Painting a car at home can be an affordable way to tackle a big job yourself. Like any automotive project, there are many factors that could make or break your paint job. Getting or making sure you have the correct size air compressor is one of the first things you should do after you decide on the color.
We often get calls asking about how many gallons the compressor tank should be to paint a car. Although the tank size is a factor, asking about it first thing is often a misconception when looking into the painting process. Here are the important things to consider when looking at what size air compressor you need for car painting.
1. Fit Your Compressor to the Paint Gun
First, you need to decide on what paint gun you’re using to paint your car. The air consumed is controlled by the paint gun you use. Paint guns like our Concours Paint Gun line can require as little as 4.5 CFM while a high-end professional gun can require 12 CFM or more to spray paint correctly.
If you already are set on or own a certain paint gun, you can try and match your compressor to the gun or vice-versa. The capacity of the compressor isn’t usually an issue, but the compressor itself and the CFM it puts out are issues. Just like paint guns, there are large high-end compressors that will put out the air needed, and there are smaller air capacity compressors that will have a high CFM rating and can keep up with airflow needed with no issues.
2. Compressor Tank Size and CFM
Before considering the tank size of your compressor, you should match the paint gun CFM to the CFM rating of the compressor. For more information, visit our Air Compressor Selection Guide or our article about What Size Air Compressor Is Needed To Paint a Car. Make sure the gun you’re using requires LESS than the maximum output of the compressor so you aren’t running it constantly when painting. A good rule of thumb is to use a compressor with a CFM rating at least 50% higher than the paint gun.
At the end of the day, the CFM rating is more important than the gallons of air the compressor tank has on reserve. But that’s not to say tank size doesn’t play a role. A tank that is too small will frequently need to be refilled during full-vehicle coatings and other large projects, which makes these projects take a lot longer. Smaller compressor tanks can also cause more variance in the paint flow and pressure. That being said, most air compressors with an air tank capacity of 30 gallons and up can usually handle painting a car. If you’re painting a classic full-size car or want to play it safe, a tank of 60 gallons or more should be enough to coat the vehicle in a single pass.
3. Self-Contained Paint Systems
If you don’t have the need or shop space to get an air compressor for painting, you can look into self-contained turbine-style paint gun kits. These have a built-in air compressor that produces a very high CFM but has almost no air reserve. A reserve isn’t needed because of how they operate — the turbine generates the air volume needed on-demand by drawing it into the system. Most can be stored under a workbench and can paint an entire car with no problem.
The major downside to independent turbine compressor painting is the cost-effectiveness. A quality turbine kit can get expensive, and a high-end turbine paint gun kit could cost you almost as much as an air compressor. In the end, you will need to decide which system suits your workspace and project the best.
If you still have painting questions or need help choosing an air compressor, feel free to give our tech team a call — they can walk you through your decision. You can reach them at 1-800-343-9353 seven days a week. See our full line of air compressors here. Other automotive painting tips are available in the Eastwood Garage and How-To Center.