Field Touchup/Repair of Powder Coatings

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Field Touchup/Repair of Powder Coatings

• 2003 Air Force Corrosion Program Conference
• March 10 14, 2003
• Dr. Douglas Neale
• NCI Information Systems, Inc.
• Mr. David Ellicks
• Air Force Corrosion Prevention and Control Office
• Robins AFB, Georgia

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Field Touchup/Repair of Powder Coatings

• Air Force Inventory Of OEM Powder Coated
  Equipment Continues to Increase
• Influence of success in commercial applications
• Performance
• Cost
• Environmental Compliance
• AF Depot Level Powder Coating Capabilities Are
  Emerging
• Hill AFB
• Robins AFB
• Tinker AFB
• Others

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Field Touchup/Repair of Powder Coatings

• Powder Coatings Encountered
• Thermosets polymer powders applied
  electrostatically and baked (250oF 450oF)
• Classes of powder chemistries for AF applications
• Epoxy very good physical/chemical performance
  for
• interior use (UV-sensitive)
• Polyesters very good physical/chemical
  performance for
• interior/exterior use
• TGIC
• Urethanes
• Selection based on performance requirements and
  application characteristics of the coating

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Field Touchup/Repair of Powder Coatings

• How to Repair When Flawed or Damaged?
• Requirements/expectations (depot and field)
• Repair process practicability
• Compatibility with existing powder coating
• Performance mechanical, chemical and
• corrosion resistance (durability)
• Appearance
• Production/depot sites
• Strip and re-coat entire part
• Touch-up (original process, aerosols, brush
  kits)
• Field sites
• Original process not practical
• Touch-up with available military/commercial
  materials

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Field Touchup/Repair of Powder Coatings

• Project Purpose Develop Experience Base with
  Materials/Techniques for Field Repair of Damaged
  Powder Coatings
• Cleaning/preparation
• Coating materials
• Commonly available military/commercial products
• Innovative
• Application processes

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Field Touchup/Repair of Powder Coatings

• Project Elements
• Lab - relative corrosion performance screening
• Select common touch-up/repair coating materials
• Select simple application process/technique
• Evaluate relative corrosion performance
• Modified Q-Fog CCT-1 (common automotive
  standard)
• Cyclical corrosion
• 4 hrs salt fog, 2 hours dry-off, 2 hours
  humidity
• Down-select
• Field
• Environmental exposure of repaired coupons
• Florida Coastal
• Repair damaged support equipment

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Field Touchup/Repair of Powder Coatings

• Laboratory Screening Tests
• Powder coating materials selected
• Epoxy
• Polyester TGIC
• Urethane polyester
• Substrates clean
• Aluminum no pretreatment
• Steel iron phosphate Bonderite pretreatment
• Coupons supplied/prepared by commercial vendors
• Morton (Rohm Haas)
• Sherwin Williams

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Field Touchup/Repair of Powder Coatings

• Laboratory Screening Tests (continued)
• Repair materials
• Common MILSPEC primers/tie-coats/topcoats
• Commercial topical pretreatments/VCI coatings
• UV-cured topcoats
• Direct-to-metal waterborne acrylic latex
  topcoats
• Urethane protective barrier tape

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Field Touchup/Repair of Powder Coatings

• Laboratory Screening Tests Repair Materials
• Solventborne primer / high solids topcoat
• Baseline -23377, Type 1, Class C / - 85285,
  Type II
• -23377, Type 1, Class N / -85285, Type II
• Waterborne primer / high solids topcoat
• -85582, Type I, Class C2 / -85285, Type II
• Pretreat / high solids topcoat (-85285, Type II)
• Alodine 1132
• Sanchem Safegard 6100C or 13150A
• T.O. 1-1-8 non-chromated epoxy tie coat
• Cortec VCI 386

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Field Touchup/Repair of Powder Coatings

• Lab Screening Tests Materials (cont.)
• Solvent-borne primer / water reducible topcoat
• -23377, Type 1, Class C /- 64159, Type II (Army
  CARC)
• -23377, Type 1, Class N / -64159, Type II (Army
  CARC)
• Waterborne primer / water reducible topcoat
• -85582, Type I, Class C2 / -64159, Type II (Army
  CARC)
• Pretreat / water reducible topcoat (-64159, Type
  II)
• Alodine 1132
• Sanchem Safegard 6100C or 13150A
• T.O. 1-1-8 non-chromated epoxy tie coat
• Cortec VCI 386

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Field Touchup/Repair of Powder Coatings

• Lab Screening Tests Materials (cont.)
• Single coat
• Cortec VCI 386
• UV-cure coatings (2 manufacturers)
• Stand-alone (no primer or pretreat)
• Over Alodine 1132 pretreatment
• Over Sanchem Safegard 6100C or 13150A
• Over Cortec VCI 386

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Field Touchup/Repair of Powder Coatings

• Lab Screening Tests Materials (cont.)
• Direct to metal acrylic latex (DTM)
• Stand alone (no pretreat)
• Over Alodine 1132
• Over Sanchem Safegard 6100C or 13150A
• Over Cortec VCI 386
• 3M 8681 HS polyurethane tape over pretreat
• Alodine 1132
• Sanchem Safegard 6100C or 13150A
• Cortec VCI 386

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Field Touchup/Repair of Powder Coatings

• Auxiliary Touch-up Coating Development
• Corrosion Office initiative
• Powders dissolved directly in environmentally
  compliant solvents (acetone, PCBTF)
• Brush/aerosol application of coating with matched
  chemistry
• Local thermal cure (heat gun, IR lamp)
• Coating produced, properties under investigation

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Field Touchup/Repair of Powder Coatings

• Lab Screening Tests - Coupon Preparation
• Powder coating removal in center band (PMB)
• Roughen bare metal and adjacent powder coating
  with polymer abrasive pad
• Isopropyl alcohol wipe
• Brush application of primer/pretreat and topcoat

3 X 6 Typical
Original Powder Coating
Touch-up coating (1/2 Overlap)
Original Coating Removed (1.5)
Original Powder Coating
Scribes (two)
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Field Touchup/Repair of Powder Coatings

• Lab Results General
• 640 hours 80 cycles, Modified CCT
• All Touch-Up Coatings Proved Chemically and
  Physically Compatible with Substrates/Powder
  Coatings Evaluated
• Abrasive Pad/Alcohol Wipe Provided Suitable
  Surface Prep (Coating and Substrate)
• Brush/Sempen Used for All Coating Application
  (Cosmetics Not Optimum)
• See Final Tech Report for Detailed Analysis

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Field Touchup/Repair of Powder Coatings

• Lab Results Quantitative Evaluation of Coating
  Systems Used for Repair
• Numerical Composite Rating of Performance
• Creepage
• General Corrosion
• Blisters
• MILSPEC Baseline Comparison -23377 / -85285

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Field Touchup/Repair of Powder Coatings
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Field Touchup/Repair of Powder Coatings

• Field Tests
• Down-selected Candidates from Original Matrix
• New Coatings Identified After Start of Lab Tests
  
• Battelle Florida East Coast Test Site
• Repaired Damaged Coatings on Coupons
• 6 Month Exposure
• Evaluate Performance (Visual Quantitative)
• Corrosion penetration, creepage
• Blisters
• Coating appearance
• Test Analysis/Report Due in March, 2003

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Field Touchup/Repair of Powder Coatings

• Field Tests - Down-Selection from Original
  Matrix
• 1 -23377 Type I, Class C / -85285 Type II
• 2 -23377 Type I, Class N / -85285 Type II
• 3 -85582 Type I, Class C2 / -85285 Type II
• 8 -23377 Type I, Class C / -64159 Type II
• 9 -23377 Type I, Class N / -64159 Type II
• 10 -85582 Type I, Class C2 / -64159 Type II
• 15 VCI, Single Coat
• 24 Alodine / HS Polyurethane Tape
• 26 VCI / HS Polyurethane Tape
• 28 Alodine / Water-Borne DTM Acrylic Latex
• 30 VCI / Water-Borne DTM Acrylic Latex

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Field Touchup/Repair of Powder Coatings

• Field Tests - Added Coating Systems
• T1 DTM Acrylic Latex Primer / DTM Acrylic
  Latex Topcoat
• T2 DTM Acrylic Latex Topcoat (Two Coats, No
  Primer)
• T-3A Zero Rust Primer (Aerosol)
• T-3B So Sure (Aerosol)
• UV UV Cured Liquid Applied at Manufacturer
  Facility
• Z -23377 Type I, Class N / -85285 Type III
• ( 50 mg/l VOC)

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Field Touchup/Repair of Powder Coatings

• Damaged Test Coupon Configuration

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Field Touchup/Repair of Powder Coatings

• Field Test Results - Aluminum

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Field Touchup/Repair of Powder Coatings

• Field Test Results - Steel

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Field Touchup/Repair of Powder Coatings
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Field Touchup/Repair of Powder Coatings
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Field Touchup/Repair of Powder Coatings

• Conclusions Lab and Field
• All coatings used for touch-up were chemically
  and physically compatible with the powder
  coatings
• Scuff sanding and alcohol wipe provide good
  bonds
• Multi-component MILSPEC paint systems provide
  best performance available in small touch-up
  kits for field
• Non-chromated MILSPEC primers generally
  performed as well as chromated under MILSPEC
  topcoats
• HS polyurethane tape provides excellent
  protection
• UV cured liquid technology not ready for field
• Innovative powder/solvent not viable
• Powder coatings are not magic - current
  touch-up/repair procedures and techniques apply
  for powder coatings

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Field Touchup/Repair of Powder Coatings

• Questions?

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MOPAF
2003 Air Force Corrosion Program Conference March
10 14, 2003 Dr. Douglas Neale NCI Information
Systems, Inc. Mr. David Ellicks Air Force
Corrosion Prevention and Control Office Robins
AFB, Georgia
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MOPAF
MOBILE
MODULAR
POWDER
COATING
APPLICATION
FACILITY
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MOPAF

• PRAM PROJECT
• TWO YEARS SEPT 01 -? SEPT 03
• PURPOSE
• ACCELERATE IMPLEMENTATION OF POWDER COATING
• TECHNOLOGY INTO AIR FORCE MAINTENANCE
  ACTIVITY
• DEMONSTRATE CAPABILITY ON MAJOR PRODUCTION
• COATED COMPONENTS/EQUIPMENT
• PROMOTE ENVIRONMENTAL COMPLIANCE
• REDUCE/ELIMINATE HAZMATS, VOCS, HAZWASTES

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MOPAF

• PROJECT ELEMENTS
• SURVEY/SELECT CANDIDATE PROCESS/STAKEHOLDER
• OGDEN ALC - PRIMARY
• OKLAHOMA CITY ALC - SUPPORT
• VALIDATE POWDER COATING PROCESS ON CANDIDATE
  APPLICATION
• AIRCRAFT WHEELS
• LANDING GEAR COMPONENTS
• DESIGN/BUILD/VALIDATE MODULAR FACILITY
• IN PROGRESS
• IMPLEMENT MODULAR FACILITY AT STAKEHOLDER SITE
• SUMMER-FALL 2003

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MOPAF

• PROCESS VALIDATION
• MATERIALS
• T-38 WHEELS - 2024 ALUMINUM ALLOY
• LANDING GEAR COMPONENTS
• 7000 SERIES ALUMINUM ALLOY (ACTUATOR)
• 4340 HS STEEL (STRUT - 260 KSI)
• COATING SYSTEMS COMPARATIVE PERFORMANCE TESTING
• SURFACE PREP
• WHEELS ANODIZED, PEENED/ANODIZED
• LANDING GEAR ALUMINUM ANODIZED
• LANDING GEAR STEEL CAD PLATE, IVD ALUMINUM
• BASELINE -85582 TYPE I CLASS C2 / -85285 TYPE I
• POWDER TGIC POLYESTER (275OF CURE)
• SINGLE COAT
• -85582 PRIMER / P0WDER

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MOPAF

• COMPARATIVE COATING PERFORMANCE TESTS
• CORROSION CCT, FILIFORM, B-117
• TENSILE STRENGTH (ALUMINUM) 5 BAKE CYCLES
• FATIGUE (ALUMINUM) 5 BAKE CYCLES
• HYDRAULIC FLUID IMMERSION 3 FLUIDS
• GRAVELOMETER IMPACT _at_ ROOM, LOW TEMPERATURE
• TEMPERATURE SHOCK
• ABRASIVE RESISTANCE
• CLEANABILITY
• STRIPABILITY

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MOPAF

• EQUIPMENT SYSTEM DEVELOPMENT
• DESIGN
• BUILD PROTOTYPE
• DELIVER/ASSEMBLE HILL AFB
• FAMILIARIZE AF MAINTENANCE PERSONNEL
• OPERATION/MAINTENANCE
• START- UP/VALIDATION
• INITIATE PRODUCTION OPERATION
• FIRST ASSIGNMENT CONTINGENT ON SUCCESSFUL
  COATING PERFORMANCE TESTS

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MOPAF

• ISO CONTAINER CONFIGURATION
• ONLOAD OVERHEAD CONTINUOUS CONVEYOR
• CLEANING TOUCH-UP ROOM
• MANUAL WET SPRAY BOOTH
• MANUAL POWDER SPRAY BOOTH
• THERMAL CURE OVEN
• COOL DOWN/UV CURE (FUTURE)
• OFFLOAD
• MAIN CONTROLS/STORAGE
• UTILITIES
• MAXIMUM ARTICLE SIZE
• WEIGHT - 200 LBS
• VOLUME - 3 FT. X 3 FT. X 3 FT.
• NOMINAL 5 FT. HOOK SPACING

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MOPAF
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MOPAF

• CURRENT STATUS
• MOPAF CONSTRUCTION
• MARCH 2003 COMPLETION
• COMPARATIVE COATING PERFORMANCE TESTS
• (_at_ CTIO)
• SPECIMEN PREPARATION INITIATE MARCH 2003
• CONDUCT TESTS JUNE - AUGUST 2003 (ESTIMATE)

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MOPAF

• REVIEW
• VERSATILE/TRANSPORTABLE MODULAR POWDER,
  CONVENTIONAL COATING APPLICATION FACILITY
• STAND-ALONE OPERATION AT A DEPOT OR FIELD SITE
• INSTALLATION WILL NOT DISRUPT EXISTING PRODUCTION
  OPERATIONS
• PROCESS VALIDATION PRIOR TO COMMITTMENT TO
  POWDER TECHNOLOGY INTEGRATION OR CHANGEOVER
• PRODUCTION USE DURING INTEGRATION/CHANGEOVER

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MOPAF

• QUESTIONS ??