We use the premium Enamel Sparex paint.
We not only sell the paint, but we also run a full-service restoration shop so we know how to best apply it as well. What we found was to mix a 50/50 paint with a reducer that can be bought at Tractor Supply, hardware stores, and Walmart.
We high pressure wash the complete tractor and use a putty knife to get the hard to reach and remove those unwanted materials. We also use carburetor cleaner on fuel and oil spots still remaining. Any oil solvent will work.
We do on average 4 sprays, allowing the previous application to dry enough to be tacky before applying the next. It's totally up to you of how you want to apply it. Each of our sprays is a light coating that holds up to the elements over time.
If you have any questions on applying this, please send us a message and I can either get you the answers you need or put you on the phone with someone that knows exactly how best to set the guns, the mix and the best way to apply.