Let me ask one question. If the required range is 5mpa. Dolly has removed from the substrate on 6mpa, but it shows cohesive failure. Can we accept because it has removed from 6mpa.
It all depends on whether you accept cohesive failure at this value. In general, yes, if the result is 6 MPa / 870 psi and you have a minimum adhesion of 5 MPa / 725 psi in the specification, then the requirement is met.
Hi, what is the thickness of paint you have chosen? or how thick would you have painted the paint to be sufficient for this test? thank you in advance!
It is depending on type of paint, agreement with client and thickness in real-life application. If we compare set of paints in the lab conditions we use the same thickness ensuring comparable results.
The pull-off test is also used as a field method. However, we only use it under controlled temperature and humidity conditions in our laboratory. We do not perform field tests.