With so many surface coating products for sale, it can be confusing to know what each does and how it compares to other products. Polycrylic seems to cause a lot of confusion with readers, who regularly ask how it relates to polyurethane and where you’d use it.
Over the past 40-odd years of woodworking, I’ve relied heavily on oil-based polyurethane as a surface covering. Particularly so when the timber I’m protecting may be exposed to moisture, heat, or high UV. However, the range of polyurethane-based products has expanded to a bewildering degree. Polycrylic is one of those new-breed polyurethanes, and it’s worth considering for your next project.
We’ll look at polycrylic, its advantages, and disadvantages and discuss where best to use it. Stay with me for a couple of minutes, and we’ll give you everything you need to know.
Is polycrylic the same as polyurethane?
Yes, polycrylic is the same as polyurethane. Polycrylic is a brand name created by MinWax, an architectural coatings manufacturer. As the name suggests, it contains polyurethane resins suspended in an acrylic base. It is one of the more recent varieties of water-based polyurethane and, depending on your use, has distinct advantages over other forms of polyurethane.
What is polyurethane?
- Protects indoor wood surfaces such as furniture, windows, cabinets, trim and more
- Water based formula dries fast and cleans up with soap and water
- Dries to the touch in 30 minutes with coverage up to 31.25 sq. ft., recoat after 2 hours
Polyurethane was synthesized as a substitute for natural rubber during the second world war. It is a polymer or plastic which is chemically modified to give us fabric, foam, adhesives, or surface coatings. The polyurethane we’re discussing is a clear plastic finish that coats wood and other products, protecting against moisture, heat, impact, and UV rays.
While there are many products on the market, there are two basic categories: oil-based polyurethane and water-based polyurethane. The ‘base’ that we refer to is simply the liquid that carries the plastic resin in suspension. The carrier liquid helps us apply the product and lets the resins flow and level before evaporating, leaving the resins behind. The resins then harden or ‘cure’ on contact with air, a process called cross-linking.
Manufacturers add flattening agents to polyurethane to modify the amount of light reflected by the finished coating, giving four sheens. Matte is the flattest look, followed by satin, semi-gloss, and gloss. These sheens are purely for aesthetic reasons and do not alter the chemical attributes of the coating.
The presence of flatteners in polyurethane means it is important to stir the product well and frequently when completing a job. Otherwise, the flatteners can settle in the tin, giving different sheen levels across a large surface and marring the overall appearance of your work.
What is polycrylic?
- PROTECT WOOD SURFACES – Minwax Polycrylic Protective Finish protects and adds beauty to your interior wood projects, including woodwork, furniture, doors and cabinets. The clear top coat protects...
- CRYSTAL CLEAR FINISH THAT LASTS – The crystal clear finished offered in this protective coating is ideal for use over all Minwax Oil-Based and Water-Based Stains and colors, as well as all wood...
- SATIN SHEEN – Give your wood projects a sleek finish with a satin clear varnish. It not only protects the natural beauty of the wood, but offers an attractive, classic sheen for a modern and subtle...
Polycrylic is a proprietary name for a water-based polyurethane product manufactured by MinWax. It is designed for interior use only and offers low odor and fast drying. It dries clear in most cases, and all clean-up is with soap and water.
Polycrylic does not require thinning, and items finished with it can be gently handled after 3 hours and assume normal use after 24. MinWax suggests using 220-grit sandpaper to smooth each coat and ensure correct adhesion of the next when applying the product. Do not sand the last coat.
What is the difference between polycrylic and polyurethane?
Polycrylic is a water-based polyurethane. It is thin and milky in the tin, unlike oil-based polyurethane, which is viscous and amber in color. It uses an acrylic base, so brushes and rollers wash out in water. While oil-based polyurethanes can have a very strong odor, the smell from polycrylic is far milder. Finally, polycrylic dries fast and clear, while oil-based polyurethanes dry slowly with a slight amber cast.
When to use polyurethane
Polyurethane offers three main benefits:
Oil-based polyurethane is ideal for external use, resisting moisture, heat, UV, and scuffing. It also has a faint amber tint, enhancing the color of dark stains and timbers. However, it takes longer to dry and has a stronger smell when wet. Clean-up requires mineral spirit, which is flammable and can pose disposal difficulties.
Water-based polyurethane is ideal for interior use and protects against moisture, heat, and impacts. It dries clear, not altering the underlying color in any way; therefore, it’s preferred for light colors. It dries rapidly and has less odor while drying, returning rooms to normal use quickly. Clean-up is simple, requiring only soap and water.
When to use polycrylic
Polycrylic is ideal when you wish to protect or enhance interior furniture, trim, or paneling. It will protect wood against water stains, abrasion, impact, and most normal household chemicals. It is not recommended for use on floors, as it will need constant recoating in high traffic areas.
As polycrylic dries clear, it enhances wood grain or maintains underlying paint or stain colors. Three notes of caution however, MinWax suggests that polycrylic should not be applied over a red mahogany stain and that using it over light-colored oil-based stains may result in slight ambering. It can also give a slightly milky look if heavy coats are applied over dark surfaces. If in doubt, find an inconspicuous spot to test.
If you need a room to return to normal use quickly, polycrylic is an ideal clearcoat. It will dry within 2 to 3 hours, and the room can return to full operation in 24-hours. Although polycrylic has a low odor, do be sure to use adequate ventilation and a protective mask to prevent being overcome by the fumes which are damaging to humans.
Which is better, polycrylic or polyurethane?
Polycrylic is a water-based polyurethane; however, if we apply the term polyurethane to mean an oil-based product, neither is better than the other in absolute terms. Each is better suited to specific applications.
Polycrylic is more environmentally friendly than oil-based polyurethanes, being water-based. It is also thinner and dries very quickly, which returns a room to service faster but can make application difficult. Polycrylic is designed solely for interior use but should not be used on floors. It is most suitable when you wish to preserve the natural color of the underlying surface.
Oil-based polyurethanes can be used indoors or outdoors, offering superior protection against UV, moisture, and heat. You can also use it on wooden floors. However, it requires clean-up with mineral spirits, dries more slowly, can lightly tint light underlying colors, and has a strong odor. It is easier to apply than polycrylic and lasts longer.
Can you put polyurethane over polycrylic?
Yes, you can. Ensure the polycrylic is dry, allowing at least 2 hours, preferably longer. Lightly sand the polycrylic with 220-grit sandpaper to smooth the surface and improve adhesion. Clean and vacuum the surface thoroughly, using a painter’s tack cloth before applying the polyurethane.
Can you put polycrylic over polyurethane?
Yes, you can. Ensure the polyurethane is fully dry, allowing at least 4 to six hours. Lightly sand the polyurethane with 220-grit sandpaper, which assists in leveling the surface and improving the adhesion of one coat to another. Use a vacuum and a painter’s tack cloth to remove dust before applying the polycrylic.
Is water-based polyurethane the same as polycrylic?
Yes. Polycrylic is a proprietary name for a water-based polyurethane manufactured by a company called MinWax.
Is polycrylic toxic?
Yes. Polycrylic contains alkyl propanols, ethylene glycol, glycol ethers, and n-methyl pyrrolidone. Polycrylic can irritate the respiratory tract and should only be used when adequate ventilation. Wash thoroughly with soap and water if you get it on your skin. If you get it in your eyes, flush them with water for 15 minutes, and get medical attention. If swallowed, seek immediate emergency help. It is toxic to reproduction and contains chemicals believed to cause cancer.
Is Minwax Polycrylic flammable?
No, Minwax Polycrylic is not flammable.
Does polycrylic smell?
Yes, polycrylic has a mild odor in its liquid state and while drying. Once the polyurethane is fully cured, no further odor will be released.
Is polycrylic suitable for outdoor applications?
No. Polycrylic is suitable only for indoor use.
Is polycrylic heat resistant?
When properly cured, polycrylic tolerates heat well. I have read it will tolerate heat up to approximately 90oC or 200oF; however, I wouldn’t be putting it to the test with such high temperatures. It should adequately resist heat from domestic items such as hot cups and plates.
Is polycrylic scratch resistant?
Not particularly. While it will tolerate light scratching, use an oil-based polyurethane if scratch resistance is important.
Does polycrylic make wood shiny?
That depends on the gloss level you select. Polycrylic comes in four sheens, matte, satin, semi-gloss, and gloss. The last two of these will make the wood shiny.
Is polycrylic waterproof?
I’d use the term water-resistant rather than waterproof. It’s designed for interior use only and protects timber from splashes, spills, and a bathroom’s damp conditions.
What is more durable, polycrylic or polyurethane?
Oil-based polyurethane is more durable than water-based polyurethane such as polycrylic, being more resistant to scratches, moisture, and heat. When properly applied, oil-based polyurethane will last 8 to 10 years versus the 4 to 5-years for water-based polyurethane such as polycrylic.
Which is better for kitchen countertops?
You can use polycrylic for kitchen countertops, but oil-based polyurethanes are more resistant to scratches, moisture, and heat. In my opinion, oil-based polyurethane is the better choice.
Polyurethane vs polycrylic: final word
There is no difference between polycrylic and polyurethane. Both are polyurethane products, but polycrylic is a brand name for a water-based polyurethane product produced by MinWax. It’s a popular product as MinWax is a highly regarded manufacturer, and polycrylic dries rapidly and clearly, requiring only soap and water for clean-up.
If you intend to use polycrylic, remember the cautions not to use it over a red mahogany stain, be prepared for a faint yellowing if used over light oil-based stains, and you may get a milky sheen if you use heavy coats over a dark color.
Those issues aside, polycrylic is a great product when used per manufacturers’ guidance. I trust this article answered your questions and good luck with your project.