This specification covers a fast drying chlorinated rubber inhibitive primer for use on steel surfaces or exterior non-submerged surfaces, as well as most submerged surfaces prior to being overcoated with additional chlorinated rubber coatings. When applied as a shop coat to steel expected to be exposed to normal weathering or mild chemical environments for more than 60 days, it is recommended that either an additional coat of primer be applied or that the next succeeding coat be applied in the shop.
This coating is not recommended for areas exposed to strong organic solvents, oxidizing acids, or to areas where the surface temperature exceeds 165°F (74°C). Straight chain unsaturated acids, and fats and oils of animal or vegetable origin will cause softening and swelling of the coating.
This primer, when applied over properly prepared steel surfaces and coated with SSPC-Paint 18, “Chlorinated Rubber Intermediate Coat Paint,” and followed by at least one (optional) finish coat of SSPC-Paint 19, “Chlorinated Rubber Topcoat Paint,” is suitable for exposures in Environmental Zones 1A (interior, normally dry), 1B (exterior, normally dry), 2A (frequently wet by fresh water), 2B (frequently wet by salt water), 2C (fresh water immersion), 2D (salt water immersion), 3A (chemical, acid), 3B (chemical, neutral), and 3C (chemical, alkaline).
Steel surfaces shall be blast cleaned in accordance with SSPC-SP 6, “Commercial Blast Cleaning,” for atmospheric use or with SSPC-SP 10, “Near-White Blast Cleaning,” for immersion or heavy chemical use. Steel may also be prepared according to SSPC-SP 8, “Pickling.”
This primer is intended for application by brush, roller, or spray and is to be applied in accordance with SSPC-PA 1, “Shop, Field, and Maintenance Painting of Steel.”
If this coating is applied over alkyd- or oil-base enamels, there is the possibility of lifting, particularly on interior surfaces. A spot check is necessary to determine suitability. If lifting occurs, then a seal-coat, as recommended by the manufacturer, may be required. For immersion service, this coating should not be applied over alkyd or oil-base enamels.
This primer is a mixture of inhibitive pigments, extender pigments, chlorinated rubber, chlorinated resins, plasticizers, and solvents. Details of the composition are given in Table 1.
This primer contains a minimum of 32% by volume of nonvolatile film-forming solids (pigment and binder). The minimum theoretical spreading rate for a 1.5 mil (38 micrometers) dry film thickness is 340 square feet/U.S. gallon (8.4 square meters/liter). Actual spreading rates can be significantly lower.
