The use of a fine grain clay bar may  be required to safely remove various contaminants from the finish such as paint overspray, rail dust, petro based chemical byproducts, ash, asphalt, rust, tree pollen and other organic materials picked up from road ways. Once a vehicle has been clayed, the micro pores in the vehicle’s finish will be free from contaminants, clean and more ready to accept and retain waxes and paint sealants.