25-REHABILITATION OF THE EAST ELEVATED STORAGE TANK

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6. Method of Application: Apply paint materials by brush, roller or spray (air or airless) as dictated by the manufacturer's instructions and as approved by the Engineer. When spraying, each coat shall be sprayed on in strict accordance with the manufacturer's recommendations. The type of spray nozzle, the fluid pressure at the gun, the air pressure at the gun, the distance from the gun to the surface being painted and the speed of travel of the gun shall be exactly as recommended by the manufacturer. Thinning shall be done as recommended by the manufacturer. All paint in the fluid pot and lines shall be cleaned out with thinner before application of the paint is begun. The thinner may be used also for cleaning the painting equipment at the end of each day's painting operation. Each coat shall be dry to touch before the next coat is applied. At least iwo hours drying time shall be allowed between coats, however, it is best to follow the recommendation of the manufacturer. The Contractor is cautioned that small amounts of the paint fumes are intoxicating and large amounts tend to be toxic and fatal. The Contractor shall make provisions to keep the tank well ventilated during the spraying and drying operations to protect the personnel and to facilitate drying of the coating by solvent evaporation. 20.07 INSPECTION During the sandblasting, to whichever degree of cleanliness is specified, checks must be continually made to insure that the cleanliness called for is being met; and that the proper profile as required by the coating system to be utilized is being achieved. The cleanliness is covered by the SSPC Visual Standards and the profile may be checked by use of a Testex Micrometer Dial Thickness Gauge. During and after each coating of paint, all ferrous metal surfaces shall be checked with an Elcometer, Microtest, Posi-Test or other approved dry film thickness gauge to insure that the specified dry film thickness has been attained. After the paint thickness on the inside meets the required thickness of these specifications, the Contractor shall furnish a holiday detector such as a Tinker and Rasor, or other suitable instrument, and test the entire surface of the paint system for holidays. This is done by connecting the holiday detector ground connection to the shell of the tank and connecting the detector lead to a damp sponge mop and wiping it over the surface of the tank. Areas where holidays are found shall be marked in chalk and recoated. After recoating, the areas shall be again rechecked with the holiday detector. If additional holidays are found, the areas shall be recoated and rechecked until the entire surface is free of holidays. After the holiday checking is completed, the point of ground connection of the holiday detector shall be thoroughly painted. Holiday detection shall not be required on the exterior surface of the tank. TS20-6 . - 461