Abstract: A method and apparatus for testing the bond strength of materials such as a coating (101) on a substrate (100) wherein a stub (102) is placed on the coating (101) with a light curable adhesive (114) therebetween, the stub having a threaded section extending upwardly and being made of light transparent material, or a material that is at least partly transparent, a high intensity light (111) is positioned over the stub and operated to irradiate the adhesive through the stub to cure the adhesive, after which a force is applied to the stub in a direction normal to the coating tending to separate the coating from the substrate and is measured to determine the amount of force required. The apparatus includes a stand off ring (23) positioned around the stub for supporting cylinder housing (1) in spaced relationship to the coating, the housing having a cavity therein formed by inner (7) and outer (3) walls and a lower plate for receiving piston (9) therein retained by reaction plate (14).