BS EN ISO 2409:2020 pdf download – Paints and varnishes – Cross-cut test
8.1.5 Number of determinations For routine testing, carry out a single determination. If a higher precision is required, carry out the test in at least three different places (see 7.1) on the panel. If the results do not match, the differences being more than one classification unit, repeat the test at three other places, if necessary using different panels, and record all the results.
8.2 Cutting the coating using the manual procedure
8.2.1 Place the test panel on a rigid, flat surface to prevent any deformation of the panel during the test.
8.2.2 Before the test, inspect the cutting edge of the blade and maintain its condition by sharpening or replacement. Perform the cutting manually, following the specified procedure. If the panel is of wood or similar material, make the cuts at approximately 45° to the direction of the grain.
8.2.3 Hold the cutting tool (5.2) with the blade normal (perpendicular) to the test panel surface. With uniform pressure on the cutting tool and using the appropriate spacing guide (5.3), make six cuts in the coating at a uniform cutting rate. The minimum cut length shall be significantly longer than the width of the multi-cut tool. All cuts shall mark or scratch the substrate. The depth of indentation into the substrate shall be as low as possible, however. For some substrates, e.g. plastics, there is the risk of tearing and flaking of the coating if the cutting tool penetrates the substrate too deep. If it is not possible, due to the hardness of the coating, to penetrate to the substrate, the test shall be declared invalid and so reported.
8.2.4 Repeat this operation, making a further six parallel cuts, crossing the original cuts at 90° to them so that a lattice pattern is formed.
8.2.5 Remove any loose paint from the area of cutting. Examples of suitable methods are given in Annex A.
The method for removing the loose paint shall be agreed between the interested parties and shall be stated in the test report.
8.3 Cutting the coating using a motor-driven tool If the cutting tool is used with a motor-driven apparatus, take care that the points described in the manual procedure are observed, particularly with respect to the number and spacing of the cuts and the number of tests. Each cut shall continue on beyond the outermost of the cuts perpendicular to it for approximately 1 mm to 2 mm to give definite intersection points. Remove any loose paint from the area of cutting. Examples of suitable methods are given in Annex A. The method for removing the loose paint shall be agreed between the interested parties and shall be stated in the test report.
9 Evaluation and expression of results Carefully examine visually the cut area of the test coating in good lighting as specified in ISO 13076, using normal or corrected vision or, if agreed between the interested parties, using a viewing lens (5.4). During the viewing process, where appropriate rotate the panel so that the viewing and lighting of the test area are not confined to one direction. Classify the test area in accordance with Table 1, by comparison with the illustrations. NOTE Additional guidance is given by the descriptions in Table 1.
For a multi-coat system, report the interface at which any flaking occurs.
If test results differ, report each test result. In the case of a multi-coat system, report the site of separation (between coats or between coating and substrate).
If delaminated flakes occur, interested parties shall agree on a pass/fail criteria.
10 Designation of the test result
A designation code which may be used to indicate the test result is given below. It shall comprise a reference to this document, a reference to the cutting tool used and the classification achieved. For example:
ISO 2409:2020 — 1a — 2
Number of this document — Cutting tool and method used — Classification
Key for cutting tool and method used:
1 Single-blade cutting tool:
1a Hand-held single-blade cutting tool
1b Single-blade cutting tool used in motor-driven apparatus
1c Cutter with rigid blade with V-shaped cutting edge (see 188.8.131.52)
2 Multi-blade cutting tool:
2a Hand-held multi-blade cutting tool
2b Multi-blade cutting tool used in motor-driven apparatus
See Table 1 for the classification of test results.