Underbody Coating

                                                                          UNDERBODY COATING

In the process of painting several layers of coatings are given over the surface of the car to make it suitable to withstand damage occurring by mechanical and chemical exposure. This coating process requires some additional coatings or different coatings depending upon the purpose for which it is served. The coating process which is done to underbody components between electrode deposition and primer coating processes is known as underbody coating. [ADVANTAGE] It is done to prevent the underbody components of the automobile from corrosion, chipping (scratches and wear occurring while rocking and stone strikes), heat resistance, noise resistance, vibration, and elimination of water leaks. Poly Vinyl Chloride (PVC) and acrylic resins are the materials used in the under-body coating. [DISADVANTAGE] The cost of the underbody coating will increase depending upon the surface area introduced for underbody coating processes.

                               

                                                                              Under Body Coating

Underbody components:

Rear Floor Panel, Tunnel, Front Shock Tower Wheel House, Front Side Rail, Rear Shock Tower Wheel House, Rear Seat Panel, Dash Cross Member, Rear Back Panel, Rear Side Rail, Rear Floor Cross Member, Side Sill Inner, Front Floor Panel.

Modern procedure for automotive coating processes:

• Pre-Treatment - The excess material is removed and the surface is cleaned to make it suitable for the coating process. The dirt and welding residue is cleaned and removed during pre-treatment. The pre-treatment also consists of 4 stages [Hot Water, Degreaser, Surface Conditioner, Phosphate] which are done before electrode deposition processes.
• Electrodeposition - The electrode deposition coat provides rust and corrosion protection. It is done over Body in White. The metal underbody and the frames are coated to prevent corrosion. While areas that are not coated are primed before applying the additional coating. 
• Rustproof materials [Sealers/PVC] - The underbody coating has some specific advantages when compared to that of electrode deposition. The underbody coating has noise reduction, vibration reduction, and anti chipping properties in addition to that of underbody coating. 
• Primer - The primer is applied over the top body of a car to improve weather resistance, improve appearance, chipping resistance, improve adhesion between electrodeposition coat and topcoat, and reduce the volatile organic compounds that cause the atmospheric pollution.
• Topcoat - The topcoat has two stages, they are base coat and clear coat. The base coat has the primary coloring pigment, while the clearcoat provides a protective coating against environmental effects, ultraviolet light degradation, unmatched color retention and a smooth even finish. 

Underbody coating methods:

• Rubberized underbody coating - It is mainly coated to the underbody to prevent it from scratches. Applying rubberized underbody coating is a convenient process. 
• Polyurethane underbody coating - Polyurethane-based underbody coating protects the lower surface or underbody of the vehicle from cracks and fractures. Paint can be directly applied after Polyurethane-based underbody coating.   
• Wax or Paraffin underbody coating - This type of underbody coating is applied to prevent the underbody surface from moisture. The major disadvantage of this process is this type of coating is not long-lasting but is affordable. 
• Asphalt-based underbody coating - Paint cannot be directly applied after Asphalt based underbody coating. It is a time-consuming coating process that is preferred for heavy-duty vehicles for its high protection capabilities than Rubberized underbody coating. However, this material has little rubber content for sound insulation.