Buzz
A polyurethane finish provides durable protection to wood, making direct painting challenging. However, with proper preparation and technique, you can successfully paint over it. Begin by cleaning the surface and addressing any flaws. Sanding the finish allows primer and paint to adhere effectively. Once primed, apply multiple paint coats to achieve desired results.
Essential Tips
- Directly painting over polyurethane may lead to peeling over time.
- For optimal results without stripping, use enamel paint after priming.
- If not fully stripping, sanding the surface to remove sheen is recommended.
- For the best outcome, completely remove polyurethane, apply three coats of oil-based primer, and then proceed with painting.
Step-by-Step Instructions
Preparing the Surface for Painting
Protective GearWear rubber gloves, safety glasses, and a facemask to shield from TSP exposure. Ensure proper ventilation by working in a well-ventilated area or using fans if indoors.
Mix Cleaning SolutionIn a bucket, combine 1/4 cup of TSP with 1 gallon of water. Stir well to blend. Use caution to prevent splashing and maintain cleanliness by using a clean bucket.
Alternative: For a milder option, mix 1 gallon of warm water with 1 tablespoon of dish soap to create a soapy solution.
Scrubbing the SurfaceUsing a sponge, scrub the polyurethane surface with the cleaning solution. Apply pressure in circular motions to remove dirt and residue. Ensure cleanliness to facilitate smooth paint application.
Ensure Surface Is Completely DryWait for the surface to dry thoroughly, typically around 10-15 minutes. Use a dry towel to speed up the drying process if needed.
Fill Cracks and Holes with Wood PuttyApply wood putty to fill any cracks, chips, or holes. Use a flexible putty knife to spread it evenly. Allow the putty to dry completely before proceeding.
Preparing the Surface with Sanding
Protect Yourself with a Face MaskWear a face mask to prevent inhalation of dust during sanding. Choose a mask from hardware or department stores, or use a bandana as an alternative.
Sand the Surface with Fine-Grit SandpaperUse 120 to 220-grit sandpaper to scuff up the polyurethane surface. Employ circular motions to ensure even sanding. For efficiency, consider using an automatic sander for larger surfaces.
Pro Tip: For an even smoother surface, switch to 60 or 80-grit sandpaper after finishing with fine-grit sandpaper to further refine the surface.
Remove Dust with a VacuumUtilize a shop vac or vacuum cleaner hose to suction dust from the sanded surface and its surroundings. A handheld vacuum is handy for surface dust removal.
Wipe Clean with a Damp RagMoisten a clean rag with water and wipe down the polyurethane surface to eliminate any remaining dust. Alternatively, use a damp sponge or paper towels for cleaning.
Priming and Painting Techniques
Select Appropriate ToolsOpt for a foam roller for larger areas and a bristled paintbrush for smaller details. This ensures efficient coverage, with rollers ideal for broad surfaces like walls and brushes suited for intricate areas such as trim and edges.
Prepare Oil-Based PrimerPour white, oil-based primer into a paint tray, ensuring it's well-stirred. Slowly fill the tray, avoiding overfilling to prevent spillage.
Apply Primer and Allow to DryDip your brush or roller into the primer, removing excess on the tray's ridges. Apply a thin, even coat to the polyurethane surface using smooth motions. Let the primer dry completely before proceeding.
Primer Trick: For dark wood or polyurethane, apply a second primer layer once the initial coat is dry.
Prepare Oil-Based PaintPour oil-based paint into a clean tray after stirring it thoroughly. Ensure the tray is free of primer residue to maintain paint quality and appearance.
Apply Thin Paint LayerWith a roller or brush, apply a thin layer of paint to the surface, working in sections. Wipe off excess paint on the tray's ridges and use smooth strokes for even coverage. Multiple coats may be necessary for full opacity.
Ensure Proper Drying and Apply Additional CoatsAllow each paint layer to dry for at least 30 minutes before adding another coat. Check for coverage and add more coats as needed to achieve the desired finish.
Helpful Tips
Materials You’ll Need
- Protective gear: rubber gloves, safety glasses, and a face mask
- Trisodium Phosphate (TSP)
- Medium-sized bucket
- Scrubbing sponge
- Wood putty (if required)
- 120 to 220-grit sandpaper
- Paint roller or brush
- Oil-based primer
- Oil-based paint
- Paint tray
