Primer paint is a preparatory coating that's applied to the body of a vehicle before the paint is applied. Its purpose is to make it easier for the paint to adhere to the surface of the vehicle and can also provide some additional protection to the vehicle's body. Some car primers are used as surface fillers and corrosion inhibitors.
There are different primers for different uses. To reduce the chance of bubbling paint, it's important to make your primer paint selection carefully. Here are a few things for you to consider.
Know the Different Types of Primer
Car primer paint can be divided into 3 different types: etch primer, wash etches and high-build primers.
Etch Primer - Phosphoric-acid based primers designed to protect against corrosion and promote paint adhesion. This primer provides protection even if the paint film has been chipped away.
Wash Etches - A very thin primer with no build-up that can easily be brushed onto the body of the vehicle. Does not require spraying which means there are less fumes when this primer is used. Great to use when the vehicle has been stripped to bare metal or if repairs need to be protected.
High-build Primer - Usually used in the final stage of the repair process. It's very thick and difficult to apply with an aerosol spray bottle and can cause significant build-up. Great at filling in scratch marks from coarse sand paper.
Sometimes there's a concern that the primer will show through if the base coat is too thin or has poor opacity. Most of the different types of primers are available tinted in beige, white or gray. But if you need a specific color, you can check into spectral primers. Or you can tint the primer paint to your choice of color by mixing a small amount of old paint with your primer to create a lighter version of the new paint color you'll be applying to your vehicle.
Application Method Affect Final Appearance
When choosing primer paint for a vehicle, you'll need to decide on how you would like to apply it. Many do-it-yourselfers use brushes or spray cans because they're easily available and economical, but these methods don't work with all types of primers. Brushes can cause uneven surfaces and increase the amount of sanding required. Spray cans can cause stripes that need to be sanded. Try using an HVLP paint gun instead and rent or borrow a compressor.
Local Environmental Regulations Matter
If you're adding car primer paint to your vehicle at home, you need to check your local environmental regulations before purchasing your primer. Different cities and towns have different regulations concerning what you can or can't spray or mix in your backyard. A local autobody shop can direct you toward a primer that meets your needs and that you can use at home without breaking any environmental regulations. Your local fire department may be able to provide you with this information too.