How can I tell if the powder is cured?

Without the use of specialised lab equipment it can be difficult to ascertain whether a powder coating is fully cured using only one method.

Different powder chemistries result in coatings with different finished physical and chemical properties.? For instance fully cured standard architectural polyesters will pass the falling weight test, however so-called superdurable architectural polyesters will crack.? This does not mean that the superdurable systems are less well cured.

However, for polyesters and epoxy-polyester hybrids a very useful and quick test is the solvent rub test.? Here, a rag dipped in methyl ethyl ketone (MEK) is rubbed back and forth across a small area (3-4 inches) 20-50 times.? A cured system will show little or no staining on the rag and the surface, whilst softened, will not scratch down to the substrate surface.