A question we get asked often is, “Can you paint latex over oil?"
The answer is “yes”.
But you can’t treat it like latex or water-based surfaces.
If you put latex paint over oil, you’ll end up with that fruit roll-up look all over your house because they just can’t adhere. Since they’re not compatible, they won’t form a good bond.
15-30 days after painting, you’ll even be able to peel that paint right off after getting the surface wet.
Yikes!
Why We Don’t Use Oil-Based Paint
Many older homes we paint in East Grand Rapids have oil-based paint on the plaster walls, trim, and cabinets. Oil-based paint was popular in the ’70s and ’80s, especially on trim, cabinets, and doors. The most popular paint was a product called Satin Impervo.
There are a couple of reasons we don’t use oil-based paint anymore:
It emits a host of harmful VOCs (volatile organic content) that harm the environment.
Cleanup is messy since you have to use paint thinner
Latex paints are more flexible than oil-based paints, and modern formulas are just as durable.
How To Tell If It’s Oil Or Not
To see if a surface has oil-based paint, we like to use a test affectionately named, “The Oil Paint Test” (We’re painters, not professional namers)
To do this test, simply use denatured alcohol from a brand like Klean Strip and rub it on the surface with a rag or cotton ball.
If the paint does NOT come off, the surface is oil-based paint.
If it doesn’t, then it’s water or latex-based paint.
How To Paint Over Oil-Based Paint
Ok, so you’ve done the test, and it comes back positive for oil-based paint; what do you do now?
Preparation
Clean the surface: Thoroughly wash the acrylic-painted surface with warm water and mild detergent to remove dirt, grease, and oils. Rinse well and allow to dry completely.
Assess the current finish: Determine if the existing acrylic paint is glossy. If so, you must create a rougher surface for better adhesion.
Sand the surface: If the acrylic paint is glossy, lightly sand the entire surface with fine-grit sandpaper (180-220 grit) to create a slightly rough texture. This step is crucial for improving adhesion.
Remove sanding dust: Use a tack cloth or vacuum to remove all sanding dust from the surface.
Repair imperfections: Fill holes, cracks, or damaged areas with a spackling compound. Allow to dry completely, then sand smooth.
Priming
Choose the right primer: Select a high-quality bonding primer for use over acrylic paint. Look for products labeled as "adhesion primers" or "bonding primers."
Apply primer: Use a roller or brush to apply a thin, even coat of primer over the entire surface. Pay special attention to any repaired areas.
Allow primer to dry: Follow the manufacturer's instructions for drying time, typically 24 hours.
Painting
Select latex paint: Choose a high-quality, 100% acrylic latex paint for best results.
Prepare the room: Cover floors and furniture with drop cloths. Use painter's tape to protect trim and other areas you don't want painted.
Cut in edges: Using an angled brush, paint around the edges of the walls, ceiling, and trim.
Roll the main areas: Use a roller to apply the latex paint in a "W" or "M" pattern, then fill in the spaces to ensure even coverage.
Apply multiple coats: Allow the first coat to dry completely (usually 2-4 hours), then apply a second coat for better coverage and durability.
Finishing
Remove painter's tape: Carefully remove any tape while the paint is still slightly wet to avoid peeling.
Clean up: Wash brushes and rollers with soap and water.
Allow proper curing time: While latex paint dries to the touch within hours, allow at least 24-48 hours before hanging anything on the walls or exposing them to moisture.
Additional Tips
Work in a well-ventilated area and consider using a fan to improve air circulation.
Maintain a "wet edge" while painting to avoid visible lap marks.
If you're unsure about compatibility, test the latex paint on a small, inconspicuous area first
Consider applying a clear topcoat once the latex paint has fully cured for extra protection.