Webb

Single Coat & Rapid Cure Tank Coating Systems: 

Single Coat & Rapid Cure Tank Coating Systems Improved Tank Preservation Processes April 2004

Program Team: 

Program Team Program Sponsor Office of Naval Research Transition Sponsor/Materials Technical Authority Naval Sea Systems Command 05M Fleet Demonstration Partners COMNAVSURFLANT, COMNAVSURPAC COMNAVAIRLANT, COMNAVAIRPAC Technical Development and Implementation Labs Naval Research Laboratory, Code 6130 Naval Surface Warfare Center, Carderock Division, Code 613 Naval Research Laboratory Arthur A. Webb (202) 404-2888, awebb@ccs.nrl.navy.mil Paul Slebodnick 202-404-7298, Slebodnick@nrl.navy.mil Bill Groeninger 757-652-4838, Groeninger@ccs.nrl.navy.mil Naval Surface Warfare Center Bill Needham 301-227-5034, NeedhamWD@nswccd.navy.mil Rich Hays 301-227-5135, (HaysRA@nswccd.navy.mil

Program Objectives: 

Program Objectives Develop Single Coat and Rapid Curing Coating Systems to Reduce Labor and Time Associated with Tank Preservation Replace Current 3 Coat System Coating Systems with Edge Retention Environmental Compliance High film build in single application Tanks can be returned to service quickly Assess performance of coating systems Industrial application Actual service conditions Determine application limitations Representative service Range of complexities Multi platform applications- Amphibious, Carrier, Combatant Ships Low complexity for initial installations Increasing complexity as application experience increases and producibility issues are addressed Tanks scheduled for preservation Select tanks in work package designated for represervation Program provides funding for coating application, coating, tech assistance, and QA Cost Sharing with Fleet funding for surface preparation

Background: 

Background Definitions Single Coat A single application product with shorter production cycles Currently employing solvent-free polyurethanes Rapid Cure A multiple application product with shorter cure and overcoat characteristics resulting in reduced production cycles Currently employing solvent-free epoxy coatings

Cure Speed Classification: 

Cure Speed Classification General classification of coatings based on cure times Typical cure times at various temperatures for coating types

Slide6: 

Single Coat Application Not a “single pass” application Process is the application of a polyurethane system One complete coating system during work shift Operation consists of three distinct coating applications each within perspective overcoat window for product Work progresses in “sections” within tank When section completed, application moves to next section Allows for real-time (concurrent) QA/QC

Slide7: 

Application Sequence 1 1 2 2 3 3 1 Completed 2 Completed 3 Using a Single Coat System Sequence Approach: 2-10 minutes between sections Done! All inclusive process, no leaving tank between subsequent coats First Pass Second Pass 3rd Pass (Completed) Legend

Current Single Coat Candidates: 

Current Single Coat Candidates Futura Protec II PW-ER MIL-PRF-23236 testing completed, passes all tests SW, Fuel, Comp Fuel, CHT, PW Futura Futurathane 527 Initial MIL-PRF-23236 testing underway Madison Chemical Industries Corrocote II Progressing with 23236 laboratory qualification SW, Fuel, Comp Fuel, CHT, PW Edge retention of first and second versions failed 4rd version ER under review Product not yet qualified Polyurethane Systems

Current Rapid Cure Candidates: 

Current Rapid Cure Candidates Sherwin-Williams Fast-Clad Progressing with 23236 laboratory qualification SW, Fuel, Comp Fuel, CHT No potable water Product not yet qualified International Intergard 783 MIL-PRF-23236 testing initiated Aug 03 SW, Fuel, Comp Fuel Sigma EX 1762 Initial MIL-PRF-23236 qualification underway Formulated for all tank applications, except potable water

Current Rapid Cure Candidates: 

Current Rapid Cure Candidates Curing Performance for Current Fast Cure Candidates ND= no difference or change from dry hard reading coatings were cured through at the dry hard measurement time

Single Coat Demonstrations: 

Single Coat Demonstrations USS GUNSTON HALL (LSD-44) May 2002 Madison Marithane 1 Tank: 3-121-1-W USS WHIDBEY ISLAND (LSD-41) Aug 2002 Madison Marithane 2 Tanks: 3-129-1-W & 3-103-1-W USS GEORGE WASHINGTON (CVN 73) June 2003 Madison Marithane 1 DC Void: 3-123-1-V USS TORTUGA (LSD-46) Nov 2003 Futura Protec II 1 Tank: 5-140-1-W USS ASHLAND (LSD-46) Jan 2004 Futura Potable Water 2-Tanks: 6-41-1-W & 6-41-3-W Successive demonstration of same product involves tanks with progressively higher complexity and size

Slide12: 

Corrosion Sensors USS GUNSTON HALL LSD-44, Single Coat Application Insertable Stalk Inspection Sys (ISIS) Coatings Assessment Images In-Service Inspection, 6 months

Slide13: 

USS WHIDBEY ISLAND LSD-41, Single Coat Application Aug 2002 PMA, NORSHIPCO VA Seawater Ballast Tank 3-129-1-W & 3-103-1-W Application of Madison Marithane II Ultra Polyurethane

Slide14: 

USS TORTUGA LSD-46, Single Coat Application Futura Protec II applied in Tank 5-140-1-W , September 2003

Rapid Cure Demonstrations: 

Rapid Cure Demonstrations USS WASP (LHD-1) June 2003 Sherwin-Williams Fast Clad 1 Tank: 5-104-1-W USS TORTUGA (LSD 46) Nov 2003 Sherwin-Williams Fast Clad 2 Tanks: 5-125-1-W, 5-129-1-W USS ASHLAND (LSD-46) Jan 2004 Sherwin-Williams Fast Clad 4-Tanks: 3-98-1-W, 3-103-2-W, 3-129-2-W, 5-129-2-W Successive demonstration of same product involves tanks with progressively higher complexity and size

Slide16: 

USS WASP LHD-1, Rapid Cure Application Sherwin-Williams Fast-Clad applied in Tank 5-140-1-W , 12 June 2003

Slide17: 

USS TORTUGA LSD-46, Rapid Cure Application Sherwin-Williams Fast Clad applied in Tank 5-129-1-W , September 2003

Demonstration Process Requirements: 

Demonstration Process Requirements Surface Preparation SSPC SP-10 Conductivity <30mS/cm Profile 2-4 mils Environmental Control 50% RH maximum Dew point and ambient temperature >5o difference Certified applicator Completed training and demonstrated proficiency prior to commencement of job Coating application Holiday inspection on all angles and flange backsides Development of optical holiday detection techniques

Lessons Learned: 

Lessons Learned Single Coat systems exhibit propensity for rapid turn-around Tank can be completely coated and finished in one day Applicator training is absolutely essential Urethane systems less user friendly Requires plural pump and dual feed or impingement mix gun Coating is susceptible to moisture during application Rapid cure systems allow for reduced maintenance cycle Painting cycle time can be significantly reduced Applicator training less critical but necessary for plural component usage. Epoxy-based systems more user friendly Uses plural pump with single feed guns Less affected by moisture during application

Lessons Learned: 

Lessons Learned General Product Selection Guidelines

Need for Improvement: 

Need for Improvement Single coat polyurethanes Curing speeds extremely attractive Low temperature capabilities also of interest Solvent free formulations ideal for shipbuilding and repair However current polyurethane systems not ideally suited for marine and industrial application environment Poor control of overcoat windows Susceptible to application errors Can exhibit limited adhesion Limited chemical resistance (fuel and alkaline conditions) Corrosion inhibition properties can unpredictable Formulation difficulties Limited raw materials base (resins) New resin technologies needed Need corrosion inhibition, chemical resistance and adhesion of amine-cured epoxies with the rapid cure properties of a polyurethane

New Technology: 

New Technology NRL Novel Resins Functional polyol resins synthesized from current widely available raw materials Solvent free Cured using all commercial isocyanates Aromatic for chemical resistance Aliphatic for weatherability

Background: 

Background Current high solids and solvent free polyurethanes Polyether polyol blends Low viscosity Moderate moisture absorption (polyether backbone) Low to medium isocyanate demand Chemical resistant linings using aromatic isocyanates Low molecular weight acrylic or polyester polyols High viscosity Moderate moisture absorption Poor alkaline resistance (acrylic side chains & ester backbone) Low isocyanate demand Used for weatherable coatings (aliphatic isocyanate cured)

Novel Resins: 

Novel Resins Modified aliphatic backbone Alkaline resistance Low moisture pick up Primary and secondary hydroxyl functionality Primary OH for reaction Secondary OH for adhesion Solvent free Low and medium viscosity Medium to high isocyanate demand Enhanced chemical resistance (aromatic isocyanate)

Standard Features: 

Standard Features Solvent free Requires no solvent during manufacturing Rapid cure system ~30 Minutes @ 25C Instant cure system < 1 minute @ 25 C Variable Viscosity < 100 Cps for weatherable systems 10,000 Cps for chemical resistant systems High adhesive strength >2000 psi

Special Features: 

Special Features Zero VOC No solvents employed in manufacturing or application Variable functionality Equivalent weights ranging from 76 to 250 Gloss retention Comparable to acrylic polyurethanes Chemical Resistance Comparable to current epoxies Rapid cure capability Controllable via structure and catalyst levels

Physical PropertiesComparative Properties of NRL Resin Systems: 

Physical Properties Comparative Properties of NRL Resin Systems

Physical Properties: 

Physical Properties Viscosity vs. Temperature for 3 Systems* * Constant shear rate of 1333/s

Mechanical Properties: 

Mechanical Properties Effect of Post-Cure Baking 1 hr @ 100C Tensile Values of NRL Resins Compared to Epoxy* * Bis-A Epoxy cured with aliphatic polyamine Tensile Strength (psi)

Adhesion Performance: 

Adhesion Performance Comparison of NRL Systems to Commercial Epoxy

Slide31: 

Chemical Resistance Methanol and Xylene Resistance Compared to Commercial Epoxy Systems

Weathering Resistance: 

Weathering Resistance Systems Cured with Desmodur N3600 Note: no light stabilizers added

Targeted Uses: 

Targeted Uses Solvent Free Rapid Cure Nonskid Solvent Free Exterior Topcoat Casting Resin and Thermal Barriers Solvent Free Tank Lining

Comparative Properties: 

Comparative Properties NRL System Design Features Good color and gloss retention Solvent free aliphatic topcoat Good hydrocarbon fuel resistance Solvent free aromatic system Excellent direct to metal adhesion (self priming) Good cathodic disbondment resistance (hydrolytically stable)

Coatings Formulation: 

Coatings Formulation Resin system can be synthesized by any well equipped coating/resin manufacturer Specialized reactors and handling equipment not required Compatible with most pigment materials Utilizes standard production processes Accepts most pigment types High flexibility non-skid

Summary: 

Summary Points of Contact NRL Technology Transfer Office Jane Kuhl (202) 404-8411 Center for Corrosion Science and Engineering Arthur Webb, Head, Marine Coatings Section (202) 404-2888; awebb@ccs.nrl.navy.mil Jozef Verborgt, Marine Coatings Section Consultant (202) 404-3858; jefverborgt@aol.com Keith Lucas, Branch Head, Center for Corrosion Science and Engineering (202) 767-0833; klucas@ccs.nrl.navy.mil