Can I use polyurethane over wood filler?

My husband and I did a lot of research before we moved into our current home. One of the things we were most concerned about was the condition of the wood floors because they looked really good when we saw them in the showroom but were actually pretty worn down by the time we moved in.

We wanted to restore them as much as possible, so we bought a variety of paint, stain, and putty to see how long it would take us to get rid of all those scratches and blemishes.

We found that staining over existing stains worked best for us—no matter what color you’re going for!

Can you put polyurethane on wood filler?

Polyurethane is a clear coat and not a stain. It will not fill in the scratches and it will not seal the wood filler. It is designed to protect, but you’re going to need to sand first if there are any noticeable high spots on your wood surface.

Polyurethane also has an advantage over shellac because it dries faster, allowing you to apply another coat after only 24 hours as opposed to three days for shellac.

Can I polyurethane over Minwax wood putty?

The short answer is yes. You can use polyurethane over Minwax wood putty and you will find that it will seal the wood putty as well as provide protection from moisture and stains.

However, polyurethane alone won’t cover the Minwax wood filler completely; it will leave an almost white tint behind where you applied it.

If you want your finished piece to look like it’s made out of one material (rather than two different materials), then I recommend using a darker color for your fillers instead of using white or light-colored fillers.

This way, when you apply polyurethane over them, less contrast between their colors will be visible.

Can you seal wood filler?

Below are some options you can use to seal your wood filler.

  • Polyurethane: This is not the best choice as it will not adhere well to the filler, particularly if sanded. The polyurethane will also become brittle and crack over time.
  • Varnish or shellac: These products are better suited for sealing your wood filler due to their flexibility and ability to stick well to wet surfaces.
  • High quality paint: Choose a high quality acrylic latex paint that will provide good coverage with little need for multiple coats of paint. If you want the most durable finish then opt for a gloss finish but otherwise, matt finishes work just fine too so long as they are applied correctly and allowed plenty of drying time between coats (1 hour).

How do you cover fillers in wood?

Fillers are a great way to smooth out imperfections in wood. That said, you’ll need to treat the filler with care so that it doesn’t get covered up by your paint or stain.

  • For small areas and minor filling, use a brush: Fill the gap with wood filler and then lightly brush over it with water until there is no more sign of the filler.
  • For larger areas and deeper filling, use a roller: Roll on some polyurethane onto your wood followed by several coats of primer before applying two coats of paint or stain. This will work well if you aren’t trying to match an existing finish because it gives you time to sand down after letting each layer dry completely (the primer acts as an evener).

Can you put varnish on wood filler?

Yes. You can seal wood filler with varnish or polyurethane.

Varnish is a liquid that dries to form a film on top of the wood filler, which helps to protect it from moisture and other elements.

This type of sealant is best for projects such as furniture that require high protection against wear and tear.

Polyurethane is also a liquid, but it penetrates deeper into the surface than varnish does, making it ideal for filling holes in floors or walls where moisture may be present.

Will polyurethane fill in scratches?

Polyurethane is not a good way to fill in deep scratches, but it can be used as a topcoat. If you have small scratches that are less than 1/16 of an inch deep, polyurethane may be able to fill them in.

To do this, you will need to apply two coats of polyurethane over the wood filler. Once all three layers have dried, sand them down with fine-grit sandpaper until there are no bumps or ridges on the surface of your project.

Does Minwax wood filler Harden?

If you’re working with Minwax wood filler, as long as it’s in its water-based form, it won’t harden or dry out.

That means you can apply the polyurethane over top of your wood filler without worrying about the two products interacting or clogging your brush.

Should you use wood filler before or after staining?

  • Fillers are used to filling holes and cracks in wood, which can be caused by a variety of things. They can also be used to fill dents and gouges, gaps between boards, and gaps between molding and walls.
  • Since you’ll want your filler to match the color of your wood stain after it dries, use wood filler that matches your intended finish before staining.


We hope that you’ve found this guide helpful in answering your questions about using polyurethane over wood filler.

If you have any additional questions, we encourage you to reach out to our customer service team. We are happy to help and will do our best to answer your question or concerns!

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Martin Flood

Martin Flood has been working in the construction industry for over 20 years as a general contractor with expertise in remodeling projects that are large or small. He has furthered his career by specializing in epoxy resin flooring, providing excellent service to both commercial and residential clients. Martin’s experience enables him to offer professional advice on how to choose the right type of project based on your needs and budget.

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