Paints and varnishes. Cross-cut test

BS EN ISO 2409:2007, BS 3900-E6:2007 Paints and varnishes. Cross-cut test

BS EN ISO 2409 is an international standard that describes a test method for assessing the resistance of paint coatings to separation from substrates when a right-angle lattice pattern is cut into the coating, penetrating through to the substrate.

The property measured by this empirical test procedure depends, among other factors, on the adhesion of the coating to either the preceding coat or the substrate. This procedure is not to be regarded, however, as a means of measuring adhesion.

Where a measurement of adhesion is required, attention is drawn to the method described in ISO 4624.

Although the test is primarily intended for use in the laboratory, the test is also suitable for field testing.

The method described may be used either as a pass/fail test or, where circumstances are appropriate, as a six-step classification test. When applied to a multi-coat system, assessment of the resistance to separation of individual layers of the coating from each other may be made.

The test can be carried out on finished objects and/or on specially prepared test specimens.

Although the method is applicable to paint on hard (e.g. metal) and soft (e.g. wood and plaster) substrates, these different substrates need a different test procedure.

The method is not suitable for coatings of total thickness greater than 250 μm or for textured coatings. The method, when applied to coatings designed to give a rough patterned surface, will give results which will show too much variation.

BS EN ISO2409 has been revised, and the new edition includes changes for the requirements for the adhesive tape, and precision data have been added.

Contents of BS EN ISO 2409 include:

• Scope
• Normative references
• Apparatus
• Sampling
• Test panels
• Procedure
• Supplementary test conditions
• Evaluation and expression of results
• Precision
• Test report
• Bibliography

BS EN ISO 2409:2007 replaces BS EN ISO 2409:1995, BS 3900-E6:1992, which has been withdrawn.

Also available for paint and varnish:

BS 3900-0:2010 Methods of test for paints. Index of test methods