The surface of your paint is covered with tiny, microscopic contaminants like oil, grease, dirt, acid rain and fallout that sticks to the paint. Run your fingers over the surface. If you feel any bumps, drag or a sanding sound, you need to clay. Paint Cleaning Clay is an easy way to remove these contaminants without the abrasive nature of polish which removes paint. And, the clay will not remove your protective wax. It requires a lubricant to allow the clay to slide over the surface, and pick up the contaminants. Always use a soft, pliable clay as some are quite abrasive, and can scratch and or leave behind a residue. Once you try Paint Cleaning Clay, you’ll use it every time you polish or wax your vehicle.
This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2006/05/01/paint-cleaning-clay-tip