A Guide to Spray Gun Cleaning & Maintenance

DIY-ing your own vehicle paint job is actually a pretty simple process. As long as you have the proper work space and tools, painting your own vehicle can be painless and easy.

Clean-up doesn't have to be a long drawn-out process either, especially if you take good care of your tools in between uses. Items like paint spray guns might seem like a hassle to keep clean and ready-to-use, but with a few tips and tricks, it can be very simple.

All About Paint Guns

Paint guns are used for a variety of automotive updates. Whether you're repainting your own vehicle or applying undercoating to protect from rust and damage, they can make it much easier to quickly complete various tasks.

There are a few different types of paint guns, but most are generally manufactured with the same components. Each gun will feature two different passageways -- one for the paint, and one for air. A vacuum is formed when the paint gun is in use by the air rushing past the fluid chamber while simultaneously pulling the paint or fluid directly into the air stream.

Gravity Feed automotive paint guns use gravity to supply a steady flow of paint, and therefore require less air pressure (usually supplied by a small compressor) and provide more control.

HVLP (or high volume low pressue) automotive paint guns also need less pressure to complete a good coat, and make up for this by using more air.

Tips For Using a Paint Gun

When it comes to utilizing your paint gun, make sure you have the proper tools assembled first. You'll need:

An air compressor
The right type of paint or topcoat you'll be spraying
A spray gun cleaner or other automotive-grade paint gun cleaning solvent
A few spare buckets for cleaning
Gloves
A respirator to avoid breathing fumes
Access to a hose or other water source
A few small brushes to make clean-up easier.

How To Clean a Paint Gun

It's important to clean your paint gun immediately following use. This helps keep it functioning like new and prevents you from having to run out and buy a new one for every project. Even allowing the paint to sit for a few hours is not recommended, as at that point even soaking the gun won't remove very much residue.

Most home mechanics won't have access to spray gun wash stations like an auto body shop would, but it's easy to achieve a thorough clean job without one thanks to the various paint gun cleaning products available. From paint gun cleaning kits to basic paint gun washers, cleaning has never been easier.

When cleaning your paint gun, wearing gloves is recommended, as this will keep your hands protected from chemical thinners and hardeners.

Steps 1-6: Removing Paint Residue

Detach the air regulator from the paint gun. Before doing this, make sure the air compressor is also detached.
Remove ALL of the paint from your paint gun. If you've added a hardener to your paint, DO NOT return the paint to its original paint can, as the hardener will also set the remaining paint in the can as well. If you were merely applying a basecoat with no added hardener, feel free to empty that back into its can for another use.
Wipe the container and its lip with paper towels to remove as much leftover liquid as possible. This will make it easier to deep-clean with the thinner of your choice.
Pour a small amount of your selected thinner into the paint gun's cup, filling the gun's throat as well. Put the cap back on the cup and shake the gun gently but thoroughly to ensure that the thinner coats the inner surfaces and also helps dissolve excess residue.
Run the thinner through the gun's mechanisms by emptying the contents of the cup into a waste container. Point the nozzle and squeeze the trigger as you would during paint application.
Dry the gun with paper towels, and repeat steps 4-5 at least once. 3-4 cycles is recommended for the best deep-cleaning.

Steps 7-13 : Spray Gun Cleaning

Now it's time to clean the actual gun to ensure that it will be operable for your next project. Any sticky paint residue will make it harder to use and isn't good to leave sitting in the mechanisms. The small paint gun parts that you remove will need to be individually cleaned in thinner as well. Have a small container of the thinner sitting by so that you can place them in it as you take them off.

Remove the clean paint cup from the gun. If you would like, you can soak it in thinner again to ensure all residue is completely removed.
Remove the fluid adjustment knob from the gun (generally the center knob located on the rear of the gun, but may vary according to model) and then remove the now exposed spring. Press on the trigger, and gently pull the fluid needle out. This helps prevent the needle from getting bent or damaged during the cleaning process.
Remove the air cap on the front of the paint gun (turning it counter clockwise). Now you can remove the fluid nozzle and both pieces should be placed in the thinner bath with other pieces so that all the paint is removed.
Rinse the entire gun first in thinner, and then in water. If the small pieces that have been soaking in the thinner need an extra scrub, go ahead and do that now. Make sure you also clean paint from any gaskets and hard-to-reach areas, using Q-tips or an old toothbrush. This part of the process can seem long and drawn-out, but a thorough cleaning now will ensure your paint gun is fully ready to be used the next time.
Dry all exposed parts of the paint gun with paper towel after rinsing, and then go over the entire gun with compressed air, making sure you're drying all the holes and moving parts to remove any excess water. Double check your work and dry the gun completely as any residual water drops can be blown back into the mechanisms of the gun.
Rinse and dry all of the individual parts of the gun you have removed and reassemble your paint gun. This task is a lot easier if you lubricate any threads and moving parts as you go.
Wipe the gun clean to remove any excess oil, and check to make sure that it will function properly the next time you go to use it.

Your paint gun is now completely clean and ready to store.

Keeping Your Paint Gun Clean - Tips and Tricks

Using the right spray gun cleaner solvent to keep your paint gun clean is crucial to the task. Most store-bought paint thinner tends to not be heavy-duty enough for enamel and oil-based paints, or undercoating and Rustoleum. A paint gun cleaning solution or an automotive grade lacquer thinner will work best for a thorough cleaning.
Disposable paint cup liners for your paint gun are also available to use if you'd prefer to keep your exposure to harsh substances in cleaners to a minimum.
There are also more naturally-based cleaners that still do a decent job removing paint from your paint guns. One is citrus-based, using d-Limonene as the primary cleaner, which is derived from citrus plants. It can be used to flush the paint gun much like a standard thinner or paint remover, but is not a good fit for cleaning waterborne coatings. This type of cleaner also requires more dry-time, so make sure you dry your paint gun thoroughly if using citrus-based cleaners.
If you're between coats of paint of the same color, and need to allow the first coat to dry, remove the paint nozzle from the spray gun and give it a quick rinse so it doesn't dry and clog. You can even let it rest in a bath of thinner until you're ready to apply the second coat. Set the spray gun off to its side out of the sun or heat, and if paint solidifying in the aircap is a concern, you can wrap it in a wet rag til next use. Make sure thinner is completely removed from the tip before replacing and continuing with the second coat.
Spray guns should absolutely be cleaned between coats if you are switching from paint to lacquer, or will need to use a second type or color of paint. Follow the cleaning steps above to ensure your paint gun is ready to be used again.
Most paint guns, regardless of whether they're gravity or HVLP paint guns, can all be cleaned following the steps above.

No matter how big or small the job, Auto Body Toolmart is bound to have the perfect paint gun for your needs. Browse our spray guns online to shop all your favorite brands, including 3M, DeVilbiss and more.