[Mspbcguy]

I got that car last year and it had an awful big chip in the hood. I cleaned it, put multiple layers of paint and seal coat on it and sanded it. in the end it looked decent except that it was slightly darker then the rest. now over the winter it started cracking and now I have paint chips just falling out.
what do I need to do to fix this permanently? Should I prefill that chip with something?

[Mosaud1998]

Just by a new hood

[whyzee125]

For a lasting repair you'll probably need to get your hood resprayed. I just had my whole front clip redone and I'm going to get it wrapped in paint protection film to keep it from chipping again.

[CCM11285]

That looks like a pretty nasty chip. If the rest of the paint in the area is in good shape, you could find a reputable shop to touch up the area. It would involve sanding, primer and blending in of the area. Or just get the entire hood resprayed.

[Mark963]

I've noticed so many times that touch-up on cars doesn't last more than a year or two, but with proper pre-treatment and primer, it'll last for at least 8 years that I've seen.

If it's down to the metal, the metal needs to be treated with zinc phosphate. This is what chassis are treated with at the factory before any primer. I have a bottle of Oxisolv that's zinc phosphate and a million years old. I think Por-15 Metal Prep and KBS Rust Blast are similar.

It bubbles, eating any rust and plates the steel with a layer of zinc phosphate that seals the steel and gives paint or primer something it can really grip. It'll bubble as it works and it can be a challenge to put on vertical surfaces. Masking tape can be used to form a little cup around the damage and hold the solution on it to some degree. Or just reapply every several minutes for an hour.

I've always followed that up with an epoxy zinc primer and then painted over that with the touchup paint. I'm not sure how much the primer helped - I was just throwing everything I had at it. I've tried various "rust converter" products that are kind of like a primer and they turn black and they dry - wasn't so good. I've never seen the zinc phosphate treated patches fail.