An air compressor utilizes pressurized air to power tools such as ratchets and paint sprayers. Performing a professional car painting job at home has become much more possible recently thanks to how-to videos and the internet making paint guns so easily available.

To paint an entire car, it’s best to have an air compressor that has at least a 50 gallon tank and can provide 15 to 19 CFM of air flow. If you are using an HVLP (High Volume Low Pressure) sprayer, you can use an air compressor with as little as 20 PSI, but if you are using an older-style paint sprayer, you could need air pressures in excess of 90 PSI. 

If you are looking to buy an air compressor to paint a car, then it’s important to know what size air compressor to get. In this article, we will take a look at some fundamental aspects of air compressors and we will help you find the best air compressor size to paint a car.

Air Compressor Tank Size

Tank size is one of the most important aspects of any air compressor, but it is of particular importance when it comes to what size air compressor to paint a car.

This is because it’s important to get the painting process done in a single pass. So, if your air compressor has a tank that is too small, you will more than likely end up with an uneven application paint, resulting in a poorly finished paint job. 

An air compressor with a small tank will leave you having to wait for the tank to refill, which can affect the quality of your paint by slowing down its application. Or, if you don’t know what size air compressor you need to paint a car, you may over-buy and end up with a tank far larger than is necessary, which would be a waste of money. 

Painting a car is a big job, so an air compressor with a 50 gallon tank or larger is ideal. A tank that size will let you paint an entire vehicle evenly in one shot. The size of the tank, however, is not the only important aspect of an air compressor for painting a car. CFM and PSI are also critical properties to consider.

Get The Paint Gun Before You Get The Air Compressor

The paint gun is the first place to start when setting out to paint a car. The paint gun is what determines the amount of CFM and PSI your air compressor will need to deliver. 

Entry-level paint guns generally require around 5 CFM of airflow, while higher-end professional sprayers can need as much as 10 to 15 CFM to paint a car. So, if you get your paint gun first, you will be prepared for buying the air compressor. 

CFM Rating 

CFM, or Cubic Feet per Minute, is the measure of how much air volume is traveling through the air compressor system.

So, always make sure to look for an air compressor’s CFM rating when you are comparing different models. The higher a CFM rating is, the more air can be pushed through the compressor for a given PSI. 

Remember, getting an air compressor with a high enough CFM rating will allow you to paint your car in a single pass. 

If you get an air compressor with too low of a CFM rating, it will result in an asymmetrical and inconsistent application of paint. This will manifest itself by some areas having a different finish than others. 

For the absolute best car painting results, make sure to get an air compressor that has a rating of 15 to 19 CFM. This requires quite a heavy-duty air compressor, but that is what is needed to paint an entire vehicle. For small, minor issues that require much less painting, you can get away with using a smaller air compressor that has 4 to 6 CFM of air flow.

CFM is as important as tank size when it comes to painting a car because if you have a large tank and a low CFM, you still won’t be able to paint an entire car in a single pass. 

PSI Rating 

PSI, or Pounds per Square Inch, is the amount of air pressure that an air compressor can provide.

This is a critical factor to take into consideration when looking for an air compressor to paint a car. It used to be the case that the higher the PSI the smoother the coat. Innovations in paint sprayer technology, however, have changed the paradigm a bit. 

The introduction of HVLP (High Volume Low Pressure) paint sprayers have made it so that very high air pressures are no longer required to achieve consistent, professional results.

With a modern HVLP paint sprayer, you need about 10 to 12 PSI for the base coat and a little over 20 PSI for the clear coat. That, of course, is if you are using an HVLP sprayer. When using a standard high-pressure paint sprayer, around 90 PSI is the ideal air pressure for painting a car.

Are HVLP Guns Better?

HVLP guns are, by far, superior to their conventional counterparts. This is because HVLP guns have a much higher transfer efficiency and use much less air pressure to operate.

That means more paint sticks to the surface that you are painting. That, of course, results in less cleanup and less waste. In fact, with an HVLP paint system, an experienced painter can achieve an efficiency of around 60%. 

In contrast, conventional spraying cannot achieve a transfer efficiency any greater than 50 percent. 

So, these new paint sprayers don’t just use less air but they also apply more paint than a conventional paint sprayer. This is because HVLP paint sprayers have a much higher transfer efficiency than a traditional high pressure system.

For these reasons and others, we recommend only to use an HVLP paint sprayer when painting a car. 

Can You Paint A Car With A Pancake Compressor?

In theory, if you have a low CFM paint gun a small pancake compressor can keep up. The problem is the fact that the tiny air tank on most pancake compressors simply doesn’t have enough reserve capacity for the amount of air that even an HVLP paint sprayer will demand. 

Remember, when you are painting a car you will be continuously running your paint gun with the trigger pretty much wide open for extended periods of time. So, the diminutive tanks found in most pancake air compressors will cause its motor to continuously run. 

If you run a compressor constantly, it will get hot and lose efficiency. Also, it will cause the air compressor to put out hot air which naturally has more moisture in it and can affect the painting process negatively.

How Much HP Does An Air Compressor Need To Paint A Car?

HP, or Horsepower, is an antiquated rating representing how much work the air compressor motor is capable of.

There are many instances in which an air compressor with a lower horsepower is capable of generating more PSI and CFM than its higher horsepower counterpart. 

So, having a higher HP rating does not necessarily make an air compressor more powerful or any better of a compressor.

Can You Paint a Car With An 8 Gallon Compressor?

Not an entire car. This is because you need at least a 30 gallon tank for a continuous spray. A tank anywhere between 7 and 29 gallons can for intermittent spray, such as painting a bumper or a fender.

Can You Paint A Car With A 30-Gallon Air Compressor?

Now we are getting closer. If you have the right equipment and you are very experienced with painting a car and can do so quickly, then yes, you can paint an entire car with a 30 gallon air compressor.

Realistically speaking, though, you will need a 50 gallon tank to get the best results without being rushed through the process. 

Remember, for an even application of paint it’s important to get the painting job done in one pass. Waiting for an air compressor to refill its tank could be the difference between a perfect paint job and one that has runny marks and lines in it. 

Conclusion 

Air compressors have become a mainstay in many workshops due to their power and versatility. When it comes to painting a car, getting the right air compressor is of critical importance. 

It can be hard to find the best air compressor size to paint a car if you are unfamiliar with the different key aspects of air compressors and paint sprayers.

As long as your air compressor has at least a 50 gallon tank, 14 to 18 CFM of airflow, and 20 PSI (90 PSI if you are not using a HVLP sprayer), you will be able to use it to paint an entire car. 

We hope this article helped you find out what size air compressor you needed to paint your car. Thanks for reading!