2477Powder Coating

2477.1DESCRIPTION

This Work consists of the following for shop applications of powder coating systems for new construction:

A Definitions For the purpose of the Work specified in section 2477, “Powder Coating,” the Department defines: Coating System The surface preparation and application of specific coating classifications (i.e., Inorganic Zinc-Rich, Organic Zinc-Rich, Polyurethane, Acrylic, Polyurea, Latex, Galvanize, Powder, etc.) of coating products to provide a film forming a unified whole for the purpose of corrosion protection and/or aesthetics. Coating Thickness The Dry-Film Paint Thickness (DFT) above the peaks of the blast profile. Contractor Shall mean the fabricator, paint contractor, applicator, or other entity that prepares the surfaces and applies the coatings. Duplex Coating System A system whereas galvanizing replaces the zinc-rich primer and subsequently intermediate and top coated in accordance with this Specification.

Edge An exposed, through-thickness surface of a plate or rolled shape. This may be the as-rolled side face of a beam flange, channel flange, or angle leg, or may result from thermal cutting, sawing, or shearing. Edges may be planar or rounded, and either perpendicular or skewed to adjacent faces. Lot The amount of components that are baked at one time in a curing oven. If a continuous feed oven is used a “Lot” shall be defined in the QM. Powder System A set of interacting film forming powder Materials and products which combine to make up a complete coating system. Prime Coat Application of a zinc-rich coating to a bare metal substrate. Quality Assurance (QA) The process and person(s) responsible for verification of the conformance of Materials and methods of application to the governing Specification, in order to achieve a desired result. Quality Assurance Inspector (QAI) The Department’s representative responsible for duties specified in the Quality Assurance Plan, with the authority to accept Work that meets Contract requirements. Quality Control (QC) The process and person(s) responsible for administrative and production procedures employed to attain the desired product outcome and quality. The job foreman or production painter cannot be this person. MnDOT Quality Manual (QM) The formal written document prepared by the Contractor that describes the policies and procedures that ensure and verify that the coated structural steel component will satisfy the Contract requirements. Shop (in shop coating) The indoor facility where structural metals are prepared and coated. Verification Testing Testing of powders currently listed on the APL by applicator that did not perform the initial qualification testing. Well Lighted A minimum of 50 foot candles of artificial light or natural daylight. Use a light meter with readings in foot candles to verify the adequacy of the lighting.

2477.2MATERIALS

Provide a Powder System listed on the APL, Bridge, “Bridge Railing Powder Coating.” Deliver the powder to the applicator in the original unopened containers. Provide the Bridge Engineer with Material Safety Data Sheets (MSDS), Material certifications, and Technical Data Sheets (TDS) for each powder shipment. Ensure a manufacturer’s technical representative with knowledge of this P owder System is available to assist during coating application.

2477.3CONSTRUCTION REQUIREMENT

A Qualification for Shop Applicators Before the start of Work, the supplier will be qualified on Approved Suppliers for Fabricated Structural Metals Products list as maintained by the Structural Metals Engineer on the Bridge Office website or become qualified. To become qualified, the supplier is to submit a Quality Manual (QM) with a Verification Testing procedure to the Bridge Engineer for review and acceptance, at least 60 Calendar Days before beginning Work. The QM and the Verification Test is to meet the requirements of the MnDOT Supplier Qualification Standard which will be the basis for acceptance by the Bridge Engineer. Upon acceptance of the QM, a supplier is qualified and will be listed on the Approved Suppliers for Fabricated Structural Metals Products list. In addition to routine inspections, the Bridge Engineer will audit suppliers with approved QMs on a biannual or annual basis or as otherwise directed by the Bridge Engineer to ensure the implementation of the QM. The Department will invoke its Corrective Action Process if the routine inspections or audits indicate non-conformance. Corrective actions deemed appropriate by the Bridge Engineer, are effective immediately and apply to any Work remaining on a current Project and future Projects. If the Bridge Engineer determines that Work does not comply with the QM or that fabrication does not follow approved fabrication procedures, the Bridge Engineer will deem the Materials as non-conforming in accordance with 1503, “Conformity with Contract Documents,” and 1512, “Unacceptable and Unauthorized Work.” If the Bridge Engineer finds non-conforming Work, direct the supplier to immediately correct the procedure and submit a written Nonconformance Report, containing data required by the Bridge Engineer to ensure compliance with the QM, Specifications, and drawings. Perform additional testing as required by the Bridge Engineer at no additional cost to the Department. For repeat offences or negligence, the Department will require corrective action of hiring a third -party Quality Control Inspector at no additional cost to the Department. The Contractor may obtain a copy of the Department’s Corrective Action Process from the Bridge Engineer. B General Preserve or transfer erection markings to ensure legibility when erecting members. Provide removable markings or place markings at locations not visible in the completedS tructure. Use marking Material that will not damage the Powder System. Protect the environment and property as required by federal, State, and Department regulations. C Inspection Perform QC inspections of the Shop coating process in accordance with an approved QM and Table 2477.3-1. Perform coating application and QC inspections of coated products by persons with normal color vision, in a Well Lighted area during each coating phase and prior to final acceptance. Use a light meter with readings in foot candles to verify the adequacy of the lighting. The Department will appoint a Quality Assurance Inspector (QAI) as a Department representative to accept Work meeting the Contract requirements. C.1 MnDOT Quality Manual (QM) Requirements Provide the minimum requirements and frequencies in the QM as shown in Table 2477.3-1:

Table 2477.3-1 Powder Coating Inspection Requirements Requirement Criteria Frequency/Event Date and Time Each Lot of Work Each Lot of Work

Compressed air test ASTM D4285* Daily – When abrasive blasting or blow down operations are occurring

Final Coat Dry Film Thickness (DFT) As submitted by Manufacturer (listed on the APL) SSPC-PA 2, Procedure for Determining Conformance to Dry Coating Thickness Requirements Surface Preparation Abrasive blast clean Duplex System (prior to galvanizing) Duplex System (prior to powder) Powder Only System (prior to powder)

Surface cleanliness (all systems)

SSPC-SP6, Commercial Blast Cleaning, SSPC-SP 16, Surface Preparation Specification/ASTM D7803ǁ, SSPC-SP10, Near-White Metal Blast Cleaning

SSPC-PA1, Shop, Field and Maintenance Coating of Metals Each component to be powder coated Pre-Bake for Outgassing Surface cleanliness SSPC-PA 1 100 percent Visual examination prior to coating Pre-bake oven temperature Same procedure used to pass qualification/verification Each Lot of Work prior to each out-gassing event Baking procedure ASTM D7803† in conjunction with the same procedure used to pass qualification Each Lot of Work Prime / Intermediate Coat Powder product number Track for each Lot Each batch of powder Surface cleanliness inspection SSPC-PA 1 Visual examination prior to coating (within 1 hour of coating) Prime / Intermediate coat oven temperature Same procedure used in qualification / verification Each Lot of Work Temperature of component at time of coating Same procedure used in qualification / verification Each Lot of Work Verification of coating coverage 100 percent Coverage of powder 100 percent Visual Inspection Top Coat Powder product number Track for each lot Each batch of powder Surface cleanliness inspection SSPC-PA 1 Visual examination prior to coating Top coat oven temperature Same procedure used in qualification / verification Each Lot of Work Final cure temperature of component Same procedure used in qualification / verification Each Lot of Work Curing time Per manufacturer Technical Data Sheet Each Lot of Work

Requirement Criteria Frequency/Event Coating evaluation / repair Visual Inspection: Coating shall be smooth and uniform free of runs, drips, sags, pinholes, blisters, and other deleterious conditions. (Pinhole density shall not be greater than 5 pin holes per square foot in any given area) 100 percent Visual Inspection (without the aid of magnification) * ASTM D4285, Standard Test Method for Indicating Oil or Water in Compressed Air ǁ ASTM D7803, Standard Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Product and Hardware Surfaces for Powder Coating † ASTM D7803, Standard Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Product and Hardware Surfaces for Powder Coating

Provide written records meeting the QM powder Coating inspection requirements in Table 2477.3-1 to the Bridge Engineer on an ongoing basis as the Work is being performed. Provide written records meeting the QM Powder Coating inspection requirements in Table 2477.3-1, in its entirety, at the completion of the job, prior to receiving final payment. The QAI or the Bridge Engineer may reject the Coating System or apply a monetary deduction per 1512, “Unacceptable and Unauthorized Work,” if the Contractor did not adhere to the approved QM or provided inadequate documentation of adherence to the QM. Conduct subsequent testing with the QAI or the Bridge Engineer’s approval, at no additional cost to the Department, to determine compliance. D Surface Preparation The QAI or Bridge Engineer will inspect the surface preparation as it is done, after its completion, review the QM documentation, or any combination of the three. Notify the QAI or the Bridge Engineer at least 5 Working Days before beginning surface preparation. D.1 Cleaning D.1.a Solvent Cleaning Clean areas containing organic and synthetic and other visible contaminants with solvent meeting the requirements of SSPC-SP 1, Solvent Cleaning. Protect the adjacent environment and property while solvent cleaning. D.1.b Abrasive Cleaning D.1.b(1) Duplex Coating Systems Perform preparation of galvanized surfaces prior to the application of powder in accordance with SSPC SP16, Brush-off Blast Cleaning of Non-Ferrous Metals and ASTM D7803, Standard Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Products and Hardware Surfaces for Powder Coating. Inspect brush-off blasted surfaces for fins, tears, reduced DFTs that fall below the required minimum, or any other damage. Submit to the Bridge Engineer an NCR documenting all damage prior to repairing the surface. D.1.b(2) Powder Only System Perform preparation of bare steel surfaces prior to application of powder in accordance with SSPC-SP10, Near-White Metal Blast Cleaning.

D.1.c Post Blasting After blast cleaning, remove blasting debris from surfaces using procedures that leave the surfaces free of moisture and contaminants. Remove the blasting residue from the containment area, specifically the floor area, to prevent dust from being airborne once coating process starts. E Application of Powder E.1 General Prior to application of powder, submit documentation to the Quality Assurance Inspector (QAI) showing that the powder manufacturer's technical representative trained, directly involved Shop personnel (including QC) on the proper storage, handling, and application of the Coatings System for the Project. Make training curriculum available to the Bridge Engineer upon request. Do not start applying powder until the QAI or the Bridge Engineer accepts the surface preparation. Before applying powder, clean the surface of oxidation, dust, dirt, grease, oil, moisture, overspray, and other deleterious contaminants that will prevent the powder from adhering. Apply powder to produce a smooth and uniform film free of runs, drips, sags, pinholes, blisters, and other deleterious conditions. Apply powder in accordance with manufacturer’s printed instructions except as follows: Do not apply powder to metal surfaces when weather conditions that the manufacturer’s literature defines as unsatisfactory are present, and when:

Do not apply powder if other Work operations or wind causes the air to carry dust, dirt, or sand onto the prepared or newly coated metal surfaces. The QAI or Bridge Engineer will suspend coating operations if the applicator does not properly control coating application. Powder coat sweep blasted galvanized railing with the subsequent coat(s) within the time frame defined in ASTM D7803, Standard Practice for Preparation of Zinc (Hot-Dip Galvanized) Coated Iron and Steel Product and Hardware Surfaces for Powder Coating, or within the same 8-hour shift, maintaining manufacturer defined control and environmental conditions. The powder coating applicator’s QC personnel shall document that parameters were followed. Remove surface contamination, if any exist. Repair or replace defective previously applied coats as required by the Bridge Engineer, at no additional cost to the Department. Submit coating repair procedures to the QAI or the Bridge Engineer for approval. Ensure the color of the first coat presents a distinct contrast from other coat(s). E.2 Applying Powder Apply and cure powder per the same procedure used in qualification/verification. Apply powder in a neat and workman-like manner to evenly coat surfaces.

F Powder Coats F.1 Measurement of Coating Thickness The Department refers to “Dry Film Thickness” (DFT) when using the term “thickness” in this section. Use a properly calibrated thickness gage to measure the coating thickness and average thickness meeting, at a minimum, the requirements of SSPC -PA 2, “Measurement of Dry Coating Thickness with Magnetic Gages.” Measure coating thickness from the top of the peaks of the blast profile. For Duplex Coated Systems use a DFT measurement thickness tool capable of differentiating the individual thicknesses of both Powder Coating System and galvanizing Layer. Perform coating operations as recommended by the manufacturer’s literature, unless otherwise specified in this section. F.2 Prime Coat For powder only systems, apply a zinc-rich primer powder. Remain within the minimum and maximum DFT limits as defined by the manufacturer. For Duplex Coating Systems, the hot-dip galvanize coating replaces the zinc-rich prime coat. F.3 Intermediate Coat Remain within the minimum and maximum DFT limits as submitted by the manufacturer. Ensure the color of the intermediate coat has sufficient contrast with the P rime and finish coat. F.4 Finish Coat Remain within the minimum and maximum DFT limits as submitted by the manufacturer. Ensure the finish coat color matches the color standard required by the C ontract. Ensure the finished surface is uniform in color and free of visible lap marks and other blemishes. F.5 Total Coating Thickness Ensure the total Coating Thickness of the entire system remains within the minimum and maximum thickness limits defined by the manufacturer of the C oating System. If the Bridge Engineer finds total Coating Thickness deficient or excessive over any part of a Structure and if the Bridge Engineer does not require additional applications or removal of coating, the Department may apply a monetary deduction for the appropriate item of Work. G Handling, Storage, and Shipping of Powder Coated Components Do not damage the coated steel in the shop and field during shipping, erection, and construction of the Project. Do not move or handle the coated steel items until the coating cures and cools in accordance with the applicator’s approved procedure. Use nylon straps, padded hooks, slings, or other non-metallic lifting devices to protect coated components or products during handling and loading. Use softeners and edge protection devices to protect the steel from binding chains. Use padded hooks and slings to hoist the coated components. Store completed items in accordance with 1606, “Storage of Materials,” and the following:

Bridge number, Project number, manufacturer number, and the applicator job number in the identification markings.

the full weight of the members or items and stable enough to maintain bundles, members, or items within the supporting substrate. Inspect and store bundles, members, or items in one general location before final acceptance unless otherwise approved by the QAI or the Bridge Engineer. Support individual items or bundles of coated products in transit in a manner that will prevent damage to the coating. Do not drop or drag individual items or bundles of coated products. Pad when shipping, bundling, or banding Materials to protect the components from direct contact with packaging Materials that may damage the coated products finish. Use softeners and Edge protection devices in conjunction with high-density foam or other acceptable packaging Materials at points of contact. Any damaged coated surfaces, identified through either Quality Control or Quality Assurance inspections as being unacceptable, either after the application of the powder coating or during handling of the powder coated components, is subject to the provisions of 1512, “Unacceptable and Unauthorized Work” or will be repaired as described in the Powder Coating Applicators repair procedure. H Coating Repair H.1 Shop (prior to receiving at job site) Any damaged coated surfaces, identified by the Bridge Engineer as being unacceptable is subject to the provisions of 1512, “Unacceptable and Unauthorized Work,” and will be replaced or repaired. Submit a Non-conformance repair Plan to the Bridge Engineer for acceptance. Once accepted in writing by the Bridge Engineer, perform repairs using the accepted methods and procedures authorized by the Bridge Engineer. Coating damage is classified in two extent types: Type 1 – damage is any type of abrasion that caused a surface imperfection not exposing the galvanized surface or exposes an area of galvanized surface that is smaller than 1 square inch in size. This damage may be repaired in the shop using an accepted Non- conformance repair Plan as stated above (i.e. abrade the damaged area and apply an intermediate and finish coat per 2478, “Organic Zinc-Rich Paint System.” (Note: Alkyd Enamels will not be allowed as a repair. Aerosol spray paint is not an acceptable repair procedure.) Type 2 – damage is any type of surface imperfection that exposes the galvanized or steel surface larger than 1 square inch and/or exposed base metal in an area larger than 1/2 square inch. Repair this damage in the Shop using an accepted Non-conformance repair Plan. H.2 Field (once received at the job site) Any damaged coated surfaces, identified by the Engineer as being unacceptable is subject to the provisions of 1512, “Unacceptable and Unauthorized Work,” and will be replaced or repaired. Submit a Non-conformance repair Plan to the Engineer for acceptance. Once accepted in writing by the Engineer, perform repairs using the accepted methods and procedures authorized by the Engineer. Coating damage is classified in two extent types: Type 1 – damage is any type of abrasion that caused a surface imperfection not exposing the galvanized surface or exposes an area of galvanized surface that is less than 1 square inch in size. This damage may be repaired in the field or the Shop using an accepted Non-conformance repair Plan as stated above (i.e. abrade the damaged area and apply an intermediate and finish coat per 2478, “Organic Zinc-Rich Paint System”). (Note: Alkyd Enamels will not be allowed as a repair. Aerosol spray paint is not an acceptable repair procedure.)

Type 2 – damage is any type of surface imperfection that exposes the galvanized surface larger than 1 square inch and/or exposed base metal in an area larger than 1/2 square inch. Remove sections of damaged rail from the site and repair in the Powder applicator’s powder application facility. (Repair the damaged area utilizing an accepted Non-conformance repair Plan.)

2477.4METHOD OF MEASUREMENT - BLANK

2477.5BASIS OF PAYMENT

The Contract Unit Price for 2475, “Metal Railing,” includes the cost of powder coating.