Do I Need to Thin Paint for Airless Sprayer?


Last updated: March 30, 2023

Professional Painters Comprehensive Guide to Thinning Paint for Airless Sprayer!

Paint sprayer in work to stress the point 'Do you need to thin paint for airless sprayer'

Do I need to thin paint for airless sprayer? As a professional painter, thinning paint for a sprayer may be necessary when working with a spray can or gun, but not an airless sprayer.

You don’t need to thin latex or oil-based paint since such formulas are designed for spray painting without additives like thinners. But there are a few instances where you might need to use an automotive lacquer thinner when working with an air-driven sprayer. 

To help you get a broader picture of when and how to thin paint for sprayers, we created this comprehensive guide to address all questions related to paint thinning, airless sprayers, and the best spray paint for an airless sprayer.

Let’s delve in.

Do I Need to Thin Paint for Airless Sprayer?

No. If you’re working with latex, water-based, or oil-based paints, you don’t need to thin them for an airless sprayer. Such paints are formulated for use without the need for thinning. The only exception is when the paint becomes too thick and leaves a bumpy mess instead of a smooth finish on the surface. In that case, you could add a paint thinner to loosen it up and create a balanced formula. 

What Is an Airless Sprayer?

An airless sprayer is a spray painting tool every painter should have. It works by spraying paint or other liquids without using compressed air. This tool uses gasoline, electricity, or other similar energy sources to atomize the liquid. Notable features and functions of an airless sprayer include:

  • Low-pressure or high-pressure applications 

  • Versatility. They can be used to spray any liquid, such as paints, lacquers, adhesives, water, lubricants, and epoxies.

  • Some models are designed with integrated motors to power the sprayer without external gearboxes or belt drive pulleys.

Working with an airless sprayer involves pressing the trigger button to start the paint flow from the nozzle. The paint then flows through the tube and into the tank. From here, you can release it in the form of high-pressure droplets through the nozzle when you press the button again. 

Due to advancements in technology and design, modern and advanced models are more effective than traditional airless sprayers. Working with a traditional model can be frustrating, and the results might be disappointing compared to using new models.

In essence, an airless sprayer is but an advanced sprayer can. 

What to Know About Thinning Paint for Airless Sprayer?

One quick and straightforward way of achieving a smooth and long-lasting paint job is to ensure the layers are thin and even. It means making sure you work with light paint by thinning when necessary. 

Most paints are made with paint thinners which allow the paint to thin as it sets on the surface. That means, in most cases, you’ll only have to add a little extra thinner should you need to. 

A perfect time when paint thinning might be necessary is during cold weather when the paint is likely to freeze or harden, and you may need to thin it to achieve the desired texture. Understanding paint thinning is recommended since it’s something you’ll have to do at some point. 

Fortunately, you don’t need any expensive or complicated equipment and tools for this. Knowing which paint thinner to use with which type of paint and the right amount of paint thinner is all it takes for you to get started. The process is even more straightforward and entails these steps:

  • Pick a paint brand with good consistency. Some brands are light and runny, while others are thick and require additional thinning to work better. 

  • Follow the package instructions for mixing equal parts of paint with the thinner in a container. 

  • Shake the paint, then transfer it to the paint sprayer. 

By following the mixing instructions on the package, you’ll maximize the performance of any type of spray paint on porous surfaces and significantly increase the paint’s durability. 

Why Should You Thin Paint for an Airless Sprayer prayer?

When you need to spray paint a large or medium-sized surface area faster, an airless sprayer is the best option. This tool is also ideal when you need to spray paint on metal surfaces or on surfaces with high moisture, like cement. 

What are the Benefits Of Using Thinning Agent In an Airless Sprayer?

Thinning agents are liquid substances, usually chemicals, which are added to the paint to create a thin solution that spreads uniformly over a surface. Using a thinning agent in an airless sprayer comes with several benefits, including:

  • Saves time and reduces workload 

  • It helps prevent cracking after spray painting, creating the desired finish without needing to fix anything, which would take additional time.

  • Reduces surface tension which prevents dripping when spraying.

  • It creates low viscosity, which makes it easy to blend with the paint.

  • It allows you to mix more liquid into a thinner mixture, providing better coverage than water-based paints. 

How To Thin Paint For A Sprayer: Be Prepared With The Right Equipment

Paint can be water-based or oil-based (also known as alkyd paint). Latex is a good example of water-based paint, while oil-based paints are mostly petroleum-based solvents. Water-based paint can be diluted with water to reduce thickness, but overall, thinning agents generally include the following solvents and glycol ethers:

  • Acetone
  • Naphtha
  • Lacquer
  • Toulene
  • Turpentine
  • Methyl ethyl ketone
  • Mineral Spirits or White spirits
  • Butoxyethanol

The most common tools and equipment you’ll need for paint thinning include the following:

  • A spray gun

  • A funnel: For determining and maintaining paint viscosity and consistency.

  • A small piece of cardboard for testing the thinned paint and making sure it sticks and adheres to the surface.

How to Thin Different Types of Paint

With your preferred paint thinner and the necessary tools and equipment ready, let’s now take you through the process of thinning different types of paint, starting with latex paints.

How to Thin Latex Paint Before Spraying

Latex is typically a thick paint, so thinning it is something you can only do when necessary. For example, if the paint has hardened beyond the preferred texture or if it’s slightly frozen and you want to loosen it a bit. 

Here’s What You Will Need:

The Process of thinning latex paint for spraying:

1.Blend the paint thoroughly, especially if the paint has sat on the shelf for some time. If it’s something you just bought from the store, you can skip this step since, most probably, the paint was passed through a mixing machine.

2. Add a small amount of paint into a container. Remember, paint quickly hardens when exposed to moisture, so if left too long in the container, it can only get thicker. To avoid this, you must determine how much to thin paint for a spray gun. 

3. Use a quarter cup of water to thin the paint and maintain an even consistency without over-diluting the paint. Adding small amounts of water helps you adjust a more accurate viscosity without having to go back and forth, adding more paint and water into the container.

4. Stir the mixture until it’s consistent. 

5. Test the mixture on a test surface like cardboard to see if it’s the desired application. Using a funnel spout, run the paint through it into the bucket. A well-mixed and thinned paint should be able to flow evenly out. 

6. Fill the spray gun or sprayer with the thinned paint and spray-test it again on a piece of cardboard. If it creates the desired layers, your paint is ready for spraying.

7. Repeat the thinning process if you notice inconsistency in paint and water until you achieve a uniform finish. 

Thinning Paint For Spraying Acrylic Paints

Like latex, you can also use water to thin acrylic paint. It’s a cheap and easy option, but it requires you to control the amount of water you use. Too much may make the paint too runny. Too little may cause inconsistency and undesirable outcomes. 

The recommended water ratio should be  50% water to paint. This mount creates a perfect matte finish when applied to an absorbent surface since the water soaks into the substrate, creating a soft layered watercolor effect. 

To thin acrylic paint with water, estimate the volume of paint you’ll need, pour a small amount of it into a bowl, and add 50% water. Blend and transfer to an airless sprayer. 

Thinning oil-Based Paint For Spray Guns 

Before applying oil-based paints such as semi-gloss enamels, it’s best to thin them first before application. However, with oil-based paints, you’ll need to use paint thinners like the ones listed above since water is not recommended in this case.  

Such paints tend to be slightly thinner, but extra thinning may be necessary for best results. Most paint brands come with a manual guide which you should refer to for determining the ratio of paint to thinner in a spray gun. 

Similarly, the guide from the manufacturer may list which oil-based paints are compatible with which paint thinners. Some oil-based paints need at least 10% thinner depending on the type of application desired, the quality of paint, and the spray gun or airless sprayer you’ll use. 

Do I Need to Thin Paint for Airless Sprayer?

Thinning Emulsion Paint For Spray Guns

Emulsions are generally water-based paints and can be thinned with water. Most paint manufacturers recommend a 70/30 ratio, where 70% is paint, and 30% is water. You might even apply an 80/20% ratio depending on the type of paint you use and how thick it is. Follow the mixing steps above to thin out emulsion paint for a spray gun. 

How to Thin Paint for Different Paint Sprayer Types

There are different types of paint sprayers you can work with, and each requires a specific formula for thinning paint. You can work with a high volume, low pressure (HVLP) paint gun or an airless spray gun. Let’s look at how thinning is achieved with each of them. 

1. HVLP (high volume, low pressure) Paint Gun

HVLP is mostly used for spraying oil-based and latex paints. It’s best for indoor paint application, and thinning should be within a 90/10 ratio where only 10% water is added. You should only exceed this ratio if you fail to achieve the desired consistency, in which case an 80/20 ratio would be better. 

Paint conditioners also work best on water-based paints like latex. If possible, consider using a paint conditioner on emulsion paint instead of water. 

One reason paint conditioner is a better alternative is its thinning properties, which make the paint spray easy and evenly without necessarily thinning out and without compromising adhesion.  

When working with an HVLP spray gun, always use a cone-shaped strainer, which helps remove any lumps of paint, especially with airless sprayers. 

2. Airless Spray Gun

An airless spray gun is primarily suitable for oil-based and latex paints, and using it, you may not need to thin your paint at all for spraying, you can use the paint directly from the container or can. 

However, this is only possible with larger airless spraying systems, as the smaller and cheaper ones require thinned paint to function better. If you decide to use an airless spray gun, we recommend using it with oil-based paint, which does not require thinning before application.

Additional Guidelines For Thinning Paint for Sprayer

To ensure the paint is adequately thinned out, you must be able to measure the paint and paint thinner accurately. That’s when a viscosity cup comes in handy. Most high-quality paints come packaged with a viscosity cup which you can use as a funnel to check the paint’s viscosity. 

To use it, pour some paint into the cup and monitor the flow and texture of the paint. If it flows out evenly and smoothly, then your paint is good to use. 

Otherwise, if it turns into a runny liquid, it’s over-thinned, and you should add more paint. If it produces thick blobs, you’ll need to keep thinning it to achieve a uniform paste. A well-mixed paint should flow through the viscosity cup evenly and smoothly.

Best Thinners For Spraying Acrylic Paint

Thinning spray paint is only useful if the paint and thinner are compatible. Although there are many paint thinners in the market, most brands are specific on which thinners should be used with each of them.

That’s why some brands sell both paint and thinner as a single package. But what if you have a different brand of paint and need to know which thinner would work with it? In this case, you’ll need to work with multipurpose paint thinners that are generally proven to be compatible with any type of paint. 

Again several brands provide these, and you may need clarification about which one to choose. To help make things easier for you, we’ve narrowed the search and brought you the following list of the best thinners for spraying paint. 

1. Klean Strip Acetone

Klean Strip Acetone is a multipurpose paint solution that can be used as a powerful thinner and paint remover. This alcohol-based formula is formulated to thin oil-based and latex paints, clean adhesives like glue, polyester resins such as wood filings, and epoxies such as primers and sealers. 

You can use it to thin out thick paint for an airless sprayer or remove marks and scuffs from tile floors without leaving behind a cloudy film.

2. Chelsea Classical Studio Lavender Spike Oil

Oil painting enthusiasts love Chelsea Classical Studio Lavender Spike Oil, one of the safest and non-toxic paint thinning choices. Besides being a reliable oil paint thinner for resin and varnish mediums, this product can also be used in aromatherapy and for making handmade soap.

3. Sunnyside Lacquer and Epoxy Thinner

Sunnyside Lacquer and Epoxy Thinner is a fast-dissolving paint thinner among Amazon’s top-rated thinners thanks to its multipurpose properties. It can thin out thick paint the same way it can act as a powerful degreaser for cleaning auto parts, tools, and other machine components. 

You won’t go wrong with having Sunnyside Lacquer and Epoxy Thinner in your garage to not only thin paint but also to effectively clean your spraying tools like sprayers and airbrushes after use. 

Solving Spray Gun Issues – Smart DIY Tips

Sometimes you may have to deal with spray gun issues from tone to time. Knowing how to quickly troubleshoot them as they come is key to avoiding frustrations. The following DIY tips can help you avoid a bad spraying day should you face problems while spray painting, especially with spray guns. 

  1. Always ensure the spray nozzle is clean before use. Cleaning helps prevent clogs and other complications, such as thin paint or uneven spray.

  2. Use the right amount of distilled water in your sprayer. Working with distilled water helps prevent corrosion on the inside parts of the sprayer.

  3. Always ensure you maintain safety when using a sprayer and have an emergency plan in case of an accident. 

  4. Safety should come first.  Wear protective gear like goggles, gloves, and overalls when working with power tools like an airless sprayer.

FAQS – How to Thin Paint for Sprayer 

Can I Use Solids or Liquids to Thin paint

Traditional paint thinners like solids and liquids tend to be powerful and toxic. You can use them to thin the paint, but if you’re looking for something milder, you can whip up a mixture of linseed and lemon to thin oil-based paints. Alternatively, acetone or mineral spirits can also do a great job in thinning oil paint. So long as you use the recommended ratio of thinner to paint and maintain safety, these alternative thinning options should work. 

Do you thin paint when using an airless sprayer?

In most cases, thinning is necessary when working with HVLP sprayer systems. For example, latex paints and other oil-based paints tend to be thick, and thinning is necessary before using the paint on an airless sprayer, a handheld spray gun, or HVLP sprayers. Use the correct ratio of water to paint as per the instructions in the manual. 

Do you have to dilute paint when using a sprayer?

As a water-based paint, latex should be thinned with water, especially if you want to apply it with a spray gun or nozzle. While using water to thin latex paint, ensure you achieve the desired viscosity to avoid over-thinning.

Can paint be too thick for a sprayer?

Even after thoroughly stirring, the paint that produces thick globs is thick and should be thinned to avoid creating a bumpy, uneven finish. Overall, thinning too thick paint before using it with a sprayer is necessary to avoid clogging the sprayer, or you’ll constantly have to de-clog it. 

Can You Use a Paint Conditioner?

A paint conditioner is an excellent alternative to water. Using it to thin, thick paint instead of water helps improve paint flow and workability. A good example of a powerful and versatile paint conditioner is Floetrol which can transform interior and exterior emulsion and acrylic paints into something like oil-based paints. 

What is The Number One Rule When Using an Airless Spray Gun?

One rule of thumb when using an airless sprayer is to always maintain a distance of one foot or 12 inches from the object you’re spraying and ensure the sprayer stays in a perpendicular position to it. Avoid spraying from any angle since doing so will result in an undesired finish. 


At the beginning of this article, we promised you we’d answer your question on how to thin paint for a sprayer, and we’ve done just that.  From this guide, you’ve learned that although thinning paint is not necessary with some paint types, it’s recommended if you want the sprayer to function correctly without clogging and to ensure you achieve a fine coating with a fine finish. 

In addition, working with thin paint reduces waste, and you can cover a large surface area which is a fantastic cost-cutting trick. Next time you want to use a sprayer and feel your paint is too thick, you know you need to thin it before using it with the sprayer. Go ahead and implement the tips shared here to ensure a perfect job. 

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