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Contamination — Remove all grease, dirt, paint, oil, laitance, efflorescence, loose mortar, and cement by the
<br />recommendations listed in the surface preparation section.
<br />Surface Condition — Hollow areas, bug holes, voids, honeycombs, fin form marks, and all protrusions or rough edges are to
<br />be ground or stoned to provide a continuous surface of suitable texture for proper adhesion of the coating. Imperfections may
<br />require filling, as specified, with a recommended Sherwin-Williams product.
<br />Concrete Treatment — Hardeners, sealers, form release agents, curing compounds, and other concrete treatments should be
<br />removed to ensure adequate coating adhesion and performance.
<br />Methods of Surface Preparation on Concrete per SSPC-5P13/NACE 6 or ICRI 03732 Surface Cleaning Methods:
<br />Vacuum cleaning, air blast cleaning, and water cleaning per ASTM D4258.
<br />Used to remove dirt, loose material, and/or dust from concrete.
<br />Detergent water cleaning and steam cleaning per ASTM D4258.
<br />Used to remove oils and grease from concrete. Prior to abrasive cleaning, and after abrasive cleaning, surfaces should be
<br />cleaned by one of the methods described above.
<br />Mechanical Surface Preparation Methods:
<br />Dry abrasive blasting, wet abrasive blasting, vacuum assisted abrasive blasting, and centrifugal shot abrasive blasting per
<br />ASTM D4259. Used to remove contaminants, laitance, and weak concrete, to expose subsurface voids, and to produce a sound
<br />concrete surface with adequate profile and surface porosity.
<br />High-pressure water cleaning or water jetting per SSPC-SP12-NACE5.
<br />Used to remove contaminants, laitance, and weak concrete, to expose subsurface voids, and to produce a sound concrete surface
<br />with adequate profile and surface porosity.
<br />Impact tool methods per ASTM D4259.
<br />Used to remove existing coatings, laitance, and weak concrete. Methods include scarifying, planing, scabbling, and rotary
<br />peening. Impact tools may fracture concrete surfaces or cause microcracking requiring surface repair.
<br />Power tool methods per ASTM D4259.
<br />Used to remove existing coatings, laitance, weak concrete, and protrusions in concrete. Methods include circular grinding,
<br />sanding, and wire brushing. These methods may not produce the required surface profile to ensure adequate adhesion of
<br />subsequent coatings.
<br />Chemical Surface Preparation Methods:
<br />Acid etching per ASTM D4260. Use to remove some surface contaminants, laitance, and weak concrete, and to provide a
<br />surface profile on horizontal concrete surfaces. This method requires complete removal of all reaction products and pH testing
<br />to ensure neutralization of the acid. Not recommended for vertical surfaces. Etching with hydrochloric acid shall not be used
<br />where corrosion of metal in the concrete is likely to occur. Adequate ventilation and safety equipment required.
<br />Clean surface per ASTM D4268
<br />Wet surface with clean water
<br />Etch with 10-15% muriatic acid solution at the rate of 1 gallon per 75 square feet
<br />Scrub with stiff brush
<br />Allow sufficient time for scrubbing and until bubbling stops
<br />If no bubbling occurs, surface is contaminated. Refer to ASTM D4258 or ASTM D4259
<br />Rinse surface two or three times. Remove acid/water each time.
<br />Surface should a texture similar to medium grit sandpaper.
<br />Neutralize surface with a 3% solution of tri-sodium phosphate and flush with clean water.
<br />Allow to dry and check for excess moisture.
<br />Cement Composition Siding/Panels — S-W 6: Remove all surface contamination by washing with an appropriate cleaner,
<br />rinse thoroughly and allow to dry. Existing peeled or checked paint should be scraped and sanded to a sound surface. Glossy
<br />surfaces should be sanded dull. Pressure clean, if needed, with a minimum of 2100 psi pressure to remove all dirt, dust, grease,
<br />oil, loose particles, laitance, foreign material, and peeling or defective coatings. Allow the surface to dry thoroughly. If the
<br />surface is new, test it for pH, many times the pH may be 10 or higher.
<br />Composition Board (Hardboard) — S-W 9: Some composition boards may exude a waxy material that must be removed with
<br />a solvent prior to coating. Whether factory primed or unprimed, exterior composition board siding (hardboard) must be cleaned
<br />thoroughly and primed with an alkyd primer.
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