Attachment 2 City of Portland Standard Construction Specifications Section 593~1.pdf

City of Portland 2020

00593.03

Section 00593 - Powder Coating Metal Structures

Description

00593.00 Scope - This work consists of preparing and powder coating new metal structures and features in the shop and preparing and coating existing metal structures at the project site. This includes all:

• Interior and exterior steel surfaces

• Steel railings, bridge bearings, and bridge expansion joint assemblies

• Other miscellaneous steel

• Galvanized and aluminum surfaces

00593.01 References - In this section, references such as SSPC-SP 1 and SSPC-PA 1 refer to Volume 2, "Systems and Specifications" of SSPC's "Painting Manual."

00593.03 Required Submittals:

(a) Powder Coating Plan - At least seven (7) calendar days before the date that preparation and coating operations are scheduled to begin, submit a project-specific powder coating plan for the approval of the Owner’s Representative. Include the following:

• The name, location, and contact information (mail address, phone, and e-mail) for the firm performing the powder coating operation.

• Quality assurance and quality control (QA/QC) programs established and followed by the firm performing the powder coating operation.

• A product data sheet and material safety data sheet of each type of coating material to be used, including the products to be used for field repair of damaged areas.

• A description of the cleaning, surface preparation, pre-heating, application, curing, shop and field coating repair, handling, and storage processes to be followed for structures and items to be coated.

• A letter from the firm performing galvanizing, if other than the Contractor, certifying that neither water quenching nor a chromate conversion coating will be used on the surfaces that are to be powder coated.

Do not begin preparation or coating work before the powder coating plan has been approved.

(b) Coating Materials Certification - At least seven (7) calendar days before the date that preparation and coating operations are scheduled to begin, submit a manufacturer's certification stating that each coating material in the coating system:

• Meets the requirements of this section.

Attachment 2 City of Portland Standard Construction Specifications

00593.10

• Meets the specifications of the manufacturer's data sheets.

• Is compatible, including coating repair materials.

Materials

00593.10 Coating Materials - Furnish coating materials meeting the requirements of these specifications and the applicable portions of SSPC PA 1, "Shop, Field and Maintenance Painting" when not in conflict with these specifications.

(a) Coating System:

(1) Steel Substrates - Provide a two-coat system for steel substrates consisting of a zinc-rich epoxy primer and a polyester topcoat conforming to the following:

Test Test Method Limit or Value Adhesion ASTM D3359, Method B B5 (no failure) Flexibility ASTM D522, Method B Pass 1/4" mandrel bend Pencil hardness ASTM D3363 H Plus Specific gravity ASTM D792 2.30 minimum Zinc in dry film Calculated weight 50% minimum

(2) Galvanized and Other Non-Steel Metallic Substrates - Provide a two-coat system for galvanized and non-steel metallic substrates consisting of an epoxy primer and polyester topcoat conforming to the following:

Test Test Method Limit or Value Adhesion ASTM D3359, Method B B5 (no failure) Flexibility ASTM D522, Method B Pass 1/8" mandrel bend Pencil Hardness ASTM D3363 H Plus Specific Gravity ASTM D792 1.25 minimum

(3) Topcoat - Furnish a polyester topcoat meeting the requirements of the American Architectural Manufacturers Association (AAMA) Specification 2604.

(b) Color - Unless otherwise specified, furnish top-coat color that conforms to the following:

• SAE AMS-STD-595 color #20059 for weathering steel

• SAE AMS-STD-595 color #24272 for ODOT green

• SAE AMS-STD-595 color #26357 for miscellaneous metal on concrete bridges concrete gray

• SAE AMS-STD-595 color #27038 for black

(c) Slip-Critical Connections - The primer coat on steel-to-steel contact surfaces at all slip-critical bolted joints using high strength bolts shall conform to Class B (slip coefficient of 0.5) coating requirements in "Test Method to

00593.42

Determine the Slip Coefficient for Coatings Used in Bolted Joints" as adopted by the Research Council on Structural Connections.

00593.11 Blasting Abrasives - Provide abrasives that have no corrosion products, water, oil, or any other material detrimental to the application and adherence of the coatings. Provide abrasives that conform to SSPC-AB 1. When directed, test cleanliness according to ASTM D7393 and ASTM D4940.

Conductivity results from ASTM D4940 shall not exceed 100 microsiemens per centimeter.

00593.12 Caulking - Furnish structural steel caulking from the CPL and approved for use by the coating manufacturer. Unless the caulking is to be over coated, the caulking color shall be clear or shall approximate the color of the top coating.

Furnish industrial grade polystyrene or polyurethane backing material of sufficient diameter to fill the crevices or gaps as required.

Obtain approval from the Owner’s Representative of the caulking and backing material before using.

Construction

00593.40 General - Structures to be prepared and powder coated include new and existing steel, galvanized, and non-steel metallic substrates.

00593.41 Special Fabrication, Preparation, and Coating:

(a) Inaccessible Surfaces - Before fabrication, prepare and coat, with all coats, steel surfaces inaccessible to preparation or to coating after fabrication.

Protect from blast-cleaning, powder coatings, overspray, and drippings all contact surfaces within slip-critical joints that are not to be coated. Remove or repair unintended coatings or other damage on these surfaces to the satisfaction of the Owner’s Representative at no additional cost to the Owner.

(b) Welded Areas - Schedule fabrication, preparation, and coating so that welding or fabricating processes do not damage the coating system.

Neutralize weld areas, and remove smoke stain and spills according to SSPC- SP 1. Remove weld slag and spatter by mechanical means before blast-cleaning. Supplement blast-cleaning by other treatment as recommended by the manufacturer of the coating system and as required in 00593.42.

Do not apply coatings within four (4) inches of the weld before the welding operation is complete.

00593.42 Preparation of Surfaces:

(a) Steel Structures - Clean new steel structure surfaces to be coated according to SSPC-SP 10 / NACE No. 2 "Near White Metal Blast Cleaning"

00593.42 except as modified by these specifications. The appearance of the final blast-cleaned surface shall closely approximate Pictorial Standard SP 10 of SSPC- Vis 1 and have a 1.0 to 2.5 mil profile finish.

(b) Non-Steel Metallic Substrates:

(1) Galvanized Substrates - Clean and prepare galvanized surfaces to be coated according to ASTM D6386, the approved powder coating plan, and the following:

• Newly Galvanized Steel - Smooth and clean surfaces according to ASTM D6386, Section 5 and prepare surfaces according to ASTM D6386, Section 5.4.1.

• Partially Weathered Galvanized Steel - Check and prepared according to ASTM D6386, Section 6, then smooth and clean surfaces according to ASTM D6386, Section 5, then prepare surfaces according to ASTM D6386, Section 5.4.1.

• Weathered Galvanized Steel - Prepare according to ASTM D6386, Section 7.

(2) Aluminum, Stainless Steels, and Non-Ferrous Metals - Prepare surfaces by using one (1) of the following methods:

• Solvent clean surfaces to be coated according to SSPCSP 1, followed by a light brush blast according to SSPCSP 16 “Brush-Off Blast Cleaning of Coated and Uncoated Galvanized Steel, Stainless Steels, and Non-Ferrous Metals” with a maximum nozzle pressure of 75 psi.

The prepared surface shall have a 1.0 to 2.5 mil profile finish.

• Hand sand the surface, creating a minimum one (1) mil profile.

• Clean the surface according to the manufacturer’s recommendations.

(c) All Metal Structures - Remove fins, tears, slivers, sharp edges, and hardened or damaged edges according to SSPC Paint Application Guide No. 11. Clean all surfaces of material detrimental to the application of the coating system as follows:

(1) Cleaning Methods - Blast-clean surfaces using one (1) or more of the following methods to discharge the abrasive:

• A stream of high-pressure air

• A rotating centrifugal paddlewheel

Surfaces shall be dry before cleaning. Use methods specified in SSPC-SP 1, "Solvent Cleaning," SSPC-SP 2, "Hand Tool Cleaning," SSPC-SP 3, "Power Tool Cleaning," and SSPC-SP 15 "Commercial Grade Power Tool Clean" as necessary to augment blast-cleaning.

(2) Abrasives - Perform blast-cleaning using an abrasive of a size that will continually produce an angular surface profile of at least one (1) mil but not

00593.43 more than four (4) mils as measured according to ASTM D4417 using replica tape on the prepared surface. Blast-cleaning shall result in a roughened steel surface comparable to a Keane-Tator surface profile comparator for sand or grit using ASTM D4417.

If a centrifugal wheel with a grit mixer is used for blast-cleaning, inspect each member after blast-cleaning, and, for those members not meeting the comparator or profile requirements, perform a final blast-cleaning with high-pressure air with an abrasive to obtain the specified profile.

Use abrasives conforming to 00593.11. Wet abrasives are allowed if wet sandblasting methods are used.

(3) Air - For blast-cleaning or blowing down, use high-pressure air that is free of water, oil, or any other material detrimental to the coating system.

Test compressed air cleanliness daily according to ASTM D4285 or as directed.

(4) Cleaning Procedures - Perform blast-cleaning operations and pressure washing as required without damaging partially or entirely completed portions of the work. Do not blast-clean adjacent to areas being coated.

Examine blast-cleaned and pressure washed surfaces for any traces of corrosion, water, oil, grease, soluble salts, and other material deposited during the cleaning operations. If present, remove any detrimental material by solvent cleaning and blast-clean the surface again.

(5) Final Preparation - Do not begin coating before:

• Blowing down prepared surfaces using high-pressure air within the fully enclosed containment, with the specified ventilation operating, and supplemented by brushing if required.

• Determining that the prepared surfaces are free of all residues per

SSPCPA 1.

• Repairing all damaged galvanizing according to ASTM A780.

• Obtaining approval from the Owner’s Representative.

00593.43 Coating Metal Structures:

(a) Description - When not in conflict with the specifications, perform powder coating application according to the following:

• The applicable portions of SSPC-PA 1.

• The recommendations of the coating manufacturer.

• The best practices of the trade according to SSPC Painting Manual, Volume 1, “Good Painting Practice.”

00593.43

(b) Application of Coating Materials - Apply the powder coating system according to the following requirements:

(1) Surface Condition - Ensure that the surface to be coated is free of moisture, dust, grease, rust, or other substance that would prevent the bond of succeeding applications. Prepare contaminated surfaces to the satisfaction of the Owner’s Representative before applying the coating.

(2) Application Methods - After surface preparation, apply the two-coat system according to the powder coating manufacturer's recommendations, the approved powder coating plan, and the following:

• Pre-heat surface.

• Apply the epoxy primer coat followed by a partial cure.

• Apply the polyester finish coat followed by the finish cure.

Apply each coat in a uniform layer completely covering the preceding coat.

Furnish each individual coat in a sufficiently different shade so that skips and holidays can be easily detected. Correct skips or other deficiencies before application of succeeding coats.

(c) Coating Requirements:

(1) Minimum Dry Film Thickness - Apply all coats to the following minimum thicknesses:

• Primer: 2.5 mils

• Topcoat: 2.5 mils

(2) Coating Thickness and Coverage Requirements - Each coat shall consist of as many applications as necessary to cover the work and achieve the minimum thickness specified. Apply each coat in sufficient thickness to achieve uniform and complete coverage and appearance. If all thickness measurements are not within the specified minimum dry film thickness, or if the visual inspection does not satisfy the Owner’s Representative, make additional applications as necessary to meet the thickness and coverage required. Film thickness will be measured above the peaks of the profile of the anchor pattern in the substrate.

The dry film thickness will be measured for acceptance using a Type 2 gauge according to SSPC-PA 2. If a question arises about an individual coat thickness or coverage, it will be verified using a Tooke gauge according to ASTM D4138. If the Tooke gauge shows a prime coat to be less than the specified minimum thickness the total coating system will be rejected even if the thickness of the total system equals or exceeds the total specified thickness.

(3) Additional Top Coat Requirements - Even if the total thickness of the prime coat exceeds the prime coat specified thickness, apply the top coat

00593.44 to at least the minimum required topcoat thickness to provide uniform and complete coverage and appearance.

(d) Time of Application - Apply the prime coat within four (4) hours of the final cleaning and before any visible rust forms.

(e) Caulking - Apply the caulk after complete application of the top coat. Fill and seal crevices and gaps between structural shapes and plates, around bolt heads or nuts, and similar areas that would retain moisture with the following:

• Caulk if the crevice or gap cannot be filled with coating materials.

• Backing material and caulk to fill the crevices and gaps that exceed 1/4 inch. Apply caulk over the backing material to form a watertight seal.

In areas that collect or channel water, apply caulk even if coating fills the gap.

(f) Adhesion - Perform adhesion tests according to ASTM D4541, Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers, using "Test Method D, E, or F" as warranted or at the direction of the Owner’s Representative. Ensure that minimum pull-off strength of 650 psi is achieved for zinc-rich primers and based coatings and minimum pull-off strength of 1000 psi is achieved for all other coatings, including those over a zinc-rich primer. When testing a coating or coating system with a DFT of more than 12 mils, score around the test fixture.

00593.44 Inspecting - Conduct or make arrangements for powder coating tests required in the approved powder coating plan.

Aspects of the preparation and coating process to be inspected and tested include but are not limited to:

Test Test Method

Ionic contamination of abrasive material .................................... ASTM D4940 Cleanness of compressed air .................................................... ASTM D4285 Pictorial surface preparation standards..................... SSPC-VIS 1, 3, 4, and 5 Surface profile by Keane-Tator comparator ............................... ASTM D4417 Surface profile by replica tape ................................................... ASTM D4417 Hardness ........................................................ AAMA 2604 and ASTM D3363 Dry film thickness by magnetic gauge.......................... SSPC-PA 2 (modified) Dry film thickness by Tooke gauge ............................................ ASTM D4138 Pull-off strength of coating .......................... ASTM D4541 (Method D, E, or F)

Provide the Owner’s Representative access to the powder coating facility to visually inspect the assemblies for the presence of coating holidays and other unacceptable surface imperfections and to witness the coating thickness testing, the hardness testing, and the adhesion testing.

00593.60

Provide documentation of the QA/QC testing to the Owner’s Representative.

Assemblies failing these tests will be rejected. Repair and recoat the rejected assemblies as directed.

Do not ship assemblies to the project site without approval from the Owner’s Representative.

Repair coating system damages resulting from Owner inspection and testing at no additional cost to the Owner.

00593.45 Protecting Against Damage:

(a) Contaminated Surfaces - If the prepared surface becomes contaminated by material other than rust, clean the surface in a manner satisfactory to the Owner’s Representative before making the succeeding application. If the prepared surface becomes contaminated by rust, prepare the contaminated area again according to 00593.42 and recoat with all specified coats. Clean, reprepare, and recoat at no additional cost to the Owner.

(b) Surfaces Not to Be Coated - Protect surfaces that are not to be coated from blast cleaning, overspray, and drippings. Remove or repair unintended coatings or other damage on these surfaces to the satisfaction of the Owner’s Representative at no additional cost to the Owner.

(c) Handling, Shipping, or Surface Damage - After curing and acceptance, individually wrap coated assemblies with multiple layers of bubble wrap or other protective wrapping materials specified in the approved powder coating plan.

During storage and shipping, separate each wrapped assembly with expanded polystyrene spacers and other spacing materials specified in the approved powder coating plan.

After erection, repair marred and damaged coated surfaces due to the Contractor's shipping, storage, handling, and erection operations according to 00593.60.

Repair marred or damaged coated surfaces with the same materials and to the same condition as specified at no additional cost to the Owner. At the completion of all work, the coating shall be complete and the surfaces undamaged and clean.

Maintenance

00593.60 Repair of Damaged and Unacceptable Coatings - Repair damaged surfaces and surfaces not in compliance with requirements of 00593.43 as follows:

(a) Surface Preparation - Repair localized damage, corrosion, and unacceptable coatings.

00593.90

Prepare the surface according to SSPC-SP 1, SSPC-SP 2, and SSPC-SP 3.

Use a solvent that is acceptable to the coating material manufacturer. Extend the prepared area at least two (2) inches into adjacent, tightly adhering, intact coating.

In areas exhibiting coating defects that do not extend down to the metal substrate, remove all loose, delaminating, non-intact, non-sound or otherwise defective coating down to sound, still performing coating. Extend the prepared areas at least two (2) inches into adjacent tightly adhering, intact coating.

(b) Feathering of Repair Areas - Feather the existing coating system surrounding each repair location for a distance of one (1) inch to two (2) inches to provide a smooth, tapered transition into the existing intact coating.

Verify that the edges of coating around the periphery of the repair area are tight and intact by probing with a putty knife according to SSPC-SP 3.

Roughen the existing coating in the feathered area to ensure proper adhesion of the repair coats. Overlap the intact, still sound surface at least two (2) inches.

(c) Coating Application in Repair Areas - When the bare metal substrate is exposed in the repair area, apply all coats of the system to the specified thicknesses.

When the damage does not extend to the bare metal substrate, apply only the affected coats.

Maintain the thickness of the system in overlap areas within the specified total thickness tolerances, and overlap the intact, sound existing coating at least two (2) inches.