You'll want to hit the hood with the thinner/grease remover before you start sanding. This will prevent you from building up a wax layer on your sandpaper. I'm hoping you're planning on removing the hood from the car first. Much easier to work all the angles off a set of sawhorses than having it still on the car. If the hood is in good shape and there is no flaking or damage to the clear or paint, yes, you can get away with just a wet sand of the first surface to prep the surface. Make sure the sandpaper you're using is a wet/dry paper. If the hood is in rougher shape, you'll want to use an orbital sander to take it down a smooth surface. In this case, you'll want to prime the surface to prep it for paint.When you wet sand you use a fine sand paper and water with soap as a lube to stop the paper from clogging up. If you are prepping for paint you would use a heavier grit paper than wet sanding paper (wet sand paper should be from 1000 and higher) you should be using some paper in the 400-600 git to prep for paint, after you have sanded, clean with laquer thinner to remove leftover grease, oil and wax.
I'm sure most of you have heard the term "wet sanding" or "color sanding." What do these terms mean and when and how should you use these procedures? Sometimes the only way to remove or lighten a heavy imperfection is by sanding the paint surface. This can be a fast and effective way to remove a heavy scratch or scuff, if you are skilled and very careful. On the other hand, this method may lead to a trip to the spray booth if you are over zealous and not aware of when to stop.I am planning on painting the hood of my car. I was told by someone that I needed to wet sand my hood before I paint it. Is this true? Any suggestions on what sort of wet sander i should use?