Don’t use an automatic car wash, because they tend to leave behind a lot of soap residue and other contaminants. In fact, most auto detailers will likely tell you to never use automatic car washes.
In the hands of an experienced auto detailer, medium grade bars usually won’t result in any marring, and can remove a great deal of contamination from a car that’s gone years without a “claying. ” However, especially if you’re a novice “clayer,” a fine grade bar is the safer bet. If the clay bar kit doesn’t come with a bottle of lubricating spray, buy a bottle that is the same brand as the bar. They’ll be in the same section of the auto supply store.
If you buy a larger bar, you can cut it into sections with a sharp knife and seal up the pieces you don’t need for later use. For example, you can cut a 6 oz (170 g) bar into 3 pieces, use 1 now, and seal the other 2 in zip-close bags.
At this thickness, 2 oz (57 g) of clay will create a disc that’s roughly equal to 3-4 finger-widths—which is a perfect size for “claying. ”
Start at a cleaner area of the car–like the roof or hood–and work your way to the dirtier areas–the front bumper, the bottoms of the door panels, etc. Your clay won’t get filled with debris as quickly this way. While some “clayers” claim that water works fine as a lubricant, you’ll likely get much better results if you use the lubricating spray that either comes with or matches the brand of your chosen clay bar. Never “clay” a dry car. You’ll end up with bits of clay stuck all over the surface, and any contaminants will likely scratch the finish.
You’ll hear and feel the clay picking up contaminants as it slides over the surface. You may even notice some slight resistance at first due to the contaminants, in spite of the lubricating spray. Don’t rub in a circular motion. This is more likely to create scratches from contaminants embedded in the clay.
Repeat this process until you don’t feel, hear, or see any contaminants being picked up.
Wipe the area thoroughly, but not aggressively. You just need to remove the remaining lubricating spray.
A 2 oz (57 g) bar of clay should last for 3-4 “clayings” before it’s overloaded with contaminants. However, once you can’t find a clean surface in the clay, it’s time to discard it. If you spot a larger piece of contamination in the clay, pick it out with your fingers, then fold the clay over. Always discard the clay if you drop it on the ground. It will pick up too many large pieces of debris to be useful.
Check your clay disc regularly for built-up debris, and fold it over to create a clean surface as needed. When the clay stops picking up contaminants, wipe the excess lubricant off the car with a clean microfiber cloth.
You can also “clay” plastic and chrome areas, as well as the windows—basically everything but the tires!
If you also want to polish the car’s finish, do this after you “clay” and before waxing or sealing.
If it’s not exposed to excessive amounts of contamination, you may need to “clay” a car that’s kept outside 4 times per year. A car that’s kept in a garage most of the time may only need “clayed” 1-2 times per year.
