What size air compressor do I need to paint a car? A ubiquitous question that a lot of you need the answer to. An air compressor is a tool that intakes atmospheric air and pressurizes and compresses it to provide compressed air for various different applications. This compressed air is used to run different air tools for varieties of applications. These air tools need different amounts of compressed air with different levels of pressure to do their works. This is why there are compressors with various types and sizes manufactured to be suitable for different kinds of works. So, to work efficiently and you need to use a Suitable air compressor that is appropriate for the task you need to do.

For instance, let’s take spray painting. If you are going to use an air compressor for spray painting a car, you need to consider (quite seriously, in fact) the tank size of the compressor you’ll be using. Because it is one of those tasks that need continuous air supply to provide you with a consistent paint flow and not an intermittent supply. Can you paint with a small compressor? Well, you can. But, a smaller tank will need refills at shorter intervals, which will reduce the duration of a consistent flow and cause interruptions of work. So, the paint job outcome of small capacity air compressors will not be smooth, there will be rough strokes, and the work will be inefficient.

Air Compressor Parameters to Paint a Car

1. CFM Rating

CFM (cubic feet per minute) rating is an essential factor that you need to consider for painting a car before buying an air compressor for auto painting. CFM indicates the volume of air a compressor can blow out at a given pressure at a certain time. The CFM requirements of spray guns differ from model to model. However, spray painting is a task that typically requires a higher level of CFM rating. That much is for certain. This CFM output will do the job of breaking up the paint into small particles, and this makes the concept of spray painting practicable. So, higher CFM will ensure a better result.

You can use a device with a lower CFM level. But, if you use a lower CFM level, it will result in uneven paint distribution and poor paint quality. it will become a very tough job to get the desired result. So, it is recommended to get an air compressor with a high CFM rating. You should get a compression unit that is capable of providing a 14-18 CFM rating if you want to do auto paint jobs and maintain quality and efficiency. However, if the task is minor, such as giving a retouch, then a device with 5 CFM may be enough.

2. Size of the Air Compressor Tank

The size of the compressor tank is another one of the most important parameters that you need to consider for auto painting. Using a smaller size compressor will cause interruption to work and result in a poor quality paint job.

Although, you can use a smaller size compressor with a smaller air tank. There are small air compression unit models, which are able to provide higher CFM ratings to fulfill the needed parameters for auto painting. But, we should warn you that this will require a certain sense to feel the air pressure and adjust it accordingly. So, you need a level of experience like high-end professionals. Smaller compressors will have inferior air volume capacity and will not be able to provide a continuous flow of air, which will result in work interruptions.

Also, even if you try this, the air tank of your compressing machine will get extremely hot, which happens due to the constant high pressure. Moreover, a comparatively larger amount of liquid will be accumulated inside, which increases the necessity of draining the liquid inside your machine in order to resist damage. These problems will become a great deal of pain for you.

Overall, taking everything into consideration, we recommend you to get a larger compressor with a capacity of at least 50-60 gallons. A compressor of this size will be capable of providing you an adequate supply of air flow easily and this constant flow will help you in efficiently handling the painting of your vehicle.

3. Air Pressure

Another crucial factor for auto painting is air pressure. A certain level of pressure is required to run your air spray gun and carry out the auto painting operation. So, you should get an air compressor that meets the pressure rating requirements of your spray tool and task.

There’s something worth mentioning. Many of the users think that getting a compression unit with higher PSI will ensure smooth and even coating of paint on the platform. But, that’s not necessarily the case. There are many low pressure paint sprayer models available. You can easily use a low-pressure air spray gun with a high-volume compression unit. This low-pressure spray painter system will not require a high PSI to function, and there will be a high CFM available for the operation.

4. Horsepower

The horsepower rating of a machine is the measurement of the amount of power it can provide to carry out the functions properly. This does not mean that if you have a higher HP compressor, it will enable you to get a higher level of performance from your paint sprayer. Nevertheless, we advise you to buy a compression unit that has a higher level of horsepower because then it can be used for other pneumatic tools too.

paint a car with an air compressor infographics

How to Paint a Car with an air compressor

Required Tools

  • Safety gear: Mask, goggles, and gloves
  • Suitable air compressor
  • Spray painting gun
  • Hose
  • Air spray gun attachments: filter, regulator, quick disconnect fittings (Which one these types of tools are required will depend on the work)

Working Procedure

  • Safety comes first. So, first of all, you need to gear up before starting any work.
  • Secondly, you need to connect the paint sprayer to the air compressor using the hose and other necessary attachments.
  • You need to make sure that the compression unit is providing an adequate level of CFM to the system.
  • You need to prepare the paint by mixing your paints, elements, and solvents, maintaining the recommended ratio.
  • Then, you need to test the system and the output on a  separate piece of cardboard or something similar. You need to make sure that you are receiving consistent paint flow and the outcome is matching the desired result. In general, an HVLP spray painter has a knob on the side of the air spray gun. You can regulate this knob of an HVLP spray painter to adjust the spray pattern.
  • Start applying the paint coating on your chosen surface. If it is necessary to apply a second coating, you should do it after 12-24 hours. This will allow the first coating to dry.

Final Words

Air compressor has a wide variety of applications, and one of them is auto spray painting. Maybe you run an auto workshop and want a compressor for auto painting, or perhaps you want to paint your own car at home; in either case, it is necessary to consider some measurements and parameters according to the job you will do and the level of performance the job requires before deciding which type of compressor you are going to buy. The main thing is to get the appropriate tool to get the best possible result in the most efficient way.

You can use alternatives. You can use a smaller compressor to do a job like painting your car. But, even then, you should consider the necessary changes that you need to do to properly carry out the task you have to do.

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Hi, and welcome to Toolented. My name is Michael D. Sanders. I am a Mechanical Engineer by degree, who is a blogger by passion, and this combination of knowledge and passion is what brought Toolented to life. On my blog website, you will find necessary information about your needed automotive tools, reviews of your potential choices, and comparisons between different types of tools. To learn more click here.

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