This practice provides for periodic testing to compare the relative performance of specific coatings, substrates, and/or pretreatments used on coil-coated metal for resistance to wet conditions during storage.

When performed in south Florida, this practice gives accelerated corrosion and blistering results relative to other locations within the continental United States.

This practice allows comparison of different coatings, substrates, and pretreatments when they are tested at the same time. The results must be considered relative and do not indicate absolute performance.

Because the outdoor environment shows year-to-year climatological, seasonal, and geographic variation, the absolute amount of degradation based on corrosion and blistering may vary (see Practice G 7).

Temperature, rain, and humidity are important factors in wet stack corrosion. Corrosion and blistering will accelerate with increased temperature. The preferred test location is south of 27°N latitude in Florida. Other locations may be used, but differences in temperature and moisture must be considered, and the amount of corrosion and blistering are expected to vary considerably with climate. Test sites must have the instrumentation to measure and record ambient temperature and rainfall as in Practice G 7.

This practice is not meant to support the field storage of coil-coated metal in any way other than what is recommended by the manufacturer.

1.1 This procedure describes the practice for determining relative performance of coil-coated metal in an outdoor wet stack testing environment.

1.2 The purpose of this test is to evaluate relative wet stack corrosion resistance and blistering. Substrates, pretreatments, primers, topcoats, and backers may be evaluated.

1.3 This test simulates coil or stacked building panel bundle storage at a job site in wet outdoor conditions. The results from panels tested during the same time period may be used to compare products as an indicator of actual field performance. Environments with higher temperature and moisture levels accelerate degradation.

1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.