Rationale

The proposed change involves the deletion of Section A1.4.4 of Annex A1. The section requires that three 4?in. by 4?in. by 0.05 in. [100?mm by 100?mm by 1.3 mm] steel panels coated to a thickness of 10?mils ± 2 mils [250?µm ± 50?µm] be subjected to abrasion by a Taber abraser (Test Method D4060). The weight loss may not exceed 0.0007 oz [2 mg]/1000 cycles. This requirement for testing is recommended for deletion because the nature of the textured coating is such that the coating abrades the abraser, and the issue becomes not one of weight loss but of weight gain as debris from the abraser accumulates on the panels. As a result, the test does not evaluate the abrasion resistance of a textured coating.