3.1 Prepainted metal is supplied as a painted coil, and it is fabricated into a finished part. The fabrication process induces stress to the paint system. To determine if this stress will lead to a failure in service, it is common to immerse the stressed sample in boiling water. If no failure occurs (see 7.4) after exposure to boiling water, it is very unlikely that a failure will occur in the field.

This practice establishes the standard procedures for evaluating the resistance of pre-stressed prepainted metal panels to cracking and loss of adhesion, or both, after accelerated aging by boiling water. This method shall require the use of boiling water bath, 10x magnifier, Scotch #610 adhesive tape or its equivalent, and deionized or other water as reagent.

1.1 This practice can be used to evaluate the resistance of a pre-stressed prepainted metal panel to cracking and loss of adhesion, or both, after accelerated aging by boiling water. Most coil coated products are formed and bent into specific shapes to produce a final product. These operations introduce stresses, which may be relieved by cracking of the coating after aging.

1.2 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.