New Paint - Rust issue
 

So I have been on a slow track on painting my 1960 GMC Burb. We painted the top and the hood several years ago. Thought we prepped it pretty well. While sanding and taping for more paint I noticed a rust issue in the front hood seem.

What should I do to correct and stop this problem ?

Re: New Paint - Rust issue
 

Problem is, the rust was still in the seam and even though it was painted and cleared, air can still get to it from the backside of the seam (inside the hood). Rust never sleeps.

At this point, you'll need to strip the paint at the seams and use some type of rust converter (like Rust Mort), then repaint it. You should also paint from the back side of the hood, to help seal it up.

Good luck.

Re: New Paint - Rust issue
 

You can clean the stains off with polishing compound, but like Mike said, the problem is inside the seam and until that is resolved the stains will return.

Re: New Paint - Rust issue
 

Use seam sealer once you have her really clean.
Every seam on my truck is sealed.