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SHERWIN-WILLIAMS,
<br />Basic Surface Preparation
<br />Coating performance is directly affected by surface preparation. Coating integrity and service life will be reduced because of
<br />improperly prepared surfaces. As high as 80% of all coating failures can be directly attributed to inadequate surface preparation
<br />that affects coating adhesion. Proper product selection, surface preparation, and application affect coating performance. Coating
<br />integrity and service life will be reduced because of improperly prepared surfaces. Selection and implementation of proper
<br />surface preparation ensures coating adhesion to the substrate and prolongs the service life of the coating system.
<br />The majority of paintable surfaces are concrete, ferrous metal, galvanizing, wood and aluminum. They all require protection to
<br />keep them from deteriorating in aggressive environments. Selection of the proper method for surface preparation depends on
<br />the substrate, the environment, the coating selected, and the expected service life of the coating system. Economics, surface
<br />contamination, and the effect on the substrate will also influence the selection of surface preparation methods. Recognize that
<br />any surface preparation short of total removal of the old coating may compromise the service length of the system.
<br />Verify the existence of lead based paints on the project. Buildings constructed after 1978 are less likely to contain lead based
<br />paints. If lead based paints are suspected on the project, all removal must be done in accordance with the EPA Renovation,
<br />Repair and Painting and all applicable state and local regulations. State and local regulations may be more strict than those set
<br />under the federal regulations. Verify that Owner has completed a Hazardous Material Assessment Report for the project prior to
<br />issuing of Drawings. Concluding that no lead based paints were found on project site, delete paragraph regarding lead based
<br />paints.
<br />WARNING! Removal of old paint by sanding, scraping or other means may generate dust or fumes that contain lead. Exposure
<br />to lead dust or fumes may cause brain damage or other adverse health effects, especially in children or pregnant women.
<br />Controlling exposure to lead or other hazardous substances requires the use of proper protective equipment, such as a properly
<br />fitted respirator (NIOSH approved) and proper containment and cleanup. For more information, call the National Lead
<br />Information Center at 1-800-424-LEAD (in US) or contact your local health authority. Removal must be done in accordance
<br />with EPA Renovation, Repair and Painting Rule and all related state and local regulations. Care should be taken to follow all
<br />state and local regulations which may be more strict than those set under the federal RRP Rule.
<br />No exterior painting should be done immediately after a rain, during foggy weather, when rain is predicted, or when the
<br />temperature is below 50°F, unless the products to be used are designed to be used in those environments.
<br />Aluminum — S-W 1: Remove all oil, grease, dirt, oxide and other foreign material by cleaning per SSPC-SP1, Solvent
<br />Cleaning.
<br />Block (Cinder and Concrete) — S-W 3: Remove all loose mortar and foreign material. Surface must be free of laitance,
<br />concrete dust, dirt, form release agents, moisture curing membranes, loose cement, and hardeners. Concrete and mortar must be
<br />cured at least 28 days at 75°F. The pH of the surface should be between 6 and 9. On tilt-up and poured-in-place concrete,
<br />commercial detergents and abrasive blasting may be necessary to prepare the surface. Fill bug holes, air pockets, and other
<br />voids with a cement patching compound (per ASTMD4261).
<br />Brick— S-W 4: Must be free of dirt, loose and excess mortar, and foreign material. All brick should be allowed to weather for
<br />at least one year followed by wire brushing to remove efflorescence. Treat the bare brick with one coat of Loxon Conditioner.
<br />Concrete and Masonry — Concrete, Poured — Exterior or Interior— S-W 5: The preparation of new concrete surfaces is as
<br />important as the surface preparation of steel. The following precautions will help assure maximum performance of the coating
<br />system and satisfactory coating adhesion:
<br />Cure — Concrete must be cured prior to coating. Cured is generally defined as concrete poured and aged at a material
<br />temperature of at least 75°F for at least 28 days unless specified products are designed for earlier application.
<br />Moisture — Reference ASTM F1869-98 Moisture Test by use of Calcium Chloride or ASTM D4263 Plastic Sheet Method
<br />Concrete must be free from moisture as much as possible (it seldom falls below 15%). Vapor pressures, temperature, humidity,
<br />differentials, and hydrostatic pressures can cause coatings to prematurely fail. The source of moisture, if present, must be
<br />located, and the cause corrected prior to coating.
<br />Temperature — Air, surface and material temperatures must be in keeping with requirements for the selected product during
<br />and after coating application, until coating is cured.
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