How to test coating hardness using the Elcometer 3092 Sclerometer Hardness Tester
Knowing how well a coating has dried (or cured) is important, as it helps in determining whether the coating is fit for purpose, and if further coating inspections such as adhesion or pinhole testing may be performed. This is why we test coating hardness, as it helps to assess the degree of cure in coatings. Typically, the harder the coating, the more complete the cure.
A quick and effective way to test coating hardness is the Scratch method, which is completed using a sclerometer, also known as a hardness pen or durotest stylus. So, how does it work?
A sclerometer, such as the Elcometer 3092, measures the hardness of a coating by moving a hardened tip over the surface at a predetermined force. The coating is then visually examined for damage. The harder the coating, the greater the force required to scratch it.
To begin testing, you need to select a spring, and set the tip force. There are four springs of varying ranges available for use with the Elcometer 3092, and the stiffness of each is identified by their colour. Typically, you should start testing with the softest spring.
Remember, the scratch method is a destructive test and will damage the coating, so we recommend using test panels when testing using this method.