Plastics Painting System

General Information

Today you will find a variety of plastics on vehicles that require a special painting process. The following system allows a universal treatment of all coatable plastics. Polypropylene (PP) and Polyethylene (PE) in pure form are not paintable. These plastics are used almost exclusively in modified form however. They are then paintable, for example; PP/EPDM.

Processing

1. Preparation

Crucial for the adhesion to plastic is the basic preparation and removal of mold release agent.

• Scrub with soap and warm water, then clean with Universal Cleaner for plastics #541-30.
• Dry sand with 360/P600 or with a coarse sanding pad (in combination with #541-30)
• Clean again with Universal Cleaner for plastics #541-30

PUR-Foam and PA (Polyamide) should be tempered for 1 hour at 140° F/60° C to allow mold release and water to leave the pores.

• Then clean again with Universal Cleaner for plastics #541-30
• Dry with a lint free rag.

2. Adhesion Promoter

• Spray plastic part with 1 full coat of 1K Plastics Adhesion Primer #934-0 or Plastic Primer #934-200
• Flash off for 15 min. at 68° F/20° C.
• Apply fillers.

3. Filler

Filler that has been elastified for plastic painting is now applied.

• Spray entire part with 2 spray coats of:
  Rapid Filler #285-100 or
  Tintable Primer #285-75 or
  Primer Filler MS #285-22
  
  
• To elastify the filler, Elastifier Additive #521-111 must be added before the addition of the hardener. Generally, 25% by Volume (4:1) will be added, except for PUR soft foam parts, where 50% by Volume (2:1) Elastifier Additive must be added.
  Drying time:
  #285-75 3 hrs
  #285-100: 2 hrs at 68° F/20° C
  #285-22: 2 hrs
  
  
• After drying wet sand with 400/600; P800-P1200. Clean with water and dry thoroughly. When 50% of #521 -111 is added, drying-time will be 3 hrs (#285-100) and 4 hrs (#285-75). Wet on wet application is also possible. Allow 30 min. flash before top coat.

4. Top Coat

The following top coats can be used:
Urethane Acrylic #21-
Base Coat #54-, #56-, #59-, #69- #90-
Clear Coat #923-

In the #21 - line and the Clear #923-, Elastifier Additive must be put in before the hardener. Generally 25% is okay (same as above). On plastic parts as well as all PUR soft foam parts, the total film thickness should not exceed 4 mils; when this thickness is exceeded, the flexibility of the paint decreases.

No Elastifier Additive is added to basecoats, the Additive will only be added to the filler and the clear.

In general 25 % Elastifier Additive #521 -111 is required.

For PUR Softfoam parts, filler and topcoat need 50 % Elastifier Additive #521 -111.

Fiberglass parts that are easily identifiable do not need Plastics Adhesion Primer. Filler and top coat are applied without Elastifier Additive.