Washing your car is not enough, over time you car picks up dirt and debris that become lodged into the pores of the paint. This fallout comes from parking or driving by train stations, your cars and other cars exhausts and even from your brakes and inevitably eats its way into your paint which can cause premature corrosion of unprotected metals.
You can check if your car needs decontaminated by putting your hand inside a plastic bag and running it over a clean car, if it feels rough this is due to iron deposits and tar spots. So, how do we decontaminate the car?
First things first we need an Iron Remover/Fallout Remover such as Auto Finesse Iron Out. These cleaners are sprayed on paintwork and react with the iron filings causing them to ‘bleed’ and after a dwelling time they can be safely washed away. This process can be repeated if necessary.
Next up is Tar, this wont be removed by an iron remover so we need a separate product for this…yup a Tar Remover. This pungent chemical is applied via spray or microfiber cloth and allowed to dwell on paintwork and will look as if it is melting the tar but do not let it dry or it can be difficult to remove. Once applied and left for a few minutes it is safe to wipe away the tar spots with a separate cloth.
Finally, we can get round to using the clay bar, but for this we need a form of lubrication that will allow the clay to slide across the surface of the paint, some people recommend a dedicated clay lubricant but honestly any quick detailer or diluted spray wax will do the same job.
Clay helps lift bonded contaminants from within the paint and pulls them into the clay, allowing the paint surface to become smoother.
The idea is to spray the panel with lubricant and run the clay over the panel using very minimal pressure allowing the clay to pick up any contaminants still left in the paint. You will start to see the clay turning brown, simply fold it over squash it with your hands until you have a clean side.
Once you have completed claying you now have the perfect base for a coat of wax or sealant. Also, if you run the back of your hand over your paintwork now it will feel as smooth as glass!
Bonus Nerd Knowledge: As I said decontaminating your paint increases gloss and allows waxes to bond properly to your paint but do you know HOW the gloss is increased?
As those contaminants sit in your paint they diffuse light when it hits your paint and causes it to reflect back at odd angles which in normal terms, makes it look duller. After removing these particles from your paint the light that hits your paint now bounces back in a uniform consistent pattern meaning your eyes see a brighter reflection.
(Theres more to it than that but without getting into physics thats the best I can put it without simply copy/pasting)