Today:23 June, 2024

How to thin paint in just a few steps

Imagine you are all set to paint a wall or remodel an old chair or a beat-up dresser. You have filled all the cracks and scraped everything to perfection. Now you open the paint can, dip your paintbrush, and apply your first stroke.

Nothing happens.

So, you cheerfully paint the entire area. Now, you take a step back to view the result from a distance.

What comes in your view is an un-professionally painted wall having bumps and ridges. You do not like this view at all. So, you pull out sandpaper to smoothen your artwork. Although scraping the wall can make it look presentable, but it’s time-consuming. Why would you paint a wall only to scrape it later?

Don’t worry, there’s a solution for this, and it’s three words. Thin your paint. In other words, add water or a paint-thinner to reduce the concentration of the paint so that it gives an even and smooth finish.

Thinning the paint before painting also reduces your work to half. The application becomes less complicated, the result is smooth, and a single paint bucket can end up painting more than one project.

As a beginner, some questions might be worrying you.

I am a newbie. How would I know if the paint needs to be thinned or not?

How to thin paint?

Are different paints thinned by the same method?

Do I still need to thin the paint even if I am using a spray gun?

We will address all these questions and some additional ones. By the end of this article, you will become well-versed with the art of thinning paint, and your painted walls will depict perfectionism and class.

How to thin paint without paint thinner

paints and brushes

Paints are divided into two types: water-based paints & oil-based paints. Water-based paints consist of water as a carrier to a pigment and binder, whereas oil-based paints contain natural or synthetic oil as a carrier to a pigment and resin.

Water-based paints find their application in DIY projects, doors, dressers, etc. Since oil-based paints give a firm finish, they are used to paint areas susceptible to environmental conditions.

Water-based paints are usually thinner and easier to handle than oil-based paints. They are thinned by using water. In the case of oil-based paints, a petroleum-based paint thinner is used.

How to thin water-based paint

Latex and Acrylic paints are water-based paints and can be thinned by using water. The process is simple but should be followed carefully to avoid over-thinning and ensure optimum consistency.

How to thin latex paint

To thin a latex paint at home you will need:

  1. Rubber gloves
  2. 5-gallon bucket
  3. Measuring cup
  4. Wooden stir stick
  5. Funnel

When these things are ready, follow these simple steps.

Step 1: Mix the paint thoroughly using a wooden stick.

If there are any clumps present, use a fine web strainer to remove them since they cannot be thinned by water and need to be separated.

Step 2: Check whether the paint requires thinning or not.

The test is simple. Dip the wooden stick in the paint can. Now hold it a top. If the paint falls smoothly and has a consistency of heavy cream, it does not need thinning. If the paint dangles down in drops, it can be thinned by adding water.

Step 3: Pour the paint from the can into a five-gallon bucket.

For each gallon of paint, experts recommend using 8 oz of water. In a measuring cup, take 8 oz of water and slowly add it to the paint bucket. After adding water, stir it for few minutes until the water is completely mixed. Continue adding water gradually while mixing until you achieve the right consistency.

Our advice would be to use less water since more can be added later on, but you cannot remove added water. Too much water will make the paint a runny mess and lower the coverage.

Step 4: Perform the funnel test to check whether the paint has the right consistency.

thinning latex paint

For this, you can use a kitchen funnel. Take the paint out in a clean disposable cup and pour it into the funnel.

If the hole clogs or takes too long to empty, the paint still needs thinning.

It flows smoothly – you are good to go.

If it is dripping and has a runny consistency, you might have over-thinned your paint. The best way to go about this is to add more paint to the mixture.

You can also test the consistency of the paint using a wooden stick as mentioned in Step 2.

Step 5: Test the paint application by painting on cardboard or wood.

This step is crucial to avoid letting your hard work go to waste. Before applying the paint to your project, test its application by applying it on a cardboard or a wooden piece.

Let it dry and apply another coat. Assess the result. If you like what you see, your paint is are ready for your big project.

Step 6: After you are done with your painting, pour a small amount of water over the paint.

This is to avoid the formation of the skin. Close the lid tightly to avoid the moisture from evaporating. If the cover is not tightly secured, the moisture will evaporate leaving heavy paint particles at the bottom.

Thinning the paint means applying a double coat for better coverage since you are lowering the opacity of the paint by adding water. However, this is easier compared to applying a thick paint and scraping it later or removing it altogether due to unsatisfactory results.

How to thin acrylic paint

Since acrylic paint is classified as water-based paint, it can be thinned by using either water or an acrylic medium. The different quantities of water and medium will affect the result.

Adding 30 percent water (w.r.t. to the paint quantity) can thin the paint while still coating the surface. This quantity results in a glossy appearance. Adding 60 percent water creates diluted paint. This paint is usually applied on an absorbent surface to give a stained effect.

Similarly, different quantities of acrylic medium bring forth different effects. 30 percent acrylic medium in the paint will give a smooth coating while 60 percent (or more) acrylic medium will result in a transparent and lustrous finish.

How to use paint thinner

Paint thinner is a chemical solvent used to thin oil-based paints. Unlike water-based paint, oil-based paints cannot be thinned by water. They contain oil molecules that can only be broken down by petroleum-based chemical compounds.

The most common household thinner includes turpentine, which also cleans oil-based paint stains. Mineral spirits and acetone are also popular thinners for oil-based paints.

Paint thinners are added to oil-based paints in small quantities to lower their thickness and ensure a smooth finish.

How to thin oil-based paint

Oil-based paints e.g., enamel paints, follow the same procedure of thinning as water-based paints. The only difference is that instead of water, a thinner (usually mineral spirit or turpentine) is added to the paint bucket to reduce the paint thickness.

While thinning oil-based paints, it is advised to wear gloves and be extra cautious since one is near chemicals. The bucket in use should be dedicated to oil-based paints since it cannot be reused.

The paint is poured into a large bucket and mixed. A ratio of 3:1 is used when thinning oil-based paints. For every three parts of paint, one part of thinner is used to get the correct texture.

Be sure to test the paint first on a scrap piece before moving to your actual project.

How to thin enamel paint

Enamel paints are used to paint areas subjected to temperature fluctuations and other environmental conditions such as rain, sunlight, humidity, etc. The paint dries off to form a thick layer and thus lasts for a long time.

Enamel paints are extremely thick paints that unquestionably need thinning before they can be applied. Since they are oil-based paints, they are thinned by using mineral spirits.

Commercial paint thinners are also used when thinning these paints. Although, they give more or less the same results as mineral spirits, albeit being expensive.

To thin enamel paint, half or one pint of mineral spirit is added to one gallon of paint. The paint is mixed with a stirrer and the consistency is checked by analyzing how the paint falls off from the stirrer

Along with painting fences and building exteriors, enamel paint is also used to apply a finishing touch to kitchen appliances. The paint finish results in added protection from wear and tear.

How to thin paint for spray gun

how to choose a paint sprayer

A spray gun is used instead of a paintbrush or a roller to ensure an even application on any surface. It also eliminates the need of doing a second coat.

Along with giving superior results, a spray gun also reduces the time required to paint to half. You also don’t have to worry about lines and brush marks.

To avoid the spray gun from malfunctioning, all the directions given in the manual must be strictly adhered to. When using a spray gun, the paint must be thinned to avoid clogging the nozzle. The paint that is not properly thinned, comes out in spurts and ruins the surface.

Here are few easy steps to thin paint for a spray gun

  1. Mix the paint inside the paint can using the downside of a brush or wooden stick.
  2. Pour the amount of paint you need for your project into a bucket. Slowly add a quarter cup of water. The water is added in small increments to avoid over-thinning the paint
  3. Blend it thoroughly. The paint should have a smooth consistency for even application. Remember the amount of water you added to reproduce the same results next time
  4. There are two types of spray guns. One is used in smaller projects like drawers, chairs, dressers. Other is for larger projects like walls, doors, house exterior, etc. The paint has to be thinned to the correct viscosity depending on the application and spray gun being used.
  5. To check whether the paint is ready or not, use an industrially calibrated viscosity cup for accurate measurement. A viscosity cup is a funnel with a calibrated hole underneath. Measure the time the paint takes to empty from the cup and compare it with the instructions given in the manual.
  6. You can also use a simple funnel to check the paint thickness. If the paint flows smoothly without blocking the nozzle, it is ready. If it doesn’t, thin it further by adding a small quantity of water.

Once your paint is thinned, pour it into the paint sprayer and tightly secure it. Adjust the nozzle vertically or horizontally, whichever way you want to paint, and start painting.


  • I don’t have a paint thinner at home. Can I use water to thin oil-based paint?

No, you cannot use water to thin oil-based paint. Oil particles in such paints can only be broken down by a chemical thinner. Adding water in oil-based paint will cause emulsification since oil and water cannot mix.

If you do not have a paint thinner at home, you can use mineral spirit. It gives similar results, is cheap, and available in markets.

  • How to thin oil-based paint for a spray gun?

Mix the amount of paint thinner instructed by the manufacturer in the paint. It could be ½ pint or 1 pint per gallon. Empty the paint into the gun and check if it spreads evenly. If it does not, add the maximum amount specified in the manual. If it still doesn’t, use a different method for application.

  • How much should I thin the paint before application?

Paint thinning depends on the application method you are using for your project. If you are painting using a spray gun, the paint needs more thinning since the nozzle is a small area from where it is released. When painting using a paint brush, the paint should be thin enough to make fine brush strokes and not leave any lines.

It also depends on the object you are painting. E.g., if you are painting exterior walls, then the paint needs to be comparatively thicker than when painting interiors, chairs, and tables.

  • Are there any disadvantages to thinning paint?

No, there aren’t any disadvantages. The only drawback – you can say – is that you will have to apply more than one coat. Although, this is more convenient than glopping a thick paint on the wall and scraping it later to get a smoother look.

Remember, there’s a difference between thinning and over-thinning the paint. Over-thinning paint is as bad as not thinning it at all. Make sure to add water in small quantities to avoid over-thinning.


Paint thinning is not as laborious as it seems. It is a simple process that anyone can carry out if they know the ins and outs of paint thinning. If you are using a spray gun, keep the manual in front of you and consult it at all times. For a paintbrush, thin the paint by following the given pointers, and you will be as good as a pro.

Paint thinners are readily available in any paint shop that you can use to thin the paint. If you are using water-based paints, you can accomplish your task by using water. Remember to test the paint first on a small piece before going big. Plus, always keep an emery paper handy to smoothen any imperfections.

Joseph is the founder and Chief Editor of "Indoor To Outdoor". He is an entrepreneur with experience in sales of household products. He also travels a lot, takes pictures and loves to ride a bike.

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