Good coating adhesion is vital to the success of a Cortec® Coating system—or any paint job, for that matter. Without it, the paint will peel off, and the surface will be unprotected. To prevent such premature failures, painters can now watch Cortec’s coating adhesion test demo video and follow the directions to make sure their paint job is headed for success!
When to Do Adhesion Testing
An adhesion test comes in handy when a painter is waiting to apply the second or third coat of paint but doesn’t know if the previous coat has cured. This is especially a problem in cool, damp weather, when water evaporation rates, and hence dry times, slow down. To be safe, it is often best for painters in these conditions to wait overnight before applying the next coat to make sure the first coat has had plenty of time to dry and cure. If time is limited, painters can do an adhesion test to see if the coating has already cured and is ready to topcoat. Adhesion testing is also important when coating over a previously painted surface; it can confirm that the old coating is still adhering and will provide a strong base for the new coating.
Two Ways to Test Adhesion
In Cortec’s demo video, Technical Services Manager and Cortec® Coatings expert, Rick Shannon, shows two ways to test adhesion. The first is to use an ASTM D3359 test kit complete with a cutter, a brush, and directions. The cutter cuts multiple lines through the paint at one time. Two perpendicular swipes with the cutter leave a nice crosshatched section with tiny squares that can be tested by applying tape firmly and pulling it off. Adhesion is calculated based on how many squares of paint come off. The rating system ranges from 0B adhesion (all the paint squares were pulled off) to 5B adhesion (no paint squares were pulled off). In the demo video, no squares of paint came off Rick’s test panel coated with VpCI®-395, giving it an excellent 5B adhesion rating.
Rick also demonstrated how to do the same basic test out in the field when a kit is not available. Instead of using a special cutter, the painter can simply make two perpendicular sets of 11 cuts with a utility knife and see how many paint squares come off with a piece of tape. If the adhesion is good and few to no squares of paint come off, the coating should be cured enough to repaint!
It’s Your Turn!
In the past, Rick often had to explain the coatings adhesion test individually to end users asking when it was okay to apply a second or third coat of paint. Now, Cortec® Coatings users can go directly to this demo video to see how it is done themselves or share guidance with their clients. Watch now to see how it is done! https://www.youtube.com/watch?v=XXVqiZeo4mI
Keywords: test coating adhesion, quick way to test coating adhesion, ASTM D3359, adhesion testing, prevent coating failures, paint dry times, coating over a painted surface, Cortec, VpCI, Cortec demo video
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