Definition - What does After-tack mean?
After-tack is a coating defect. After-tack occurs when tackiness becomes present after the coating material has already been set. After-tack usually occurs due to specific environmental conditions such as high humidity or heat. Some coatings are more prone to after-tack than others are.
Corrosionpedia explains After-tack
It is important to know the coating manufacturer's guidelines to avoid after-tack in various environments. After-tack can occur if a coating material is unsuitable for high heat or humid environments.
After-tack is characterized by its sticky feel. It can lead to a depletion of the coating material over time. If the coating is depleted too far as a result of after-tack, then the substrate may be subjected to corrosion. There are several tests that are used to ensure a coating is tack-free.