Can you paint over polyurethane?

With interior paint trends constantly evolving and changing, people often wonder if you can paint over polyurethane to update to a new look. Polyurethane is the topcoat applied to kitchen cabinets and other wooden furniture to protect it from scratches and scuffs. While you can most certainly paint over polyurethane, you won’t get the best results unless you do the prep work first. Without sanding or applying a primer, any paint applied will end up bubbling or peeling off. There isn’t much worse than putting hours into a project, only to have the paint peel and flake and having to start over from scratch. 

Painting Over Varnish 

So many people are discovering the joys found in refinishing old furniture and cabinets. It definitely requires some elbow grease and time but is a super inexpensive way to decorate or make money on the side. Adding new life and color to a piece can be extremely satisfying, especially when you put your creativity to work. The hardest part of the process is painting over varnish, and getting your new paint to stick properly. Even some furniture that says it’s unfinished, can come with a layer of clear coat on the wood that will need to be addressed. Here are some simple steps to painting over varnish successfully. 

Supplies To Have On Hand 

  • Sandpaper-fine grade 
  • Gloves 
  • Face Mask 
  • Protective Eyewear 
  • Paintbrushes 
  • Oil Based Primer 
  • Oil Based Paint 
  • Wood filler or spackle 
  • Clean, lint-free rags 
  • Trisodium phosphate solution 

How To Paint Over Polyurethane 

  1. Be Safe and Smart 

Many of the products used in this process have strong fumes. Be certain to only apply them in well-ventilated areas or outside if possible. Carefully read the labels on all products before using them. Wear gloves, a mask, and safety goggles during the entire process for your protection. Properly dispose of any rags soaked with primer, paint, or trisodium solution as they may be flammable. 

  1. Clean the Surface 

With your rag, gently clean the surface you’re working on with the trisodium phosphate solution. This will remove all residue such as dirt, grime, or stains from the wood. Let the wood completely dry before proceeding. 

  1. Fill In Any Holes 

If the wood you’re working with has any dents, holes, or cracks, use the wood filler to fill them in completely. Once fully dry, gently sand down the area until flush with the wood. Wipe away any sand particles or remaining debris with a cloth. 

  1. Sand the Surface 

Use fine-grade sandpaper to remove the polyurethane coating from your wood. You don’t need to sand away every bit of the coating, just be consistent. Try not to over sand in some areas and not enough in others. If you don’t sand thoroughly enough, your new paint won’t adhere to the surface of your wood. Sand until the varnished wood is smooth and the wood no longer has a sheen or glossy appearance. After sanding, wipe down your furniture or cabinets with trisodium until all dust is removed. 

  1. Time to Prime 

Applying a primer will give your paint a better surface to stick to. Apply a thin layer of oil-based primer to the wood. Use even strokes to avoid splotches. Allow plenty of time for this coat of primer to dry. The primer is dry when it doesn’t feel tacky to the touch. Add a second coat of primer. Allow this coat to dry overnight for best results. 

  1. Second Sanding 

Sand the primed surface to ensure no brush strokes are visible. This should be a much quicker sanding but a worthwhile step for a smooth, cohesive, finished look. 

  1. Paint the Surface

Using long, careful strokes, apply paint to the surface. Let the first coat dry overnight. We recommend applying a second coat of paint but in some cases, the primer has done such a good job that only one coat is necessary. 

What Paint Will Stick to Polyurethane? 

Both oil-based and acrylic paints are perfect when you need to paint over polyurethane. For a more durable surface, oil-based paint is a good option. One drawback is that it produces very strong-smelling fumes. You can get close to the same results with acrylic paints, minus the fumes and harsh odor. If you live in the Boise area, you can buy the paints you need from Sherwin Williams. That’s where we get all of our paints. 

Can I Paint Over Polyurethane Without Sanding?

If you’re going to attempt to paint over varnish but really don’t want to hassle with the sanding process, there is a product you can use. Deglosser, or liquid sandpaper, is a chemical that will etch the varnish, allowing the paint to stick. Remember to wear the proper eye, hand, and mouth protection anytime you’re working with chemicals. Read the labels carefully for proper instructions and use.

Painting Over Stained Wood 

You can definitely paint over stained wood. It’s basically the same process as painting over varnish or lacquer. If you’re working on an outdoor project, be sure to use paint that is an interior/exterior formula to protect it from the elements. Always take the time to put on two full coats for best results. 

Can You Put Polyurethane Over Paint? 

Because polyurethane is a topcoat that dries clear and hard, it can absolutely be used over paint. It comes in both oil-based and water-based finishes. It can however crack in the sunlight so we don’t recommend it for outdoor use. 

You can use polyurethane to go on top of latex or oil-based paints. It’s important to note that water-based polyurethane dries clear. So if you’re wanting to display the painted surface, it’s your best choice. Oil-based polyurethane tends to yellow over time but dries harder, offering a more protective coating. You’ll have to decide whether you want a more protected surface or a more aesthetically pleasing finish.

Helpful Tips 

  • Before you open your can of polyurethane, don’t shake the can as you might with regular paint. Instead, use a stir stick to mix it thoroughly. This technique keeps the polyurethane free of bubbles that could prove troublesome down the road. 
  • Don’t use a cheap, foam paintbrush. A bristle brush will make your job a whole lot easier and will distribute the paint more evenly across the surface. 
  • Before your final coat dries, run your brush over the surface of the wood to smooth out any bubbles. 
  • You can use a spray gun instead of a brush for a more professional finish. 

Polyurethane Paint Conclusion 

If you still have questions involving any painting projects you’re working on or just simply need an excellent professional painter, give Boise Home Painting a call. When it comes to professional house painters in Boise, we understand the importance of quality and attention to detail. We use only high-quality materials and work tirelessly to ensure you’re happy once the project is complete. Plus, we paint exteriors, kitchen cabinets, interiors, and more! We serve the entire Treasure Valley including Boise, Meridian, Middleton, and Nampa

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