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Polyurethane Top Coats: The Secret to Durable, Long-Lasting Spray Paint

Polyurethane Top Coats: The Secret to Durable, Long-Lasting Spray Paint
March 15, 2024 APT Spray Painting

Have you ever wondered how some spray paint jobs seem to last forever while others start to fade and deteriorate within weeks? The secret is in the quality of the paint layers, but also in the top coat. When you apply a polyurethane top coat over your spray paint, you’re adding a durable, protective shield that seals the colour and provides long-lasting protection.
A polyurethane top coat is a clear finish that goes on top of your spray paint to seal and protect the colour underneath. Unlike a basic clear coat, polyurethane forms a plastic coating that is highly resistant to scratches, stains, weather, and chemicals. It helps prevent fading by blocking UV light that can break down the pigments in spray paint.
With a polyurethane top coat, you can get years of vibrant colour from a single spray paint job. Your assets will look freshly painted even after repeated exposure to the elements. If you want spray paint that withstands the test of time, polyurethane is the secret to durable, long-lasting results.

What Is a Polyurethane Top Coat?

A polyurethane top coat is a clear sealant that protects the base coat of spray paint and provides a durable, scratch-resistant finish.

Why Use a Polyurethane Top Coat?

Adding a polyurethane top coat to your spray paint job has some major benefits. For starters, it protects the underlying paint from damage, weathering, and fading caused by exposure to sunlight and environmental factors. Without a top coat, spray paint can start to deteriorate in as little as 6-12 months.
A polyurethane top coat also provides a glossy, high-shine finish that brings out the depth and vibrancy of the spray paint colour. This wet-look sheen makes colours appear more vibrant and metallic paints really pop. The top coat fills in the tiny pores and imperfections in the spray paint, resulting in an ultra-smooth, glass-like surface.
What’s more, a polyurethane top coat seals and protects spray paint from scratches, stains, and marks. It acts as a durable shield against abrasions and impacts, preventing the spray paint from chipping or scratching. Spills and stains simply wipe away without damaging the finish. This protective quality is especially useful for high-contact areas like tables, doors, and trim.
In summary, applying a polyurethane top coat to your spray paint project will protect your work, enhance and intensify the colours, provide a glossy finish, and shield against damage – allowing you to enjoy the results for years to come. Your patience will pay off!

The Benefits of Using a Polyurethane Top Coat in Spray Paint

Using a polyurethane top coat in your spray paint system comes with some major benefits.


A polyurethane top coat creates an extremely durable, scratch-resistant finish that protects the paint underneath. This means your assets will look like new for longer, without damage from weather, scratches or stains.


The protective layer of polyurethane seals and protects the paint from exposure to elements like water, chemicals, and UV radiation that can cause fading. This is especially important for outdoor assets. With a polyurethane top coat, your spray paint job will last 2-3 times longer.

Easy to Clean

Polyurethane forms a smooth, glossy surface that is non-porous and water-resistant. This makes any dirt or stains easy to wipe clean with just soap and water. No special cleaners needed.

Customisable Finish

You can choose between glossy, satin or matte polyurethane top coats to achieve your desired finish. Glossy is highly reflective, satin has a soft sheen and matte is completely flat. So you get the durability of polyurethane with your preferred finish.

Cost Effective

While polyurethane top coats do have an upfront cost, they save you money in the long run. The enhanced durability and protection means you won’t have to repaint or make repairs nearly as often. Your assets will look better for longer at a lower overall cost.
Using a polyurethane topcoat in your spray paint system is really a no-brainer. The benefits to durability, protection, easy cleaning, customisable finish and cost-effectiveness are unmatched. Your spray-painted assets will stay looking fresh and new for years to come.

Choosing the Right Polyurethane Top Coat

Choosing a polyurethane top coat designed for spray paint applications is key to achieving a durable, long-lasting finish. There are a few factors to consider when selecting a polyurethane top coat:

Gloss level

Do you want a high-gloss, semi-gloss, or satin finish? High gloss polyurethane top coats provide the shiniest, glass-like finish but show more imperfections. Satin or semi-gloss offer a subtler sheen and hide flaws well. For most DIY spray paint projects, a satin or semi-gloss polyurethane works great.

Indoor vs outdoor

Make sure to choose a polyurethane top coat that is specifically formulated for either indoor or outdoor use. Outdoor polyurethane top coats contain UV inhibitors and weathering agents to protect against damage from sunlight and environmental exposure. Using an indoor polyurethane outside will quickly break down, fade and peel.

Applying a Polyurethane Top Coat Over Spray Paint

Once your spray paint job is complete, applying a polyurethane top coat is the key to ensuring maximum durability and longevity. A polyurethane sealant protects the spray paint from damage caused by exposure to elements like UV radiation, weather, and abrasion.


Before applying the polyurethane, APT Spray Painting, makes sure the spray paint has fully cured as directed on the product instructions, usually 24 to 48 hours. The surface should be clean, dry, and free of debris. We lightly sand any drips or imperfections, then wipe away dust with a tack cloth.


We then apply at least two coats of polyurethane, waiting at least 2 hours between coats. We utilise a high-quality sprayer to ensure a smooth, flawless finish, paying extra attention to any carved details or curved edges.

Finishing Touches

After the final coat has dried as directed, we may need to apply a very fine grade of steel wool (grade 0000) or ultra-fine grade sandpaper (400+ grit) to lightly buff the surface and smooth any imperfections before a final wipe down. This will result in an ultra-smooth finish and sheen.
We take the time to properly apply a polyurethane top coat to your spray paint project because you’ll gain a durable, long-lasting finish that protects your investment for years to come. The extra effort will be well worth the reward of a quality end result.

APT Spray Painting Can Apply The Perfect Paint System For Your Project

When it comes to spray painting assets like railings, outdoor features, machinery or industrial equipment, applying a polyurethane top coat is the key to a durable, long-lasting finish.
At APT Spray Painting, nothing is more important to us than delivering superior paintwork with a flawless finish. That’s why we only use the highest quality paints and complete all of our spray painting in a 10m x 5m x 3m, semi-downdraft booth. If you’re looking for a spray paint system that includes a polyurethane top coat, contact us today and we can get back to you with a free, no obligation quote.