Methods of forming composite coatings

A method of forming a composite coating upon the surface of a substrate, comprising the steps of:

• (a) applying a first powder base coating composition to the surface of the substrate to form a first base coat;
• (b) applying a second powder base coating composition to the first base coat to form a second base coat;
• (c) applying a liquid or powder top coating-composition to the second base coat to form a transparent top coat and thereby form a composite coating;
• and
• (d) heating the composite coating so as to substantially cure the composite coating;
• the application and heating steps being conducted in either of the following ways:
• (1) applying the second base coating composition comprising an effect pigment in flake or platelet form to the first base coat prior to heating the first base coat and then heating the first and second base coats to a temperature sufficient and for a period of time sufficient to melt and substantially level the second base coat composition and allow migration of the effect pigment to a surface region of the second base coat but not sufficient to cause the second base coat to cure;
• and
• (2) applying the top coating composition to the second base coat after the heating step and heating the resultant composite coating at a temperature and for a period of time sufficient to substantially cure the entire composite coating;
• or alternatively,
• (3) applying the first base coating composition to the substrate to form the first base coat and heating the first base coat to a temperature sufficient and for a period of time sufficient to melt and form a generally continuous film of the first base coat;
• (4) applying the second base coating composition comprising the effect pigment to the substantially cured first base coat to form a second base coat and heating the second base coat for a period of time sufficient to melt and substantially level the second base coat composition and allow migration of the effect pigment to a surface region of the second base coat;
• and
• (5) applying the top coating composition to the second base coat and heating the resultant composite coating at a temperature and for a time sufficient to substantially cure the composite coating.