“Clay” has only fairly recently gained credence in car preparation. It is a very effective way of cleaning the surface contaminants that have built up, and won’t wash off. These contaminants (brake dust, tree sap, bird deposits, industrial fallouts) will build up over time and you can feel a “roughness” to your paint finish, even after a thorough wash.
The traditional treatment was a “cut and polish”, but this often used an abrasive paste that could eat into your paintwork if you weren’t careful enough! Modern cars have a clear coat finish normally applied to the paintwork and an abrasive paste can easily eat into this as well.
“Claying” replaces this process and will safely remove these contaminants, leaving a glassy smooth surface ready for polishing – providing you use it correctly.
A claybar is not actually clay – but a substance similar to plasticine or ‘play doh’. You can buy just a claybar or a claying kit. Either way, you must use the bar with a lubricant (as supplied in the kit). Soapy water will suffice if you have a claybar only.
It’s really very easy to use. Simply knead the clay into a ball, cover the paint surface with the lubricant or soapy water and gently rub the clay over the surface, backwards and forwards. No need to use heavy pressure, you’ll feel some resistance initially, then it will smooth out, ready for you to move onto the next section.
It’s best to start on the roof – about 50cm x 50cm sections, and gradually work down. Fold and knead the clay regularly, and if you drop it – throw it away! It will pick up particles that will scratch your car if you use it again.
If you’re not convinced, do the polythene bag test! Put your hand in the bag and rub it on the paint. You can feel the ingrained dirt and contaminants. Then after claying, do it again – you’ll find a lovely glassy smooth finish!
So, to summarise – here’s what you do: