Painting over Varnished Wood: Dos and Don’ts

I think everyone has been in that one situation where they want to change the look of their furniture, maybe because it is old looking or too dark. But most old or high-quality wood furniture is sealed with varnish so, naturally, the question arises if it is possible to paint over varnish directly or if the protective layer has to be removed before painting the wood underneath. In this article, I will go over all the dos and don´ts when it comes to painting over varnished wood.

First of all, you can paint over varnished wood but the wooden surface has to be prepared by sanding and priming it correctly before applying the paint. Depending on your choice of paint a different primer will be necessary. Furthermore, a topcoat should be applied on top of the paint to further protect it.

So it is generally not a problem to paint varnished wood as long as the surface has been prepared correctly.

Why is it Important to prepare the surface?

It’s actually quite simple. The varnish topcoat is meant to protect the underlying wood or paint job from scratching, water, the sun, and more. So it will create a strong seal, that will keep water and oils from clinging to the surface of the wood.

Almost all paints are water or oil-based. So if you apply the paint directly on varnish then they will have a hard time sticking to the surface.

How to Paint Over Varnished Wood

Now, that we have established why it is so important to get rid of the varnish before painting it, its time to have a look at how to actually prepare any varnished wood for painting.

By the way, even though it is important to get rid of the varnish before painting the wood there are some ways to paint varnished wood without sanding it first. You can read more about that further down below.

Sand the Wooden Surface

First of all, you have to sand the surface in order to get rid of most of the varnish or to at least rough up the surface of the varnish a little bit.

Fine-grit sandpaper is more than enough in order to sand the surface.

I would recommend using sheets of sandpaper to sand the furniture instead of a sanding block because you can easily get into every corner with the sandpaper sheet.

It is important to sand every bit of the furniture as evenly as possible. If you are not thorough enough then you may end up with paint chipping or peeling off in some areas along the way.

I would also recommend sanding outdoors because the sand dust will get everywhere.

If you never sanded anything before, then you can learn more about sanding wood in this guide. Simply skip the coarse-grit-step and move to the fine-grit right away because you are working with already build furniture or doors. So there is no need for any rough sanding anymore.

Clean off the Dust

When you are done sanding your wood furniture then its time to clean it from all the dust and dirt from the previous step.

Simply take a bit of soapy water and carefully clean the sanded surfaces with it.

Don´t use too much water! You only want to clean the surface from dust. You don´t want to drench the bare wood with water.

Once the furniture is cleaned properly leave it to dry overnight.

It is important to let the wood dry completely before applying the primer.

Apply a Primer to the Wooden Surface

Now it is time to apply a primer to the wooden surface.

A Primer is basically an undercoat, that will prepare the wood for painting. Using a wood primer will increase the durability and longevity of the paint job later on. It also makes it so, that the paint adheres better to the wooden surface.

You can read more about wood primers and why you should use one right here.

I always recommend using KILZ Premium wood primer for priming wood. It is non-staining and easy to apply. You can get it right here on Amazon or at your local hardware store.

You can apply the wood primer with a paint-brush or with a paint roller. I personally prefer the paint roller because the results are more even and I avoid brush strokes. I usually only use paintbrushes for hard to reach areas.

Make sure, that the primer is spread evenly and that the primer covers the surface of the wood completely. If you can still see some wood through the primer then simply apply another layer after the first one has dried.

It is always better to apply multiple thin layers of primer than one thick layer.

Let the primer dry for at least 24 hours. The drying time varies from primer to primer so it is best to read the instructions on the package of your primer.

Smooth the Surface of the Primer and Start Painting

After the primer has dried you may see some brush marks or uneven parts on the surface of the primer. Don´t worry, you can smooth the surface by lightly sanding it with some fine-grit sandpaper.

If you decide to give the primer a final light sanding then make sure to clean the surface from dust again before you start painting.

Now, finally, you can start painting.

The choice of paint is completely up to you but you should make sure, that the primer is a good foundation for the paint of your choice.

So if you are using an oil-based paint make sure that the primer is fitting for oil paints. And the same goes for water-based paints.

I personally recommend using either acrylic paint or latex paint for painting wood. Mainly because oil-based paints are very smelly while they are still wet and acrylic and latex paint are way easier to use.

The Primer, that I recommended above is for Latex paints but you can also use it for acrylic paints.

If you want to use oil-based paint, then you should use an oil-based primer as well. I recommend the KILZ Multi-Surface Oil-Based Primer for that. You can buy it right here on Amazon.

You should apply multiple thin layers of paint. If you apply the paint too thick then you run the risk of your paint bubbling up or staining after.

I personally like to use a roller for larger surface areas and a brush for more detailed work but it is entirely up to you. In my experience, it is just easier to get a smooth finish when using a roller.

Let the paint dry completely between every layer. You can check the package for more details on the drying time of your paint of choice. But usually, any non-oil-based paint will dry within 12 hours.

Seal your Paint Job With a Topcoat or Varnish

This step is not always necessary but I highly recommend it.

A topcoat is used to protect the paint job from scratches, moisture, the sun, and more. Normally, you don´t have to apply a topcoat if the furniture is in a secure place where it can´t get wet or scratched.

But I usually still seal my projects with a top coat just to be sure regardless of where they stand.

The choice of topcoat is entirely reliant on the paint that you want to seal.

If you want to seal Acrylic paint, then use a sealer for acrylic paints like this one from Mod Podge. You can use the same one for Latex paint or you can use Varnish for pretty much any type of paint. I prefer the satin varnish from Minmax.

Simply apply the topcoat directly to the painted surface with a brush. Try to apply it as evenly as possible for a nice finish.

Then let the topcoat dry for at least 24 hours. If you missed a spot or if you want to be sure, that you applied enough of the topcoat then simply add another layer on top of the first topscoat layer.

Don´t add more than three thin layers of any topcoat or the topcoat may lose its transparency slightly resulting in a white film on top of your paint job.

And after your topcoat has dried you are finally done with painting your varnished wood properly and permanently.

There is a fantastic video from Thrift Diving about the biggest mistakes that you can do when painting furniture and how to avoid them. It is very helpful if you should run into issues.

Painting Over Varnished Wood Without Sanding

From all the steps, that I explained above, the one most new crafters dread is the sanding part. And I can fully understand why. It is by far the most time consuming and tedious part especially if you have to do it by hand. So naturally, I get asked a lot if there is a way to paint varnished wood directly.

You can paint over varnished wood without sanding it but it is generally not recommended to do so. You can use Chalk paint and seal it with a topcoat to protect it permanently or you can use a special bonding primer to prepare the surface for painting without the need of sanding anything beforehand.

So there are multiple ways to paint varnished wood without sanding it first but the two main methods, that I personally found most effective especially in the long run, where using chalk paint combined with a topcoat or using a special bonding primer.

Using Chalk Paint for Painting Varnished Wood Directly

You can use Chalk Paint to paint directly on varnished wood.

This type of paint is actually very popular amongst furniture painters and crafters.

And for good reason. It will stick to almost anything and if you seal it with a topcoat afterwards it will also stick to the painted furniture for a very long time.

Simply apply it to the varnished wood directly after you cleaned the wood from any dust and dirt. Add multiple layers while making sure to let each one dry completely.

Once you are satisfied with the opacity of the paint simply seal it with a topcoat like a varnish or with an acrylic sealer. Both topcoats will work nicely for chalk paint.

Use a Special Bonding Primer to Paint directly on Varnished Wood

When you have your doubts about using Chalk paint directly on varnished wood then you can also use a primer, that is designed to be applied to surfaces, that have not been sanded before hand.

One such primer is B.I.N from Zinsser. This primer will stick to almost any surface even if it has been sealed with varnish beforehand.

Just apply the primer directly on top of the varnished wood, let it dry for a couple of hours and then apply the paint of your choice on top of the primer.

The primer will create a bond, that will make the paint stick to the wooden surface extremely well even if it hasn’t been sanded before.

You can seal the paint ob with a topcoat afterward but it will not always be necessary. I personally like to seal everything, that I painted just to be on the safe side but that´s just personal preference.

Does the Same Apply to Polyurethane Varnish?

The most commonly used type of varnish is polyurethane-based varnish. At least until recently. So if you are painting an old piece of furniture then chances are, that it has been sealed with a polyurethane varnish. Polyurethane is a synthetic resin type varnish usually used to seal various kinds of woodwork. Here is an article, that will explain polyurethane varnish a little more in-depth.

You can paint over water-based polyurethane if you either sand and prime the surface before applying the paint or if you use a special bonding primer to prepare the surface properly for the paint of your choice. You should not apply any paint directly on polyurethane varnish.

This kind of varnish is especially resistant to water and oil so most paints won´t hold on the surface at all and the few, that will hold won´t stick to it very well.

So you should always prepare the surface either with a special bonding primer, as mentioned above, or by sanding and applying a regular wood primer to the surface.

Otherwise, your paint job will not survive for long.

Can Gesso be Applied over Varnish?

Most of you out there will probably want to use acrylic paint for painting their furniture. I personally love acrylic paints and it is a solid choice for painting wood. But you should not apply acrylic paint directly on varnish because water-based paints will not stick to surfaces, that have been treated with varnish. Most artists among you will probably ask themselves if you have to prime a surface for acrylic paint why not use gesso? It works fine for canvas so why should it not work on varnished wood? Well, the answer is quite simple.

You can use gesso over varnish but only on some, very rarely used types of varnishes. Because of that, it is recommended to sand the surface before applying any gesso to it. Just to make sure, that the gesso can get a grip on the wooden surface.

So you can use commercial gesso, or your own homemade one, to prime the wooden surface for an acrylic paint application.

But you have to sand the surface before applying any gesso just to make sure, that the gesso has a roughed up surface to hold on to. Otherwise, the gesso will just splinter off of the surface after it has dried.

You can apply multiple thin layers of gesso before applying the paint as long as you make sure, that the gesso dries in between the individual layers. This is important to avoid spotting and to ensure a strong bond.

You can seal the acrylic paint after you applied it to protect it from the elements but you normally don´t have to. I usually still recommend doing it, however.

Can You Apply Acrylic Paint on Varnished Wood?

And, as always, people try to avoid any unnecessary sanding. So a lot of new crafters ask me if it is possible to simply apply acrylic paint directly on varnished wood. And while it seems to stick to its surface initially it won´t stay on for very long.

You can not apply acrylic paint on varnished wood directly. You either have to sand the wood before applying any paint to it or you have to apply a primer before painting it with acrylic paint. If you apply acrylic paint directly on varnished wood it will simply not stick to it for long.

Varnish is used to protect the wood underneath it from dust, dirt, and water.

Acrylic paint is a water-based paint and as such it will not stick to the surface of the varnished wood for long.

Even oil-based acrylic paints will have a hard time sticking to a varnished surface. So you either have to apply a primer before painting the wooden surface or you have to sand the surfaces in order to give the paint some tooth to stick to.

Either way, I always recommend using a top coat to protect your paint job afterwards.