Car Paint Preparation: Sanding, Primer and Clear Coat

Good car paint preparation starts long before we pick up the spray gun. Did you know that around 70% of the final result comes down to the preparation – sanding, filler and primer? Rush these stages, and a few months later you could be looking at ripples, patches and a visible line between the old and new paint. And putting that right gets expensive. Come on, I'll show you how we prepare a panel in our body and paint department at Das Auto Service.

How do we carry out car paint preparation?

1. First, we thoroughly clean and degrease the panel.
2. We straighten out the dents as much as possible before reaching for any filler.
3. We sand down the old paint around the damaged area.
4. Where needed, we apply a thin layer of body filler and sand it until we've restored the panel's original shape.
5. We apply primer to protect the metal and level the surface.
6. We sand the primer with fine-grit sandpaper until everything is as smooth as glass.
7. We mask off the rest of the car so no paint gets onto it.

Why do I insist on keeping body filler thin?

If we apply a thick layer of body filler, it can shrink and crack over time. And if there's moisture trapped underneath, rust can start forming too. That's why we straighten the metal as much as we can first, then use filler only for the final shaping of the panel.

When do we apply the colour and clear coat?

Only when all the preparation is finished do we start applying the colour. Then comes the clear coat – that's what gives the paintwork its lovely shine and protects the paint underneath. Finally, we dry the panel at a controlled temperature, keeping dust well away.

What if you've only got a few small stone chips?

You don't need to respray an entire panel for every little stone chip. With genuine touch-up paint matched to your car's paint code, you can fill in those small chips before rust has a chance to start.

A tip from Kris Mladenov: If you spot bubbles under the paint, don't pick at them. They often mean rust has already started forming underneath. To put things right, we need to prepare the affected area properly.

If your car has paintwork damage, come and see us in the body and paint department at Das Auto Service. We'll look over the panel together and give you a straight answer about what actually needs doing.

What can you find in our shop?

Genuine Audi / VW L041 touch-up paint, solid black

Genuine touch-up paint matched to your car's paint code is just what you need for those little stone chips that don't justify respraying the whole panel.

View in our shop

Read more

• Car body repairs and paintwork services
• Touch-up paint matched to your car's paint code
• Inside our body and paint department: how we paint a panel so you can't tell the difference
• Stone chips after winter: how do I repair them with genuine touch-up paint?
• Door edge protectors: protecting your car from car park damage

Frequently asked questions

Why is preparing the car for painting so important?

Because it's what makes the difference between a smooth finish that lasts for years and one that doesn't. Spraying the paint is only part of the job.

Is body filler a bad thing?

Not at all, as long as it's applied properly in a thin layer. Trouble starts when it's too thick – over time, it can shrink and crack.

How long does it take to paint a car body panel?

It depends on how badly the panel is damaged. But proper preparation and drying take time. Rush either of them, and the mistakes will show in the finished paintwork.