is a primer needed when repainting faded OE paint?

[Josh]

I'm curious; my car's a fresh acquisition from the south, and has zero rust, thankfully!

But the old paint is faded, and the clear coat is breaking off of the hood, roof, and trunk.

Can't I just sand down the existing finish to provide something for the fresh paint to grab ahold of?

I'm not concerned about the visibility of dings or any sheetmetal imperfections; I simply want to protect the car's metal and gain a finish that's slightly more appealing to the eye.

PPG Concept or Omni is what I'll likely use. Is any primer necessary in this scenario?

[Chris L]

As long as its not cracked,peeling etc you can.Without primer or sealer,you just have to watch what grit paper you finish with so you dont leave sand scratches in the finish.Sand it with 320 dry or 400 wet,then run over it with 6-800 wet and paint it.

[Dennis N. Schmidt]

Chris L is right on. I've just got done doing this exact repair on my Grand Prix. I live in Phoenix and this is a super common condition. On my car, due to the way I park it at work, the problem areas were the rear bumper cover, the roof and the rear spoiler.

I would recommend doing basecoat/clearcoat however especially if the paint's a metallic. Easier and the clearcoat offers much better UV protection.

When you're sanding you will be able to tell when you've gone enough. The bad paint comes off about three times faster than the good paint underneath it. Stop sanding when you get to the good paint. In my case I had to go to metal in a couple of small spots. I just covered these with epoxy primer, which I smoothed out with P1000 wet paper and shot basecoat. Worked great. Then I loaded up the clear and buffed it to a great shine. Car looks better now that it did when new.