Ultimate Guide to Removing Fish Eyes from Automotive Paint

02/14/2024

Eliminating Fish Eyes in Polyurethane-Based Automotive Paint

Fish eyes disrupt the smoothness of a paint job, creating unsightly blemishes that detract from the vehicle's appearance. Understanding the root causes and solutions is essential for painters aiming for perfection.

Causes of Fish Eyes

Fish eyes are primarily caused by surface contaminants that repel the paint, such as:

  • Oil and Grease: Residues from automotive oils, greases, or silicone-based products.
  • Wax and Polishes: Waxy substances or polishing compounds that haven't been thoroughly removed.
  • Airborne Contaminants: Particles from aerosol sprays, silicone-based products, or even certain types of air fresheners used in the painting environment.

Preventing Fish Eyes

Prevention is the best strategy to avoid fish eyes:

  • Thorough Cleaning: Before painting, clean the surface meticulously with a high-quality degreaser or solvent designed to remove oils, waxes, and silicones. Repeat the cleaning process if necessary to ensure all contaminants are removed.
  • Use a Tack Cloth: After the solvent has dried, use a tack cloth to pick up any remaining dust or fine particles that could cause fish eyes.
  • Control the Environment: Keep the painting area clean and free from airborne contaminants. Avoid using silicone-based products or aerosols in or near the painting environment.
  • Filter Air Supply: If using a compressed air system for painting, ensure it's equipped with filters to remove oil and moisture from the air supply.

Correcting Fish Eyes

If fish eyes appear during your paint job, all is not lost. Here's how to correct them:

  • Stop Painting Immediately: Continuing to paint can worsen the problem. Allow the affected area to dry completely.
  • Sand the Affected Area: Once dry, lightly sand the area with fish eyes using fine-grit sandpaper (e.g., 600 to 800 grit) to smooth out the imperfections.
  • Re-clean the Surface: After sanding, thoroughly clean the area again with a degreaser or solvent to remove any remaining contaminants and sanding dust.
  • Apply a Fish Eye Eliminator: Some manufacturers offer products specifically designed to counteract fish eyes. If using, follow the manufacturer's instructions carefully and only in the affected area to avoid potential issues with paint adhesion or finish.
  • Reapply Paint: Once the surface is clean and prepared, carefully reapply the paint. Consider applying a light coat initially to observe if the problem persists and adjust your approach as necessary.

Conclusion

Fish eyes can be a frustrating obstacle in achieving a perfect paint job, but with careful preparation, environmental control, and the right corrective techniques, they can be effectively managed and eliminated. By understanding the causes and employing these strategies, painters can ensure a smooth, impeccable finish on vehicles painted with polyurethane-based automotive paint. Remember, the key to a successful paint job lies in the details and the commitment to cleanliness and quality at every step.