Why Is My HVLP Spray Gun Spitting?

As an Amazon Associate we earn from qualifying purchases.

HVLP spray guns are precise machines, known for their ability to produce a smooth and even coat of finish with minimal overspray. However, there is a learning curve for using these powerful machines. If your HVLP spray gun is spitting fluid instead of emitting a fine spray, read this article to find out why and how to fix it. 

Why Do HVLP Spray Guns Spit? 

HVLP spray guns usually spit instead of spray when there is air entering the spray system inappropriately. Your spray gun works by tightly controlling the flow of air. Air should only enter the system through the air cap and spray tip. If a leak or improperly fitting connection is allowing excess air to enter, this can often cause HVLP spray guns to spit. 

Reasons your HVLP Spray Gun Might Be Spitting

Run through this list and check all the connections on your HVLP spray gun system to eliminate unwanted sources of air that cause spitting.

  • Wrong size fluid needle. You must use a fluid needle that is compatible with your machine and an appropriate size for the fluid you are spraying. The fluid needle is matched to the air cap. Double check the manufacturer’s recommendations against the fluid needle and air cap installed on your machine, and adjust as necessary. 
  • Paint cup is loose. The paint cup must be threaded properly and tightly connected to the spray gun.
  • Fluid nozzle is loose/worn. The fluid nozzle should be tightly screwed onto the spray gun. Make sure it fits well, that there are no gaps, and that the nozzle doesn’t look worn. 
  • Pick up tube not immersed in spray medium. If you have a model of HVLP spray gun that is compatible with a pickup tube, make sure there is enough fluid in your large container to cover the pickup tube intake. Keep the larger container close to where you’re working, to ensure the tube isn’t pulling out of the fluid as you move around to spray.
  • Connecting hoses are cracked. Visually inspect the entire surface of the hose that connects your HVLP sprayer to your compressor or turbine. Bend the hose back and forth to reveal any minute cracks or leaks. If there are any holes, replace the hoses. Make sure the replacement hose fits tightly and snugly. 
  • Packing or packing nut malfunction. The fluid needle is held in place by packing and a packing nut, which compresses the packing to keep the fluid needle from sliding around. If the packing is worn out or damaged or the packing nut is not properly adjusted, spitting can be the result. Make sure the packing nut is tight, but not overly tightened. 
  • Dirty or damaged air flow distribution ring. Some paint spray systems have a small part called the airflow distribution ring. When this part becomes dirty or damaged, it affects the airflow and can lead to spitting. You can try disassembling the machine and thoroughly cleaning the airflow distribution ring. If that doesn’t work, replacement rings are inexpensive and easy to install. 

Read our HVLP Spray Gun reviews to find the right one for your project.

My HVLP Spray Gun Is Still Spitting — What Else Can I Try? 

If you’ve gone through the list of common culprits, here are some other things you can try to eliminate spitting in your HVLP spray gun. 

  • Replace the fluid needle. The fluid needle on an HVLP spray gun can wear out with heavy use. It is also easily bent and may have become damaged during cleaning. Fixing the problem may require replacement of the fluid needle. 
  • Replace the fluid tip. A worn-out fluid tip distorts the spray coming from your HVLP spray gun. Popping a new fluid tip on the gun can sometimes fix the problem. 
  • Clean the fluid tip. Check the fluid tip for dirt, debris, or dried paint. To prevent a clogged fluid tip, always strain your paint before adding it to your paint cup. Make sure to completely disassemble and clean your machine after every use

Conclusion

Most HVLP paint sprayers will spit instead of spray from time to time. Double-check all the components of your sprayer to make sure they are in good condition, connected appropriately, and tightly fitting. If the sprayer still spits, you may have to replace a component to get back to the job at hand. 

Christmas Scroll Saw Template Packs for Sale

Ellenkate grew up on job sites run by her family’s construction company. She earned her theater degree from The Hartt School, a prestigious performing arts conservatory in Connecticut. Her design and DIY work from her Chicago loft was featured in the Chicago Reader and on Apartment Therapy.