If the primer is:
* In good condition, properly adhered, and smooth: You can likely apply a new coat of primer (possibly a sealer primer) and then paint directly over it. However, it's crucial that the primer is compatible with your chosen paint. Check the manufacturer's instructions for both the existing primer and the new paint to ensure compatibility. Sanding the existing primer lightly to create a better bonding surface is also generally recommended.
* Damaged, cracked, peeling, or poorly adhered: You absolutely *must* strip the old primer. Painting over damaged primer will lead to problems like peeling, bubbling, and an uneven finish. The new paint won't adhere properly.
* Of an unknown type or age: It's best to err on the side of caution and at least test a small area. If the primer is old or the type is uncertain, it may not be compatible with modern paints. If the test area doesn't look good, it's safest to strip the primer.
Before you start anything:
* Clean the surface thoroughly: Remove any dirt, grease, or debris from the primered surface.
* Assess the existing primer: Carefully inspect the entire car for damage.
* Check compatibility: If keeping the primer, verify compatibility with your chosen paint.
* Consider professional help: If you're unsure about any step of the process, it's best to consult a professional auto body shop. They can assess the condition of the primer and recommend the best course of action.
In short: Don't just assume you can paint over it. Thorough inspection and appropriate preparation are key to a successful paint job.
