How to Thin Latex Paint for a Spray Gun

By: Contributors  | 
spray gun
Latex paints are made of new synthetic resins, which are compatible with water, have a thinner consistency and are wet enough to be used in a spray gun. Astrid Stawiarz/Getty Images

Paints are divided into two broad categories: oil-based paint, also known as alkyd paint, and water-based paints, known as latex paint. Oil-based paint uses petroleum-based solvent as its medium, while latex paint uses water as its medium [source: JoePullaroInc].

There was a time when you could only spray with oil-based paints, since they were thinner than latex paint, did not dry so quickly and did not clog the spray gun's nozzle. But today’s latex paints are made of new synthetic resins, which are compatible with water, have a thinner consistency and are wet enough to be used in a spray gun. Today you can use an airless gun or aerosol can for spray painting with latex paint. However, you still may find that your latex paint is too thick for your spray gun's nozzle and needs thinning. Here's how to thin latex paint so it can be used in a spray gun.


Materials you will need:

  • 5-gallon (18.9-liter) bucket
  • Water
  • Funnel

Here's what you do:

  1. Pour the paint into the bucket.
  2. Add ½ cup (118 milliliters) of water for every gallon of paint.
  3. Mix thoroughly.
  4. Check the thickness by running the paint through a funnel. If it flows freely through the funnel, you know the paint is thinned enough. If the paint is too thick, add an additional ⅛ cup of water (30 milliliters) per gallon (3.8 liters) of water and mix.
thin latex spray gun
Using a spray gun is simple, but making sure your paint is the right consistency before you start will make the job much easier.
Andia/Getty Images

Remember, adding water will change the color of the paint and alter the drying time. The water also will necessitate using more coats of paint to achieve the desired finish [source: Sherber].

If you want to get a smooth finish, you may want to spend a little extra money and rent an airless paint sprayer, which doesn’t require you to thin the paint to a precise consistency. Be sure to wear a respirator mask and cover anything around you that might get paint droplets on it [source: Stimpson].


Latex Paint FAQ

What is latex paint?
Latex is a water-based paint that is made with acrylic resin, making it similar to acrylic paint. Latex paint should be used to paint large areas or for general painting projects. The paint comes in a number of finishes, with some containing enamel, which makes it easier to paint hard, less porous surfaces.
Is latex paint waterproof?
Latex paint is not waterproof. If you do want waterproof paint, you’ll need to add a top coat of acrylic gloss or varnish. You can also mix in a waterproofing additive, which is a common method for outdoor paint jobs.
Is latex paint washable?
Latex paint is the preferred choice for many applications because it is washable after it dries. All you need is a little soap and water to remove stains or blemishes.
Can you use latex paint on furniture?
If you opt for a latex paint to paint furniture, you’ll need a latex primer first. It is recommended to use a semi gloss or satin finish in a latex or oil-based paint when painting furniture.
Who invented latex paint?
Latex paint, which was originally named Super Kem-Tone, was invented in the 1940s by Sherwin-Williams.