Problem Solving Forum
March 2 - March 6, 2015
How do you adequately assess the adhesion of a newly applied coating?
Selected Answers
From
David Zuskin of Indepedent on
March 13, 2015:
Rodney, you might be looking at a first coat prior ...read more
Rodney, you might be looking at a first coat prior to a second coat and be concerned about first coat adhesion to substrate. You might be looking at an intermediate coat prior to a topcoat and question adhesion of the second coat to the first. If it is going to fail, let it fail cheap before you pile on more coats that all have to come off to get to the defective interface. Coating systems applied close to dry-to-recoat times happen fast sometimes. You might need to test a recent application.
From
David Zuskin of Indepedent on
March 10, 2015:
I will assume we are talking about a recent spray ...read more
I will assume we are talking about a recent spray application of a coating. Most of the time when the coating reaches "dry to recoat," brush and roll touch-up of the sprayed coat (fill in the blanks) begins. With touch-up in progress and material available, I perform a simplistic X-cut with a razor knife and pick at the intersection with the tip of the blade. Excellent adhesion is obvious, but some lack of adhesion of a “newly applied” coating may not really indicate a problem. Still, it may warrant a recheck once the coating has reached full cure (for the temperatures experienced). If I have performed an X-cut, I use a piece of sandpaper to fair the X-cut spot and have the painters touch up my test location.
From
Rodney White of Independent Consultant on
March 4, 2015:
The question itself is a bit problematic--how do y ...read more
The question itself is a bit problematic--how do you define a “newly applied” coating? Obviously, testing an uncured coating of any generic description would yield skewed results. Once the coating is cured, however, let the testing begin. ASTM lists a number of testing methods, depending on the coating and/ or substrate.