When Do You Need Primer for Car Touch Up Paint?

Quick answer: primer is most useful when a repair exposes bare metal, bare plastic, filler or another substrate that needs sealing or adhesion. A tiny chip that still has sound factory paint or primer beneath it may not need an additional primer layer.

When do I need primer for car touch-up paint?

• Bare metal is visible.
• The original coating has been sanded through.
• Body filler or repair material is exposed.
• Bare plastic is exposed and the substrate requires a suitable plastic primer/adhesion system.
• The colour coat manufacturer specifies primer for the repair.

When might primer not be necessary?

If a very small stone chip has only removed the colour layer and the original factory primer beneath it is clean, stable and intact, adding more primer can sometimes make a small repair unnecessarily thick. Clean the area and assess the exposed layer first.

What does primer do?

Primer can improve adhesion, isolate the substrate, provide a more uniform surface for the colour coat and help protect exposed material. The correct primer depends on whether the substrate is metal, plastic or repaired filler.

How much primer should I apply?

Use enough to cover the exposed repair area while keeping the application controlled. Build thin coats and follow the product instructions for drying and sanding. Heavy primer build in a tiny chip can make the final touch-up sit above the surrounding paint.

Do I put primer before or after colour?

Primer goes before the colour coat. The normal sequence is preparation, primer where required, colour coat and then lacquer/clear coat if required by the paint system.

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