Why Is My HVLP Spray Gun Spitting?

HVLP spray gun is a widely used tool in the painting industry. It has occupied the whole market of painting equipment. It has completely changed the style of working saving time and labor.

Those were the days when the painters had to spend exhausting working hours painting a surface and making it charming. HVLP gun is a unique gift for professional painters.

As you know that many paint-producing Industries are offering their products in the market. But all types of paints are not compatible with the HVLP spray gun’s technical features. That is why many issues arise while spraying with an HVLP spray gun.

These issues are of different types but the most commonly arising issue is HVLP Spray Gun Spitting while spraying.

Some Basic Important Things To Know For Using An HVLP Spray Gun

If you use an HVLP spray gun for painting, keep in mind the following points.

  • #1: The paint in your hand must be manufactured for HVLP guns
  • #2: Read the technical data sheet of the paint company to adjust the gun with perfection
  • #3: The paint thinner must be in your hand to make the right consistency of the paint
  • #4: You should have set the air compressor of the HVLP gun in the right position
  • #5: The nozzle of the HVLP spray gun should be the same and compatible with the paint used
  • #6: You should set the right place and time to use the HVLP spray gun
  • #7: Keep all the necessary equipment for painting with you

What Is Spitting In A Spray Gun?

Spitting in a spray gun refers to releasing/leaking the fluid or liquid outside from the air cap. When the gun runs with high-level air pressure, the liquid can leak even from the slightest opening. So the air enters in fluid supply area and results in spitting.

When Does Spitting Occur In HVLP Spray Gun?

Spitting mostly occurs when the nozzle of your HVLP spray gun is not adjusted properly or screwed into the suitable right place.

Sometimes it is fitted tightly and sometimes it remains loose in a hurry. Sometimes the paint remains thicker than the standard pattern and sometimes it dries up and blocks the gun.

When Does Spitting Occur In HVLP Spray Gun

Here I have searched for some common reasons why spitting happens. After reading this article, I believe you will get the answer to the question; why is my paint spray gun spitting?

#1. Blockage In The Fluid Nozzle

When the fluid nozzle is not adjusted properly at the right position or it is loose, the gap remains between the tip of the gun and the fluid nozzle, and then the air enters the fluid supply which creates a spitting situation in the gun. It is not only dangerous but also wastes material.

If you adjust the nozzle exactly in the right position, this situation can be avoided without further damage, and the air is prevented to enter the fluid.

#2. Fitting The Unsuitable Air Cap

If the air cap is not fitted well, mostly in the suction-fed spray gun, it creates spitting issues. So the wrong adjustment of this pressure-fed air cap may cause spitting and great loss also.

#3. Loose Fluid Packing Nut

When the connection between the packing nut and paint sprayer is loose, it can cause spitting from the spray gun. These adjustments always need an expert hand to fit them properly.

So to tackle the paint gun spray pattern problems, make sure that nuts and seals have been fitted correctly.

#4. Wrong Adjustment Of Suction Cup

When the suction cup is not seated properly or tightly into the spray gun, its threads are not stripped, and your gun can start spitting.

To avoid the situation, check the cup’s thread and gun’s thread, they should be adjusted well for a perfect shape. Otherwise, buy a new gun.

#5. The Use Of Heavy Materials Or Viscosity

If the painting material is thick, dense, or weighty, it stops the spray gun to work properly.

Spitting mostly occurs due to the high level of viscosity, because, in a suction-fed spray gun, there is a wide fluid nozzle that allows the passage to paint.

#6. Low-Pressure Cause Spitting

Among the paint gun spray pattern problems, the low pressure is also an important one because the proper working of the gun needs the standard pressure.

When the pressure is less than required, the paint doesn’t come out fully and causes a lot of spitting.

#7. Cracking In Hosepipe Cause Spitting

If the hosepipe is cracked or has holes in it, it would be another addition to HVLP spray gun troubleshooting.

The paint will leak through these cracking areas and cause spitting not only on the surface but also on the sides.

So make sure that all such types of opening/cracking should be closed tightly. You may also replace the pipe if necessary.

#8. Gathering Unnecessary Material In The Air Cap Cause Spitting

One question commonly asked is why my Wagner paint sprayer is spitting paint. I generally tell them that unnecessary material gathered in the air cap is the biggest hindrance to the paint flow.

When some material is gathered and blocks the gun and you pull the trigger, it can suddenly blast and cause a lot of spitting and other loss.

#9. Dried Paint Cause Spitting

When the HVLP spray gun is not spraying properly, check the gun completely, there may be dried paint in all the parts of the gun that doesn’t allow it to run properly.

If you use a gun and keep it unwashed, the paint in the gun dries and causes blocking and spitting.

So when somebody says why my Graco gun is spitting, I usually tell him to disassemble the gun and wash it with oil.

#10. The Impurities Cause Spitting

When you want to spray paint with an HVLP spray gun, check the impurities like dirt, debris, filth, etc. which cause spitting. Now remove them neatly using a good sieve or filter. When the paint is strained, it can be used easily.

Tips To Keep In Mind

All the above-discussed points are actually precautious steps;

  • In order to minimize the spitting of your HVLP spray gun, you should keep them in view and avoid them.
  • When your HVLP spray gun spits, you can fix the issue by checking all these points in detail.

I discussed above some problems and solutions to the HVLP Spray gun that you may face while using the HVLP Spray gun.

YouTube video

Frequently Asked Questions

Is It Necessary To Use A Primer Before Spraying Paint?

Yes, it is necessary. If you spray one coat of primer before the actual paint, it will help you spray paint easily providing a fine final finish.

Without applying primer, you may need to spray more paint coats to cover the surface

Can Water-based Paint Be Thinned For The HVLP Spray Gun?

Yes, you can. Water-based paint needs ½ cup of water for thinning like latex paint. Now shake it and when it is mixed well, spray it.

But add water carefully, if added less water, the paint will be thick, if added more water, the paint will be thinner.

How To Deal With The Impurities In The Paint?

When the paint is prepared, there may be a lot of impurities in it, so take a sieve and sift/ strain the paint to remove the impurities.

How Can The Dried Paint Be Washed?

If the paint is dried in the spray gun, you can wash the dried paint using oil or sometimes with water.

Do The Seals Affect The Performance Of The HVLP Spray Gun?

Yes, of course, the seals used in the spray gun help greatly to tighten the nozzle, tip, hosepipe, and all other screws. When the gun is adjusted using all necessary seals, they don’t allow the air to pass through them and the gun’s performance remains perfect.


You can conclude and find the causes of spitting from the discussion above. After understanding these causes, you can easily solve the issues regarding spitting.

As you know that spitting occurred due to multiple reasons, so by removing all those issues or problems, you can save your HVLP Spray Gun from Spitting.


Hi, Cristopher here. I have been working in the home improvement industry for the past 15 years, and I have developed strong expertise in spray guns and paint sprayers. I have a deep understanding of how these tools work and how to get the best results from them. In addition to my practical knowledge, I am also running this website dedicated to sharing tips and tricks for using spray guns and paint sprayers.

Share on: