​How to set up air compressor for paint spraying

Omode wants to set up a painting shop for his car repair workshop in Benin city, Edo state Nigeria, and he also wants to slowly grow this his care center. He wants to start with a small compressor of 20 liters and graduate to an even larger 200Liters compressor capacity to use some of his pneumatic tools. GZ Industrial supplies supported this effort by selling some of the best-grade industrial spray painting equipment and accessories to him. While this effort was time-consuming, this article explores a great way to do this same thing while not even contacting the team GZ for official support. We have equipment for the beginner spray painter and the expert and professional spray painter. We will guide you properly on how to set up air compressor for paint spraying in Nigeria.

If you are in the market for paint sprayers, do not hesitate to contact the GZ team for support, all for free. Whenever you have issues with the process, get in touch with GZ Industrial supplies or their accredited service agent to support both equipment purchase installation maintenance and training on the best way to use them.

Our effort can not be tiring to keep Nigeria industrialized and democratizing industrial and professional knowledge. It is easy, it is available, and we want to give it out for free.

How air compressor work

Air compressors use power — generated from a motor or engine — to compress air and deliver it in a pressurized flow to drive another operation or fulfill a task. In the auto industry, air compressors are frequently used for painting cars, using compressed air to deliver paint through a nozzle in a strong yet even flow.

An air compressor for spray painting operates by breaking up paint with pressurized air and using that pressure to produce a fine mist of paint through a nozzle. The air compressor for auto painting delivers air in a strong enough flow that the paint turns into a fine, liquid particulate, which is ideal for an even coat over the vehicle.

In addition to a consistent flow that ensures efficient use of paint, a compressor for auto painting is faster and easier than other painting methods. It enables full coverage — even in difficult-to-reach areas — without the need to manually check that paint covers every surface.

WHAT CAPACITY OF AIR COMPRESSOR SHOULD BE USED TO PAINT A CAR?

The answer depends on several factors. Based on the size of your operation and the types of auto paint you will need for the job., compressor criteria may differ. For example, a full-vehicle spray painting will have more challenging requirements than a repair or touch-up job.

The list below will account for some of these more common applications:

  • Tank size: The tank size of an air compressor for spray painting cars makes a difference in the overall efficiency of the operation. Smaller tanks will need to be refilled — sometimes several times — in larger jobs such as full-vehicle coating. Smaller tanks may also introduce more variance in the pressure and flow of the paint, leading to uneven coats. Tank sizes of 100 liters or more are preferable. In contrast, a tank size of 200 gallons or more will usually mean that an entire vehicle can be coated in one pass without refilling.
  • CFM rating: A higher CFM (cubic feet per minute) is required to do the job of breaking up paint into the tiny particles that make spray painting the vehicle possible. A high volume of air will make the critical difference in making sure that paint is applied evenly and that the finished coat appears uniform. A high-volume, low-pressure (HVLP) compressor is usually sufficient to complete an auto paint job. Look for two-stage compressors that deliver close to 20 CFM.
  • Air pressure: As mentioned above, pressure (psi) is less critical in an air compressor for painting cars than CFM is. The pressure rating indicates the pressure the paint is delivered from the nozzle, which is less critical than obtaining proper atomization of the paint through high CFM. Look for a minimum of 15 psi, with some applications, such as clear coat, better suited to 20 or 25 psi.
  • Horsepower: For auto painting, a 10hp compressor will typically suffice. However, higher horsepower compressors may operate more efficiently and can be used for other tasks.

Spray painting guarantees can help you to get a much more controlled and fine finish on your work than any hand-applied brush/roller job. However, just investing in any old spray paint kit and assuming it will immediately produce optimal results will not get you too far. To avoid improper application and the dreaded "orange peel" effect, you need a suitable kit. That means getting a spray paint compressor that meets the specifications your spray gun setup requires.

This article will help you with everything you need to know regarding paint compressors and the required technical delivery elements. Then, once you know what you are doing, we will now tell you about a few of the best spray gun and compressor kits available on the GZ Industrial supplies website. We do one thing better. Make you a professional.

Check this air compressor

What is a gun compressor?

When we talk about an air compressor for painting, we are not talking about a specific type of compressor exclusive to spray painting function, but rather a suitable air compressor for spray gun use. Air compressors use a power source to create pressurized air in a storage tank, which can then be used for various applications, including spray painting. Different air compressors have other pressure limits, which is where choosing the right one comes into play.

Most air paint spray guns use a high-volume-low-pressure or (HVLP) delivery mechanism. Thus it is essential to find a spray paint compressor that delivers the required pressure and volume of air to create a consistent paint flow that will give you a perfect finish.

What is HVLP?

HVLP spray guns atomize paint coatings by employing a high air volume at low air-cap pressure, typically in a pressure range around a quarter or less than conventional methods. This means the sprayed material has less velocity, so it is less likely to "bounce back, "increasing paint transfer efficiency. The HVLP method also delivers a much softer spray which reduces material waste. However, they demand a higher air volume than conventional sprayers, meaning a bigger compressor is required.

Buy Spray gun

Have you checked the air compressor requirements for spray painting?

There are three critical measurements to consider when compressed air spray painting. The first is pounds per square inch (PSI), the second is cubic feet per minute (CFM), and the third is tank size. As you can guess from the "low pressure" part of HVLP delivery, you will not need much pressure to get the job done, but you still need to ensure you have a high enough PSI to ensure consistent delivery.

The CFM measurement is arguably the most crucial factor to consider when choosing your compressor. CFM measures the air volume produced by the compressor per minute and the quantity of air the compressor can have at a given PSI. The CFM rating of your compressor should be higher than, not equal to, the CFM requirements of your air spray gun; otherwise, you risk both pressure drop and volume loss, which are the two leading causes of insufficient coverage. As alluded to above, the "high volume" element of HVLP spray guns is a big clue that you will always require a larger compressor.

Tank size of compressors matters when it concerns spray painting. Tank size helps maintain a steady flow of air, and spray gun operation requires a constant flow of air rather than intermittent supply, as with many other pneumatic tools. Thus, your compressor needs to have adequate storage to keep up with the gun.

What is the amount of CFM you need for spray painting?

Paint gun CFM requirements differ from model to model, with small spray guns naturally requiring a lower CFM than bigger options. While some air spray guns have a rating lower than 10 CFM, we recommend your compressor CFM for spray painting is at least 12 CFM.

This figure may need to be higher for professionals – the important thing is that you should check your spray gun's CFM requirements and choose a compressor that exceeds that figure.

What is the best air pressure for spray painting?

Again, you must check your specific model's recommendations. Still, your HVLP spray gun PSI will likely sit between 25-30 PSI for something like using an air compressor for spraying cars, rising to 40 PSI in some cases where higher atomization is needed.

HOW TO SPRAY PAINT WITH AN AIR COMPRESSOR

Wondering how to use a spray gun with your new compressor? Here's what you'll need to get started:

  • Safety gear: a respirator or mask, goggles, and gloves
  • A suitable air compressor for your spray gun
  • Hose
  • Spray gun attachments: filter, regulator, quick disconnect fittings – although you might not need all of these, depending on your requirements.

Here's the process:

  • Apply your safety gear before starting any work
  • Connect your air spray gun to your air compressor via the hose and other attachments (see diagram above)
  • Ensure your compressor is delivering adequate CFM
  • Mix your paint/primer and solvent to the recommended ratios.
  • Test your pressure paint sprayer pattern on a piece of cardboard to check your compressed air spray is delivering a consistent paint flow. You can adjust your spray pattern on most HVLP spray guns via a knob on the side of the gun.
  • Apply an even coat of paint to your chosen surface, applying a second coat if required 12-24 hours later (once the first coat is dry).

YOUR AIR SPRAY GUN AND PAINT COMPRESSOR CHECKLIST

As we've already established, ensuring you've got the adequate CFM and volume in your compressor tank to do the job consistently is essential. However, despite all your best efforts and preparations, you might find that you're still facing problems with air pressure.

If you are struggling to get the results you're looking for, there's a checklist of things to go over to ensure you're getting optimal performance from your spray gun and air line setup.

How narrow is the air hose?

The hose you're using can be the source of pressure issues if too narrow or too long. The inside diameter (ID) of your hose is the measurement to look out for, with a smaller ID translating to less air getting through the line, and therefore less pressure. For example, if you're using a 5/16 inch (7.9mm) hose, you'll get less pressure than a wider diameter 3/8 inch (9.5mm) option.

With HVLP spray guns, an ID of more than a ¼ inch is advisable, with a hose larger than 5/16 inch needed to meet typical HVLP volume requirements. A word of warning, though – bigger is not always better. Bigger can often mean a longer hose, which also needs to be taken into consideration.

Is the Air Hose too long?

As the compressed air travels through a hose, the pressure decreases as distance increases from the compressor, meaning a lengthy hose can be detrimental to a high-pressure paint gun. As a rule of thumb, it's best to use as short a hose as feasibly possible with a decent width ID.

Using Quick disconnect fittings (QDs) – do you need them?

Quick disconnect fittings (QDs) are hand-fitted air connectors that allow for fast and easy connection and disconnection of the airline. They replace traditional fitting connectors, which often require assembly and disassembly tools, making them decidedly quicker to use and benefit the user experience considerably. However, depending on how many are used and their design quality, QDs can be a hindrance when it comes to maintaining air pressure.

Depending on your pressure spray gun's design and volume requirements, the pressure drop from a QD can lie between 1-25 PSI. So, you must pick your QD design carefully, choosing the least restrictive unit possible. Using many air connectors can also cause pressure to drop.

One standard pressure issue relating to QD use is a small aperture in the female portion of the component, with the narrow diameter restricting airflow, just as with a small ID hose. If you are going to use QDs, ensure you use "high-flow" options that offer the most oversized practical diameter to minimize any pressure loss.

The fundamental question is: are QDs necessary? If you're only planning to remove your air hose from your spray gun and compressor once or twice a day, the simple answer is no. you may need a simple hose clip.

Need for air regulator.

Is the air regulator high flow and of good quality? Air spray gun regulators provide precise adjustment of the airflow and air pressure, which ensures consistent results. However, their design can also restrict airflow and create an excessive pressure drop. There are two types of paint gun filter regulators - wall-mounted and gun-mounted.

Typically, larger wall-mounted regulators provide constant air pressure to the gun, minimizing the dreaded pressure drop. Your spray gun pressure regulator should be capable of flowing enough air for the spray gun to operate efficiently and offer a capacity greater than your air spray gun's demand.

To determine if the regulator is too restrictive, compare in-use and not-in-use readings on your spray gun regulator with the gauge. The difference between the two readings should be 5 PSI or less.

Although regulators control the air pressure, the system may still experience fluctuations, particularly when an air-adjustment valve-type restrictor is being used. The air will exit the air cap with an initial burst of pressure, which then levels off to the adjusted pressure, but this may vary because of changes in system pressure.

Air regulator

What is the Performance Specification of the Air Compressor?

The fundamental requirements of your compressor are that it needs to supply sufficient, clean (oil-free) and dry (water-free) air while also being the correct size to facilitate the air pressure and volume requirements of the whole system. This is important because, as previously mentioned, the restrictions of certain QDs, a narrow hose ID, and the regulator can all play a factor in alleviating pressure, which is why it's necessary to have a spray paint compressor that produces a higher CFM than your HVLP spray gun.

Always ensure to keep the system clean; to achieve this, the air tank must be drained of any water and the spray gun filters checked to determine they are spotless and functional. We recommend having a final air filter installed on the gun itself. 

Jun 10, 2021 Theodora Nnagbo

Recent events