Why is wood filler showing through paint?

Filler is a great product when it’s used appropriately. It’s easy to use and is great at hiding those pesky holes in woodwork or furniture.

But sometimes, even with the best intentions, you can end up with a situation where your filler shows through your paint job!

Don’t worry, though—it happens to everyone. We’re going to look at why this happens, how you can fix it and how you can avoid it next time around!

Why is my filler showing through paint?

Let’s break this down. Filler is a material that’s designed to fill gaps, while paint is designed to cover surfaces. The filler you’ve been using has been dry-walling compound, or something similar.

It’s not made for painting over, and it won’t work well for your purposes.

So what should you do? Well, if you want your filler to be hidden but still show through the paint, then you’ll need to find a filler product suitable for painting over (like spackle).

If you’re looking for an invisible finish that doesn’t look like it has any holes or missing bits in it at all—and let’s face it, we’ve all had enough of those—then there are specialized paints available with very fine pigments that can help achieve this effect without compromising quality.

Does wood filler stick to painted surfaces?

The short answer is yes. Wood filler sticks to pretty much every surface, but it’s important to know that not all wood fillers are the same.

Some wood fillers can be sanded or painted over without any special preparation, while others may require a primer to provide an even surface for your paint job.

How do you cover fillers in wood?

  • Use a sanding sponge. If your filler is only showing through on the surface of your wood, you can use a sanding sponge to remove it completely.
  • Use a block or power sander. If you’re trying to get rid of wood filler that has been painted over, it will be much more difficult to remove with just sandpaper alone—you’ll need something that will go deep into the pores of your wood and scrape them clean without damaging the paint coat below it. This means either using a block sander or a power sander (or both). Start by setting your machine at its highest speed setting and working with very light pressure until all traces of filler are gone; then move up in speed and pressure until all fillers are gone from every part of your project surface being worked on by this method: if there’s any remaining residue after going through all these stages, repeat each one until no trace remains!

How do I get a smooth finish with wood filler?

  • Use a good quality filler
  • Use the right tools for the job
  • Use a good quality brush
  • Use a filler that is the right color, consistency, and type for the job

Why is my paint not covering filler?

  • If you’re using a brush, roll the paint on in thin, even strokes. If it’s too thick, it can’t soak into the wood and will show through.
  • If you’re using a roller, make sure that it’s well-oiled. This helps the paint stick to the wood better.
  • When using a sponge or pad, don’t press down too hard because this could leave marks in your finished surface. Instead, dab gently with small circular motions until no more bubbles appear (this means that all of your filler has been covered).

Should you prime filler before painting?

When you’re using wood filler, it’s best to prime the surface first. Primer helps the filler stick to the surface, and it also helps paint stick to that coat of primer.

Primer is also like a paint primer in that it makes sure your new finish is smooth and even—but instead of making sure your finish doesn’t peel off, it improves its ability to adhere by creating a good foundation for adhesion between layers.

When you use wood filler on bare wood, then sand and prime with an oil-based primer (as we discussed in our sanding section), you can then proceed with painting as usual.

But if you want to save yourself some steps and do one big project instead of two smaller ones (priming + painting), this guide will help show exactly how not only how but when should be done!

How do you make fillers stick?

If you have a filler problem, there are a few things you can do to help the situation. If your filler is showing through paint because it wasn’t mixed well enough (or at all), try mixing it again with more water or thinner.

If it’s still not working, consider using another product that’s designed to be used on top of paint. Some fillers are specifically made of wood or metal, while others are designed to adhere to concrete or stone surfaces.

If you’re sure that your filler isn’t just a bad batch but rather has been improperly applied, consider using a primer before applying your new coat of paint or finish material.

Primers act as an adhesive between layers of finish materials and themselves; they’ll help ensure that whatever product is applied next adheres evenly and effectively without any gaps or other issues between layers.

Can you put filler on top of paint?

You have a couple of options. You can sand the paint off and then apply filler, or you can put filler on top of your painted surface.

If you are working with a smooth surface, such as a cabinet or piece of furniture, it’s best to sand down the area first so that there aren’t any rough spots that would tear up your finish when applying the filler.

If you don’t want to remove all of your paint (or if you don’t feel confident doing so), then consider using an exterior wood filler instead—they’re made specifically for filling holes and cracks in exterior wood products like fences or decks.

If this is not an option and your project involves removing all traces of current paint before applying new layers, it may be worth considering whether it’s necessary to use this product at all!


Hopefully, this article has helped you understand why fillers show through paint and what to do about it. Remember that there are many different kinds of fillers out there—we just covered the basics here.

But as long as you understand what type of filler you’re using (and have done your research on which ones work best), then you’ll be on your way towards making sure your project turns out beautifully!

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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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