Ask the Expert Question-and-Answer Archive

by Ron Joseph

December, 2002

Adhesion Testing for Paints and Coatings Using the Pull Test

Q. We have been recently asked to perform ashesion pull tests on painted surfaces. I am concerned with the possibility of our using an adhesive on our test puck which is incompatible with the paint being tested. In this instance, we would be breaking down the paint composition prior to testing. Hardly a level playing field! I'm sure that thwere must be certain adhesives which are acceptable with an alkyd and unacceptable with oil base etc. Can you enlighten us on this matter ?

A. Have you thought of using a solvent free, two part epoxy adhesive or a solvent-free cyanoacrylate. I assume that neither will break down the coatings since in most cases the solvents are the components that would soften the underlying coating, such as an alkyd. I haven't read the ASTM method for the pull test, but I have to believe that this issue has already been addressed. You might call the adhesion testing vendors, such as BYK-Gardner, and Paul Gardner Company, for more information. I have looked into their catalogs and have seen that they supply both types of adhesive with their pull test instruments.