GM Service Manual Online
For 1990-2009 cars only

Environmental Fallout (Acid Rain) Acid Rain

Caution: Refer to Clearcoat/Ultraviolet Screeners Caution in the Preface section.

Note: Always refer to the manufacturer's packaged instructions for the detailed procedures of materials used for compounding and/or polishing.

Since the severity of the condition varies from area to area, proper diagnosis of the contamination extent is critical to the success of the repairs. Perform the diagnosis under high intensity fluorescent lighting on the horizontal surfaces (hood, roof panel, rear compartment lid), after the surfaces have been properly cleaned by washing the vehicle with Liquid Wash and Wax GM P/N 1052870, or equivalent.

There are 3 basic types of acid rain damage:

Surface Level Contamination: May be repaired by simply washing the vehicle, cleaning the surface with a silicone wax and grease remover, neutralizing acidic residue, and finesse polishing--Refer to Surface Level Contamination Repair.

Clearcoat Etching: Slight etching is still noticeable after the above washing and finesse polishing procedure. Refer to Slight Clearcoat Damage - Wet Sanding, Finesse Polishing.

Basecoat Etching: Severe etching beyond the clearcoat into the basecoat in the affected areas will require refinishing. Refer to Basecoat/Clearcoat Paint Systems.

Surface Level Contamination Repair

  1. Thoroughly wash and dry the contaminated area with Liquid Wash and Wax GM P/N 1052870 or equivalent.
  2. Clean the affected area with silicone, wax and grease remover.
  3. Remove and neutralize acidic residue by cleaning the contaminated areas with a mixture of baking soda and water (1 tablespoon of baking soda per 1 liter or 1 quart of water). Rinse thoroughly and dry the panel completely.
  4. Apply finesse-type polish with a foam panel. If damage has been repaired, remove any swirl marks with a dual action orbital polisher and foam pad. Refer to Clearcoat Repair Specifications - 3M Products.
  5. If some damage remains, refer to Slight Clearcoat Damage - Wet Sanding, Finesse Polishing.

Slight Clearcoat Damage - Wet Sanding, Finesse Polishing

  1. Select a small contaminated test area.
  2. Film thickness should be taken prior to the sanding and polishing. Refer to Paint Gages.
  3. Wet sand and finesse polish the contaminated test area. Refer to Clearcoat Repair Specifications - 3M Products. If during the polishing you suspect or observe that etching has penetrated into the basecoat, too much clearcoat has been removed during sanding, or base color is transferred to the polishing pad during polishing, then the affected areas will require refinishing. Refer to Basecoat/Clearcoat Paint Systems.