ZINC RICH PAINTS

ZINC-RICH PAINTED PANELS HAVE BEEN ON EXPOSURE IN ENGLAND AT AVONMOUTH AND BURRY PORT FOR 43 AND 42 MONTHS, RESPECTIVELY. THESE PANELS WERE PAINTED WITH THE FIRST SERIES OF MARINE AND STRUCTURAL STEELWORK PRIMERS CONTAINING EXTENDERS. BURRY PORT, THE COASTAL SITE, GAVE A MORE RAPID RATE OF CORROSION THAN DID THE AVONMOUTH SITE. AT BURRY PORT, ONLY TWO PRIMERS WERE RATED AS PROBABLY ACCEPTABLE: MICA AND ALUMINUM EXTENDERS, BOTH AT 12-1/2 PERCENT V/V AT 70 PERCENT POLYVINYL-CHLORIDE IN CHLORINATED RUBBER AS THICK FILMS. AT THE INDUSTRIAL AVONMOUTH SITE, A LARGE NUMBER OF THICK FILMS GAVE GOOD CORROSION RESISTANCE. THE ORDER OF PERFORMANCE WITH RESPECT OT EXTENDERS WAS CONTROL ZINC OXIDE, BARYTES, MICRONIZED DOLOMITE, MICA AND ALUMINUM. WITH INCREASED LEVELS OF EXTENDERS, BEST RESULTS WERE OBTAINED WITH THE CHLORINATED RUBBER BINDER. BETTER CORROSION RESISTANCE WAS OBTAINED WITH BARYTES THAN WITH ZINC OXIDE, PARTICULARLY IN THE CATALYZED EPOXY BINDER. THE RESULTS FOR OVER THREE YEARS TESTING OF A NUMBER OF COMMERCIALLY AVAILABLE PRIMERS ARE PRESENTED IN A TABLE. THERE IS SOME EVIDENCE THAT THE PARTICLE SIZE OF ZINC DUST HAS AN EFFECT ON THE MAXIMUM AMOUNT OF EXTENDER THAT CAN BE USED. THE RESULTS INDICATED THAT A HIGHER LEVEL OF ZINC OXIDE COULD BE USED WITH A LARGER PARTICLE ZINC DUST. A TEST SERIES ASSESSING THE EFFECT OF TYPE OF SILICATE ON CORROSION RESISTANCE HAS BEEN UNDER TEST FOR MORE THAN THREE YEARS. BEST RESULTS WERE OBTAINED WITH THE ALKYL SILICATE BINDER. GOOD CORROSION RESISTANCE WAS ALSO OBTAINED WITH QUATERNARY AMMONIUM SILICATE AND TO A LESSER EXTENT WITH LITHIUM SILICATE. AS WITH ORGANIC PRIMERS, THE MAIN PROBLEM IN TOP COATING OF INORGANIC ZINC PRIMERS IS BLISTERING UNDER IMMERSED CONDITIONS. UNLIKE THE ORGANIC-BASED PRIMERS, HOWEVER, THE INORGANIC ZINC PRIMERS GAVE BETTER RESULTS IF WEATHERED BEFORE TOP-COATING. WEATHERING TESTS TO EVALUATE A RANGE OF AMERICAN ZINC DUSTS ARE NOW IN THE SECOND YEAR.

• Supplemental Notes:
  • Res Dig No 23, PP 10-13, 2 FIG
• Corporate Authors:

  Intl Lead Zinc Research Organization

  ,    
• Publication Date: 1969

Subject/Index Terms

• TRT Terms: Aluminum; Binders; Corrosion; Corrosion resistance; Corrosion tests; Crash exposure; Mica; Paint; Primers; Silicates; Weathering; Zinc
• Uncontrolled Terms: Exposure
• Subject Areas: Geotechnology; Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00216864
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 29 1994 12:00AM