This Part specifies an empirical test procedure for assessing the resistance of a coating of paint, varnish or related product to cracking and/or detachment from a metal substrate when subjected to bending round a cylindrical mandrel under standard conditions.
1.2 For a multicoat system, each coat may be tested separately or the complete system be tested.
1.3 The method specified may be carried out:
— either as a "go/no go" test, by carrying out the test with a single specified size of mandrel, to assess compliance with a particular requirement, or
— by repeating the procedure using successively smaller mandrels to determine the diameter of the first mandrel over which the coating cracks and/or becomes detached from the substrate.
1.4 Two types of apparatus are specified. Type 1 being appropriate for use on test panels of thickness up to 0.3 mm, and Type 2 for use on test panels of thickness up to 1.0 mm.