How to Use Paint Thinner

Paint thinner is a versatile solvent that can be used for a variety of purposes including cleaning paint brushes, thinning oil-based paints, removing paint splatters, and cleaning up after painting projects. Knowing how to properly use paint thinner will allow you to get the most out of this useful liquid.

Selecting the Right Paint Thinner

There are several different types of paint thinners available, each designed for specific applications. Before using paint thinner, it is important to understand the differences between the main options:

Mineral Spirits

Mineral spirits, also known as white spirits, are derived from petroleum. They are relatively mild solvents that are safe for most cleaning tasks. Mineral spirits work well for general paint thinning and brush cleaning. They evaporate slowly allowing you time to work.


Acetone is an extremely potent solvent often used in nail polish remover. It evaporates very quickly which makes it good for tasks where fast drying is desired. However, acetone can damage many surfaces so it should be used carefully. It is ideal for removing paint splatters on glass.


Turpentine is derived from pine trees. It has a strong odor and is effective at cutting through thick, oily paints. Turpentine works well for thinning and cleaning oil-based paints. However, it may cause skin irritation so gloves should be worn.

Lacquer Thinner

Lacquer thinner is the most potent of the paint thinners. It evaporates extremely quickly and dissolves paint rapidly. Lacquer thinner is specially formulated to thin lacquer paints. It should be handled carefully as it can damage surfaces and irritate skin and eyes.

For most general paint thinning and cleaning, mineral spirits are recommended as they are effective yet mild. Always select the least potent paint thinner that will accomplish the task at hand. Never substitute a harsher paint thinner when a milder one will work.

Preparing the Work Area

When working with paint thinner, it is critical to work in a well-ventilated area away from open flames or sparks. Paint thinner fumes can be very strong and flammable. Here are some tips for setting up a safe work environment:

  • Work outdoors or in a garage with the doors open if possible. If working indoors, open windows and use fans to circulate air.
  • Do not smoke or have any ignition sources present when using paint thinner.
  • Clear the area of rugs, furniture, and other items that could be damaged by paint thinner spills.
  • Cover the work surface with newspaper or a drop cloth. Have rags and paper towels handy for cleaning up drips and spills.
  • Wear appropriate safety gear like gloves, eye protection, and a respirator mask if working in an enclosed area.

Taking precautions with the work environment will allow you to use paint thinner safely and effectively.

Cleaning Paint Brushes

One of the most common uses for paint thinner is cleaning oil-based paint off of brushes. Here is the best process for cleaning brushes with paint thinner:

Step 1: Remove Excess Paint

After finishing painting, scrape off as much paint as possible from the brush bristles back into the paint can. Then swirl the brush around in a can of paint thinner to loosen the remaining paint.

Step 2: Brush Against Wire Brush

Use a wire brush to scrub the paint brush bristles while holding it over a tray filled with paint thinner. The stiff wires will help remove thick, oily paint.

Step 3: Rinse with Clean Thinner

Pour out the dirty thinner from the tray and rinse the brush with clean thinner. Swish the brush around to remove any hidden paint in the base of the bristles.

Step 4: Repeat as Needed

Repeat steps 2 and 3, using fresh thinner each time, until the thinner runs clear and all paint is removed from the brush. This may take several rounds of scrubbing and rinsing.

Step 5: Dry and Store

Once clean, use a rag to remove any remaining thinner from the brush. Allow the brush to dry completely before storing or using again.

Thoroughly cleaning paint brushes with thinner after each use will keep them soft and supple for many painting projects to come.

Thinning Oil-Based Paints

Paint thinner is commonly used to thin the consistency of oil-based paints. Follow these steps to properly thin paint:

Step 1: Stir the Paint

Begin by thoroughly mixing the paint in the can to achieve a uniform consistency. Stir for 2-3 minutes until smooth.

Step 2: Add Small Amounts of Thinner

Start by adding just a few teaspoons of paint thinner at a time directly into the paint can. Stir to fully incorporate after each addition.

Step 3: Test Consistency

After thinning, use a wooden paint stir stick to check the consistency. Properly thinned paint should flow smoothly off the stick, leaving a clean trail. Add more thinner in small increments until desired consistency is reached.

Step 4: Apply Thinned Paint

When the paint flows at the right viscocity, use as directed. Remember that thinned paint will dry faster so work efficiently.

Step 5: Seal and Store

Seal the paint can tightly after use to prevent the paint thinner from evaporating. Store thinning paint in a cool, dry place.

Avoid over-thinning the paint as this can reduce hide and durability. For best results, thin paint gradually and test frequently until optimal viscosity is reached.

Removing Paint Splatters

Paint splatters and drips are inevitable when painting. Paint thinner is great for removing errant paint before it dries. Here is the process:

Step 1: Identify Surface Type

Before using paint thinner, consider the surface the paint is on. Thinner is safe for glass and metal but can damage finishes on wood, drywall, and plastic. Test on inconspicuous area first.

Step 2: Wipe with Thinner

If safe for the surface, dip a clean rag in the paint thinner and gently wipe the paint splatter to loosen it. Change rags often to prevent spreading paint around.

Step 3: Rinse and Dry

Once paint is removed, rinse the area with clean thinner and wipe dry with a paper towel. This will remove any thinner residue and paint tint left behind.

Step 4: Clean Rags

Used paint thinner rags should be washed well with soap and water or placed in a metal container until fully dried to prevent fire risk. Dispose of rags properly.

With prompt attention, paint thinner can make quick work of removing fresh paint spatters before surfaces are permanently damaged.

Paint Thinner Safety Tips

While very useful, paint thinner also carries risks. Keep these important safety tips in mind when using paint thinner:

  • Never leave paint thinner containers open. Replace caps immediately after use.
  • Store paint thinner sealed in original container away from heat, sparks, and children/pets.
  • Use paint thinner in well-ventilated areas away from open flames. Turn off pilot lights.
  • Wear chemical-resistant gloves and eye protection when handling paint thinner.
  • Avoid breathing in paint thinner fumes. Use respiratory protection if ventilation is poor.
  • Thoroughly wash skin that contacts paint thinner with soap and water.
  • Keep paint thinner away from wood floors, finishes, plastics, rubber and other surfaces it can damage.
  • Dispose of used paint thinner according to local hazardous waste regulations. Never pour down sink or drain.

Exercising proper safety practices when handling paint thinner reduces the hazards of this caustic but useful solvent. Be sure to read and follow all manufacturer safety warnings. With responsible use, paint thinner can make many painting jobs much easier.

Frequently Asked Questions

Here are answers to some common questions about how to use paint thinner:

Can I thin latex paint with paint thinner?

No, paint thinner should only be used to thin oil-based paints. To thin latex paint, use water. Adding paint thinner to latex paint will cause the paint to clump and become gummy.

What ratio of thinner to paint should be used?

There is no set ratio for thinning paint. It depends on the specific paint. Start with a few teaspoons of thinner per quart of paint. Add gradually and test consistency frequently until desired viscosity is reached. Avoid over-thinning.

How long does thinned paint last?

Thinned paint has a shorter shelf life, especially if improperly stored. Seal thinned paint well and use within several days. Do not store thinned paint for more than 2 weeks.

Can I reuse paint thinner?

It is best to not reuse paint thinner more than a few times. As it is used, paint thinner becomes contaminated. For best results, start projects with fresh thinner. Properly dispose of used thinner.

Is it okay to thin enamel paint?

Yes, enamel paints are oil-based so paint thinner can be used to thin them. Carefully add small amounts at a time until optimal consistency is reached. Stir thoroughly and test often while thinning.

What are signs I have over-thinned the paint?

Signs of over-thinning include excessive dripping, difficulty brushing smoothly, visible drips in the dried paint, or the inability of the thinned paint to fully coat the surface.

Tips for Using Paint Thinner

  • Clearly label containers of paint thinner to avoid accidentally mistaking it for other liquids.
  • Store rags soaked with paint thinner in a covered metal container until fully dried. Never crumple and toss solvent-wet rags.
  • Work in a well-ventilated area and wear protective gear when using paint thinner for extended periods.
  • When using mineral spirits, select low odor varieties to minimize strong fumes.
  • Avoid plastic containers which can degrade and leak over time. Store paint thinner in metal cans.
  • To remove thick paint from brushes, try soaking in thinner for 10-15 minutes before scrubbing bristles.
  • Turn off any appliance pilot lights before beginning paint thinning projects.
  • Never pour paint thinner down the drain. Contact local hazardous waste centers for proper disposal.
  • Rinse paint brushes briefly in thinner then wash thoroughly with soap and water after each use.

Using these tips along with the other advice in this article will allow you to handle paint thinner safely and use it effectively for paint projects. With the proper techniques, paint thinner can save time and frustration.


Paint thinner is a workshop necessity for any oil painting task. Now that you know how to select the right thinner for your needs, set up a safe workspace, thin paint properly, clean brushes, remove paint spatters, and use thinner safely, you can take full advantage of its benefits. Paint thinner allows you to finesse and improve oil-based paints in ways that make painting much easier. Just be sure to always use caution and care when working with this caustic but useful liquid.