Underbody Coating
Underbody Coating:
Is a coating that is applied to cars in the underbody of the car by means of spring it is used to protect the undersurface of the vehicle from corrosion & rust
Types of underbody coating;
1)Rubberized undercoating
2) polyurethane undercoating
3)wax undercoating
4)Asphalt undercoating
The modern automobile coating processes
1)Pretreatment
2)electrodeposition (ED)
3)sealer
4)primer
5)paint coat
1)Pretreatment:
Pretreatment is done by dipping the biw in the hot water, degreaser, surface conditioner, phosphate
2)electrodeposition (ED):
The metal underbody and frames of automobiles are coated to prevent corrosion, whereas other areas like the roof are not rust-proofed. When not coated to prevent corrosion, the structural metals are primed before applying additional coatings for cold roll sheet metal
3)sealer:
The third step is underbody coating (UBC), seam sealing using PVC (Polyvinyl Chloride) and urethane This sealing has multiple purposes , it is mainly applied in the weld area and the gap area between in sheet metal and the sealer is made up of rust prof materal
4)Primer
A primer consists of synthetic resin, solvent, and additive agent while some primers contain polyethylene, for better durability
Some metals, such as untreated aluminum, require a primer; others may not. A primer designed for metal is still highly recommended if a part is to be exposed to moisture. Once water seeps through to the bare metal, oxidation will begin Metal primers might contain additional materials to protect against corrosion, such as sacrificial zic
The primer fills and smooths minor imperfections and scratches that may be created during prior steps and by the intermediate sanding or grinding used to remove small imperfections
5) paint coat
paint is applied to the body in three layers
a)top coat
b)base coat
c)clear coat
applying three layers provides a protective coating against environmental effects, corrosion, and UV light degradation, promotes unmatched color retention, and provides a smooth, unblemished, and even finish
after all the process it goes to inspection
paint inspection
The quality of the paint is evaluated
paint inspection tools
1)elcometer is used to measure the thickness of the paint
Niton xlt
it is used to find the composition of the paint
