How to Spray Latex Paint With HVLP Sprayer

It’s difficult to get smooth, even coverage when using a high volume, low pressure (HVLP) sprayer to apply latex paint. By following the instructions in this article, a perfect spray coat of latex paint is within your reach.

Can You Spray Latex Paint With HVLP Sprayer? 

Yes, you can spray latex paint with an HVLP paint sprayer, as long as it is thinned to an appropriate viscosity. 

HVLP paint sprayers are used to move lots of liquid (high volume) through hoses and nozzles at a high speed but low pressure, forcing it through the nozzle where it turns into a fine spray. 

Viscosity is a measure of how quickly liquid moves. Liquids that have high viscosity will not be able to move through the HVLP paint sprayer appropriately. Unthinned latex paint is too viscous to be sprayed via HVLP sprayer.

Attempting to spray unthinned latex paint results in spitting, uneven paint coverage and, more than likely, a clogged HVLP paint sprayer nozzle. 

All this can be avoided through thinning the latex paint to an appropriate viscosity for use with an HVLP paint sprayer. 

How Thin Should Latex Paint Be For HVLP Paint Sprayer?

How thin latex paint needs to be for use with an HVLP paint sprayer depends on a few factors; the paint sprayer manufacturer specifications, the makeup of the paint, and the desired results. 

HVLP Paint Sprayer Requirements

The paint sprayer that you use should include documentation indicating the appropriate viscosity for any fluid to be used in the sprayer. 

Viscosity is measured in the number of seconds it takes fluid to exit a special tool called a viscosity cup. 

Since appropriate viscosity is essential for use of an HVLP paint sprayer, many rental locations include an appropriate viscosity cup along with the rental. You can also purchase or make your own. 

Latex Paint Qualities

Interior latex paint is thinner than exterior latex paint. Some brands advertise that their product does not need to be thinned before use with an HVLP paint sprayer. 

Stir the paint for at least two minutes and then check the viscosity with a viscosity cup. If it meets the viscosity requirements of your HVLP paint sprayer, no thinning agent is needed. 

Desired Results

In general, the thinner your latex paint is, the more smoothly it will go onto your desired surface. 

If your latex paint is close to crossing over the viscosity threshold, you may get better results by thinning it, even if that’s not technically required. 

Experiment with different thicknesses of latex paint until you find the one that gives you the outcome you’re looking for. 

Thinning Latex Paint for HVLP Paint Sprayer

Because it is water-based, you can thin latex paint using water from the tap. Stir for two minutes after adding water and test the viscosity. Repeat until the paint meets the requirements. 

• Start with a 10% dilution. For a quart of paint, add about six and half tablespoons of water. For a gallon, add about a cup and a half of water. 
• If further dilution is necessary, dilute by 5% of the original volume. (Roughly three tablespoons of water per quart of paint, or three-quarters of a cup of water per gallon of latex paint). 

Spraying Latex Paint With an HVLP Paint Sprayer

Get a great finish while avoiding the headache of a clogged gun by following these instructions for spraying latex paint from an HVLP paint sprayer. 

1. Consider a pressure-fed gun. Paint sprayers can be fed by gravity, siphon, or pressure. A pressure-fed HVLP spray gun can handle thicker, heavier fluids like latex paint better than siphon or gravity fed models. 
2. Put up masking. Paint sprayers produce overspray. HVLP paint sprayers produce less overspray than traditional sprayers, but you still need to protect your surroundings. Use painter’s tape and plastic sheeting to cover anything you don’t want speckled with paint. 
3. Use a high-volume air cap. The air cap works together with the nozzle and fluid needle make sure fluid exits the spray gun appropriately. Switching out the air cap for a larger size makes it easier for your HVLP paint sprayer to atomize a thick fluid like latex paint. 
4. Choose an appropriate nozzle. For a pressure-fed HVLP sprayer, you will need a large fluid nozzle – at least 1.8 millimeters in diameter. For a gravity-fed HVLP gun, a nozzle diameter of at least two millimeters is necessary to appropriately spray latex paint. 
5. Thin the paint. Using the guidance above and the information provided by your HVLP equipment manufacturer, thin the paint to an appropriate viscosity for your spray gun. 
6. Add an extender. A latex paint extender will lengthen the amount of time that the paint stays wet. Since latex paint dries relatively quickly, and dry paint will clog your spray gun, an extender is necessary to keep everything flowing smoothly. 
7. Load the gun. Use cheesecloth or a strainer as you pour the paint into the fluid chamber. This ensures that the inside of your gun stays clean, making it less likely to clog. 
8. Adjust the fan orientation. Turning the fan allows you to spray in a horizontal or vertical pattern. Choose the orientation that makes the most sense for the surface you are spraying, or that you are most comfortable with. 
9. Set the pressure. Look at the paint can and the spray gun instructions for guidance about what level of pressure is best. Connect the spray gun to the air compressor or turbine unit. Use the regulator knob to change the pressure of the air compressor to match the needed specification, or set the turbine to the appropriate stage. Check the dial to confirm the pressure. 
10. Protect yourself. Although latex paint is not poisonous, inhaling paint fumes or particles can irritate your respiratory system. A tight-fitting respirator is therefore essential paint spraying equipment. Wear coveralls or long sleeves and pants to protect your skin. Nitrile gloves will keep your hands clean while painting.
11. Spray as usual. With your HVLP spray gun all set up, you can start spraying. Using a sweeping motion, move the gun back and forth in front of the surface you are coating. Aim for minimal overlap between passes to avoid runs. 

Learn about the differences in HVLP spray guns and an airless paint sprayer.

Conclusion

HVLP paint sprayers can be used to spray latex paint. The paint must be thineed to an appropriate viscosity. Using a dry time extender, a larger air cap, and an appropriately sized nozzle will help keep latex paint from clogging your HVLP gun.