How To Thin Paint For Sprayer (Safely Thin All Paint Types)

Using a paint sprayer makes painting more effortless, but you need to know how to use one to get the job done right. You also need your paint at the right consistency.  

If the paint is too thick, it can block the sprayer or disperse unevenly, creating splotches and bubbles on your paint job. Certain types of paint are more prone to this than others.  

This guide is to help all DIY painters learn how to thin paint for sprayer application. Read on for all you need to know about thinning paint for sprayers. 

Paint Thinner
  • Water Or Paint Thinner
    Water-based paint should only be thinned with water. It doesn’t mix with the thinners or solvents you’d use to thin oil-based paint. Add a half cup of water for every gallon of water-based paint and 1 part solvent for 3 parts oil-based paint. Read the label on your paint carefully - it should indicate whether that particular paint can be thinned and have ratios for thinning. 
  • Funnel & Filter 
    The funnel will act as a stand-in for your paint sprayer. If the paint runs through evenly, it’s the right consistency. When you pour paint into the sprayer, a filter will remove lumps. 
  • Piece Of Cardboard Or Other Test Surface 
    You can use this test surface to get some idea of how the paint spreads, what the color looks like, and how long it takes to dry. 
  • Stir Stick Or Mechanical Stirrer 
    You need to stir your paint before using it, so it cures evenly. You also need to distribute your thinner so the mixture is cohesive. 
  • Additional Paint Bucket 
    So you can pour out the paint you need and dilute it without having to thin out the entire can of paint. 

How To Thin Paint For Different Sprayer Types

Thinning Paint For Airless Sprayers

Airless sprayers can sometimes handle acrylic paints without thinning, particularly larger sprayers. But that's not a guarantee, so make sure you test the paint with your airless sprayer.

Follow these steps to thin paint for airless sprayers:

  1. 1
    Pour your paint into a paint bucket.
  2. 2
    Add half a cup per gallon of paint or follow the manufacturer's ratio if it's on the label. Then, introduce it slowly so you can gauge how it's thinning as you go.
  3. 3
    Mix with the paint stick by scooping in an arc from the bottom to the top.
  4. 4
    Pour the paint through the funnel. If it’s passing through easily, it’s where you want it. Make sure there are no interruptions as these could point to lumps or uneven stirring.
  5. 5
    Add small amounts of water or solvent if the paint is still too thick.
Airless Sprayer

Thinning Paint For HVLP Spray Gun

Unless you have an industrial paint sprayer, you’ll have to thin your paint more when using a high volume low pressure (HVLP) gun 

So you have to thin the paint a bit differently. Here’s how to get the thin latex paint HVLP spray gun models work best with: 

  1. 1
    Start with acrylic paint. Pour out some into the spare paint can.  
  2. 2
    Stir it vigorously to activate everything.
  3. 3
    Add a small amount of water and continue stirring until everything is uniform. Lift your stir stick until paint is coming off. It will be dripping in clumps at first.
  4. 4
    Add a bit more water. Repeat stirring, measuring, and adding more water until the paint is so thin that it runs off the stir stick in a single stream. The paint should drip all the way to the paint can. 

Thinning Paint For Compressed Air Sprayers 

The power of the compressed air could cause really thin paint to disperse widely, making for inaccurate spraying, a mess to clean up, and the potential for more fumes and paint in the air.  

In this case, you need to make sure you don’t add too much water. So we’d recommend thinning the paint with even smaller amounts of your diluter (water, solvents, etc.)  


Steps For Thinning Different Paint Types 

Thin Gloss Paint

How To Thin Acrylic Paints

  1. 1
    Pour between ⅓ and ½ of the paint into an empty paint bucket. 
  2. 2
    Make sure you're using water and nothing else, or you'll ruin your acrylic paint. 
  3. 3
    Stir the paint thoroughly to activate it.
  4. 4
    Get ⅓ of a cup of water for each gallon of paint. You can measure the paint you pour with smaller measuring cups to make this equal. 
  5. 5
    DON’T add all that water at once! Pour in a little and stir until you have a cohesive mixture. Continue adding water until it passes the stir stick test. 

How To Thin Latex Paints For Sprayer

Latex paints are entirely water-based [1], whereas acrylic paints are chemical-based, which allows them to expand better. You can follow the same process for thinning each one. 

Thinning latex paint for Wagner paint sprayer models is more like thinning for an HVLP sprayer, and you should try to get it thin enough before use because those Wagners are really tough to clean when they clog with dried paint.

How To Thin Oil-Based Paints

A good rule of thumb when using a sprayer with oil-based paint is to remove a bit - maybe 1.5 cups - and then add back that same amount of thinner solvent.

What I don't like about running with this rule is that it's easy to overdo it, although you do have some paint set aside if you need to thicken it, and you do have more solvent (hopefully) if you need it. 

Maybe I’m overly cautious, but I still add a bit at a time and stir thoroughly. This gives you a chance to see if the color is going in a direction you didn’t want it to. 

How To Thin Enamel Paint For Spray Gun

Semi-gloss enamel paint takes a little bit of mineral solvent to thin it out properly. You could use up to a pint of thinner solvent if the enamel paint is thick to begin with.  

The process is pretty much the same except for using mineral spirits. You’ll want to give it a test spray once it’s reached the viscosity level you think it needs to be at, so don’t fill up your paint sprayer all the way right away. 

How To Thin Gloss Paint For Spraying

Get your gloss paint to a smoother finish by thinning it out. Pour 10g of mineral spirits or turpentine per liter of gloss paint in to thin it out.  

Gloss paint tends to have a diminished finish if you thin it. To get it thin enough for low-pressure sprayers, it can get so thin that it will create a fine mist that covers everything. That’s great cause your wall will be covered fast, but you’ll spend more time cleaning up everything else.  


Why Do You Need To Thin Paint For Sprayers?

The primary purpose of thinning paint for sprayers is to get it to the right consistency so it will spray evenly without gumming up in the nozzle. If the paint is too thick, it can get stuck or even damage the paint sprayer if the buildup is left in the sprayer for too long. 

Occasionally you won't need to thin paint for sprayers, but lots of the time, you will. You might need to thin it extensively or just a little. It depends on the paint you're using and the way your sprayer handles that kind of paint. 

What is thinning paint, though? Basically, you’re diluting it with water or another fluid to increase its volume and reduce its thickness. When you’re using a paint sprayer, you’re more likely to have to dilute your paint so that it flows freely and spreads on the wall in even layers.  

Thinning White Paint

Paint Thinning FAQs

Do I need to thin paint for Graco sprayer? 

You can destroy the tip of a Graco sprayer if you spray thicker paint than it’s rated for.


Thinning it is one option, but you could also just abide by the “if it sprays, it paints” rule and replace the tip piece when it wears down. They aren’t incredibly expensive and fairly easy to find. 


Do you dilute chalk paint for sprayer? 

You can dilute chalk paint, and you should if you're going to use it in a paint sprayer. However, it's best to use hot water for thinning. 


How do you strain paint? 

You usually strain paint by putting a filter on top of a container and pouring the paint through [2].


This can be an official filter or a DIY one constructed of old pantyhose, for example. The important thing is to strain your paint to remove unwanted clumps that can disrupt an otherwise smooth paint job. 


How long does it take to thin paint? 

Depending on how thick the paint is to begin with, you could have it all thinned out in a matter of minutes, or it could take a little while longer to get it thin enough to shoot through the sprayer tip. 


Conclusion

Thinning paint isn’t necessarily difficult, but there are different ways to do it depending on what type of paint sprayer and what kind of paint you’re using.

Follow the instructions in this guide to thin out your paint and get nicer, more even layers up on the wall. 

References: 

1. https://www.paintritepros.com/blog/the-guide-to-water-based-paints/

2. https://sawsonskates.com/how-to-strain-paint/