Choosing an Air Compressor for your Automotive Shop

Air compressors are a key piece of equipment for automotive paintwork professionals, but they often don’t come cheap. For this reason, it’s super important that your first choice of air compressor is the right choice. It’s also equally as important to ensure the equipment will give you your desired paint finish each time, whether you’re using lacquer or urethane car paint types.

Here, we’ll explain why this equipment is so vital in your automotive shop, before taking you through all the necessary considerations when deciding which type to go for.

Air Compressors: Explained

Air compressors are an essential tool to help bodywork painting professionals achieve a strong and continuous flow of paint throughout their paint job.

But first, there are a few commonly mentioned technical terms to go through concerning the functions of air compressors. We’ll explain these below to help you understand what we mean by each one.

• CFM – Cubic feet per minute refers to the volume of air in cubic feet for each minute of movement.

• FAD – Free air delivery is the volume of compressed air that an air compressor discharges from the compression process. This is usually less than the CFM. 

• PSI – Pound per square inch measures the amount of pressure placed on a single square inch of space.

• HP – Horsepower measures the working capacity of the motor or engine driving the compressor.

The next thing to understand is that there are multiple types of air compressors available.

1-stage compressors only deliver 1CFM/hp, while 2-stage compressors provide around 4 CFM/hp. The most popular options that automotive paintwork professionals go for are rotary screw and piston compressors.

The reason that these are some of the most popular options in automotive shops is that they’re often quieter, more efficient and can handle the high volume of air required by paint sprayers.

Many auto repair professionals will also opt for a rotary screw compressor over a piston compressor because of its three-stage motor offering a better compression performance. Meanwhile, piston compressors run from a single-piston motor which can vibrate more and is usually louder. They also offer a less powerful compression, which isn’t ideal for painting large areas or completing jobs that might take longer.

Choosing an Air Compressor: Things to Consider

So, the next thing to consider is the required features you want your air compressor to deliver on. Below, we’ll guide you through the main considerations to ponder over when you’re deciding on which air compressor to purchase for your automotive shop.

Size

The tank size is an important consideration to think about because this will affect the efficiency of your equipment and the painting process.

A bigger tank will allow for continuous use of your air sprayer over a longer period without the need for a refill. However, a smaller tank will slow down the spray-painting process since it’s likely you’ll need to refill the tank more often when you run out of compressed air.

Cost

Cost is an important factor to consider when purchasing any piece of equipment for your automotive shop. It’s necessary to think about your budget and your needs in combination when considering the price of your air compressor.

For example, if painting isn’t a major service offered by your shop and you’re working with a smaller budget, it might be best to go for a portable or piston air compressor. While these won’t offer the same efficiency and performance as a 2-stage compressor such as a rotary screw, they will still allow you to achieve an evenly distributed paint job.

However, if you’re willing to spend a bit more and often need to use a spray painting gun, we’d recommend choosing a 2-stage air compressor. These are often more expensive but are definitely worth the investment.

Capacity/flow pressure

The flow pressure needed depends on the task at hand. For example, a lower flow pressure is often enough for painting a smaller panel with a good time gap between coats. This is because it can provide just enough CFM to paint the area before the equipment needs to build back its pressure for the next job.

However, a higher FAD or flow pressure is needed in most cases for automotive professionals because it can offer more CFM. Therefore, the pressure can flow for longer and allow you to complete a variety of painting jobs.

CFM

To achieve the best finish, it’s recommended to choose a compressor offering up to 20 CFM. Since most auto repair professionals work with high-quality low-volume (HVLP) air guns, this high volume of air in relation to cubic feet will aid with achieving the highest quality finish.

It’s usually ideal for CFM to be between 10 and 15 if possible.

What is the Minimum Size Air Compressor for Painting a Car?

The minimum size air compressor you need will depend on the size of the job at hand. However, it’s recommended that you choose a tank size over 50 gallons if you intend to use it for painting a car.

Choosing the best equipment possible can be instrumental in helping you run a successful automotive body shop. So, we hope this guide provides all the assistance needed to aid with your air compressor machinery decision.

Our tape solutions are the perfect tool for completing auto repair and bodywork jobs to a higher standard. Visit our online store to discover the full range of JTAPE products available, or contact us today to find your local distributor.