Getting the Most Out of Your Spray Gun

Spray guns atomize liquid paint coatings for even transfer onto a surface, producing smooth, uniform finishes. They are essential professional tools for automotive finishing and refinishing jobs.

For best results, keep the gun perpendicular to the surface and maintain a consistent distance between the nozzle tip and the object being sprayed. The ideal distance is 30 centimetres, which equates to the length of your arm from elbow to wrist.

How to Use

Getting the most out of your spray gun starts with choosing the right settings for the paint you’re using. Most of these can be found in the owner’s manual for your sprayer or on the manufacturer’s website.

During use, keep the gun about 6 to 8 inches (15 to 20 cm) away from the product’s surface or about a hand’s length. This distance will affect your spray pattern and overall finish. You can also spray gun adjust the air pressure setting, fluid tip and air cap to suit your project.

Most common spraying problems are solved by cleaning the gun and changing the air cap or fluid nozzle. Be sure to empty the paint and run solvent through the gun until cleaner is coming out of the nozzle before you try spraying again. The thick, inflexible hose that connects the compressor to the gun gets hot and needs to be handled carefully, especially in the first metre or so from the turbine. Consider adding a short flexible whip hose between the end of the hose and the gun to make this easier to manage.

A final tip, when painting a strip or row, point the gun at the beginning and end of the area you’re working in to avoid sagging and overlapping marks. This technique will give you even coverage.

Troubleshooting

A spray gun is a complicated piece of equipment with many parts that must work together in unison. Because of this, there are a lot of opportunities for trouble to occur. Fortunately, most issues can be fixed by a few quick tests.

Spray pulsing or fluttering (hissing sound): This can be caused by a loose nozzle that needs to be tightened. Using a socket or line wrench to turn the nozzle clockwise should fix this problem.

Uneven spray pattern: If your gun’s spray pattern is uneven it may be because the air cap is worn and needs to be replaced. You can test this by flipping the air cap 180 degrees and seeing if the irregular pattern switches to the other side of the gun.

Fluid leaking from the nozzle: If there is a leaking fluid from your spray gun this can be due to a worn needle or clogged nozzle. You can test this by removing the nozzle and checking it for a blockage and then replacing it with a new one.

If you’re using an HVLP paint gun, the same steps above should apply for repairing a soft seal. You should always do a test spray on some scrap material before jumping into your project. This is important because it lets you check the quality of your paint, adjust conveyor belt your air, fluid, and fan knobs, and make sure that your compressor has the right PSI for the job.

Cleaning

Taking the time to clean your paint spray gun after each use will help ensure that it keeps working correctly. It also allows you to switch between different types of paint quickly and efficiently. Whether you are switching from a clear coat to a base coat, or from a stain to a paint, you will need to remove and clean the needle, fluid nozzle, and air cap for each application.

Using the tools that came with your spray gun, remove the fluid nozzle from underneath the air cap. Clean this piece thoroughly with VertecBio(tm) Citrus I20, and then replace it on the front of the gun.

Next, you will need to remove the air cap from the back of the gun. This is where all of the air passes through to reach your spray nozzle. This is where the most paint accumulates, so it is important to keep it clean. Use a paper towel to wipe off as much of the hardened material (catalyzed) as possible. This will make the rinsing process much easier later on.

Now that the air cap has been removed, and all of the parts have been rinsed, or soaked in the appropriate cleaning solvent, it is time to reassemble your spray gun. Remember to take the extra time to clean out the holes in the air cap. These can clog if they are not cleaned regularly, and will interfere with the spray pattern of your gun.

Maintenance

It’s important that a shop has a daily/weekly maintenance program in place to keep spray guns clean and working properly. This will reduce the need for retouching and reapplication, as well as increase the lifespan of the spray gun equipment.

In addition, a quality maintenance program can help maintain a safe work environment. The proper removal of paint residues and contaminants can prevent accidents and injuries. By eliminating these hazards, a hygienic and organized workspace is maintained that contributes to employee morale.

A good cleaning procedure begins by relieving the air pressure in the spray gun by opening the air adjustment valve and triggering the gun until no paint comes out. Then the gun should be disconnected from the air supply and disassembled according to the manufacturer’s instructions. Care should be taken to remove and organize the parts for easy reassembly. Special attention should be given to the fluid nozzle, needle and air cap. These are delicate components that should not be submerged in water or cleaning solvent for an extended time. A clean lint free towel must be used to wipe them off after removing them from the cleaning solution to avoid damage.

It is recommended to use a high-quality storage fluid, such as Dynasolve CU-6, for spray gun equipment when it is not in use. This can eliminate the formation of polyurea and crystallized isocyanates that react with moisture in the air to cause corrosion.