Paint adhesion testing

It is helpful in giving relative ratings for a number of coated panels showing significant differences in adhesion.

The tested materials are applied uniformly to flat panels, mainly some sort of sheet metal.

When the materials have dried, the adhesion is determined by pressing panels under a rounded stylus loaded with increasing weight until the coating is removed from the substrate surface.

The force that is applied gradually increases and is monitored until a plug of coating is detached or a previously specified value is reached.

There are two methods described in the ASTM Specification;[4] An X-cut is made through the film with a carbide tip tool to the substrate.