What Size Air Compressor Do I Need To Paint A Car?

As an effective method of auto-painting your car, air compressors are always a popular choice. I often wondered, what size air compressor do I need to paint a car or need for air tools?  Amongst the crowd of information, I found my answer.

You need an air compressor with more than 50-gallon volume if you want to paint your car without refilling the tank. As for the CFM rating, it should be between 14 to 18 per unit. The air pressure varies from 10 to 25 psi, and a 10 horsepower compressor should suffice.

If you don’t understand the measurements, go through the following section to get a clearer idea about your standard air compressor size. If you don’t already know, air compressors pressurize regular air to power tools like spray painters. It’s a method you can use to paint your car all by yourself.

What Size Air Compressor Do I Need To Paint A Car?

Air Compressor Need To Paint A Car

There are four essential factors to consider while measuring air compressor size. If you’ve decided to paint your car on your own, ensure the following standards before using an air compressor.

1. What Tank Size Do I Need?

The first thing to measure while ensuring that your air compressor is of the perfect size is how big the tank is. The tank should at least be 50 gallons or more. Experts recommend that your air compressor should have 50 to 60 gallons capacity.

You should use a bigger tank rather than a small one because you can finish painting your car without refilling the tank. Using a small tank will require you to refill it halfway through. Even though it doesn’t sound like a big deal, it can make you end up with an uneven paint coating.

So, if you want an even and professional paint finish on your car, I recommend getting an air compressor of 50 gallons or more.

2. What Should Be the CFM Rating?

CFM or Cubic Feet per Minute is a crucial determinant of air compressor size. If you go for a lower CFM rating, you will end up getting asymmetrical painting on your car. Some parts of your car will have better painting compared to others. We all know how that’s going to look like.   

If you wish to paint your car in a single turn or plan to paint for a long time, you should go for a higher rating CFM. They come a bit pricier but certainly, get the job done very well. Most auto body shops possess air compressors that have a CFM rating from 14 to 18 per unit range. 

If you want to get an air compressor only for simple retouches, around 5 CFM ratings should be sufficient. For the base and a clear coat, a higher CFM is mandatory.

3. Optimum Air Pressure

The next thing to consider while determining air compressor size for auto painting is what’s its air pressure rating. The unit psi measures air pressure. Some argue that it’s the most important thing to consider. But remember that it’s not the only thing you should think of.

On the contrary, you don’t need that high air pressure to paint your car evenly. If you choose a high volume and low pressure (HVLP) compressor, you won’t need much psi to get an even coating.

Experts suggest using a 10 to 15 psi compressor for spraying a base coat. To get an even coating, they recommend you increase the psi up to around 20 to 25. Even when you choose a low volume and low-pressure (LVLP) compressor, increasing the psi too much isn’t really necessary. However, it’s important that you notice the amount of water it’s producing when you’re using an LVLP compressor.

If you’re curious, the ideal air pressure for ultimate car painting is 90 psi.

4. How Much Horsepower Should the Air Compressor Have?

The last consideration to determine air compressor size is horsepower (HP). It simply defines the amount of work that an air compressor can do. Remember that a higher horsepower isn’t an indicator of how good an air compressor is.

If an air compressor with 10 HP can offer the same amount of pressure as the one with a higher HP, then the lower HP compressor is more efficient. However, experts advise getting an air compressor that has a higher HP mainly because it can also power other tools.

Spray Gun Specs

Spray Gun Adjust With Air Compressor To Paint Car

If you want your spray gun to perform the best, make sure you match the spray gun with your compressor’s specifications. Remember that a professional spray gun will work efficiently even with a smaller capacity air compressor.

The spray gun determines the thickness of the coating. That’s why you should select a spray gun that comes with interchangeable tips. This way, you can adjust the thickness according to your preference.

As for the standard nozzle size, you can read the following readings to get a basic idea.

    • Nozzle size 1.7 to 2.2 for heavy-bodied primers and primer surfacers
    • Nozzle 1.4 to 1.6 for basecoats spraying
    • 1.3 to 1.7 for clearcoats spraying
    • 1.4 to 1.6 for sealers and single-stage urethanes

Precautions to Follow While Auto-Painting Your Car

Professionals are bound to follow some strict rules to ensure safety. But, if you’re DIY-ing your car painting job, you need to be careful about the procedure. Make sure to be mindful of the following things before you jump in to paint your car.

  • Use Ventilated Space

Automatic body paints and solvents contain harmful chemicals called volatile organic compounds (VOCs), released into the air when the paint container is opened. Even after your work is done, these vapors can stick for up to 3 days.

It’s crucial that you use a ventilated space for safety. Using an enclosed space for painting your car will result in the chemicals affecting your health. Choose a dry day to do the job, keep the door of your garage open, and use box fans to release the vapors outside.

  • Don’t forget a respirator

To prevent the harmful chemicals from entering your body, you must use a respirator. Using a respirator will filter the air you breathe and keep you safe from any harmful solvents.

To prevent the toxic materials from affecting your lungs, the highest level of security measures is a must-do chore.

  • No exposed skin

Paints containing isocyanates are specifically toxic to the lungs and skin. SO, using a respirator isn’t enough. Make sure you use a full-body paint suit, nitrile gloves, and safety glasses to keep yourself safe from exposure.

  • Take care of any spills right away

In case you spill even a little amount of paint, stop painting and clean it up immediately. The paint can travel by sticking to someone’s show and gradually result in a physical hazard. Moreover, always make sure that paint lids are tightly sealed after you finish your job.

  • Read your paint’s MSDS

MSDS refers to the materials safety data sheet of the paint you are using for your car. You can search the materials by product online.  This sheet will provide you with a clear list of chemicals it releases and other relevant information.

For example, you can find out the drying time, optimal temperature and environment for using the paint, and cleanup guidance if needed.

What Are Others Saying?

Frequently Asked Questions

Q. What size air compressor do I need to paint a car?

An air compressor’s standard size for painting cars is a tank capacity of at least 50 gallons. Smaller capacity compressors will result in uneven painting.

Q. Can I paint a car with an air compressor of 30 gallons?

It’s quite difficult to paint a car using a 30-gallon air compressor. Lower volume air compressors usually come with a low PSI and CFM rating that makes the process difficult. However, you will struggle to paint the whole car at once with a low-volume air compressor.

Q. What CFM rating do you need to paint a car?

Make sure you get an air compressor with at least 14 CFM for a clean coating. It provides a steady output to prevent pressure drop that can ruin your paint.

Q. What PSI do I need to paint a car?

An HVLP sprayer can paint your car using 10 to 15 psi without any hassle. You don’t need a higher psi. The CFM rating is more crucial and needs to be higher than psi to pain a car.

Final Verdict

In the end, if you ask me what size air compressor do I need to paint a car, I’ll answer in one line. 50 gallons or more, 14 to 18 CFM rating, 10 to 25 psi (depending on the sprayer gun), and 10 horsepower.

If your air compressor fills all these criteria, you should be good to go for your car painting job. Remember that it’s important to know everything before you paint your car all by yourself. Even though it sounds like a fun and easy activity, doing it wrong can result in ruining your car.

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