Can I Paint Over Polyurethane?

So, you’re ready to give that woodwork a new look. But what about the polyurethane?

For any painting project to be successful, you have to go into the process knowledgeably and with your eyes wide open. It’s a science just as much as an art, meaning that you can’t simply mix and match products however you’d like and expect a good outcome. Some combinations will literally repel each other, causing an immediate mess, while other times the disaster is more of a slow burn… You’ll just see the paint start to chip, peel, and flake in the weeks and months after you finish your project.

Our very best advice? Consult with a local professional painting company. Knowing your repaint is in good hands offers peace of mind and guaranteed value.

With that said, let’s dig into the topic at hand: can you paint over polyurethane? Yes, you can. But you need to follow the right steps.

What is polyurethane?

Polyurethane is a smooth, durable, transparent finish coat that is designed to protect stained or painted finishes. Glossy and attractive, it adds a beautiful shine while sealing in all that style underneath. Perfect for busy, high-traffic woodwork, like kitchen cabinets, stairways, flooring, and furniture.

What happens if you paint over polyurethane?

Well-intentioned homeowners sometimes try to paint right over the poly. Remember, surface preparation is EVERYTHING, and will literally make or break your project as a whole. If you paint over a slick, glossy finish, your paint just won’t stick. Or, it may stick for a little while, but it certainly won’t last. Plus, and here’s where the science comes in, you’ll have either an oil-based or water-based polyurethane, and if you don’t choose the right paint your poly will completely reject it. Think of it like the poles of a magnet: opposite poles snap together, while the same poles push away from each other. It might not be quite as drastic, but it’s much the same for paint: you have to pair water-based (latex) products with water-based products, and oil-based with oil-based.

Need to transition from one type to another? That’s a topic for another day and requires a very specific approach.

How do you paint over polyurethane surfaces?

Here’s our recommended process.

1. Wash the wood
Clean, degrease, then allow those surfaces to thoroughly dry. You might be sanding next, but it’s still important to work with a clean surface.

2. Sand the polyurethaned wood
It’s not always necessary to completely remove the poly, but you do want to scuff it up and create a receptive profile for your primer. Remember, polyurethane is designed to make sure things don’t stick to it - not ideal conditions for paint.

3. Apply primer
Not only does primer help build a strong foundation for your paint, but it also offers stain-blocking (or “hide”) protection. That’s especially important since, in most cases, if you’re painting over polyurethane you’re painting over a natural wood finish. And keep in mind that you need to use the right primer for the job, as we mentioned above. You can’t mix and match oil-based and water-based products.

4. Apply your paint
Paint your first coat, let it dry thoroughly, then apply your second coat. Time is your friend in most cases when you’re painting: don’t rush it, watch the details, and make sure each step is done right.

FAQ about painting over polyurethane

Q. Will paint stick to polyurethane?
No, at least not for long. You need to clean, sand, and prime the surfaces first, incrementally building a strong base for your paint to adhere to.

Q. Can I spray paint over polyurethane?
If you follow the right preparation steps and use the appropriate products, then yes. You can apply paint with a sprayer over wood previously coated in polyurethane.

Q. Can I use latex paint over polyurethane?
Only if it’s a water-based/latex polyurethane product. If it’s oil-based, you can’t apply latex paint over the top without following a very specific procedure to successfully transition from one product to another.

Q. Can you paint over polyurethane without sanding?
No, poly is slick and specifically designed to protect your wood surfaces and make them easy to clean. Paint will just sit on top without adhering.

What’s the takeaway?

Know your existing product (what’s already applied). Know what you’re getting into. Know how to truly prepare the surface. If you can check these boxes, you should have a successful project. If you don’t, you can be in for a messy, frustrating experience.

Have more questions? Contact us at Nash Painting! We’d love to help you with whatever type of painting project you might have in mind.