Undercoating

Undercoating




1. Spraying primer
Primer is used to fill cavities in the putty and primer surfacer.
- Spray primer on the exposed area.
- Spray the 2-3 coats of primer on 2-3 coats over the area you applied putty.
- Apply primer to the back of the bumper if the damage is a tear or hole.
- Bumper primer (Reference)
- Warm the primer if the ambient temperature is below 50 degrees F (10 degrees C).
- Follow the bumper primer manufacturer's instructions.
- Use the spray gun and brush.

Drying

NOTE: Take care not to let the heat lamp deform the bumper during the drying process.

Dry the bumper primer thoroughly with an infrared dryer or other suitable method.




Drying Time:




2. Filling /Sanding
Apply putty to repair any holes or deep gouges.
- Apply the putty on the damaged area in 2-3 steps.
- Glue aluminum tape on the outside of the bumper, and apply putty from the other side of the bumper.
- Remove the aluminum tape after the putty dries, apply putty from the outside, and fill the hole.
Use a special polyester putty (Reference) and a putty knife.




3. Sanding
Sand the surface evenly, particularly at the area where the PP material and putty meet.
Use a flexible block and #240-#400-#600 sandpaper.

4. Air blowing /degreasing
Use alcohol, a tack cloth, and wax and grease remover.




5. Spraying primer surfacer

NOTE: Spray the bumper primer on the area where the PP material was exposed and the around the putty.

- Spray the primer surface wider then the putty and painted surfaces of bumper primer.
- Spray 2-3 coats to get 20-30 microns of thickness.
- Use the 2-component type primer surfacer (gray) and a spray gun.
- Follow the materials manufacturer's instructions.

Drying

NOTE: Take care not to let the heat lamp deform the bumper during the drying process.




6. Sanding

After drying, wet sand the area of the intermediate coat.
Use the #600 sandpaper.

NOTE: Do not use #600 or less.

7. Air blowing /degreasing
Use alcohol, a tack cloth, and wax and grease remover.
Also clean and degrease the surfaces where the masking tape will be attached.