A cross cut can be used to assess the resistance of a coating to separation from the surface below after a cross cut has been applied down to the level of that surface.
Good adhesion is important. Because if a coating is easily removed from a surface, this can no longer protect the surface below from environmental influences.
The international standard DIN EN ISO 2409 coating material – cross-cut test stipulates an empirical procedure for this.
In a cross-cut test six parallel cuts are applied using a template and defined cutter, down to the underlying surface, but without damaging it. The distance between the cuts is 1-3mm, depending on the coat thickness of the coating.
After this, six further cuts are applied at right angles, resulting in an even rectangular pattern.
All loose particles in the area of the cross cut are removed with a soft brush.
The test surface is then assessed by comparing with images in the table, depending on distance, cross-cut values of 0 to 5 are determined.
In the case of a multi-layer system it is also stated in which of the layers separation occurs.