This National Association of Corrosion Engineers test method was prepared by Task Group T-1G-12 of Unit Committee T-1G on Protective Coatings and Nonmetallic Materials for Oil Field Use and is issued by Group Committee T-1 on Corrosion Control in Petroleum Production. The standard lists selected alternative methods of screening protective coaling systems in order that the test results may be evaluated on a comparative basis with results from other protective coating system tests.
Almost every component of offshore platforms and equipment requires some type of coating system either for protection from environmental deterioration or for aesthetic reasons. The variety of test procedures and types of tests used for screening atmospheric surface coating systems are so numerous that, in many cases, the results between different laboratories cannot be compared quantitatively, thus emphasizing the need for an effective and well-defined basis for the selection of suitable coating systems. This standard lists four of the main accelerated test procedures used by offshore operators for evaluating protective coating systems for use on offshore structures.
1.1 The most commonly used tests to evaluate atmospheric surface coatings are: (1) atmospheric exposure; (2) coating properties such as chemical, abrasion, and temperature resistance; and (3) accelerated tests such as the carbon arc radiation-water spray, intermittent immersion, and salt spray (fog) tests. Determination of coating properties, such as hiding power, pigment and vehicle, percent solids by volume and weight, etc., are supplementary toperformance tests and are listed here for those who may wish to use them as guides.
1.2 Atmospheric exposure tests, such as ASTM D 1014 and NACE Standard RP0281-86 are excellent and are recommended for long-term study of a coating's performance. The test exposure site must be as severe as the actual service environment anticipated. Atmospheric exposure tests require a number of years of exposure to the elements for comparison of test results.
1.3 Information on a coating's properties is generally made available by the coating manufacturer or supplier. This information is offered in good faith with a statement of product quality as delivered. The manufacturer of protective coatings usually has no control over the application of the material with respect to factors such as the contractor's equipment, weather conditions, job location, etc. or the condition of the surface prior to application.
Historical Document 1988