OVERCOATING: REASONS, RESOURCES AND REALITY Tuesday, March 15, 2016 | 11:00 AM – 12:00 PM Eastern Presented By Rich Burgess, KTA-Tator, Inc

OVERCOATING: REASONS, RESOURCES AND REALITY Preservation of steel bridges is high on the priority list of FHWA and owners of other industrial steel structures that deal with the cost of asset corrosion. This webinar will review reasons for overcoating, resources available to critically evaluate suitability and Examples of implementing this maintenance painting strategy

OVERCOATING: REASONS  Preserve Steel Assets By Addressing Areas Of Rust / Corrosion  Extend The Service Life Of Coating Systems  Manage Budget Limitations  Respond To Public Complaints

OVERCOATING: REASONS BENEFICIAL PROCRASTINATION: DELAYING LEAD PAINT REMOVAL PROJECTS BY UPGRADING THE COATING SYSTEM Eric S. Kline and William D. Corbett KTA-Tator, Inc Journal of Protective Coatings & Linings. Volume: 9 Issue Number: 3 Publisher: Steel Structures Painting Council ISSN: Upgrading : Application of an additional barrier coat to increase the protective life of the existing coating system and permit the owner to postpone total removal without the possible consequences of corrosion damage affecting the integrity of the structure  Alternatives to total removal of lead-based paint & postponement of coating work. Can the existing system be upgraded?  Extent of Corrosion  Existing Coating System Total Thickness (& coating layers)  Adhesion characteristics

OVERCOATING: REASONS Expected Service Life and Cost Considerations for Maintenance and New Construction Protective Coating Work Jayson L. Helsel, Michael Reina, Robert Lanterman, KTA-Tator, Inc. Paper No. 4088, Corrosion 2014 ©2014 NACE International Typical Maintenance Painting Practices  Original Painting  Spot Touch-Up and Repair  Maintenance Repaint (spot prime and full coat)  Full Repaint (total coating removal and replacement) Key Considerations Coating System - Surface Preparation - DFT - Service Environment

OVERCOATING: RESOURCES  SSPC-PA 5 “Guide to Maintenance Coating of Steel Structures in Atmospheric Service”  SSPC-TU 3 “Overcoating”  ASTM D5064 “Standard Practice for Conducting a Patch Test to Assess Coating Compatibility”

OVERCOATING: RESOURCES SSPC-PA 5 Guide to Maintenance Coating of Steel Structures in Atmospheric Service MAJOR STEPS IN MAINTENANCE COATING:  Plan And Conduct Condition Assessment Survey(section 5)  List Potential Maintenance Painting Options (Section 6)  Evaluate Economics Of Available Options (Section 7)  Select Appropriate Maintenance Painting Options And Establish Implementation Procedures (Section 8)  Implement Maintenance Painting Options (Section 9)  Plan And Implement Follow-up Activities (Section 10)

OVERCOATING: RESOURCES SSPC-TU 3 Overcoating  Factors affecting overcoating application, service and costs  Resource for facility owners and others charged with developing and implementing maintenance painting programs.

OVERCOATING: RESOURCES SSPC-TU 3 Overcoating Definitions  Coating stress: Tension a cured coating has, which and can be imparted to the steel substrate or other coating layers.  Embrittled coating: Coating that has degraded to a friable condition but still has enough elasticity to adhere to the substrate or existing coating.  Flaking: The detachment of small pieces of the coating film, usually preceded by cracking, checking or blistering.  Loose coating: Coating that has delaminated and disbonded from the substrate or other coats, but has not fallen off.  Marginally adherent coating: A coating that exhibits tape adhesion of 2A or less (per ASTM D 3359), such that the overcoating risk is moderate or high.

OVERCOATING: RESOURCES SSPC-TU 3 Overcoating Definitions  Overcoating: Application of coating materials over an existing coating in order to extend its service life. Includes preparation of rusted / degraded areas, feathering edges, LPWC to remove contaminants, a full intermediate coat over repaired areas, optional application of a full topcoat over the entire structure.  Overcoating may be a cost effective alternative to complete coating removal and repainting. When the old coating contains lead, cadmium, or chromium, overcoating may be a particularly attractive option due to economic considerations. ( Overcoating presents certain risks as well.)  Repaint: Complete removal of the existing coating system followed by application of a new coating system (including appropriate cleaning methods.)

OVERCOATING: RESOURCES SSPC-TU 3 Overcoating  Risk: the chance that the overcoated system (old paint plus new) will either fail catastrophically (e.g., delamination of the system) or not provide the desired period of protection.  Spot repair: A procedure entailing surface cleaning of isolated corrosion or paint breakdown areas using appropriate cleaning methods, and subsequent coating of these areas.  Zone painting: A procedure entailing surface preparation using appropriate cleaning methods and painting of a defined area of a structure. Zone painting may involve (a) many spot repairs within a defined area or (b) removal of all coating in a defined area, followed by application of a new coating system to that area.

OVERCOATING: RESOURCES D5064 − 07 Standard Practice for Conducting a Patch Test to Assess Coating Compatibility Procedures For Testing Coating Compatibility when overcoating is being contemplated. IT DOES NOT COVER  Procedures for assessing the integrity of the existing coating, establish the  Compatibility of the maintenance coating with the substrate or corrosion products.  Pass-Fail Criteria (for example, adhesion requirements) The materials under test are applied after proper surface preparation. After the appropriate time has elapsed, the test patch is examined for visual defects and adhesion is determined.

OVERCOATING: RESOURCES D5064 − 07 Standard Practice for Conducting a Patch Test to Assess Coating Compatibility Test Locations Properly characterize configuration of the structure and exposure; vertical, horizontal, sheltered vs unsheltered Minimum of three test locations one test patch in each Prepare the surface of the test areas using the methods specified for the maintenance painting (Alternative methods may also be evaluated in separate, adjacent tests.)  Long-Term Curing —Curing for as long a time as possible- minimum of six months preferred. Span seasonal weather changes.  Short-Term Curing —Curing at minimum times based on average daily (24 h) temperatures: 50°F,70°F, 90°F cure14 days 10 days and 7 days respectively.

OVERCOATING: RESOURCES D5064 − 07 Standard Practice for Conducting a Patch Test to Assess Coating Compatibility  Examine test patch for wrinkling, blistering, mudcracking, checking, cracking, peeling, lifting, and disbonding.  Test adhesion in a minimum of five locations per test patch in accordance with Test Methods D3359 or D6677. (If agreed upon between the purchaser Test Methods D4541 may be used.  Examine on a regular schedule, discounting rust caused by previous tests such as adhesion measurements and destructive film thickness measurements.

OVERCOATING: RESOURCES D5064 − 07 Standard Practice for Conducting a Patch Test to Assess Coating Compatibility REPORT:  Dry film thickness measurements and average of the in-place coating  Dry film thickness measurements and average of the test coating  Elapsed time for each evaluation  Visual defects noticed  Results of adhesion tests.

OVERCOATING: REALITY You Can Spot Coat A Lot!

OVERCOATING: REALITY Determining Feasibility of Overcoating Assessment Of The Existing Coating Condition  Physical  Chemical

OVERCOATING: REALITY Physical Coating Condition Assessment Degree of Rusting  SSPC-VIS 2 Standard Method of Evaluating Degree of Rusting on Painted Steel Surfaces  Custom Photographic Standards Coating Adhesion  ASTM D3359 – 09´2 Standard Test Methods for Measuring Adhesion by Tape Test  ASTM D6677 Standard Tet method for Evaluating Adhesion by Knife  ASTM D4541 Standard Test Method for Pull-Off Adhesion of Coating Using portable Adhesion Testers

OVERCOATING: REALITY Physical Coating Condition Assessment Coating Thickness  ASTM D7091 Standard Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non- Ferrous Metals Coating Layers  ASTM D 4138, “Standard Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross- Sectioning Means” Substrate Condition  Visual Examination of Substrate Exposed by Coating Removal

OVERCOATING: REALITY Public Pressure Can Impact Decisions

OVERCOATING: REALITY Degree of Rusting SSPC-Vis 2 Custom Photographic Field Guides Grade 4-G, 10% Rusted (MNDOT)

OVERCOATING: REALITY Coating Adhesion ASTM D3359 Standard Test Methods for Measuring Adhesion by Tape Test  Method A X-Cut  Method B Crosscut ASTM D6677 Standard Test Method for Evaluating Adhesion by Knife ASTM D4541 Standard Test Method for Pull-Off Strength of Coatings Using Portable Adhesion Testers

OVERCOATING: REALITY Determine Coating Adhesion

OVERCOATING: REALITY Coating Thickness ASTM D7091 Standard Practice for Nondestructive measurement of Dry Film Thickness of Nonmagnetic coatings applied to ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals ASTM D4138 Standard Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-Sectioning Means

OVERCOATING: REALITY Coating Layers Fifteen LayersThickness, Mils Top – Light Green 1.9 – 2.2 Green1.1 – 1.5 Blue3.8 – 4.1 Red0.7 – 0.8 Blue~ 1.0 Red0.6 – 0.7 Yellow0.2 – 0.7 Dark Red0.6 – 1.1 Red0.3 – 0.6 Yellow0.8 – 1.2 Dark Red1.9 – 2.0 White0.4 – 0.7 Orange2.1 – 2.5 Dark Red0.3 – 0.7 Bottom – Red3.3 – 3.5

OVERCOATING: REALITY Substrate Condition Visual Exam  Clean and Prior Blast Cleaning  Prior Blast Cleaning- Light Rust  Rust, No Mill Scale  Rust and Flaking Mill Scale  Intact Mill Scale

OVERCOATING: REALITY Chemical Characteristics  Existing Coating Type (Resin) Coating Compatibility  Toxic Heavy Metals: Lead, Chromium (III, or VI)  Soluble Salts  Asbestos Containing materials  PCBs Used in Formulation

OVERCOATING: REALITY Existing Coating Type Fourier Transform Infrared Spectroscopy

OVERCOATING: REALITY SSPC- Guide 15 Field Methods for Extraction and Analysis of Soluble Salts on Steel and Other Nonporous Substrates  Extraction of Surface Samples  Field Methods Measuring Conductivity  Field Methods Measuring Specific Ions

OVERCOATING: REALITY Toxic Heavy Metals Laboratory Analysis (ICP,AAS, AES)  Total Metal Content  Hexavalent Chromium Purpose  Worker Safety  Protection of the Public  Protection of the Environment  Waste Management

OVERCOATING: REALITY Toxic Heavy Metals SampleSample Location Total Lead Total Cadmium Total Chromium Hexavalent Chromium KTA-5 Approach Girder Web 63,600<6.2714, KTA-6 Floor Beam End of Open Steel 63,800<6.4110, KTA-7Cable Bent59,500<6.2312, KTA-8North Tower Leg64,600<5.812, KTA-9 Lower Diaphragm Horizontal 88,200<5.926,

OVERCOATING: REALITY Evaluating Risk When Overcoating

OVERCOATING: REALITY Cost Savings Corrosion in Excess of 16% typically will be as expensive to address as the cost of replacement

OVERCOATING: REALITY Cost Savings Pay ItemsOption1Option 2Option 3 Painting Existing Structural Steel$1,556,034100%$1,296, %$1,154, % Containment$1,387,018100%$1,234, %$1,193, % Disposal Of Bridge Waste$316,308100%$244, %$204, % Worker Health And Safety$33,475100%$29, %$27, % Total$3,292,800100%$2,804, %$2,579, % Potential Savings($488,200)($713,300) Pay Items Based On High Side Of Construction Cost Estimate Maintenance Of Traffic Not Included

OVERCOATING: REASONS, RESOURCES AND REALITY  Why Overcoat  Guidance for Overcoating Programs  Process and Procedures of Coating Condition Assessments  Decision Making Process

OVERCOATING: REASONS, RESOURCES AND REALITY QUESTIONS