Don't try this at home kids!
Wet sanding is scary stuff! How would you feel watching somebody take a block of sandpaper to the bonnet of your expensive car? You might feel a little apprehensive, no?
Don't worry, there is method in this madness. Obviously the deeper the damage, the deeper we have to go to remove it (see previous page) and it is far quicker to get down a few microns with glass paper than with a buffing machine. But the real reason for using a fine grit glasspaper on a sanding block is that we can remove the damaged paintwork in a controlled and even way. Because the block is flat, it won't leave dips or ripples in your top coat, and because a buffing mop is rotating soft sponge, there is a danger that with prolonged use on an area, it may go down too far in some areas and not enough in others as the edges have more abrasive power than the centre.
We start off with 1500 grit paper and then finish with 2000 grit wet and dry paper. We constantly wash and wet the area checking the progress. When we feel that we have gone down far enough we use compounds applied with the buffing mop.
Compounds are like a liquid sandpaper. They contain aluminium powders which act as an abrasive and come in many grades. The most harsh of these will feel gritty between your fingers, but we prefer to take our time, working slowly using only the very finest grades because it's far better to take off not-enough than too-much. After several grades of compound comes finishing with polish and a final coat of wax applied by hand or with an oscillating orbital polisher.
The BMW in the photos above had quite deep scratches where somebody (mentioning no names) had kept placing her shopping bags on the boot of the car. We recommended wet sanding (and getting a divorce) because there were many moderately deep scratches covering three quarters of the boot lid.
It's not nearly as scary as it looks, but it is a time consuming and skilled job which is only carried out by our most senior members of staff. It's not the kind of thing we would recommend having a go at yourself!
Footnote: I get an email every couple of months from somebody who has tried this, messed it up and asking how to fix it. The answer it to repaint the area which can be quite expensive. They must be gutted having to pay to have the whole side of a car repainted all for what started out as a tiny blemish. So, as it says at the top of the page, "Don't try this at home". Some things are best left to professionals.
|Faded Paintwork on page 3|