How to Thin Wood Stain? (5 DIY Steps)

Thinning or diluting wood stain before application makes the painting process easier. Thinning also helps to eliminate bumps and ridges in the finish but how do you thin wood stain?

To thin wood stain, you need to pick a paint thinner first. For water-based wood stain, you should pick water or a water-based paint thinner. For oil-based wood stain, you should pick an oil-based paint thinner or mineral spirits. For lacquer stains, you should pick a lacquer thinner.

You should then measure and add the right amount of thinner to the wood stain. After that, you should stir the mixture till you have even consistency and then test the stain on the wood to be sure it’s properly thinner.

But that’s not all. There is more to know about thinning wood stains and this post digs right into the topic. So let’s dive in.

Can You Thin Out Wood Stain?

You can thin out wood stain by adding the right amount and type of paint thinner to the wood stain. The recommended measurement is 1 part paint thinner to 4 parts wood stain while using water or oil-based stain.

You can also thin wood stain by adding 2 tablespoons of paint thinner for every pint of wood stain. For varnish stains, you’ll need more paint thinner to thin out the varnish since varnishes are usually thicker than regular stains.

However, you should know that thinning wood stains for large-scale tasks like staining garage doors or decks can be a bit daunting. This is because it will be difficult and time-consuming to thin large amounts of stain consistently to achieve the same color shade.

Also, you should add more paint thinner to the wood stain if you plan on using a spray gun to apply the stain. This is because spray guns and paint sprayers have a tiny opening at the end of the sprayer (called the nozzle) and it will be very difficult to get thick coats of the stain out of this opening. So you need the stain to be as light as possible.

However, if you want to apply the wood stain with a paintbrush, you don’t have to thin the stain as much. This is because paintbrushes can handle thick paints. You should also know that contrary to popular opinion, thinning out wood stain will not affect the stain’s color as long as you thin the stain with the right amount of paint thinner. The color will only be affected if you over-thin the wood stain.

So now that you know you can thin out a wood stain, what can you use to thin the stain? Let’s find out.

What Can You Use To Thin Wood Stain?

What Can You Use To Thin Wood Stain

You can use both natural and synthetic solvents to the thin wood stain. The choice of thinner will ultimately depend on the type of wood stain that you have, either water-based or oil-based wood stain. Let’s check out some popular paint thinners and see if you can use them to thin wood stains.


You can thin wood stain with water but you should only thin water-based wood stain with water. This is because water-based wood stains are dissolved in water. This means that the solvent in the water-based wood stain is water and as such, the wood stain can also be thinned with water.

You shouldn’t thin oil-based wood stain or lacquer with water because these stains have a high deposit of oils and resins that will not dissolve well in water. If you thin oil-based wood stain with water, you’ll ruin the flow and color of the wood stain.

Paint Thinner

You can thin wood stain with paint thinner but you should only thin oil-based stains and lacquer stain with paint thinner. If you are to thin water-based wood stain with paint thinner, you need to ensure that the paint thinner is water-based as most paint thinners are not.

Paint thinners are usually gotten from one of or a combination of turpentine, mineral spirits, acetone, xylene, naphtha, and toluene. All of these compounds are not compatible with water-based wood stains but you can use them to thin oil-based wood stains and lacquer stains.

Mineral Spirits

You can thin wood stain with mineral spirit. But, just like paint thinners, you can only thin oil-based wood stain and lacquer wood stain with mineral spirits. Water-based wood stains can’t be thinned with mineral spirits due to the oil and chemical-based nature of mineral spirits.

Mineral spirits are also great for thinning gel stain which for the record isn’t very easy to thin. Gel stain has a very thick consistency and you’ll need a strong paint thinner like mineral spirits to dissolve and dilute the gel. You can also use varsol in place of mineral spirits as the solvent also contains mineral spirits though not in its pure form.

Can You Thin Wood Stain With Acetone?

Acetone isn’t the best choice for thinning wood stain. Though acetone can thin wood stain, I’ll only advise you to use the solvent if you have experience using it.

This is because acetone is a key ingredient in paint-removing solvents. Acetone when introduced to stain coating separates the binder from the paint particles. This makes it difficult for the paint to stick properly and this is why acetone is a paint-removing solvent.

You should only use acetone to clean paint equipment and work area after staining wood. This way, you are at limited risk of ruining the wood stain.

Now that you know what to thin wood stain with, let’s find out how to thin wood stain.

How To Thin Wood Stain?

Thinning wood stain isn’t a difficult task but it requires caution and a bit of calculation to prevent you from over-thinning the wood stain. To thin wood stain, you’ll need the following tools:

  • A paint bucket
  • Wood stain
  • A plastic funnel
  • Paint thinner
  • A paint mixer or turning stick

Here is a quick rundown of how to thin wood stain:

  1. Open the paint container
  2. Pour out the wood stain into the paint bucket
  3. Measure and add the right amount of the right paint thinner
  4. Stir the mixture thoroughly
  5. Test the wood stain.

Now, let’s get to work.

1. Open The Paint Container

Open The Paint Container

Wood stains usually come in air-tight containers. You can open the lid to gain access to the paint. If the wood stain you intend to use comes in a spray can, you need to cut an opening at the top of the spray can you gain access to the paint. Without opening the stain’s container, you can’t thin it.

2. Pour Out The Wood Stain

Pour Out The Wood Stain

The next step is to clean the paint bucket. This is to get rid of paint residue, dust, and debris inside the paint bucket that can ruin the wood stain. To clean the paint bucket, use a rag. Tough stains can be cleaned using warm soapy water or rubbing alcohol.

With the paint bucket clean, pour out the wood stain into the bucket. You don’t have to thin all the wood stain if you don’t plan to use all of it.

3. Measure and Add The Paint Thinner

Measure and Add The Paint Thinner

To thin wood stain correctly, you need the right amount and type of paint thinner. Use water for water-based stains and mineral spirits for oil-based wood stains. Use lacquer thinner for lacquer and other sealants.

You should add 1/2 cup of thinner if you want to spray the wood stain. If you want to use a paintbrush, use 1/4 cup of paint thinner.

4. Stir The Mixture

Stir The Mixture

The next step is to stir the mixture to achieve an even flow and color. You can do this manually by using a turning stick or you can go with a paint mixer. A paint mixer will be faster and will produce even results.

If you are using a turning stick, you shouldn’t stir too fast or too hard as this can cause air pockets to become trapped in the stain coating. Instead, move the turning stick in a figure 8 motion. Also, ensure that the turning stick you are using is long enough to get to the bottom of the paint bucket. This ensures that the wood stain at the bottom of the paint bucket is also thinned.

If you are thinning lacquer, it’s better not to stir too much as this can cause bubbles to form inside the lacquer wood stain.

To mix lacquer, it’s better to pour the paint and thinner from bucket to bucket. To do this, put the lacquer in one bucket and the paint thinner or mineral spirits in another bucket. Then mix both of them by pouring from one bucket to another repeatedly. This will limit the possibility of bubbles in the lacquer.

5. Test The Wood Stain

Test The Wood Stain

The next step is to test the wood stain on cardboard or any other dispensable material. If the stain flows fine, goes on well, and dries properly, you have successfully thinned the wood stain.

But does thinning wood stain make it lighter? Let’s find out.

Does Thinning Wood Stain Make It Lighter?

Thinning wood stain doesn’t make the color lighter but it makes the paint flow or consistency lighter. When you thin stain with the right amount of paint thinner, the color isn’t affected. The color shade will only get lighter or off if you over-thin the wood stain.

However, when you thin stain, the flow is affected. This means that thick wood stain will become lighter or less thick.

This is because when you thin wood stain, the amount of solvent in the stain increases. In other words, the solvent to stain ratio increases in favor of the solvent. This makes the paint flow lighter.

Why Should You Thin Wood Stain?

You should thin wood stain for the following reasons:

  • Thinning helps the stain to become lighter so it’s easier to apply.
  • Thinning wood stain makes the stain dry faster
  • Thinning wood stain makes it easier to spray the wood stain.
  • Thinning wood stain helps to achieve a smooth and fine finish.

Final Words

Overall, wood stain can be thinned but you need to pick the right type of paint thinner to prevent ruining the stain’s consistency and color. Asides from that, you need to measure and add the right amount of paint thinner to the wood stain so you don’t wood-thin the wood stain.

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