How to Thin Latex Paint for a Sprayer

If you’ve decided to buy or rent a paint sprayer to paint your house’s exterior, congratulations, you’re well beyond most DIY painters. Many DIYers shy away from sprayer machines due to cost or fear of mechanical malfunction. Those fears are usually overblown; using a sprayer can shorten your painting time significantly. Sprayers allow you to get an even coat by keeping the nozzle moving and sweeping back and forth in an easy, relaxed motion. The biggest concern with using sprayers for your exterior paint project is getting the paint where you don’t want it to go, so make sure you tape up the parts you don’t want to spray and use drop cloths to cover areas you don’t want to drip on.

That said, a sprayer isn’t foolproof. Paint can get clogged in the nozzle and lead to uneven coverage and patterns on your exterior. The best way to avoid clogs and other issues with the sprayer is by thinning the paint slightly before using it. In the past, sprayers could only use oil-based paint, because it’s thinner than latex, but today, you can use more common latex paints in your sprayer. Latex paints are now made with synthetic resins that are compatible with water, with a thinner consistency to begin with. These paints now are wet enough to be used in a spray gun. Sometimes, though, the paint will still clog and require thinning.

Here’s the fastest, safest way to thin typical exterior, latex paint:


  • 5-gallon bucket (18.9 liters)
  • Water—preferably from a ready-to-use source like an outdoor spigot
  • Funnel

The Process

  1. Pour your paint from the can into your 5-gallon bucket. Pay attention to the weather and the air outside. If it’s hot and dry, you’ll have to work quickly to avoid the sun affecting the consistency of the paint before you try to manipulate it. Humidity can also affect consistency if you’re out in it for too long.
  2. Add ½ cup of water for each gallon of paint. Be sure to leave yourself room in your bucket for the water. You wouldn’t want to mix five gallons of paint at a time anyway. Keep in mind that adding water to the paint will alter both the color of the paint and its drying time.
  3. Mix thoroughly in the bucket
  4. Test the thickness by pouring the paint through a funnel. If the paint flows freely down the funnel, the paint is thinned enough to use in your sprayer. If the paint appears sluggish running through the funnel, add another 1/8 cup of water per gallon and mix some more.

Effects of Thinning Paint for Your Sprayer

Aside from dry times and colors, thinning your paint might also cause you to paint over your exterior with multiple coats to get your desired color and finish, depending on the type of latex paint you use. Still, even if you have to put up multiple coats, spraying your exterior will save you time on your next painting project.

Contact Ireland’s Finest Painters for more insights and tips for painting your home’s exterior.

About the Author

Comments are closed.