Air compressors are frequently used in the auto industry to paint cars, trucks, and other automobiles. Many people want to paint their car at home.

But here, a question arises: What size air compressor for painting a car?

What Size Air Compressor for Painting a Car

A 10 HP air compressor, with 60 gallons tank size and a higher CFM around 20, with 20-25 PSI air pressure, will be enough to paint a car.

However, higher PSI is recommended for clearer paint.

Higher HP air compressors may operate more efficiently and can also be used for other tasks.

Air compressors produce compressed air generated by an engine or a motor. This compressed air is then used to spray paint for cars. Painting a car yourself at home is an affordable way to tackle an expensive task yourself. Paint is sprayed with pressure on a car with the help of a spray gun and nozzle in very-fine mist liquid particles, which covers the vehicle with paint evenly coated.

Air compressors are used for many tasks such as inflating a tire, operating a nail gun or impact wrench, refilling a Co2 tank, and much more.

Using an air compressor for painting cars is a very efficient and time-saving method. It covers every difficult-to-reach part of the car very quickly.

Once you’ve decided on a color for your car, the most important thing is to ensure you have the correct-sized air compressor with all the required standards for painting your car.

What is a good size air compressor for spray painting?

The size and requirement of an air compressor for spray painting depends on multiple factors. For example, what size is your car? Do you want full-vehicle paint, minor patch repair, or touch-up work?

Below, we will discuss what size air compressor for painting a car. We will discuss every aspect and requirement in detail.

– Tank size

– CFM

– Horsepower

– PSI Air pressure

If you want to paint your car yourself, make sure to meet the following air compressor standards before starting the process.

Tank size:

The tank size of an air compressor plays a vital role in painting a car smoothly and efficiently.

Smaller tanks don’t have enough air volume CFM (cubic feet per minute) to paint an entire car at one shot.

The paint gun will start to strain as the smaller tank will run out of air while you are using it non-stop, wishing to cover the whole vehicle at once for smooth, clearer paint.

So, a smaller tank will need to be refilled several times for a full-vehicle color painting.

Another issue while using a smaller 15-20 gallons tank for car painting is that your air compressor will get hot because of constant running.

As a result, the compressor will start building water in the tank, which must drain once in a while.

Drain your compressor after covering each side of the car to be safe.

How to drain your Air Compressor

First of all, turn off your compressor and let it cool down for a few minutes. Now unscrew the drain valve of the air compressor.

It usually is a ¼ inch round brass fitting. You will find it under the belly of your air compressor tank. (as shown in the image below)

Open this water release valve by turning it in an anti-clockwise direction. You can turn the valve with a pair of pliers. You will hear a sudden sound of releasing pressurized air stored in the tank.

Wait until all the condensation and pressurized air bleed out. Once you are sure that all air is drained, now firmly turn back the water-release valve in a clockwise direction to close it back.

Recommended Air Compressor Tank Size for Painting a Car

To paint whole-car at once without refilling, you will need an air compressor with a 60 gallons tank.

In a smaller tank, the air pressure and paint flow are stopped and start again and again. It leads to an uneven color coat resulting in a slight color variation after every refilled tank.

So always use a recommended tank size for smooth, even, and clearer paint.

CFM (Cubic Feet per Minute):

CFM (Cubic feet per minute) is the volume of air delivered in one minute from an air compressor.

Smaller tanks don’t have enough air volume CFM (cubic feet per minute) to paint an entire car at one shot.

Therefore, higher CFM (cubic feet per minute) is required to paint a car efficiently.

Higher CFM breaks the paint in very-fine mist liquid particles, then sprayed with a paint-gun nozzle to evenly cover the car with paint.

Recommended CFM for Painting a Car

Look for a two-stage air compressor that delivers around 20 CFM is required to have smooth and clearer paint on your car. Higher the CFM, the softer paint you will get.

Higher air volume CFM (cubic feet per minute) is required to break the paint into very-fine mist liquid particles and cover every difficult-to-reach part of the car quickly.

Make sure you are looking at the delivered CFM, as there are several different CFM ratings out there.

Delivered CFM is the actual volume of air that will reach your spray paint gun.

The tank size should be large enough to serve more CFM than the required CFM for painting a car.
The excess CFM allows the compressor to have some time to cool down and prevent from overworking and heating up.

HP (Horse Power):

Horsepower (HP) is the amount of work that an air compressor can do. Higher HP does not necessarily mean it is better for every tool.

Recommended Horse Power for Painting a Car

A 10 HP air compressor is considered as the best air compressor for painting a car. However, higher HP air compressors may operate more efficiently and be used for other tasks.

PSI (Pounds per Square Inch) Air Pressure:

PSI (pounds per square inch) is a measurement of air pressure delivered by an air compressor. The higher the PSI, the higher the air volume that can be compressed into a tank.

When painting a car with an air compressor, air pressure is less critical than CFM. Air pressure is measured to the rate at which pressure paint is delivered from the nozzle.

Important is to obtain a higher CFM so the output of paint will be in the form of very-fine mist liquid particles, resulting in a smooth and clearer paint.

Recommended Air Pressure for Painting a Car

The recommended PSI range is between 20 – 25 PSI. But you need to set the PSI settings as per the operational requirement and personal feel.

Below, we are sharing the recommended PSI for different requirements:

– 15 – 20 PSI: For airbrushing, touch-up, shading, sun-bursting, and thin finish materials.

– 20 – 25 PSI: For soft, velvet-like coverage, with lacquers in particular.

– 35 – 45 PSI: For average spraying range for sealing and top-coating.

– 50 PSI and above: For water-based, lacquers may need this much pressure.

Can I paint my car with a small Air Compressor

Yes! You can paint your car with a small air compressor. Many air-powered tools are used intermittently, such as nailers, impact wrenches, pneumatic blowers, etc.

But paint spray guns require a continuous compressed air flow from an air compressor.

So, to keep up with the spray gun, paint sprayers require a compressor with a large tank, preferably from 50-60 gallons and above.

“Spraying paint is NOT a pressure thing, but a VOLUME of air.”

How do I paint my car with a small Air Compressor

Smaller air compressors have a smaller tank, so you must refill the tank several times for a full-vehicle color painting. Therefore, you have to paint your car in parts, but on the same day.

You may end up getting asymmetrical paint on your car, as different parts of your vehicle will have a different shade of paint which will ruin your whole effort.

But here are a few tips to achieve better paint on your car with a small air compressor.

Method 1:

You can paint your car in one shot with a small air compressor. But you have to keep your ear on the sound of the air pressure. So if you hear and feel a drop in air pressure, you have to adjust accordingly.

You have to refill your tank as soon as its pressure slightly drops. So throughout, your spray gun will receive almost even air pressure.

It will reduce the asymmetrical patterns and give a smooth and clearer paint.

To paint your car in one shot without refilling, you will need an air compressor with a 60 gallons tank

Method 2:

There is a tricky method as well 😊

As you have a small air compressor with a smaller tank, let’s paint your car in parts!

Paint the front and back bumpers first. Then the hood, and then your two front fenders.

After that, paint the roof of your car. Now paint one side of your car in one shot.

Don’t start painting any other part if you feel some pressure is left in your tank.

Refill your tank, and start painting the other side of your car.

Similarly, now paint the front and back of the car together.

In this way, you can paint your car efficiently with a small air compressor without having any asymmetrical paint on your car.

Paint your entire car on the same day to have the same color shine and shade.

Never stop yourself from trying things. No matter if you face some shortage of resources, there are always many ways to figure it out!

Precautions to Follow While Spray Painting Your Car

There are several precautions if you plan to paint your car yourself at home. Therefore, make sure you follow the following precautionary measures before starting the painting process.

– Use space having proper ventilation.

– Read your paint materials safety data sheet (MSDS)

– Must use a respirator

– Cover your whole body while painting

– Take care of any spills right away

1. Use space having proper ventilation:

It is vital to make sure you are painting your car in an open space with proper ventilation.

Automotive color paints contain hazardous chemicals called VOCs (volatile organic compounds).

These VOCs are released in the air as soon as the paint can/bottle/container is opened.

These harmful chemicals are tiny particles that remain in the air even after work for up to 4 days.

Therefore, painting in a closed or fully covered space may result in chemicals affecting your health badly.

Let the garage door open if you are doing it in your garage.

Turn on the exhaust fan if you have one in the garage. Otherwise, try arranging some table/standing fans to release the chemicals outside your painting space.

2. Read your paint materials safety data sheet (MSDS):

Whichever paint you will use for your car, always read its MSDS (materials safety data sheet).

This materials safety data sheet lets you know all the chemicals it releases in the air.

You can then search those materials on the internet and the safety measures for that particular chemical.

This MSDS (materials safety data sheet) will also guide you about the thickness of the coat, optimal temperature of the environment, estimated drying time of the paint, etc.

3. Must use a respirator:

When painting your car yourself, you must have to use a respirator. It’s a form of highest security from hazardous chemicals.

The respirator will prevent the toxic and harmful chemicals from entering your body through the lungs. It will filter out the air before breathing and keep you safe from hazardous chemicals from inhaling.

4. Cover your whole body while painting:

Before painting your car, you must wear a full-body paint suit to cover your entire body.

Because the respirator is not enough to tackle the dangerous isocyanate chemicals from entering your body.

Isocyanates are highly reactive low molecular weight chemicals. This Isocyanate is used in paints, varnishes, and other auto-body repairing stuff.

Therefore, make sure to cover your whole body using a full-body paint suit, nitrile gloves, safety goggles, and of course, a respirator.

5. Take care of any spills right away:

I recommend covering your floor around the painting space with some old newspapers. It will protect your area from any unwanted paint spots.

If you spill even a tiny amount of paint on the floor, stop painting and clean it up immediately.

Otherwise, this spilled paint can give you a headache later on.

Also, make sure all the paint lids are tightly sealed after you’ve finished your painting work.

Air Compressor Paint Gun

For painting a car with an air compressor, you will need a paint gun and a nozzle.

The air consumption is controlled by the paint gun you use, so it’s crucial which paint gun you choose.

You have to fill the paint gun with your desired color paint. AS DISCUSSED ABOVE, higher CFM breaks the paint in very-fine mist liquid particles.

The compressed air from the air compressor pushes the paint from the air gun, then sprayed with a nozzle, attached with the spray gun to shower the paint on the car.

It is vital to properly prepare the car’s body surface for a professional and smooth painting experience.

How much PSI does a paint gun need to paint a car

Paint gun takes around a minimum of 15 PSI, whereas recommended PSI for clearer coats is around 20-25 PSI.

Spray Paint Gun Specifications

Before using the spray paint gun to paint your car, make sure the paint gun matches your air compressor’s specifications.

Regardless of the air compressor capacity, a professional spray paint gun will be efficient with every air compressor. So it’s crucial to use a professional spray paint gun to paint your car.

Recommended Paint Gun for Painting a Car

HVLP (High Volume Low Pressure) Spray Paint Gun offers a softer spray using a high air volume at low air pressure.

HVLP Spray Paint Gun is also recommended for painting smaller parts like bumper, fender, or other small-detailing areas.

Recommended Nozzle Sizes

If a spray paint gun comes with interchangeable tips, you can determine the thickness of the coating. So you can change the thickness of the paint according to your requirements.

Nozzle size depends on your requirement and preference.

As for the standard nozzle size, below we are sharing the recommended nozzle sizes for different requirements:

– Nozzle size 1.4 to 1.6 for sealers and single-stage urethanes

– Nozzle size 1.7 to 2.2 for primer surfacers and heavy body primers

– Nozzle 1.4 to 1.6 for basecoats spraying

– Nozzle size 1.3 to 1.7 for clear-coats spraying