Standard Practice for Outdoor Evaluation of Wet Stack Storage Conditions on Coil-Coated Metals

Importancia y uso:

4.1 This practice provides for periodic testing for resistance to wet conditions during storage to compare the relative performance of specific combinations of coatings, substrates, and/or pretreatments used on coil-coated metal. The results must be considered relative and do not indicate absolute performance.

4.2 When stored improperly, coil-coated building panel stacks can be exposed to rainwater, which flows into gaps between panels by capillary action or gravity, and remains in the gaps because of poor drainage conditions. Such a condition is known as a “wet stack” and may cause blistering and corrosion of the painted surfaces. This practice simulates such improper storage conditions.

4.3 Because the outdoor environment shows year-to-year seasonal and geographic climate variation, the absolute amount of degradation based on corrosion and blistering may vary (see Appendix X1).

4.4 Temperature, rain, humidity, and storage practices 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 G7.

4.5 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.

Subcomité:

D01.53

Referida por:

D3794-22

Volúmen:

06.02

Número ICS:

77.060 (Corrosion of metals)

Palabras clave:

blistering; coil-coated; corrosion; wet stack;