How to Thin Wood Stain: Easy Methods for Beginners

You have selected a striking stain for your bungalow or you've just finished sanding your gorgeous antique wooden furniture. Now you're all set to stain. Don't destroy your work with a thick stain. Too much thick material will create bumps, unevenness, and or ridges on the surface.

Thick stain can drive you mad. And if you're using a sprayer for applying, this madness will get out of control

After all that effort you've put into your project, why ruin it by a thick stain?

Choose a thinner stain or simply thin your stain yourself. But it is important to know how you can thin stain with a right thinner and perfect ratio of it.

A thinner stain will also leave you in a problem. There are various stains and each one requires a special method with a specific thinning agent. Let us discuss the various thinning methods in detail.

Why do we need to thin stain?

There are a lot of benefits of knowing how you can thin a stain perfectly. A thinned stain can be easily applied by all means. On the contrary, a thick paint is very difficult to coat even if you're using a brush, sprayer, or a roller. You can get the uneven surface, traces, and more clogs in your sprayer.

It is true that you've to apply more layers of a thin stain than a thick one but will satisfy you with the smoothness of the surface. Thinning is a good technique to prevent your stain from drying quickly.

Sometimes after applying stain, we might wish that its color could be little light. A perfect tone of the color can be achieved by a thinner stain as it is applied by several coatings. One of the big advantages of using a thinner stain is that it can save you money.

How we can do that? Adding more liquid or thinner in the stain will also increase its quantity. Though it needs more coatings a diluted stain will also cover more area by spreading. Always identify the right stain and use the required quantity to enjoy all these benefits.

How to thin wood stain: various Method Discussed

1. Thinning Stain with Mineral spirits

How to thin an oil-based stain? a lot of oil-based thinners contain mineral spirits as a thinning agent. A mineral spirit in a wood stain is called as "petroleum distillates". a lot of varnish-based and polyurethane-based stains also contain mineral spirits.

For thinning purposes, try to add more mineral spirit to it. The ratio of thinner to stain is not crucial. While applying stain with a rag, try to add around 50% of thinner in it. However, this percentage differs for different stains.

For example, varnish stains are thicker than oil-based stains. They require more amount of mineral spirits.

Be aware that you'll have to apply more coats of a more diluted stain. This is because a greater number of thinning agents will reduce the measure of stain in it.

It is recommended to add thinner in a small amount while mixing it well in a solution.

Always test a stain before adding more thinner into it. Too much mineral spirit will only make the color lighter than your desired results. An ideal mixing is 3-4 parts stain to a 1-part mineral spirit.

If you're using a sprayer to apply stains, try to use less amount of mineral spirit for dilution. Too much thinner in a stain makes it difficult to apply through the spray gun. It only results in dripping and excess wiping during satin application.

Mineral spirit is less toxic than a lot of other chemicals. But It is flammable. Its fumes are still poisonous and can cause skin-related issues. More exposure to it can also result in nervous system damage. Always wear safety glasses and proper gloves before using it.

Mineral spirit is a bit expensive thinning agent and there are some alternatives for it. Always prefer mineral spirit over those alternatives as other thinning agents contain deadly chemicals.

The following are the thinning agents that can replace mineral spirit.

  • Varsol: It contains mineral spirit but not in pure form. It is also known as the white spirit.
  • Naphtha: It is a very flammable product and helps in speeding drying time. The main components of naphtha can be petroleum distillates, crude oil, and refined products.
  • Turpentine: Turpentine is best for thinning varnish-based stain it has a strong bitter smell and dries very slowly. It is more expensive than other solvents.
  • Paint Thinner: It also contains a less pure form of mineral spirit with chemicals like naphtha, acetone, glycol ethers, xylene, etc.

2. Dilute Wood Stain with Water

Water-based stains are often known as "latex Stains". Water is a thinning agent in these stains that are made up of water-compatible artificial resins. To make a more diluted solution of these stains, more water can be added to the solution.

The following materials are required for thinning water-based stains.

  • 18.9/5 gallons Liter Bucket.
  • Paint mixing sticks.
  • A big Funnel.

While using a pint of stains, add 2 tablespoons of water per pint. Never attempt to put in all water together. Use room temperature water. For better mixing of stain and water, you can also pour it from one bucket to another instead of using sticks.

Add all of your stains into a bucket. For each gallon mix 1/2 cup of water in it. With the help of a stick, stir combination carefully. Now pour it through the funnel and check its viscosity. Viscosity indicates how thick or thin material is.

If your thinned combination can flow freely through the funnel, then thinning of stain is successful. When the stain is not flowing smoothly and is blocking the pour, try to add another 1/8 cup of water for each gallon.

If by mistake you've added extra water in stain, your satin will become too thin to apply. To achieve its even consistency, start by adding 1/2 cup of stain in the bucket. Continue stirring to make a correct solution. Keep adding more paint until you get your ideal thinned stain.

Thinning latex stains require at least 4-5 coats while applying. Nonetheless, coats completely depend on how thin your water-based stain is! A standard thin latex stain will only need 2-3 coats.

To maintain the ratio in solution, try to cover your stain bucket with a lid after working on it. Uncover water-based stain will allow moisture evaporation and it will again become thicker. It is a good approach to keep stirring a latex stain to avoid more thickness in it.

Other than water, there are a lot of other thinning agents available in the market for water-based stains. They are labeled as water thinning additives. Most of the manufacturers also advertise these thinning additives as a wood conditioner.

Those products can be effective but water is the best thinning stuff to dilute any kind of water-based finish.

3. Thinning Stains with Lacquer

For any kind of lacquer-based stain, use a lacquer thinner. A cellulose thinner is another name used for it. This kind of thinner is complex and contains much acetone with a low amount of aromatic solvents. They also consist of alkyl esters and aromatic hydrocarbons.

Lacquer thinners can't be used for any stains other than lacquer-based. For thinning a lacquered stain, grab the following materials.

  • Spray gun
  • Lacquer Thinner
  • Stir Stick
  • Gloves/ Respirator

Put on your safety equipment including respirator before starting this work. start diluting your stain by adding 1 or 2 ounces of thinner. Keep stirring and mixing the stain for at least 20 seconds.

For a big project of lacquer stain, transfer half of lacquer into a gallon can. Add 1 pint of thinner into it and stir it with mixing stick.

If you're applying lacquer with a spray gun, instead of stirring it with stick shake spray bottle strongly. After mixing it well, test it in a small portion and check its evenness. It should feel smooth and not extra runny. An even surface free of bumps indicates a perfect thinning stain.

If the combination has become runnier, then add more lacquer stain in it. Always add a small quantity and test it before adding more amount. It is always recommended to use a lacquer thinner that is recommended by a lacquer manufacturer you're trying to thin.

Keep in mind that various lacquer thinners are made up of various diluting solvents. They are highly flammable materials. It is a good practice to keep them away from any heat source. Their fumes can be so deadly and poisonous that they can harm your nervous system.

Avoid thinning lacquer more than twice however it can be possible in some cases where the evaporation rate of lacquer is fast. Lacquer thinners are mostly sold as cleaning agents to clean brushes and other equipment.

Additional Tips for Getting Perfect Results

By keeping these tips in mind while thinning any kind of stain, you'll be able to achieve a perfect outcome.

1. Identify your stain

Before selecting a thinner for your stain, know which type of stain you're using. You can check the ingredients listed on the stain container. Oil-based, water-based, lacquer-based, polyurethanes based all stains carry various dyes and solvents.

Oil-based stains mostly contain petroleum distillates known as mineral spirit. Varnish stains are more viscous than oil-based stains but they also have mineral spirit in them. Water-based stains are very various from oil and varnish stains.

One major difference is water stains use water as a solvent and are mostly partially transparent ones. Modern water stains label word latex on them.

A lacquer stain has a very strong odor and can be easily identified. This strong smell is because of xylene, toluene, and ketones present in them.

For thinning oil and varnish, use mineral spirit. Thinning of lacquer stains or non-grain raising stain can be done by lacquer thinners. It is obvious to use water for thinning water-based stain.

2. When to add Thinner?

To get perfect results, it is a useful tip to add thinner just before starting your staining project. Diluting and storing earlier may result in the thickening of the whole solution. This can because of evaporation.

All kinds of stains can be thinned again and again except for varnish stains. Try to add a small amount of thinner in stain and stir it thoroughly. It will help in dissolving all types of pigments into solution.

It is almost impossible to make a satin too thin because thinner will its color. Most stains are already thin enough to use through a sprayer. However, if you're thinning for a spray staining project, do not make it extra dilute. A more diluted stain will cause dripping and running while spraying.

3. Test the Stain

After adding a small quantity of thinner in stain, it is suggested to test it before any further increment. If you don't have any extra surface or material available for testing, try to test it on a very small portion.

With the help of this, you'll become aware of stain texture and appearance. You can simply then add stain or thinner for your desired color. Repeat this process as a lot of times as you wish until you're completely satisfied.

4. Using Multiple Buckets

You may know this quotes; Don't Put All your Eggs in One Basket. Then you know what i mean about using multiple Buckets

For thinning purposes, always keep multiple buckets with you. This will help you in making the process speedier. You can use various buckets to mix stain with thinner by just pouring from one bucket to another.

Different extra buckets can also help you with storing any excess thinner, stain, or a thinned stain.


We are sure that you've can master thinning techniques after reading our useful guide on how you can thin wood stain. The main thing to become a pro is to select right thinner for stain and suitable quantity of it. Always test it and add thinner in a small amount to reach uniformity.

Whether you're using oil-based, water-based, or a varnish stain, practice the above-mentioned tips for the best outcome. It is not a challenging job and just requires a little patience. Rushing work will only damage your beautiful stain.

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