TROPICAL EXPOSURE OF PAINT
THE NAVAL CIVIL ENGINEERING LABORATORY (NCEL) MAINTAINS THREE MARINE ATMOSPHERIC EXPOSURE SITES -- KWAJALEIN, MARSHALL ISLANDS; KANEOHE, HAWAII; AND PORT HUENEME, CALIFORNIA -- TO DETERMINE THE SEVERITY OF AN ENVIRONMENT ON A PAINT AND CONVERSELY THE ABILITY OF A PAINT TO GIVE LONG TERM PROTECTION IN A SELECTED ENVIRONMENT. KWAJALEIN AND KANEOHE ARE LOCATED IN THE TROPIC ZONE AND ARE CHARACTERIZED BY SLIGHT YEARLY VARIATION IN TEMPERATURE, WIND VELOCITES OF ABOUT 10 MPH, AND APPRECIABLE MONTHLY RAINFALL. ALL THREE TEST SITES HAVE HIGH MONTHLY AVERAGE RELATIVE HUMIDITY THROUGHOUT THE YEAR, BUT AT PORT HUENEME THERE IS A LONG PERIOD EFFECT OF WET, DRY, HOT, AND COOL WHICH DOES NOT PRODUCE THE RAPID DETERIORATION THAT THE MORE FREQUENT CYCLING PERIODS PRODUCE IN THE TROPICS. TESTS WERE CONDUCTED BY APPLYING THE PAINT SYSTEMS OVER SANDBLASTED STEEL TEST SPECIMENS. THE PAINTS WERE SCRIBED THROUGH TO THE BARE STEEL TO ACCELERATE PAINT FAILURE AND WERE EXPOSED IN REPLICATE AT THE THREE TEST SITES AT 45 DEGREES TO THE HORIZONTAL AND LOCATED NEAR THE SURF FACING THE PREVAILING WIND. FOR BOTH THE EPOXY AND VINYL PAINT SYSTEMS, THE PERIODS OF PROTECTION BECAME LONGER WHEN MOVING NORTH AWAY FROM THE CENTER OF THE TROPIC ZONE. THE PAINTS EXPOSED IN THE SCRIBED CONDITION LASTED FROM ONE AND A HALF TO THREE TIMES AS LONG AT KANEOHE AS AT KWAJALEIN; MUCH LONGER PERIODS OF PROTECTION WERE OBTAINED AT PORT HUENEME. USING THESE TESTS AT KWAJALEIN AND KANEOHE, NCEL DEVELOPED A RATING SYSTEM FOR DISTINGUISHING PAINTS.
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Authors:
- Brouillette, C V
- Publication Date: 1972-5
Media Info
- Features: Figures; References; Tables;
- Pagination: p. 28-30
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Serial:
- Materials Protection
- Volume: 11
- Issue Number: 5
- Publisher: National Association of Corrosion Engineers
Subject/Index Terms
- TRT Terms: Atmosphere; Failure; Paint; Rainfall; Ratings; Tropics; Weathering
- Subject Areas: Geotechnology; Highways; Materials;
Filing Info
- Accession Number: 00217211
- Record Type: Publication
- Files: TRIS
- Created Date: Jun 28 1972 12:00AM