Powder coating is the application of a dry paint in the form of a powder onto a surface using the principle of electrostatic charging. Powder may be a thermoplastic or a thermoset polymer. It is usually used to create a hard finish that is tougher than conventional paint. After the application process the paint is cured under heat to allow it to flow and form a “skin”.
Before applying the finish, the chosen part must either chemically or mechanically cleaned, removing dirt, oils, old, finishes, and oxidation. Poor surface preparation results in powder coating problems, which is because of impurities and poor adhesion between the powder and the metal base.
Rainbow uses several cleaning methods for powder coat prep depending on size, material, cleanliness, etc. Because we do so many metal finishes in house we have cleaning methods for any metal at our disposal. Our main method utilizes a phosphate coating followed by a quick dry in the oven for Ferrous or Iron based items or an etching, degreasing combination with chromate conversion process for aluminum.