Paint thinner is a broad term defining numerous solvents designed to thin or remove paint from brushes, rollers, and other tools. Examples of paint thinners include turpentine, acetone, naphtha, mineral spirits, toluene, lacquer thinner, alcohol, and xylene.

These powerful solvents break down oil-based paints, primers, and stains, making it easier to strip paint, clean tools, and thin paint to fill a paint sprayer. Learn how to use paint thinner effectively for your projects.

Safety Considerations

Most paint thinner products contain powerful chemicals hazardous to the user's nose, mouth, throat, lungs, eyes, and skin. Always work in a well-ventilated space to avoid the build-up of dangerous fumes. Wear appropriate safety equipment, including breathing protection, gloves, a long-sleeve shirt, long pants, closed-toe shoes, and safety goggles with a rubber seal to prevent eye irritation. Paint thinner is flammable, so do not work near any flame or heat source. Store paint thinner and used rags in a fireproof container.

How to Use Paint Thinner to Clean Painting Tools

1. Fill a Container With Paint Thinner

   Get a bucket or small container to hold the paint thinner so it's easy to dip paintbrushes, paint rollers, and rags. Do not use a plastic container, because the paint thinner may destroy the plastic and leak through the container.
   

2. Clean Paintbrushes and Paint Rollers

   Place the brushes and rollers into the container with the paint thinner. Move the paint brushes around in the thinner for about 30 seconds to break down the paint. Remove the tools and clean them with warm, soapy water to remove the paint-thinner residue, then rinse and dry.
   

3. Clean Paint Cans, Paint Trays, and Other Objects

   Use a dry cloth or rag to clean up a mess on the sides of paint cans, in the bottom of the paint tray, or on any other objects that are safe for use with paint thinner, but cannot fit inside the container.

How to Use Paint Thinner to Strip Paint

1. Choose the Correct Paint Thinner for the Material

   Find the correct paint thinner for the intended use. There are options formulated specifically for hardwood, drywall, aluminum, steel, and more. However, you will likely need a paint stripper product for thorough removal from a surface if the paint is old and dried.
   

2. Apply Paint Thinner

   Use an inexpensive paintbrush to apply a thin layer of paint thinner to a small section of the wall, ceiling, or any other surface. Check the manufacturer's directions for how long the paint thinner should sit on the surface. It typically takes about 20 minutes for the paint to soften.
   

3. Remove the Paint

   Use a plastic paint scraper to scrape the paint off the surface. If all the paint does not come off with the plastic scraper, apply additional paint thinner or use a paint stripper. However, do not use too much paint thinner because it can seep into porous materials, like wood.
   

4. Clean off the Paint Thinner

   Wipe down the area where the paint thinner was applied using clean water and a cloth or rag. This step helps to protect the wood or metal surface and prepare it for repainting.
   

How to Use Paint Thinner to Thin Paint

1. Choose an Appropriate Paint Thinner

   Pick the appropriate thinner for your type of paint. Check the manufacturer's label for the right selection. In general, select the following:

   • Oil-based thinner, such as turpentine or mineral spirits, for oil-based paints, varnishes, and stains
   • Lacquer thinner for lacquer paint
   • Denatured alcohol for shellac
   • Water for thinning latex paint (chemical paint thinner causes latex paint to separate and become unusable)
     

2. Measure and Mix the Paint Thinner

   Mix the paint thinner with room-temperature paint (cold paint appears thicker than it is). Use a 3:1 or 4:1 ratio of paint to paint thinner. An incorrect ratio may ruin the paint. However, always refer to the manufacturer's recommendations for the right mixture. Start with a small batch until you are happy with the mixture.
   

3. Test the Mixture

   Apply a small amount of paint to the desired surface or load it into a paint sprayer to test the viscosity, appearance, and adhesion. The paint should completely cover the surface and not run or drip excessively. If the paint still seems too thick, add small amounts of paint thinner and repeat the test until you are satisfied with the results.
   

Storing Paint Thinner

• Store paint thinner in a sealed, fireproof container, such as one made of metal, until it can be brought to a hazardous waste collection site.
• Put rags used with paint thinner in a sealed, fireproof container, fill it with water, and dispose of it at a hazardous waste collection site.
• Place the container in a cool, dry location, such as a basement, workshop, garage, or shed.
• Refer to the manufacturer's directions for the ideal storage temperature. The storage area should remain cool during the summer months.
• Avoid storing paint thinner in an area with high temperatures which can cause evaporation, explosion, or spontaneously catching fire.