How To Thin Latex Paint For Sprayer Like A Pro


Last updated: July 11, 2023

Achieve a Smooth and Even Finish by Following these Simple Tips and Techniques For Thinning Latex Paint

Knowing how to thin latex paint for sprayer is crucial because latex paints are relatively thick, and most spray guns require a runny paint viscosity to work properly.

Thinning your paint also helps you get the right consistency to get a smooth surface and achieve professional-looking results. 

You are probably aware of various paint thinners in the market, but latex paint is water-based, so you won’t be able to dilute it using any of those popular solvents. Instead, thinning latex paint, like any water-based product, requires adding water and mixing thoroughly. 

Straightforward, right? Probably.

This article provides a detailed guide on thinning latex paint in the correct way for use in a spray gun. 

Can Latex Paint Be Thinned?

Latex paint can be thinned, indeed. The secret is to use the correct latex paint thinner, which is tap water. Latex paint is a water-based product, so you cannot dilute it with solvents used to thin oil-based products. Water and oil don’t mix, so adding a paint thinner to latex paint will only damage your paint. 

Why You Should Thin Paint When Using a Sprayer

While airless spray guns can work with thicker paint consistencies, most other paint sprayers require the paint much thinner to work properly. 

Since most paint types, such as latex paint, are relatively thick, you must dilute them to come out of the sprayer’s nozzle properly. The right viscosity is necessary for the paint to come out of the sprayer in mist form. 

This rule applies across the board for all paint types. Working with a viscous product in a paint sprayer may not give the desired results if not damage your sprayer altogether. The paint particles will simply not come out of the nozzle as desired. 

How to Thin Latex Paint for Sprayer 

Most brands recommend the right thinner for their products and indicate the ratio of paint to thinner. However, some products may not have this information. Thankfully, this guide has the answers you need.

Now that you know the recommended latex paint thinner for spraying, it’s time to learn how to complete the task. 

Tools and materials 

  • Latex paint
  • Tap water (latex paint thinner)
  • Funnel for testing the paint thickness
  • Measuring cup 
  • Stirring stick
  • 5-gallon bucket.   
  • Paint filter for cleaning the paint 
  • Your paint sprayer 
  • Scrap piece of cardboard (test surface) 

Procedure for Thinning Latex Paint for a Spray Gun 

After collecting the tools and materials for the job, follow the steps below to complete the project. 

Step 1. Prepare Your Workspace 

You may not have to wear a respirator mask for this process, but you sure will need to clear your workspace. Remove any objects that might be in your way, or cover them with plastic sheeting.

Latex paint and most water-based paints are mild to low odor. They are also low in volatile organic compounds (VOCs). While fumes from any paint can have adverse health effects when inhaled, you will unlikely be exposed to them for a long time; hence no need for a respirator. 

Step 2. Prepare the Paint for Thinning 

Once your workspace is ready, open the can of paint and mix it thoroughly. You can use a mechanical paint mixer or stirring stick. 

After mixing, determine the amount of paint you will need. For a big project, you may need to mix the entire gallon. But for a small project, you may need only a small amount of paint, so transfer only the amount you need into your mixing container. 

If you don’t need the entire gallon of paint for your project, ensure you measure the amount you need to help you determine the amount of water you will use to thin it. 

Step 3: Calculate the Amount of Water to Use

As a rule, the volume of water should be 10% of the amount of paint you’re thinning. Unless the manufacturer says otherwise, this is the percentage to go for. 

Suppose you want to thin the entire gallon of paint; remember that a gallon has 16 cups. So, 10% of 16 cups will be 1.6 cups. This is the volume of tap water to add to your paint.

Step 4: Pour the Water Into the Paint in Your Mixing Container

Now that you have determined how much water you need measure that amount and add it to the paint already in your mixing container. 

Step 5: Stir the Mixture With a Stirring Stick 

After adding the water, use a stirring stick to stir the mixture gently until the water and the paint have formed a uniform aqueous solution.

The water should disappear in the paint, resulting only in a thinner paint with no noticeable water.

Do not use a mechanical paint mixer at this point, as it might introduce unneeded bubbles in the paint. 

Step 6: Check its Viscosity

After stirring for a good few minutes, use the funnel to check the new thickness of your paint. Simply dip it into the mixture and check the flow. 

The paint should flow freely if it is thin enough. However, if it appears thick as it comes out of the end of the funnel, you may need to add more water, a little at a time, and mix thoroughly.

Test the paint consistency after each addition and mix until you see it flow freely from the funnel. 

Step 7: Use the Strainer to Filter the Paint 

The whole idea of using a paint sprayer is to apply the paint to the surface in the form of a fine mist. Having large particles in the paint may affect the quality of your results, so ensure you pass the thinned paint through a strainer to filter out any large, unwanted particles. 

When you thin latex paint for spraying, the process does not affect any impurities such as dirt and lumps in the liquid. So you must manually strain them out of the mixture.

Step 8: Test the Paint 

Once you are done preparing the paint, load it into the spray gun and test the mechanism on a piece of cardboard or any similar test piece.

If the paint comes out of the nozzle freely in a mist form, proceed to use it on your project. 

How to Thin Latex Paint for an HVLP Spray Gun

If you are using an HVLP (High Volume, Low Pressure) spray gun to paint a surface with latex paint; you must thin the paint. HVLP is among the various types of spray guns that won’t work properly if the paint is thick.

The sprayer is primarily used with oil-based paints but can also work with latex paint if the product is sufficiently thinned.

Usually, thinning the latex paint with 10% water is enough to prepare it for an HVLP sprayer, but we recommend testing out the thinned paint to be sure before using it on your project. 

If it doesn’t come out of the nozzle as a mist while testing it, consider adding more water and mixing it thoroughly. 

You can also add a paint conditioner to the latex paint to make it more suitable for an HVLP spray gun. 

Here is how to thin latex paint for an HVLP sprayer

  • Pour the amount of paint you need into a mixing container, preferably a 5-gallon bucket. 
  • Add approximately 1.6 cups of water per gallon of paint and stir gently with a stirring stick to mix.
  • Run the thinned paint through a funnel to check its consistency. The paint is ready if it flows freely through the tip of the test funnel.
  • Feed some of the thinned paint into your HVLP sprayer reservoir and test spray it onto a scrap piece of cardboard and observe it. If the paint comes out freely, it is ready for use. If it still appears thick, add a little more water and mix, then rerun the test. 
How To Thin Latex Paint For Sprayer

How to Thin Latex Paint for Airless Sprayer

Ideally, you don’t need to thin latex paint for use with an airless spray gun. The sprayer is designed to work with oil-based, latex, and standard water-based paints without thinning. 

Airless sprayers are an incredibly powerful mechanism spitting out paint at a whopping 2000 psi without any air involved. This pressure is typically enough to pump out most paint types under high pressure through a small hole where the liquid becomes a mist. 

Therefore when working with latex paint, you can feed it into the sprayer’s reservoir and apply it to your project without thinning. 

However, if you must thin the paint as a preference, follow the procedure below.

  • Pour the latex paint into a mixing container, preferably a 5-gallon bucket. 
  • Measure approximately 1.6 cups of water per gallon of paint and add it to the paint.
  • Stir the mixture gently with a wooden stir stick until it forms a uniform aqueous solution.
  • Test the thinned paint’s viscosity by running it through a test funnel. If the paint flows freely through the tip of the funnel, transfer it to your airless sprayer for use in your project; it is ready.

When is the Paint Sprayer Paint Thin Enough?

The paint is thin enough if it flows freely through the tip of a test funnel. This means you need to test your thinned paint by running it through the funnel and observing its flow to determine if it is thin enough for use in standard paint sprayers. 

The paint should neither be too thick nor too thin. If it flows then drips, it is likely thicker than desired. If it runs out of the funnel too quickly, you probably need to add more paint because it is too thin. However, if it flows smoothly, it is just about the right consistency. 

Safety Tips to Follow When Thinning Latex Paint

Latex paints are water-based. Therefore, they have a decently low toxicity profile, are low-odor, and low in volatile organic compounds. 

These paints will probably not harm you when you inhale the few fumes they emit. However, prolonged exposure to paint fumes can harm your health, and some precautions will go a long way. So, observe the following tips to keep you safe through the process. 

  • Wear protective clothing to protect your skin from staining 
  • Wear a pair of gloves to keep your skin from coming in contact with the paint. 
  • Protect your eyes with safety goggles. Paint sprayers spit out the liquid in mist form, increasing the likelihood of getting the paint particles into your eyes.  
  • Wear a protective face mask or respirator. You don’t want to inhale the paint fumes, especially when coming out of the sprayer. 
  • Work in a well-ventilated area. Proper air circulation will help prevent the paint fumes from saturating the air you breathe.  

FAQs-Thinning Latex Paint for Sprayer 

Can You Thin Latex Paint With Alcohol?

Thinning latex paint with rubbing alcohol is not recommended. The alcohol is a drying agent, so it can make the paint dry faster than desired. Mixing latex paint with rubbing alcohol can also cause some ingredients in the paint to dry out and thicken the paint instead, ultimately spoiling it. 

Can You Thin Latex Paint With Mineral Spirits?

Never. Latex paint is a water-based product that is immiscible with oil or petroleum products. Any product referred to as paint thinner or mineral spirits is likely petroleum-based, and such solvents simply won’t work with a water-based product such as latex paint.

So you can thin oil-based paint with mineral spirits, but you cannot do the same with latex paints.

Is Water the Best Solution to Thin Latex Paint?

Absolutely. Water is the base of latex paint, making it the ideal solvent for thinning paint to the appropriate consistency. Ensure the water is clean to avoid introducing dirt or impurities into the paint. Tap water should be excellent. 

Can You Use Paint Thinner to Thin Latex Paint for the Sprayer?

No, you cannot use paint thinner to thin latex paint for a paint spray gun. Like acrylic paint, latex paint is a water-based paint that is immiscible with oil or petroleum products. Paint thinner or any product going by the same name is likely a petroleum-based solvent and will not mix with a water-based product like latex paint.

Should Latex Paint be Thinned Before Spraying?

Yes, always thin your latex paint before spraying unless you are using an airless spray gun. Airless sprayers use a powerful mechanism that spits out the paint at 2000 psi without any air involved. This means it has enough pressure to pump out latex paint without necessarily thinning it. 

What is the Best Way to Thin Paint for a Sprayer?

The best way to thin paint for a sprayer is to use mineral spirits, turpentine, or paint thinners for oil-based paint and water for latex paint. The latter, latex paint, is a water-based product, so thinning it requires mixing in about 10% water and stirring gently to achieve the desired consistency. 

Thinning Latex Paint for Sprayer – Content Summary

Even though latex paint usually has a relatively thin consistency, most paint sprayers cannot spit it out properly without thinning it further. So adding about 10% water to the latex paint is usually recommended to get the appropriate consistency for sprayers like the HVLP spray gun. 

You don’t want the paint too thin either; as such may not provide the desired coverage. Therefore, knowing how to thin latex paint for a sprayer is crucial. 

This article explains how to mix latex paint for use in various paint sprayers to make your work easier. We hope this guide helps make your next spray painting project successful. 

Share your experience with us in the comments. 

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