. On a calculated basis, the VOC content is 220 g/L (1.9 lb/gal).
