This is the act of removing said contamination. The aim of turning a contaminated area into a pure and perfectly clean area. Decontamination can be achieved in several different ways.
Why would you do decontamination?
When treating a surface, you want to have as much control as possible. When you apply a protective product, you want to understand what it is going to do, and why. When a surface is contaminated, you have little or no control on how it behaves. Mainly because you don’t know exactly what the contamination is. How much of it is sand? How much is oil? How much is treesap? Without knowing this perfectly, you don’t know how the product will behave. Decontamination will remove these unwanted particles, and will give you a surface of which you know how the product will interact with.
It’s similar when using a polish. You want to be able to understand how the polish will interact. If there are unwanted particles on the surface, these will mix with the polishing product and will be dragged over the surface. A polish particle is designed to do just that: polishing. The controlled removal of a very fine layer of the surface. Since you don’t know exactly how the contamination will interact with the surface, you can’t predict how the end result will be.
Where does it fit in?
Technically speaking, even the normal weekly wash is a form of decontamination. The normal weekly wash will remove dust, sand, bird droppings, tree sap and much more. Most of it without you even knowing it is there. However, it will not remove 100% of the contamination. For example: let’s say that the weekly wash removes 90% of the contamination. That would mean that after 1 week there is 10% contamination left. After 2 weeks, this is 10% more etc. After 3 months, it will have build up to enough contamination that it is time to decontaminate the surface.
There is no need to do it every week, although there are technique that help to increase the amount of contamination that you remove.
In more general terms, decontamination is often used to described act of removing decontamination via a process like claying, traffic film removers and such. These is done every few months in most cases.
How to remove contamination
There is a good article on how to remove contamination. It will feature all the steps you need to know for a basic decon. The general practise is the use of , clay, fallout remover, tar removers and/or silicon removers.