Adhesion Testing on Steel PaintSquare（钢铁PaintSquare附着力测试）.pdf

ApplicatorTrainingBulletin Adhesion Testing on Steel S uccessful corrosion protection of This month’s column was written by Lloyd M. Smith, steel depends on good adhesion of Ph.D., of Corrosion Control Consultants and Labs, Inc., a coating to the substrate. Adhesion test- ing determines how well a coating is Herndon, Virginia, USA. bonded to the substrate (i.e., whether it ✔ is anchored to the substrate itself or just to a thin layer of material on the surface of the steel). the blade. When this is done with a sharp blade and a lot There are various reasons for wanting to evaluate adhe- of pressure, a well-adhered coating may slice, but it will not sion. The specifier and contractor would want to assess ad- disbond from the surface. hesion when considering or performing overcoating work The knife adhesion test is subjective, and experience is the because the new coating may act more like a paint stripper best teacher. It’s a good idea to run this test on all sorts of than a protective coating if adhesion of the existing coating coatings, especially the ones that are going to be removed. system is poor. Another reason for testing adhesion is for bidding purposes. Knowing the adhesion of the existing Tape Test coating will tell something about production rates that can A more formal knife adhesion test is the tape test. The incisions be achieved. Adhesion is sometimes measured during ap- are made the same as th