Good morning friends, I ask you about the car's carter, it has some places with rust. I passed sandpaper 220 only in those places and the sheet was left in the air (or it could be aluminum since it was dark when sanding). Now I put motor oil in those areas so it does not oxidize, I leave it like this with the oil or I paint it with a brush and can I use synthetic enamel? Greetings and thanks