Overhaulin'

How to sand a car to prep for paint job?

I'm getting ready to paint my car. I'm doing it myself for a number of reasons I don't want to get into. This is a beater car, not a super-expensive car or classic. Just a regular, 9-year-old, commuter car. The only part of the job I'm not completely sure about is the sanding part. In the prep stage, before doing any primer or paint, do I sand dry or wet? and do I use an electric sander or do it by hand? And in the later stages, after each layer of primer and paint, do I sand by hand or with an electric sander? I forgot to mention that there are a couple of layers of bad paint jobs (done by so-called professionals) on 80% of the car, that I need to be sanded through. So, all of the sanding should be done by hand?

Public Comments

1. Do not wet sand with an electric sander. If the vehicle does not need any body work other then scratches then it shouldnt be too bad with wet sanding by hand to get the surface ready for paint. wet sand with 2000 to 2500 grit depending on the condition. If u dont want to do it by hand then use a pneumatic buffer that u can put sticky sandpaper on and use that dry. either way u get about the same result just how much time/effort you invest. p.s. dry sand with 2500+
2. the only part you are not sure about is the prep work. that is most important part of the whole process. dont want to sound mean but just pay someone to do it. i do paint and body work for a living. i have redone so many cars for people who think they know how to paint. do yourself a favor and just pay to have it done.
3. I'm not sure what the "couple of layers of bad paint jobs" look like. If they are adhered OK but dull, or full of orange peel, they may not have to be completely sanded off. If peeling though, they gotta go. That can be done with a 180 grit and a DA sander. If you get past primer down to bare metal you will need to prime again. If the existing paint is good and "stuck", wash the car with Comet and a scrub pad, then wet sand with 320 grit wet or dry paper. Use a pad for the paper (flat rubber block) to get a good flat surface.