June 27, 2021

Can You Paint Latex Over Oil?

Whether you can paint latex over oil has been debated for years. I cannot tell you how many times that question comes up, “Can You Paint Latex Over Oil?” So have the answers changed? Indeed they have, as both methods of priming wood are now seen as having merits for the other. Some woodworkers will tell you they love latex. It allows them to spray directly on bare wood without any danger of showing through the surface.  Others swear by oil for the fact that the surface retains its color.

Can you paint latex over oil?

You are allowed to apply paint latex over oil. However, you cannot use oil-based paint over latex. The surface creates a quality bonding primer for the process. Allow the primer to dry before you apply the paint. Two coats are practical on the surface. 

The oil-based paint is well-cured. Glossy surfaces need proper cleaning and priming so that they accept latex. Make sure you have enough paint to cover your surface area. Use Spruce’s Paint Calculator to get the required paint for your surface. 

If your budget allows, buying an extra gallon is a practical idea. Use a high-quality paintbrush, fine 180-220 grit sandpaper, medium sandpaper of 100 grit to 150 grit, a putty knife, and tack. 

Apart from these tools, you need materials to complete the painting, such as wood putty, trisodium phosphate, primer, soft sponge, and protective wear. The soft sponge is for applying trisodium phosphate. Protective wear includes glasses and gloves. 

The use of oil-based paint over other substances

The reason why oil-based paint over other substances is to prevent peeling or chipping. That happens when you apply other substances on top of oil-based paint. Other substances do not bond to an oily surface. 

Using oil-based paint over other substances speeds up the drying time and gives better resistance to discoloration from sunlight. When oil-based paint gets damaged, you can easily repaint it over other substances. 

If you apply oil-based paint on paint that has not cured, there is room for it to cure. Washing the paint does not bring damage to the walls. It is easy to use water and soap. 

How to paint latex over oil

The first step comes with preparing the surface. De-gloss the surface using sandpaper. The reason for scuffing the surface is to improve stackability. Getting rid of the old gloss is not about removing the old paint but preparing the painted surface for the new primer and adhering to the surface. 

If the sandpaper fails to comply, you are allowed to use medium-grit sandpaper. Hand sanding is better than power sanding since there is too much pressure with a power sander. 

Remove loose paint from the walls using a putty knife. Repair the imperfections on the surface. These include cracks that you fill up with wood filler. When the holes are dry, sand the gaps lightly using fine-grit sandpaper. Dry the surface when the surface is dry. Use a soft and clean cloth. Clean the surface, removing dirt and grease. A TSP is ideal for deep cleaning combined with hot water. 

Use a damp cloth as you wash the surface. Rinse and air-dry the surface. Prime the surface to avoid premature peeling of latex over oil paint. When the primer is dry, get ready to paint. Let the paint dry for two or more hours. 

When it is dry, you may apply a second layer of paint. Do not let your brush take more latex paint. A thick layer of paint takes forever to dry. Dip the tip of the bristles into the paint and apply slowly.  Make sure your strokes are even and maintain a wet edge. 

Applying it

  • Sand the surface using 180 to 220 grit as you remove the gloss.
  • Clean the surface using a cloth or sponge dipped in trisodium phosphate mixed with water. 
  • Wipe off the cleaner with a sponge and clean water. 
  • Allow the surface to dry naturally.
  • Apply a coat of primer for bonding between latex and oil-based paint.
  • Use two coats of latex paint as a finisher using a brush. 

How long does it take to dry?

Latex takes two hours to dry. On oil-based paint, it takes eight hours. More hours do not harm the process, but they are safe for the user to start working on the surface.

What are the risks of peeling?

Peeling is hazardous to your health. Even if you are cautious enough not to ingest it, inhaling dust-containing paint is dangerous. It should not be ingested to avoid a complicated healthy life. 

Peeling paint contaminates the soil as well. The dust accumulates on window sills and countertops. Some diseases of peeling paint are nerve damage, kidney damage, headaches, and anemia. 

Primer needed

Priming is necessary when preparing to paint latex over oil. It improves the bond between the surface and the paint. That creates excellent adhesion to the surface. An oil-based primer is ideal for the project. 

The primer is the foundation of your final paint finish. The adhesion gives uniformity, smoothness, consistency, and an even texture, and the primer prevents the peeling and flaking of the topcoat. The primer comes in multiple forms. 

Oil-based latex is reliable and versatile. The oil-based primers perform better when painting latex over oil. The surface has to be bare and clean before applying the primer. Failure to prepare the surface leads to cracking and flaking. 

That might not happen overnight, but you cannot run away from the shortcomings with time. That costs you more than priming itself. Applying an oil-based primer on painting latex over oil gives you an exceptional finish. The surface is made strong, smooth, and durable. 

How to repair peeling

Make sure you have enough tools and materials before you start. These include protective gloves, a ladder, patching material, a putty knife, sandpaper, a scrapper, a wall patch, and rags. Take a scraper or 100-grit sandpaper. 

Use it to remove peeling paint from the damaged area. Remove dust, debris, and dirt using a rag to remove excess peeling paint. Take a putty knife so that you start applying a layer of patching material. Let it dry. 

The second round requires 220-grit sandpaper for a smooth surface on the patch. Use it on the surface for uniformity. The patching material should be the same as the original one unless you are repairing the whole surface. 

There are chances of having the patched area shrink. You overcome that by sanding lightly, cleaning the area, and applying layers of patching material. No stipulated layers are expected, but you can tell when the surface becomes even. Get rid of dust and debris for a final finish. The finish has to match the existing surface.

Check the chemical compounds that make up the paint

Know the chemical substances that make up your paint. It helps you know if the latex paint is compatible with other substances. You know the chemicals the paint contains and how they work. 

In case of a problem, it is easy to identify the cause. The paint comes as organic and inorganic. It differs in brightness and stability and comes with different adhesion levels and thicknesses. See how to remove paint from wood.

David D. Hughes

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