Kia Sportage (2005+). Instruction — part 35

Plastic parts

61-3

Repair method for PP bumper

Damage to the bumper that reaches the surface of the polyporpylene cannot be fixed just by painting. Use the repair
methods shown below to repair damage that reaches the surface of the polypropylene.

1. Rough cut the damaged area 45

using a knife and then sand the angle smooth.

A

A'

B

B'

C

C'

D

D'

Hole

Section A-A'

Section D-D'

Section B-B'
Section C-C'

Crack

Scar

4

3

2

1

4

2

1

3

Cut with a knife.

Section

45

Make an angle with a sander.

Make an angle with a sander.

Surface of polypropylene

Section D-D'
Cut with knife.

C-C'

B-B'

A-A'

Angle of 45 is required for accumulation of polypropylene welding rod.

Upper layer(coating)

Primer surface layer

Primer layer

Polypropylene layer

61-4

Plastic parts

2. Welding damaged area

a) To repair cracked area, melt the area using a heat gun and attachment.

b) To repair a hole, remove oil from the damaged area and apply aluminum tape to the rear side of the damaged area.

3. Melt polypropylene welding rod using a heat gun and fill in the cracked area.

Notice
• Heat and melt the area indicated.
• Melt the welding rod carefully so that it does not over-melt. If the welding rod over-melts like jelly, the

welding strength will deteriorate.

• Use the heat gun 0.4~0.8 in.(10~20 mm) away from the repair area to be welded.
• Welding rod should not move until the welded area is cooled.

Heat gun

Apply on surface

Remove oil.

Melt here

Polypropylene welding rod

Tape

Plane view

Section A-A’

Polypropylene welding rod

Surface of
polypropylene

Polypropylene
welding rod

Melt here.

Polypropylene welding rod

Section A-A’

Apply aluminum tape on the rear side of the damaged area.

Surface of polypropylene

Section view after melt

Melt the surface using a heat gun.

A-A’

Section

B-B’
C-C’

Plastic parts

61-5

4. Grind polypropylene surface carefully. It melts easily due to the heat generated by friction. If melted, remove that

area. Also, grind the area where solvent is to be applied.

5. Apply polypropylene primer evenly with a brush over an area wider than the area to be repaired.

Dry it at 20

O

C(68

O

F) for more than 10 minutes.

6.

Mix main filler material and hardener at a ratio depending on paint specifications. Mix filler material and apply over

the damaged area.

Notice
• Mix main filler material and hardener so that no bubbles are made.
• Work immediately after mixing filler material because the filler material hardens quickly(in about 5 minutes).
•

•

•

Dry it at 20

O

C(68

O

F) for about 30 minutes before sanding.

Filler material consists of two types of epoxy.
When the filler material hardens, you will have a desirable finish with flexibility like polypropylene.
Use only filler material designed for use on polypropylene bumpers.

Do not grind continuously.

Area to apply solvent

Paint

Grind painted area and rough surface.

Apply primer wider than the area to repair.

Polypropylene primer

Filler material

Weld

Surface of polypropylene

Do not allow bubbles to be created.

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Plastic parts

7. Sand the damaged area with sandpaper using #180~#240 grit paper.

Notice
• The surface will not be even if excessive force is applied during sanding.
• If there is fuzz in the damaged area, heat it a little bit with a heater gun and melt it.

8. Degrease the painted surface.

9. Mix polypropylene primer and hardener at a ratio depending on paint specifications.

Spray polypropylene primer on the surface of the damaged area and the bumper.

10. Apply polypropylene primer.

Notice
• Use only water to clean after applying polypropylene primer. Solvent, if used, will melt the primer.

Use the primer within 16 hours after it is mixed.

Polypropylene primer

Primer hardener