I am looking to treat some surface rust under my 88 Jeep grand wagoneer. I was wondering what products to use to help clean the surface, prep, and then rust”treat” the entire underbody. Can I use the aerosol rust preventing products and if so how many cans would I need? It seems that the aerosol can would make life simpler since I do not have compressed air and a spray gun. Do you recommend doing 1 coat with 1 color and a second coat with a different color in order to ensure good coverage?