465 MISCELLANEOUS COATINGS FOR METAL (STEEL)
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- Furnish and apply various coatings to metal surfaces as specified. Refer to Sections 435 and 436 for cleaning and painting new and existing bridge structural steel, respectively.
Paint System C 912.05 Fusion Bonded Epoxy Powder Coating for Steel 917.02 Fusion Bonded Polyester Powder 917.03 Hot Dip Galvanized Zinc A123, A153, and 465.03.05(c) Galvanizing Repair A780 and 465.03.05(c)
- Use paint and powder coating material selected from the Qualified Products List (QPL).
- Perform cleaning and coating in an approved environmentally controlled plant. Provide the Administration with access to each part of the process. The Administration reserves the right to witness or perform any Quality Assurance testing on a random basis.
- Use polyester powder coating when coatings other than paint are specified for steel or aluminum or as directed.
- The powder coating applicator shall have demonstrated the ability to properly apply and cure the materials of the system and shall be on the Administration’s Approved List of Applicators prior to application of any coatings. Coaters shall be qualified for paint and for powder coating as specified in 435.01.04. Galvanizers shall be on the Administration’s Approved List of Galvanizers.
- 465.03.01 Nongalvanized Carbon Steel. Prepare steel metal surfaces as specified in 436.03.10(h). All cut edges shall be broken. Clean all items to be coated of any oil or grease according to SSPC SP-1 and abrasive blast to Near White according to SSPC SP 10. Remove weld spatter, slivers, hackles, or other defects. Protect cleaned surfaces from high humidity, rainfall, and surface moisture. Do not allow cleaned surfaces to flash-rust. Ensure that the blast profile is 2 mils to 3 mils according to D4417, Method C.
- (a) Epoxy Powder Coating System. The system consists of a single coat of epoxy powder coating. Ensure that the thickness of the cured coating is 7 +/- 2 mils when measured according to SSPC PA2..
- (b) Polyester Powder Coating System. The system consists of a zinc rich prime coat; Coat I of System C or Coat I of Powder Coating System and 5 mils to 9 mils of a polyester powder finish coat. Apply primers and the powder coating according to the manufacturer’s recommendations and in manner that immediately applies the powder after the organic zinc rich primer has fully cured if Coat I of System C is used. Use a two-stage approach for the zinc rich powder that partially gels the zinc primer prior to application of the top-coat powder. Measure coating thickness according to SSPC PA2.
- 465.03.02 Hot Dip Galvanized Carbon Steel. Metals for primary members that have reactive steel chemistry require the galvanizer to document the steps to be taken to ensure proper adhesion in their Quality Control Plan. Remove weld spatter, slivers, hackles, or other metal defects prior to galvanizing. Reactive steel for structural elements shall be abrasive blast cleaned to SP6 with a 2 mil to 3 mil profile prior to galvanizing.
- The galvanizer shall ensure that the finished galvanized product to be coated is free of excessive zinc areas, spikes, slivers, ash, and dross or other detriments. Paint or powder coat hot dip galvanized steel as specified. Galvanized items shall not have been galvanized more than one month prior to coating and shall not have been water or chromate quenched.
- Store items to be coated in an environment free of moisture and dust for a period of 12 hours maximum, when coating application does not immediately follow the sweep blast surface preparation.
- (a) Paint System. Clean and profile surfaces to be coated by sweep blasting according to D6386. Ensure that all paint within the paint system is from the same manufacturer and that intermediate and finish coats conform to Coats II and III of System C. Apply all coatings using methods and under conditions recommended by the paint manufacturer. Measure the thickness of the coating according to SSPC PA2.
- (b) Polyester Powder Coating System. Clean, sweep blast, and outgas surfaces to coated according to D7396. Use an anti-out-gassing type powder coating material for galvanized items. Follow the powder coating manufacturer’s instructions for the metal surface temperature, applying the coating material and maintaining the cure parameters.
- 465.03.03 Aluminum. Clean and prepare aluminum surfaces to be coated using a five step or more process consisting of cleaning, rinsing, pretreatment or conversion coating, rinsing, then sealing. Do not use any product that contains hexavalent chromium. Use water break test according to Federal Standard TT-C-490F after all cleaning methods to check for freedom from organic contaminants. Submit the coating process to be used and the quality assurance plan, along with the coating manufacturer’s recommendations, for approval prior to coating.
- 465.03.04 Adhesion. Adhesion of the paint or powder coating system to either bare or galvanized metal or aluminum shall be at least 4 A when tested according to D3359, Method A.
- 465.03.05 Touch Up System. Provide a compatible touch up system to repair defects, areas damaged during erection, and all visible open areas. Prepare areas to be repaired and apply touch up systems according to the coating manufacturer’s recommendations.
- 465.03.06 Defects. Visually inspect all items for pinholes, blisters, bubbles, sags, handling damage, and other defects. Repair all pinholes, blisters, and bubbles to intact surface by grinding. Repair any sags or damage that have resulted in cracks or delamination as specified in 465.03.05, if required. If defects exceed 1/2 of 1 percent of the surface area of the item and total repairs exceed 1 in. in the narrowest dimension, the whole item shall be touched-up and coated.
- 465.03.07 Holiday and Pinhole Testing. The paint and powder coat finished surfaces shall be holiday and pinhole free when tested with a low voltage holiday detector (minimum 67 1/2 volts) according to D5162. Repair all holidays and pinholes detected with additional coating.
- (a) Select the epoxy powder touch up material to be used from the Administration’s Approved List.
- (b) Polyester powder touch-up system shall be a two-component aliphatic polyurethane meeting 912.04.02 in the same color as the polyester powder. The coating thickness of the touch up material for the powder coating shall be applied in multiple coats and shall be the same thickness as the powder coating. Use Coat I of System C to repair damage to the coating that penetrates to the metal surface; followed by the polyurethane.
- (c) Make any necessary repairs to the galvanizing according to A 780. Use Coat I of System C selected for use at the bake temperature. Use the solder or metallizing method for repairing the galvanizing if it is to be powder coated.
- 465.03.08 Color. The color of all coatings and touch up systems shall match Federal Standard 595 and the following:
COLOR COLOR NO. Brown 20040 Black 27038 Green 24108
- 465.03.09 Certification. Paint shall meet 912.01.03, epoxy powder coating shall meet 917.02.02, and polyester powder coating shall meet 917.03.
- The acceptance of hot dip galvanized zinc will be based on inspection and shall meet A123, A153, and the Contract Documents.
465.04 MEASUREMENT AND PAYMENT
- Coatings for metal will not be measured but the cost will be incidental to the pertinent items specified.