Car Restoration

[clowny]

So I took on a BIG project. I purchased a 1978 El Camino, as my first ever car to restore. There are some rust holes and surface rust, I am doing all the work my self except final paint. I have a question I have currently sanded down the hood to bare metal, not completely as there are dips and dings that were filled in with primer and paint. I am storing this car in a heated warehouse that has lots of dust and sand, and birds... What is the best way to prep the car for paint including primer as I am going to do this restoration over years. I started with the hood being sanded down by hand not machine as I can buy the crowl hood if need be. My first question is now that the hood has been sanded down to metal should I prep and apply primer now or leave as bare metal until all priming is being done right before paint?