2022-2024 Toyota Models Acid Rain Paint Damage TSB

Acid rain, formed from industrial chemical impurities in the atmosphere, can cause significant damage to vehicle paint finishes, particularly on horizontal surfaces like the hood, roof, and decklid. This damage often appears as stains resembling hard water spots, but unlike water spots, it cannot be removed by standard washing.

Acid rain can etch and soften paint, making traditional buffing or polishing ineffective and potentially causing further damage. This TSB, T-SB-0035-24, outlines specific repair methods for different levels of damage and supersedes Service Bulletin No. B091-020.

Symptoms

Owners of 2022-2024 Toyota models, including the Toyota Camry, may notice stains on their vehicle's paint surface that resemble hard water spots. These stains are indicative of acid rain damage. The damage is categorized into three main types:

• Minor damage: Requires only buffing for repair.
• Moderate damage: Typically requires neutralizing, color sanding, and buffing.
• Severe damage: Extends beyond 1/2 mil of clearcoat on pearl, metallic, or solid colors, necessitating neutralization, sanding, and repainting.

Important Warnings

Toyota highlights several critical warnings within the bulletin that owners and technicians should be aware of:

• Matte Paint Finishes: "The following process can be followed but with matte paint finish safe products ONLY. Using materials listed in this document can lead to paint damage to matte paints."
• Buffing Procedures: "To minimize the possibility of burning through or hazing paint surfaces, the following buffing procedures should be performed only by personnel experienced in rotary power buffing."
• Paint Film Thickness: When performing color sanding, "When performing this procedure, be sure to measure paint film thickness before, during (continuously), and AFTER sanding with a film thickness gauge to prevent excess paint removal." It also states, "The Ideal instruments to monitor paint film thickness during the color sanding operation are magnetic or digital thickness gauges."
• Sanding Direction: "ALWAYS sand in one direction and never in a circular pattern."
• Clearcoat Removal: For color sanding, "remove no more than a total of 1/2 mil of the clearcoat on pearl, metallic, and solid colors."
• Primer Coat Protection: "While it is recommended to sand down into the primer coat, the underlying electro deposition coat should NOT be exposed, since it provides essential corrosion protection."
• Buffer Pressure: "Use only LIGHT pressure on the buffer to prevent burn-through damage to the paint surface."

Diagnosis / Trigger Conditions

Identifying acid rain damage beyond minor cases often requires professional assessment. For moderate or severe damage, determining the actual depth of acid penetration usually involves color sanding a representative affected area until visible etching or depressions are gone. This is followed by measuring the amount of paint removed using a magnetic or digital-type film thickness gauge such as an Elcometer® 211 Mechanical Coating Thickness Gauge or a Fischer® Deltascope DMP30.

Repair Procedure Summary

The repair process for acid rain damage varies based on its severity:

Minor Damage Repair:

1. Move the vehicle out of direct sunlight to cool the paint surfaces.
2. Wash the vehicle with automotive liquid soap and water.
3. Neutralize any remaining acid with a solution of one tablespoon of baking soda per quart of water, applied with a commercial-grade plastic garden sprayer.
4. Rinse the vehicle thoroughly with fresh water.
5. Measure and record paint film thickness in affected areas.
6. Buff affected areas using appropriate pads and liquid compounds, periodically measuring paint film thickness. Lightly affected areas may use the 3M™ Perfect-It™ System.

Moderate Damage Repair:

1. Follow steps 1-4 for minor damage.
2. Soak #1500 or #2000 grit wet-dry sandpaper in a pail of clean water mixed with automotive washing soap.
3. Carefully color sand affected paint areas with the soaked sandpaper and a soft foam rubber sanding pad, frequently applying clean water and wiping down sanded areas.
4. Install a recommended buffing pad and set the buffer speed to 1200–1800 rpm for foam pads or 1500–1800 rpm for wool pads.
5. Apply buffing/polishing material sparingly and buff the area until the haze is almost gone.
6. Inspect for remaining acid spots; re-sand and polish if necessary, continuously measuring paint film thickness.

Severe Damage Repair (Requires Repainting):

1. Wash the vehicle with automotive soap and water, then rinse with deionized water. Clean affected areas with a silicone/wax remover (e.g., DuPont 3939, PPG DX330/DX380).
2. Completely sand affected areas with a dual-action sander to eliminate depressions.
3. Finish sanding with wet-dry sandpaper as recommended by paint manufacturers.
4. Wash and rinse the vehicle again with deionized water.
5. Clean sanded areas with an appropriate silicone/wax remover.
6. Apply a quality urethane enamel color coat or base coat/clear coat for maximum durability, following the paint manufacturer's recommendations.

Required Tools or Parts

To perform these repairs, technicians will need specific tools and materials:

• Liquid Automotive Washing Soap
• Baking Soda
• Water Pail
• 3M™ Finesse-It™ II Machine Polish (or Equivalent)
• 3M™ Perfect-It™ System (or Equivalent)
• 3M™ Finesse-It™ II Wool Pad (or Equivalent)
• 3M™ Perfect-It™ Foam Pad (or Equivalent)
• #1500 or #2000 Grit Wet-Dry Sandpaper
• Variable Speed Rotary Buffer (1200 - 1800 rpm)
• Elcometer® 211 Mechanical Coating Thickness Gauge, Magnetic (or Equivalent)
• Fischer® Deltascope DMP30, Digital (or Equivalent)
• Commercial grade plastic garden sprayer
• Soft foam rubber sanding pad
• Silicone/wax remover (e.g., DuPont 3939, PPG DX330/DX380)

Owner Action

To minimize the risk of acid rain damage, especially for your Toyota Camry, perform frequent vehicle washing, even daily during periods of high heat and humidity. This is particularly important in geographical areas known for high frequency and concentration of acid rain and industrial fallout. If you notice any signs of acid rain damage, contact your authorized Toyota dealer. They have the necessary tools and trained personnel to properly diagnose and repair the issue according to the procedures outlined in T-SB-0035-24.

NHTSA ID: 11003589