A clay bar is a tool used to remove embedded contaminants such as iron, sap, dirt, road film, overspray, etc. from your car’s paint, glass, or metal. It is made from a synthetic material with a clay-like consistency, hence the name clay bar. It works by using micro-abrasives within the sticky clay and can come in different levels of abrasiveness such as fine, mild, or aggressive depending upon the difficulty of contamination that needs to be removed.
Using a clay bar is a method that should only be done to your car when necessary to avoid potential scratching of the paint. Proper lubrication will help by allowing the clay to glide over the surface smoothly and effortlessly. This allows the clay to grab onto the contamination and pull it off.
There are some simple ways to determine if your car needs to be clayed. One way is simply looking to see any stuck on overspray or specks of sap or tar. The other is by running your hand along the surface of the paint and determining whether it feels rough or smooth. Ideally, you would want the paint to feel as smooth as glass.
How your car is parked during the day and night will greatly affect how often your car will need to be clayed. Try to avoid parking under trees, around construction, and/or railways and bridges.
My favorite clay bar is Meguiar’s Mild Clay Bar