How to Thin Water Based Paint for a Spray Gun

How to thin water based paint for a spray gun is easy and fast.  Because latex paint is thick, you will need to thin your paint if you plan on spraying your DIY projects.  

Follow our 4 simple steps to get your paint thinned.

how to thin water based paint
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Is Latex Paint Water Based?

Yes!  This means when you thin it according to our instructions below, you will thin it with water.

Do You Have to Thin Paint for a Sprayer?

Thinning latex paint is most likely going to be necessary.  This is especially true if you own an HVLP sprayer. 

You will need to thin the latex paint before spraying your projects.   

Why?  Because of paint viscosity.  Viscosity means how easy the paint flows.  Latex paint viscosity is very thick.    This is what makes it so durable. 

If your latex paint is too thick, then it will clog the nozzle of your spray gun. That creates a massive mess behind the trigger and can even ruin your equipment.   

Even the best latex paint sprayer or best HVLP paint sprayer might require you to thin the latex paint before beginning your project. 

Thinning the paint for your sprayer means that each coat that you apply is thinner than if you rolled or brushed it on.   

Thin latex paint for spraying typically requires 3-4 coats for complete coverage and a desired finished, compared to 1-2 coats of standard latex. 

How to thin latex paint for brushing is the same steps as thinning it for a spray gun.

How to Thin Water Based Paint (Latex Paint) 

thinning latex paint

How do You Thin Latex Paint for a Spray Gun? 

Thinning latex paint for your sprayer is an easy process and will guarantee your paint flows smoothly through your paint sprayer. 

Be sure to grab the following materials before mixing paint for your HVLP Spray Gun. 

You’ll also want to have your preferred latex paint available. Once you’re ready to get to work, you’ll want to follow the steps below.

How To Thin Latex Paint for an HVLP Spray Gun 

How to thin latex paint for your HVLP, gravity feed or cordless sprayer etc., is the same regardless of the type of paint sprayer you are using. 

Follow our directions below and you will be spraying latex paint in no time. 

#1. Pour all of your paint into the bucket that you intend to use for that day. 

#2. Add ½ cup of water to the paint for every gallon of paint that was placed in the bucket. 

#3. Mix the paint and water thoroughly with a clean stirring stick. 

#4. Check the consistency of your paint by running it through the funnel. 

If the thinned latex paint is able to flow freely through the funnel, then you have the correct consistency. 

Should the latex paint clog up in the funnel, then add another 1/8 cup of water to the paint/water mixture in the 5-gallon bucket for every gallon of paint used. 

Then thoroughly mix the product with another clean stirring stick or your drill attachment. Continue this process, adding 1/8 cup per gallon, as necessary until the paint flows freely through the funnel. 

Once water is added to latex paint, the characteristics of the paint will change. The color may be lighter or darker and the drying time may be different. 

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Troubleshooting: Spray Paint is Too Thin 

When thinning water based paints such as latex, you should be adding 1/2 cup water to your paint and then thoroughly stirring. 

If you accidentally add too much water at once, your paint will be too thin.  You’ll basically be spraying or painting with water.  This isn’t going to get you those professional results you’re looking for. 

Add 1/2 cup of paint slowly into your bucket or container and stir it with a paint stir stick.

Keep on adding more paint and stirring in-between each part of paint that you add until it becomes thick enough to just run through a paint funnel.   

This is called paint viscosity.  Once the viscosity has reached the right level, you can then use it to spray your projects.   

Even the temperature around you can affect paint viscosity for spraying. 

How to Measure Paint Viscosity for a Spray Gun

Measuring paint viscosity is an essential step in ensuring a successful and efficient spray gun application. To measure viscosity, you need a viscosity cup. A viscosity cup is a small metal or plastic cup with a small hole in the bottom.

Here are the steps to measure paint viscosity for a spray gun:

  • Prepare the paint: Stir the paint thoroughly to ensure it is well-mixed. If the paint is too thick, add some solvent or thinner according to the manufacturer’s recommendation. Do not add too much solvent or thinner, as this can affect the quality and performance of the paint.
  • Pour the paint into the viscosity cup: Fill the viscosity cup with the paint, making sure it is completely full.
  • Measure the viscosity: Hold the viscosity cup level and allow the paint to flow out through the small hole. Use a stopwatch to time how long it takes for the paint to flow out of the cup. The viscosity is determined by the time it takes for the paint to flow out of the cup, which is measured in seconds.
  • Adjust the spray gun: Once you know the viscosity of the paint, you can adjust the spray gun accordingly. If the paint is too thick, you may need to increase the pressure or use a larger tip size. If the paint is too thin, you may need to decrease the pressure or use a smaller tip size.
  • Repeat the process: It is important to measure the viscosity of the paint periodically, especially if you are using a large quantity of paint or if the temperature or humidity changes. This will help ensure that the paint is always at the optimal viscosity for the spray gun.

How to Measure Paint Viscosity for a Spray Gun Video Walk Through

Check out this video here to watch how to measure paint viscosity.

Can You Thin Acrylic Paint with Water? 

For painting your projects around the house, acrylic paint is water based so you would thin it with water. 

If you are an artist painting with acrylic paints, you should read through this post as water is probably not your best bet. 

Chances are though, if you’re reading this, that you will be using latex paint to paint your walls or ceilings.  

Acrylic paint is water based.  You may find paint labelled either latex OR acrylic They are the same thing and you use them in the same way.  Thin and clean with water.  

Floetrol for Spraying Latex Paint 

Floetrol isn’t used to thin water based paint for spray guns.  It’s a paint conditioner not a paint thinner.  It works by making your latex spray more like oil paint.   

Floetrol helps you paint if you are painting in less than ideal conditions such as higher temperatures and low humidity.   

These conditions can cause your paint to dry too fast.  You definitely don’t want your paint drying in your paint gun. 

Your latex paint will also spray easier through your spray gun if you add Floetrol, because, technically, the paint IS thinner.  If you just want to thin your paint and not condition it, stick with water. 

Pro Tips and FAQs for Using Floetrol 

  • Don’t use Floetrol with oil based paints 
  • Can make paint more runny, so you have to be more precise with your spray 
  • Increases paint dry time, so plan accordingly 
  • Floetrol reduces gloss in high gloss paints,  mix with water to reduce the effects and maintain the glossy finish 
  • Reduces brush and roller marks 

For more info on Floetrol, check out

Can You Thin Latex Paint with Alcohol? 

You shouldn’t stray too far from thinning your paint with what the manufacturer recommends.   

Larger paint sprayers and newer HVLP units come with different tips, fluid feed, fan and air adjustments, and air caps.   Thinning latex paint with water is your safest bet to get great results. 

Conclusion How to thin water based paint for a spray gun

How to thin water based paint for your spray gun is super easy with Our 4 simple steps to get painting. Get your projects done is record time with Professional results when you thin latex paint the right way. 

FAQs How to thin water based paint for a spray gun

Can you use water based paint in a spray gun?

Yes, water based paint can be sprayed with a paint sprayer.

How do you thin water based paint?

Water based paint is thinned with water. You mix the two together until the paint is thin enough to be sprayed with your paint sprayer.