The formation of local concentrations of moisture under the applied coating that is revealed as a form of fine bubbles on the surface of the top coating.
- insufficiently cleaned surface,
- wet sanding of polyester materials,
- water in the installation of compressed air,
- too thin coat thickness leading to increased permeability of moisture.
- thoroughly clean the surface before applying coat,
- polyester materials should be dry sanded only,
- apply appropriate filters to stop moisture in the compressed air installation,
- observe recommended thickness of coating.