Products recommended in the post contain affiliate links. If you purchase something through our posts, we may receive a commission at no extra charge to you. See our full disclosures here.

How do you mix paint thinner with a spray gun?

There are many different types of paints. If you intend to paint with a spray gun, you need to use proper paint or thin the paint. Thinning the paint will help the paint flow freely when you use a spray gun. 

To thin the paint, you can mix it with paint thinner or water. The ratio depends on each type of paint. You can find the detailed guide in this article.

How do you mix paint thinner with a spray gun?

There are 5 steps in mixing paint thinner with your spray gun

  • Mix the paint with water or paint thinner by the ratio of 10:1
  • Pour the mixture through the funnel
  • Add water or paint thinner as needed
  • Test the paint on a test board or surface
  • Start painting with your spray gun

To mix paint thinner with a spray gun, you will need the following supplies

  • Paint
  • Water or paint thinner
  • A funnel
  • A test surface like a cardboard
  • Gloves
  • Safe goggles
  • A face mask


Thinning the paint will help the paint flow freely when you use a spray gun 


Now let’s take a closer look at each step:

1. Mix the paint with water or paint thinner by the ratio of 10:1

First, put on gloves, safety goggles, facemask, and gloves. Paint is a mixture of chemicals, so you should protect yourself from the toxins. 

Then, take a quantity of water or paint thinner equal to 10% of the volume of paint you plan to use. That means for each gallon of paint, you will need 12-13oz of water or paint thinner. Use a measuring cup to take the exact amount. 

Depending on the type of paint used, you will decide to mix it with water or paint thinner. For water-based paints, you can use water. You will need paint thinners like mineral spirit if you use oil-based paints. Before adding water or paint thinner, remember to stir the paint well.

Then, mix the water or paint thinner with the paint with a stir stick. 

2. Pour the mixture through the funnel

A funnel will help you to test the viscosity of the paint. You can use a funnel or a paint strainer. Put a bucket under the funnel so that the paint will not drop on the ground. 

Pour a small part of the paint mixture into the funnel and see it flowing down. If it flows freely, you have reached the required consistency to use for a spray gun. If the paint clogs in the funnel, move to the next step.

3. Add water or paint thinner as needed

As the mixture doesn’t flow freely through the funnel, you need to add water or paint thinner. Continue to add another 10% of water or paint thinner. 

Don’t rush to pour a larger amount of water or paint thinner into your paint. Too many thinning agents will create air bubbles in the paint. This will make your finish not smooth, and decrease the adhesive of the paint. Add little by little and test with the funnel until the paint can flow freely through it.

4. Test the paint on the test board or surface

After the paint has reached the desired consistency, put it into the spray gun. You need to spray on a test board or test surface.

If the spray gun doesn’t get stuck or slow down, the spread will be even and clear. That means your paint is thin enough to use for the spray gun. 

If there is any clog or you find it difficult to spray, continue to thin the paint. Repeat the process in step 3 and test again. 

In case that the paint runs after you spray on the board, it is too thin. You will have to add more paint or start mixing again. 

When you test the mixture, pay attention to the distance and how you spray. You should spray at the same distance and use the same technique as you’ll do with your real finish. That will bring precision for the test. 

5. Start painting

After the paint has passed the test, you can use it to paint anywhere you want. Remember to hold the same distance during painting to avoid overlapping areas. After spraying the first coat of paint, let it dry before applying the second coat.

When you finish painting, clean the spray gun as soon as possible. The dry paint will be more difficult to clean and may clog your sprayer. After cleaning, load some water in the gun and spray to remove any residue. 

Useful tips when painting with a spray gun

A spray gun is a useful tool for painting large surfaces such as walls or floors. Here are some useful tips when using a spray gun you should know.

1. Keep moving the gun

If you hold the gun in a spot for too long, the paint will run and cause an uneven coat. So, always keep it moving when spraying. You should move it before starting applying paint.

2. Keep a consistent distance

The ideal distance between the spray gun and the painting surface is 12 inches. With this distance, you can control your gun and have a nice coat. Always keep this distance consistent, because a slight change can make your coat uneven. 

3. Remember to overlap

You should overlap each pass about 1 inch to the previous pass. This will ensure an even amount of paint on the surface and prevent light spaces.

4. Quickly paint around the corners

When you paint the edges or corners, move the spray gun a bit quicker. This will prevent paint overload in these areas.

5. Keep the spray gun clean

Wash the spray gun right after finishing the painting to avoid any clog. If you use oil-based paints, you can clean the spray gun with mineral spirit, then rinse again with water. Keeping the gun clean will help lengthen its lifespan.

Final Words

Above are the step-by-step guide to mix paint thinner for your spray gun. By thinning paint, you won’t need to use different paints. So, you can save a lot of time and money. We hope that the information provided will be useful for you.

> Read more:

Best latex paint sprayers in 2021