Before applying latex paint over oil-based paint, you must first prepare the surface by sanding, cleaning with detergent, and coating with a primer. The primer can be either oil-based or latex, but in either case it should labeled as a “bonding primer.”

Watch the video above to find out more. Then, read the section below for more information on combining different types of paint.

VIDEO TRANSCRIPT

If you want to apply latex paint over oil paint you have to first prepare the surface by sanding, cleaning with detergent, and coating it with a primer. The primer can be oil or latex, but in either case it should labeled as a “bonding primer.”

The same is true for applying oil over latex. However, latex paints are more flexible than oil and many modern formulas are just as tough as oil, so it may be best to simply stick with latex for the new topcoat.


Why Oil Paints Don’t Mix

Oil-based paints have been used for centuries, and despite numerous innovations, a few facts have remained prominent in the artistic world. The first is that oil paints take a long time to dry. Modern oil paints dry much faster. However, they still dry at a different rate than latex or acrylics.

Furthermore, if you use oil paint over latex, the new paint will expand and contract at a different rate than the underlying layer, causing it to crack. Latex will not properly stick when applied directly on top of an oil-based layer without preparation and may easily crack or peel.


Using Latex On an Oil-Based Primer

There are many reasons to use latex paint over an oil primer, and the results are a strong, lasting surface. Generally, latex primers are used for drywall and softwoods, although there are a few notable exceptions. Oil primers and paints take longer to dry and require additional ventilation, meaning a blend of latex and oil can reduce time and discomfort without sacrificing durability.

Reasons to Choose an Oil-Based Primer

While some brands of primer can work universally with oil and latex paints, there are times when an oil-based primer is more efficient than a latex primer. These instances include:

  • Varnished or unfinished wood
  • Wood prone to bleeding tannins, such as redwood and cedar
  • Painting over chalky or badly damaged paint
  • Wood which has been severely weathered
  • Damp environments such as bathrooms
  • Can be tinted at the paint store if you will be using very light or dark colors
person painting a bathroom wall with a paint roller
Image Source: Canva

Determining If Your Walls Have Oil-Based Paint

  1. Feel the wall. Oil is smooth and glossy, while latex tends to be matte and has a more rubbery finish.
  2. Dip a cotton swab into acetone and test the painted surface. Latex will dissolve slightly, while oil will remain unaffected.
  3. If you have determined the existing paint is oil-based, you must rough the surface using 100-grit sandpaper until the gloss has vanished, then wash the surface and allow it to dry. You will now be able to add the bonding primer.

Placing Latex Over the Oil Primer

Oil-based primers take at least eight hours to dry. You may have to lightly sand the primer over smooth wood surfaces with 180-grit sandpaper to provide an easier bonding surface. Be sure to wash away any dust caused by the sanding and allow the area to dry before adding your paint. Generally, two evenly applied layers of latex paint will be required over the primer. Allow between two and four hours for each layer to dry.

A room will take approximately 16 hours of drying between the primer and two latex layers. This does not include the drying time after cleaning or the time required for the painting process. However, you may spread the project over a period of days so long as the job is completed within two weeks of applying the primer.

Further Information

Editorial Contributors
avatar for Danny Lipford

Danny Lipford

Founder

Danny Lipford is a home improvement expert and television personality who started his remodeling business, Lipford Construction, at the age of 21 in Mobile, Alabama. He gained national recognition as the host of the nationally syndicated television show, Today's Homeowner with Danny Lipford, which started as a small cable show in Mobile. Danny's expertise in home improvement has also led him to be a contributor to popular magazines and websites and the go-to source for advice on everything related to the home. He has made over 200 national television appearances and served as the home improvement expert for CBS's The Early Show and The Weather Channel for over a decade. Danny is also the founder of 3 Echoes Content Studio, TodaysHomeowner.com, and Checking In With Chelsea, a décor and lifestyle blog.

Learn More