Car paint primer is important because it helps to smooth the body of the car or the part of the car's body that has been exposed to the elements by removal of paint. It helps to keep the steel parts of the body of the car together, and it also helps the paint to stick to the car a lot better. There are only a few times that spray paint primer is necessary, and those will be discussed below. You will also find a guide for priming your car listed here so you can get started on the project.
When there has been no paint on a body before, car paint primer is needed to help the paint stick to the bare frame. This primer provides the perfect texture for the paint to adhere to.
If you get a new replacement part for your vehicle, you will need to prime it again, because it is still bare metal. This will ensure a good paint job and will help the overall look of the car paint finish.
Bad Paint Jobs
If the previous paint job on the car is not very good, you may need primer to cover up the old mess-ups. This will provide a clean slate for you to work with.
Priming the Car
If you are doing a new paint job yourself, the first thing you are going to want to do is remove all of the old paint and primer. Look for any rust spots and sand them out either by hand or with a grinder. Fill the rut spots with a filler, and after it has dried, sand it smooth. You also should remove any dents there might be in the car. If they are small dents you can just use a hammer to pound them out. With larger dents you can always use a dent puller to get those out. If you do not want to sand your car, you can always buy a liquid stripper and apply that to the car to remove the paint and primer.
Wash to remove any dirt or dust caused from the sanding. Use an air compressor to blow out any excess water that remains after the car is washed. After you have done all of this, you can mix the primer and put it on the car. Tape up the areas of the car that will not need the required primer. This would be headlights, tail lights, mirrors, turn signals, and all things that you don’t want the primer on.
Take a container and fill it half way with paint thinner and add primer to fill up the container the rest of the way. Mix the two together with a paint stick until the primer is completely mixed in. After all of this, the primer is ready to be put on. Make sure to wear a respirator when you apply the primer. Then spray in thin layers until you get the desired coating.