Plastic Parts Paint Repair - Repair Processes

Many plastic parts are used for exterior parts of a vehicle. In addition to sheet metal repairs, it is sometimes necessary to repair plastic parts. The major large plastic parts include: bumpers, side sill garnishes, and spoilers. They may be constructed of PP, ABS, PC, or nylon-polyester-based materials. In many damage situations, plastic part replacement is preferred over repair.
Before attempting repairs, identify the plastic part’s construction and select the most appropriate repair materials.
Follow the manufacturers’ instructions for the repair materials.
Be careful to avoid part deformation and damage during forced-dry with heat during the repair process.

1. PP (Polypropylene) Bumper Repair Processes
Example of damage: Scratches and hairlines on PP bumper.
1.
Preparation and cleaning:
Wash the damaged area with water.
Thoroughly clean both the front and rear sides of the damaged area using a degreaser to remove wax and oils.
2.
Stand and study raw surface.
Featheredge the damaged area using P80 to P120 sandpaper.
Then degrease the surface.
3.
Application of primer.
Apply primer for PP bumper in the damaged area where filler will be applied.
4.
Mix the filler and hardener.
5.
Filler:
Fill in the damaged area using epoxy-type body filler.
Restore the part's original shape by applying sufficient filler to the damaged area using 2-3 separate thin coats.
6.
Standing and surfacing:
Rough sand with P120 sandpaper first and finish sand the surface with P180 to P240 sandpaper.
Use the wet sanding method when possible.
7.
Refinish the part (base coat/clear coat).