Method for coating metal part with synthetic resin including post coating step for heating coated part to eleminate voids

A method of applying a synthetic resin layer to an outer surface of a metal plate, comprising the steps of:

• heating said metal part to a temperature higher than a melting point of a thermally fusible synthetic resin;
• subsequently embedding the heated metal part within a powdered mass of said synthetic resin, thereby melting a portion of said powdered mass surrounding said outer surface of said heated metal part;
• holding said heated metal part with said powdered mass for a first time period sufficient to permit the molten portion of said powdered mass to be coated on said outer surface of said heated metal part as said synthetic resin layer;
• removing said metal part, coated with said synthetic resin layer, from said powdered mass;
• and
• maintaining the removed metal part at a temperature higher than said melting point and lower than a thermal decomposition point of said synthetic resin, for a second time period sufficient for air to escape from said synthetic resin coating and for preventing flow of said resin coating, said second time period being between 10 and 40 minutes, wherein said step of embedding the heated metal part within said powdered mass comprises immersing said metal part in said powdered mass while maintaining said powdered mass in a fluid state, and wherein said step of holding said heated metal part within said powdered mass includes maintaining said powdered mass in a non-fluid state.