What Does
Tie-Coat Mean?
A tie-coat is a layer of coating that acts as a bridge between a primer or undercoat and a finished coating layer. The tie-coat provides a transitional layer that bonds or improves the adhesion of the two separate coatings. This type of coating is so-called because it "ties" adjacent layers together.
Corrosionpedia Explains Tie-Coat
One of the most crucial properties of paints and coatings is adhesion, which refers to the strength of the bonds between coating layers. Adhesion failure occurs when either the bonds fail, or the adhesive loosens from the substrate. Loss of adhesion can be observed in several ways, such as:
- Cracking
- Sagging
- Running cissing
- Blistering
- Peeling, and
- Flaking
Some coated surfaces are naturally slick or greasy, and therefore do not make good adherends. These surfaces must be properly prepared before another coating can be applied. The tie-coat act as "glue" that helps a new coating adhere to previous coating layers.