Underbody Coating
Underbody Coating Process
Manual process - The person sprays the coat by lifting the vehicle to an appropriate height. Nowadays this is performed by High speed robots that ensures a thorough coating on intricate positions.
Another process is where the automobile frame is kept in a bath of liquid coat. The liquid in made to fall in a plent of amount and than the frame is allowed to get dry and the coat gets set on the frame.
Purpose of Underbody Coating:
This treatment is designed to provide long-term protection from rust to the under chassis. It protects the underbody substrates from:
- Environmental conditions
- Impacts
- Dampens sound and vibration
- Insulates against cold and heat
- Protects against Corrosion
- Seals off seams
- Hides welds, repairs & bodywork with spray
Types of Underbody Coating
- RUBBERIZED UNDERCOATING
- ASPHALT-BASED UNDERCOATING
- POLYURETHANE UNDERCOATING
- WAX OR PARAFFIN-BASED UNDERCOATING
Steps that are carried out before under body coating process these days :
1) Pre - Treatment
Pre-treatment removes & clean excess metal & forms an appropriate surface structure enabling bonding of a corrosion protection layer. It consists of cleaning the body surface to remove remaining oils from the staming process & welding residues through three primary liquid dip processes of degreasing, conditioning, & phosphating. Pretreament helps the primer to bond onto the metal. A phosphate treatment applies an inert layer of metal phosphate, providing resistance to corrosion spread.
Fig.1.0
2) Electrodeposition
E-coating involves dipping automobile bodies into the coating solution & passing an electric current through the body & the liquid ED paint solution. Because of the charged nature of this coating process, the ED paint penetrates into places a spray would not reach.
During operation, a mixture of resin, binder, & a paste containing the pigments is fed into the ED tank. The automobile body is lowered into the tank, & an electric current applied; the solution in the tank consists of 80-90% deionised water & 10-20% paint solids.The resin is the backbone of the final paint film & provides corrosion protection, durability, & toughness. Pigments are used to provide color & gloss. After E-coat, the automobile body enters a bake
oven, in which heating & keeping at a temperature of 160_C for 10 min causes film curing to promote maximum performance properties.
Fig.2.0
3) Underbody Coating
The third step is underbody coating & seam sealing using PVC. Fig.3.0 displays the lower door sections & rocker panel locations where PVC or urethanes are applied as an anti chipping protection, & shows the cross section of this layer with respect to the other coatings on the body parts.
Fig.3.0
Conclusion
Hence the underbody coating is very much required and also very important as It requires expert application, or it can crack, letting in moisture and cause other problems as discussed. This undercoating works best when applied to the undercarriage of a new vehicle.