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How to Waterproof Painted Wood? (Answered)

You might have painted lovely garden furniture. But now you’re considering how to make the paint waterproof or prevent it from peeling and fading off.

The simplest method is to seal the painted wood. Although time-consuming, the top coating application technique is worthwhile.

Waterproofing Painted Wood

By adding sealants like polyurethane, polyacrylic, or wax, painted wood can be rendered waterproof. The paint must be smoothed out with sandpaper before a top coat is put on top of it. By using a sealer, you may shield your furniture from Sunlight, moisture, and temperature changes.

Different placement of the wood requires different treatments. Let’s find more about it.

For outdoors

Preparing the Wood:

Preparing the wood for coating is the first thing you need to do. Grab a bucket and some hot water. Incorporate Trisodium Phosphate (TSP) as directed by the manufacturer.

Put on some strong rubber gloves, dunk a cloth or sponge in the liquid, and carefully wipe the wood off. Now, give the wood 24 hours to dry.

Sanding the Wood:

The wood will be sanded with fine-grit #220 sandpaper in the following stage. Sand the wood sparingly to avoid affecting the paint.

Removing the Dust:

Remove sand particles with a brush-attached vacuum. To clear dust, use a regular cloth or a tack cloth coated with beeswax.

Applying Primer:

Apply a primer before sealant to smooth and workable the surface. This will increase the sealant’s longevity and smoothness.

Applying the Sealant:

Outdoor furniture or wood can use polyurethane. Wear a mask, gloves, and eye protection. You can spray the coating or use a synthetic brush for better control.

Leaving the Wood to Dry:

Make sure there is ventilation and permit the initial coating to completely dry. The coating will require roughly three days to completely dry. Different sealants might exist.

Applying More Coats:

Apply additional coats of paint for a flawless finish after lightly sanding the surface with #220 grit sandpaper and then #320 grit sandpaper.

For bathroom

Preparing the Area:

First, the wood must be polished. Get a pail of hot water. Follow manufacturer directions before adding trisodium phosphate (TSP). Wear rubber gloves, soak a cloth or sponge in the solution, then wipe the wood. Dry wood for 24 hours.

Lightly Sand the Wood:

With fine-grit #220 sandpaper, now sand the wood. Sand the wood very lightly to avoid disturbing the paint.

Removing the Dust:

With a vacuum and brush, clean sand dust. Use a regular cloth or a tack cloth soaked with beeswax to eliminate dust.

Applying Primer:

Now apply primer before sealant to make the surface smooth and workable. It will look excellent, have a smooth finish, and be more durable.

Applying the Sealant:

Choose Polyurethane or Polyacrylic based on the bathroom’s wood. You require eye protection, a mask, and gloves. Use a synthetic brush for more control or spray the coating if you’re confident.

Ensuring Ventilation:

Given that you are working in a restroom, make sure there is adequate ventilation. It needs about three days to thoroughly dry.

Scuff and Reapply Coating:

Sand the surface lightly with #220 grit paper, then use #320 grain paper to add more coatings for a flawless finish.

For kitchen

Preparing the Area:

First, the wood must be treated. Bring buckets of warm water. Add trisodium phosphate as prescribed (TSP). Wear rubber gloves, soak a cloth or sponge in the liquid, and wipe the wood. Dry wood for 24 hours.

Lightly Scuffing the Wood:

Apply fine-grit #220 sandpaper to the wood now and sand it. To avoid affecting the paint, sand the wood lightly.

Removing the Dust:

Remove sand particles with a vacuum and brush. Use a regular cloth or a tack cloth, which is impregnated with beeswax.

Applying Primer:

Apply primer before sealant to make the surface smooth and workable. This smooths out the sealant and increases its longevity.

Applying the Sealant:

Kitchen wood can be polyacrylic-coated. Wear a mask, gloves, and goggles. Use a synthetic brush or spray for more control.

On bathroom wood, use polyurethane or polyacrylic. Wear a mask, gloves, and goggles. Use a synthetic brush or spray for more control.

Leaving the Wood to Dry:

As you are working in a kitchen, make sure there is adequate ventilation. It needs about three days to dry completely.

Scuffing and More Coats:

Apply more coats for a flawless finish after lightly sanding the surface with #220 grit paper and then following up with #320 grit paper.

Can you put water seal over painted wood?

Applying a sealer over the paint is a great idea to preserve the painted wood from moisture. After the paint has cured, the sealant must be used. For painted wood, an oil-based sealant would be a wise choice because it will ensure longevity.

Hydrophobic qualities of Water Seal, however, have the potential to negatively impact the natural stickiness of painted and wood elements.

Only uncoated brick, stone, or concrete that hasn’t already been coated in another element is eligible for Water Seal application.

Wood is a dried material, thus it absorbs water easily. Using wood sealant to weatherproof painted wood is simple. The painted wood is moisture-resistant.

Should you use polyurethane over paint?

Whether you should or should not use polyurethane over paint will depend on what object you are trying to waterproof.

If you need to use sealant over an outside object such as, garden furniture, Adirondack chairs, benches etc. you better go for polyurethane. Also, polyurethane is perfect sealant for floors as well.

Polyurethane seals well. It’s oil or water based. Oil-based polyurethane gives wood a subtle amber hue, so avoid it on white furniture.

Also, water-based polyurethane won’t give off an amber hue, but it will damage white and light-colored wood. Most light-colored furniture turns yellow or hazy.

Polyurethane takes time to dry and emit gas during the drying process. Proper ventilation is required for that matter.

However, the durability and adhesion of polyurethane is incomparable. Comparing to that Polyacrylic is not as durable and is meant to be used only on interior surfaces such as cabinets, furniture, and trim.

What can you put on paint to make it waterproof?

Sunlight and moisture cause paint to crack and peel. Applying a topcoat preserves furniture and paint. What sort of sealer to apply depends on the furniture and paint. Paint sealants include,


A synthetic material is polyurethane. It can be used to protect both painted and unfinished wood surfaces. Oil- or water-based polyurethane is also possible. A brush or spray can be used for the application.

Because the off-gas from this coating is harmful, it must be applied in a well-ventilated location. This sealer is advised to be applied to outdoor furniture and floors. Sandpaper has the ability to remove it.


A brush is used to apply the water-based finish coat polycrylic. It doesn’t smell as bad as polyurethane does. It won’t be any less durable than polyurethane and is simple to clean off with water.

Nevertheless, it endures nicely. For indoor furniture and furniture that might be used by youngsters, this sealer is advised. When wet, polycrylic has a milky or white appearance; when dried, it becomes clear.

Paste wax:

Paste wax is a naturally occurring material, like carnauba or beeswax. It might be found dissolved in a solvent. With a brush or rag, wax can be applied, and any extra can be wiped off. To expose its luster after drying, it must be rubbed.

To give polyurethane a richer appearance, it can be applied over it. However, paste wax needs to be reapplied at least once a year because it is not long-lasting.

When to seal painted wood?

You need to seal painted wood, when you are required to coat the painted surface of your furniture. You can easily sand the painted layer and apply coating over it. Sanding will smooth out the surface before coating.

You can quickly add a layer of coating on top of the layer of chalk paint, milk paint, or interior grade paint to protect it and make it waterproof. 

The weather, UV radiation, and dampness can occasionally have an adverse effect on the furniture’s appearance. Additionally, wood has a propensity to swell and contract. Either the furniture’s color can be preserved, or the wood can simply be glossed. 

To give the paint color an amber or sepia tone, you might also consider covering it with a weatherproof material.

Final Thoughts

To make painted wood waterproof polyurethane and polyacrylic are popular. Sealants are helpful for wood because they shield it from UV radiation, weather fluctuations, or the natural expansion of the wood. Applying sealants requires caution because they emit harmful fumes.