To effectively remove contaminants using a clay block in car detailing, follow these steps:

1. Prepare the Surface: Wash and rinse your car thoroughly to remove loose dirt and debris. This prevents scratching when using the clay block.

2. Lubricate the Surface: Spray a clay lubricant or quick detailer onto a small section of the car's surface. This lubrication helps the clay block glide smoothly and prevents scratching.

3. Use the Clay Block: Flatten the clay block in your hand and gently rub it over the lubricated area using light to moderate pressure. Move the clay block back and forth in straight lines or a cross-hatch pattern.

4. Check for Smoothness: As you work, feel the surface with your hand to check for any remaining rough spots or contaminants. Continue until the surface feels smooth.

5. Rinse and Dry: Once an area is complete, rinse off any residue with clean water. Dry the surface thoroughly with a microfiber towel to prevent water spots.

6. Inspect and Repeat if Necessary: After claying, inspect the surface to ensure all contaminants have been removed. If there are still rough areas or contaminants, repeat the process in that specific area.

7. Apply Protection: After claying, it's recommended to apply a wax or sealant to protect the paint and maintain its shine.

By following these steps, you can effectively use a clay block to remove contaminants from your car's paint, leaving it smooth and ready for further detailing or protection. Regular claying helps maintain the cleanliness and appearance of your vehicle's exterior.