I had a guy who was suppose to paint my car for me it was stripped to the metal with most of the body work....this guy went out of business and gave my car back to me with just primer..I was removing some dents and filling some small imperfections and noticed a brownish color that was under the primer this guy sprayed the car with....My question is ...do I have a rust problem or is this something that happens when the car is primed...the plan was to use a base/clearcoat...I am not sure what primer he had used. What can I do at this point if any to encapsulate the rust or do I have to strip the car down again to do it right... yes the care was out in the weather through the winter

 

Primer doesnt seal the surface, and moisture gets through, so unfortunately, that is rust under the primer. You will probably have to have it stripped off, and done again. Sorry

 

Its not really so bad. Least you know where it is. Lots of times you can clean up some metal and get ride of all the rust, prime n paint n a few months later its back. I find it to be an up side of the process. Do the car well and primer it then let it stay in primer for a while. sure enough you will find spots that you cleaned n treated well that will come back.

Of course then you need to redo the whole car and the primer. Primer sun n weather exposed would need sanded well and re-shot.

especially if your not spending $5-10,000 on some paint, doing a $1000 DIY job. Its a good idea to let it sit in primer. No matter how well you thought you did it the first time. Some small spots will come back. You will get a better job in the end.