Old cars are the heart and soul of our hobby, and often the only ones we can actually afford. Of course, the older (and cheaper) the car, the more likely it is to show the scars of its age. The simple way to improve its image is to pull into a body or restoration shop, toss them the keys, and have them call you when it's done. The problem is, that's expensive. But there's a better way.
We're going to break the process of refinishing a car into several categories, and then explore the different means of accomplishing the various tasks within each category. Hopefully this will provide some guidance when you're planning your next project. Just keep in mind that there isn't really a way to completely avoid the need for particular skills and tools/equipment during the refinishing process. Check it out.
StrippingUnless the car you're working on has only one prior paint job, and it's still in good shape, you should figure on stripping the surface to metal. This may sound excessive, but again, the cars we usually deal with have been around a long time, and very few of them are blessed with original paint. Several re-sprays later, there's no telling what sins have been concealed. Even if the body itself is free of damage and filler but has the remnants of a few paint jobs, it's best to get them all off. Any problems with any of the prior finishes can manifest itself in your new paint job later on, and trust us, you only want to do this once. Removing that paint can be accomplished in several ways, from brutally basic sanding to high-tech chemical stripping. Consider your options:
SandingThis is the most basic means of removing old paint from your car, but it's also the most tedious and time consuming. However, if the current finish on your car is thin or peeling, it may not take much effort with a sander to get it down to bare steel. If you go this route, you'll probably be using a dual-action or "DA" sander. These are primarily air-powered and can be used for a variety of tasks during the refinishing process, so they're usually worth the investment. The dual action is the spinning of the sanding disc coupled with the spinning of the base that the sanding disc is mounted to. This results in an orbital motion that is desired because it tends to remove material more evenly than a simple spinning motion.
Most DA sanders can be switched to a single spinning motion, considered grinder mode, though this is generally reserved for heavy, localized material removal. Using a grinding action on the painted surfaces can create gouges in the finish, which is less of an issue when stripping to the bare steel as opposed to prepping a painted surface. However, grinding with aggressive grit, as you would when paint-stripping, can actually mar the steel, creating minor waves that can show up later. For the same reason, heavy-duty grinders, especially high-torque electric units, should not be used by the novice to strip paint. These machines have the ability to grind right into the sheetmetal, leaving scars that will have to be filled later. An 8-inch sanding disc with 80-grit paper on a DA should do the trick. The proper sandpaper for a DA usually comes in rolls of pre-cut paper discs with adhesive backing. You'll need a bunch to do the whole car.