How to apply polyurethane

As an Amazon Associate we earn from qualifying purchases.

In this article, you will learn about stain and poly. We’ll define each product, and tell you how long to wait after applying stain to follow with a coat of poly. Then, we’ll explain the factors that affect the dry time of stain, before reviewing how to mix and match water and oil-based products.

What Is Stain?

Wood stain is a liquid used to change the surface color of wood. It can be transparent or close to opaque. Dyes or pigments are mixed with a liquid, called the ‘vehicle’. The vehicle could be oil or a mix of water, solvents, and acrylic resin. Binders are often added to help the stain adhere to the wood.

Stain is simply to apply to wood. You can brush it on, or for larger projects, use a sprayer.

Stain changes the color of the wood. It does not protect it. Therefore, it is often covered with a clear, film-forming finish that repels water and prevents impact damage. Polyurethane is a popular choice for covering stained wood.

Read more about our top choice for stainable wood filler.

What Is Poly?

Poly, short for polyurethane, is a kind of varnish used to protect and finish wood. It can be brushed, rolled, sprayed, or wiped on. It is a buildable finish that dries to a hard, durable protective barrier.

How to apply polyurethane

Polyurethane is a film-forming finish, which means the barrier sits on top of the surface of the wood rather than seeping into the pores.

Polyurethane is one of the most durable wood finishes available, while also providing excellent protection from moisture. It hardens through a two part process.

  • First, the solvents evaporate, leaving it dry to the touch.
  • Then, the molecules rearrange themselves more closely together as they are exposed to oxygen, creating an extremely hard finish.

When fully cured, it is food safe and difficult to scuff, scratch, or dent. Polyurethane is used when wood needs heavy-duty protection.

Applying Polyurethane After Staining – How Long Should I Wait?

Rule number one of applying polyurethane on top of stain is to check the labels of both products. While there are general guidelines, every formulation is slightly different, and following the manufacturer’s instructions will usually give you the best results.

  • As a general rule of thumb, wait 72 hours after your final coat of stain before applying polyurethane.
  • 24 hours is the minimum amount of time you should wait before covering stained wood with polyurethane.
  • A 48 hour window between stain and polyurethane is a good middle ground.

The danger of applying the polyurethane too early is that the stain and polyurethane will mix. This can result in uneven colors, a blotchy appearance, and poly that takes a long time to dry or doesn’t dry at all. The polyurethane may not properly bond to the wood surface if applied over stain that is not fully dry.

Factors That Affect Dry Time

For best results, wait 72 hours between your last coat of stain and your first coat of poly. In most circumstances, this will be plenty of time to ensure the stain has fully dried. However, there are a few additional factors to keep in mind.

How to apply polyurethane

First, the brand of stain affects it’s dry time. The atmospheric conditions also affect dry time, so you should monitor the ambient temperature in your workspace. Keeping track of the humidity is also important when ensuring stain adequately dries.

To speed dry time, consider increasing the circulation of air in the area where the stained wood is drying.


If you need to finish a project quickly, look for a stain that advertises a quick dry time. The range of dry times for stain under normal atmospheric conditions is between six and 24 hours.


Room temperature, or about 70-75 degrees Fahrenheit, is ideal for drying stain. The manufacturer’s instructions assume you are applying stain under ideal conditions.

You can apply stain in colder weather, down to about 50 degrees Fahrenheit, or hotter weather, up to about 90 degrees Fahrenheit. However, the further away from ideal temperatures you get, the longer your stain will take to dry.

When the temperature is below 50 or above 90, it is not a good idea to stain wood. If you can, bring your project into a climate-controlled environment, or simply wait for better weather.


Humidity refers to the moisture content of the air. When the air is already moist, it is more difficult for the solvents in the stain to evaporate, and this slows the dry time significantly. In very humid weather, you may have to wait twice as long as the product label advertised before you can apply polyurethane.

By the same token, an extremely dry environment will encourage stain to dry more quickly. Running a dehumidifier in your workspace on humid days is an effective way to combat slow dry times.

How to apply polyurethane


Air moving over the surface of the stain will help it to dry, allowing you to follow up with a coat of polyurethane in the smallest possible amount of time.

Opening the windows helps if you’re staining indoors. You can also set up a fan (or multiple fans) to blow across the work surface. Dust or insects may stick to the stain while it dries. You can carefully sand the surface with very fine grain sandpaper to remove debris without removing the color.

What Polyurethane to Apply Over Stain

Both stain and polyurethane come in water-based and oil-based formulations. Water-based poly can be applied over water-based stain without a problem. The same goes for oil-based formulations.

Theoretically, it is possible to apply water-based poly over oil-based stain. To do so, you must ensure that the oil-based stain is completely dry. Wait at least 72 hours.

In practice, this works best when you choose a polyurethane and stain from the same brand

Applying an oil-based stain over a water-based poly is faster — you only need to wait 24 hours for the stain to dry.


Choose a quick-drying stain and wait at least 24 hours to apply polyurethane for the fastest results. Controlling temperature, humidity, and circulation will give you the best drying conditions. Make sure the polyurethane and stain are compatible to ensure long-lasting coverage.

Ellenkate grew up on job sites run by her family’s construction company. She earned her theater degree from The Hartt School, a prestigious performing arts conservatory in Connecticut. Her design and DIY work from her Chicago loft was featured in the Chicago Reader and on Apartment Therapy.

SawsHub is a collection of DIY enthusiasts and woodworking experts. Learn about the team! How to apply polyurethane

Share this story

  • Share this on Facebook
  • Share this on Twitter

Share All sharing options for: Best Ways to Apply Polyurethane

  • Pinterest
  • Email

How to apply polyurethane

Polyurethane is so durable and water-resistant, it has largely replaced shellac and varnish as a wood finish. Originally, it had to be brushed on, but different formulations mean it can now be applied as a spray or by wiping it on with a rag. Here’s how to gauge which approach is best for your project.

Brush-on Great for broad, flat, horizontal surfaces—floors, tabletops, chair seats. Forms a thicker coat, so the finish builds up fastest. Polyurethane coatings brushed on vertical or contoured surfaces are more likely to drip and run. Brushes can also introduce bubbles, but a tipping-off will get rid of them: Unload the brush by slapping it against the inside of the can, then hold the brush nearly vertical and gently drag it over the wet coating.

Wipe-on This less-viscous poly is best for round, vertical, or contoured surfaces—crown molding, wainscoting, stair balusters—where brushing might create drips. Each wipe-on coat is thinner than one brushed on, so four coats are needed for good protection.

Spray Handy when coating hard-to-reach surfaces, such as shutter louvers and chair spindles, or encapsulating flaking paint on flea-market finds. Or use it to touch up a scratched or damaged finish. Sprays require careful application and some practice to avoid drips.

How to apply polyurethane

How to apply polyurethane

Deane Biermeier is an expert contractor with nearly 30 years of experience in all types of home repair, maintenance, and remodeling. He is a certified lead carpenter and also holds a certification from the EPA. Deane is a member of The Spruce’s Home Improvement Review Board.

How to apply polyurethane

  • Pin
  • Share
  • Email

How to apply polyurethane

BanksPhotos / Getty Images

  • Working Time: 6 – 8 hrs
  • Total Time: 6 days – 1 wk
  • Yield: 500 square feet
  • Skill Level: Beginner
  • Estimated Cost: $120 to $200

Your beautiful solid hardwood or engineered wood floor deserves the best possible finish. Polyurethane floor finishes are easy to apply, and they cure rapidly. They offer rock-hard, waterproof, long-lasting protection for flooring, plus they let the beauty of the natural wood show through.

What Polyurethane Finish Is

Polyurethane finish is a liquid resin used to coat wood flooring and other wood surfaces, such as cabinets and furniture. As a synthetic floor finish, polyurethane is made from raw materials that are derived from crude oil.

Polyurethane floor finish comes in either water-based or oil-based versions. Water-based polyurethane is easier to work with and quicker to dry but wears down faster than the oil-based finish. Oil-based polyurethane finish, while hard and durable, is noxious when applied and takes at least twice as long to dry.

Oil-based polyurethane finish is more work during and directly after application, but this is balanced by the need for fewer reapplications and less maintenance. Meanwhile, water-based polyurethane is less work at the beginning, but it does require frequent touchups and reapplication about every two years. The frequency of reapplication depends on the amount of traffic on the floor, along with any potential damage from pets and UV rays.

Polyurethane finish is transparent. It comes in a range of sheens, from flat to glossy. It resists fungus, mold, and mildew well. One feature that makes it particularly good for flooring is that it is waterproof. Because polyurethane dries to a hard finish, it’s especially good at resisting scratches and scuffs.

Basics of Polyurethane Floor Finishes

Oil-Based vs. Water-Based Finishes

Slow drying time

Cleans with mineral spirits or paint thinner

Extremely hard surface

500-600 square feet per gallon

Best for all areas, including high-impact areas

Transparent, but with a slight amber tint

Fast drying time

Cleans with water

Hard surface, but not as hard as with oil-based finishes

260-320 square feet coverage per gallon

Best for moderate or light-use areas

Number of Coats

Most manufacturers of polyurethane finishes recommend a minimum of two coats to achieve the desired level of durability and sheen.

Drying Times

Water-based polyurethane floor finishes generally dry to the touch in about two hours and can be recoated in about four hours. For oil-based finishes, double the drying time. For either finish, the floor should be safe to walk on after about 48 hours (but refer to the manufacturer’s instructions to be sure). Allow one week for the surface to fully cure.

Temperature, humidity, and ventilation affect drying times. Keep the room between 55 and 90 degrees Fahrenheit and maintain a relative humidity of around 50 percent. If necessary, increase humidity with a humidifier or decrease it with a dehumidifier. Ventilating the room with a fan on a low setting will expedite drying.

Alternatives to Polyurethane

Though polyurethane is the most popular type of on-site floor finish, some alternatives offer other advantages and disadvantages:

  • Penetrating Oil: Penetrating oil soaks into the wood and requires several coats. It sheds water but isn’t good at resisting scratches.
  • Varnish: Made from wood sap and alcohol, varnish predates polyurethane as a floor finish. Varnish has more solids than polyurethane, producing a thicker coating.
  • Wax: Wax is spread in multiple thin coats after the stains have been applied. Then, it is buffed to the desired level of gloss. Though wax is inexpensive, it does require frequent reapplication.
  • Aluminum Oxide (Pre-Finish): Aluminum oxide is an extremely hard finish that rivals even oil-based polyurethane’s durability. The downside is that it cannot be reapplied on-site; it can only be applied in the factory when the floor is being manufactured.

Safety Considerations

Sanding, scraping, or removing old paint on floors can be hazardous if that paint contains lead. Lead is toxic and can cause illness and even brain damage in children. Always wear a NIOSH-approved respirator. Clean up with a HEPA vacuum and a damp mop. Adhesives may contain asbestos. If you believe that the surface may contain asbestos, have it tested before sanding it.

Prepare your workpiece

A glass-smooth finish begins with a level, even surface. To achieve this on open-grain woods (oak, ash, walnut, or mahogany, for instance), first fill the pores with a wood-grain filler, photo below.

Quick Tip! Wood-grain fillers come in different colors; you can choose one to blend with the color of the workpiece for an even appearance, or select one that contrasts for more pronounced grain.

Scrape off the excess and let dry. Sand the workpiece to 220 grit.

Apply stain and poly

Move to a low-dust setting: somewhere without lots of foot traffic and with dust-free surfaces. You can create such an area by hanging an inexpensive vinyl shower curtain in a corner of your shop. With your workpiece wiped clean, apply stain, photo below. (Skip the stain if you intend to leave your workpiece natural-color.) Let dry.

Prepare the polyurethane by reducing it about 10 percent with mineral spirits, unless you’re using water-based polyurethane, which doesn’t need thinning. Thinning the polyurethane makes it flow on more smoothly and reduces brush marks.

Quick Tip! To reveal flaws (bubbles, brush marks, etc.) as you work, shine a light at a low angle across the surface.

Brush on three thin coats with a foam brush. (You can use a natural bristle brush with oil-based poly, but keep an eye out for loose brush hairs.) Coat the entirety of your workpiece, but don’t brush excessively or you’ll create areas with too little polyurethane. Allow each coat to dry fully. To give the subsequent poly layers something to bond to, sand lightly between coats with 320-grit sandpaper wrapped around a hard block. Note: The first coat needs the most sanding to appear smooth; don’t worry if it doesn’t look as flawless as you’d like at first.

After the third coat, sand with 320-grit, then 400-, and finally 600-grit sandpaper. Sand in alternating directions with each abrasive to make it easier to see whether you’ve removed the scratches from the previous grit. Sand with the grain on the final pass. Then, wipe off the dust with a rag dipped in mineral spirits.

Put on the polish

The final coat gives your workpiece its smooth feel and flawless appearance, so give it extra attention. Spray on this coat using an aerosol polyurethane and let it cure overnight, photo below.

Then, remove any dust nibs with 1,500-grit sandpaper or a piece of brown paper bag. Finally, using a soft cotton rag or polishing pad, buff the finish to a high shine using automotive paste wax, photo below, which has fine abrasives that polish the finish even further.

Polyurethane is a hard, polymeric finish that can be applied to numerous areas, including concrete floors. It creates a seal against dust and liquids and also helps to protect the floor from scuffing and scratching.

They provide a non-skid surface to walking areas such as hallways in the home. Two coats of polyurethane supported by an earlier primer coating yield long-lasting results on any concrete floor.

Here is how to apply polyurethane to concrete floors:

Step 1: Clean the Floor

Clean the floor surface with odorless mineral spirits to remove any contaminants like dirt, dust or grease. Make sure the concrete is completely dry before applying any finish. Clean the floor properly to ensure adhesion.

Step 2: Apply the Primer

Take an oil-based primer to apply at least a coat on the floor before applying polyurethane. To get the best adhesion, let the primer dry overnight. You may even skip this step and start with the next step, but that will surely make the finish less lasting. Remember that without primer, polyurethane fails to get stuck to concrete and becomes vulnerable to moisture delamination.

Step 3: Apply the Polyurethane

The primed floor is now ready to be applied with polyurethane! Stir the polyurethane in a container slowly using a paint mixer to ensure an even mixture.

Pour a quarter-sized amount of polyurethane in an area about 6 inches square. Spread it with a paintbrush, roller or squeegee so that the polyurethane covers an area 1 foot by 1 foot.

Allow it to dry for 20 minutes before spreading additional coats on adjacent areas of the concrete flooring. Let each coat dry for 24 hours before walking on it to avoid damaging the new surface.

Step 4: Apply the Second Coat

Let the first coat dry for 24 hours before applying the second coat. Using a brick trowel on large surfaces and small hand trowels on corners, edges, and other hard-to-reach places will ensure an even finish. You can even use a sprayer for a more even coating.

Step 5: Final Step

If you are not happy with the look after two coats, repeat the application process up to three or four times in order to build up the thickness in high-traffic areas.

Allow 48 hours between applications so that sections of the floor can dry completely. It is unnecessary to allow time between applications if you are just trying to get a thick finish on a tiny area in your home.

What Else to Use on Concrete Floors if Not Poly?

Some other sealers such as Epoxy, Acrylic, Polyaspartic or Polyurea can show better results on concrete for being more effective on granular materials. However, acrylic and epoxy last long on concrete floors only if they are interiors. But for exterior concrete floors, you must pick polyaspartic or polyurea, avoiding epoxy, acrylic.

Tips on Polyurethane Concrete Floor Maintenance

Should you maintain a primer and polyurethane-coated floor or floors coated by other competent sealers as stated in the prior paragraph, the finish can last even up to ten years! Let’s come to the maintenance process.

  • Use an industrial dust mop to dry mop the floor daily in order to prevent degradation of the conductivity.
  • Use a mix of water and non-residue alkaline to wet mop the floor every week, then dry.
  • Soft scrub with pads (red buffer or soft nylon bristle) to remove floor contaminants every two weeks using diluted non-residue alkaline floor cleaner. Too aggressive scrubbing may dull the floor gloss. But if you need to remove scuff marks mandatorily, use detergent. Of course, let it soak before scrubbing. But make sure the detergent is of a non-residue nature.
  • You can also wax the floor as an extra measure for shining. Remember, once you wax, it should be a regular process.

Summing Up

Polyurethane is a great way to protect your concrete floor if applied accordingly. It is a great alternative to concrete dye if you are looking for something that isn’t permanent.

If you want more information on sealing your concrete floor, visit our website, we’ll help you design your floor.

We use polyurethanes in one form or another every day – at home, in our offices and cars, for sport and leisure activities and on holiday.

Polyurethane is a plastic material, which exists in various forms. It can be tailored to be either rigid or flexible, and is the material of choice for a broad range of end-user applications such as:

  • insulation of refrigerators and freezers
  • building insulation
  • cushioning for furniture
  • mattresses
  • car parts
  • coatings
  • adhesives
  • rollers and tyres
  • composite wood panels
  • shoe soles
  • sportswear

Polyurethanes are versatile, modern and safe. They are used in a wide variety of applications to create all manner of consumer and industrial products that play a crucial role in making our lives more convenient, comfortable and environmentally friendly.

Polyurethanes were invented back in the 1930s by Professor Dr. Otto Bayer (1902-1982). There are various types of polyurethanes, which look and feel very different from each other. They are used in a diversity of products, from coatings and adhesives to shoe soles, mattresses and foam insulation. However, the basic chemistry of each type is essentially the same.

Widespread use of polyurethanes was first seen during World War II, when they were utilised as a replacement for rubber, which at the time was expensive and hard to obtain. During the war, other applications were developed, largely involving coatings of different kinds, from aeroplane finishes to resistant clothing.

By the 1950s, polyurethanes were being used in adhesives, elastomers and rigid foams and, in the latter part of the same decade, flexible cushioning foams similar to those used today.

Subsequent decades saw many further developments and today we are surrounded by polyurethane applications in every aspect of our everyday lives. While polyurethane is a product that most people are not overly familiar with, as it is generally ‘hidden’ behind covers or surfaces made of other materials, it would be hard to imagine life without polyurethanes.

Science and Research on Polyurethanes

Polyurethanes are plastic polymers made by combining diisocyanates ( TDI and MDI) and polyols. There are literally hundreds of different types of polyurethanes and each is made in a slightly different way:

  • Carbon dioxide is used as a blowing agent to create the soft, comfortable feel of a mattress or sofa. The more blowing agent is used, the softer the resulting foam.
  • In rigid foams, a gas such as pentane is “trapped” in the closed cells of the foam, optimising its insulation capacity.
  • Rollerblade wheels, on the other hand, do not require a blowing agent and instead have a dense and hardwearing consistency.

Polyurethanes and energy efficiency

Because polyurethanes are so versatile and known to be excellent insulators, they offer many solutions to the challenges of energy conservation and eco-design. The polyurethanes industry is always seeking to reduce its impact on the environment and is currently exploring ways of increasing the energy efficiency of manufacturing processes and creating end products that can be used to save energy, such as building insulation. These products help families and businesses reduce their energy bills, while at the same time helping to protect the environment. The future is likely to bring further improvements in production processes, resulting in less expensive and even more environmentally friendly polyurethanes.

Through time, your pieces of wood furniture will likely deteriorate. Because of this fact, having an excellent topcoat becomes an essential thing. Thus, you should learn how to apply polyurethane. However, although this task would seem to be very basic to some people, others are still not knowledgeable about the proper steps of applying polyurethane.

This article will feature a tutorial for this task. You will later learn how to proceed with the project. Just take time to review the contents and you will surely appreciate your curiosity to learn new things – especially if it has something to do with the preservation of your furniture.

What Do You Need to Follow this Tutorial?

Applying polyurethane to your furniture is actually an easy task. However, it will not be possible for you to carry out this tutorial if you do not have the necessary things:

  • Materials, Tools, and Supplies

Obviously, this task would require an oil-based polyurethane. You’d prefer to use oil-based polyurethane as it gives incredible depth and color. Its quality is quite incomparable to water-based ones. You must also prepare mineral spirits, automotive polishing compounds, and automotive rubbing compounds.

Furthermore, this tutorial requires certain tools and supplies. Get ready with your shop vacuum and a sanding block. You will also need sandpapers and brushes. Prepare tack cloth, lint-free cloth, and wet/dry sandpaper, too.

Step-by-Step Instructions

Step #1 Sand the Area of your Object

Before you proceed with applying polyurethane, you have to sand the area of your object first. For this step, you should use increasingly finer grits. Sandpaper with greater grit gets rid of the deeper scrapes developed by using lower grit sandpaper.

Most of the time, you will have to use 100-grit sandpaper for the initial sanding, then followed by 150-grit, then 220-grit sandpaper.

Step #2 Get Rid of Any Dust

Once you have freed the object from blemishes, you should then remove any dust left. To easily carry out this step, you can get a shop vacuum that features a soft brush. However, you must reinforce it by wiping down the surface with a clean cloth drenched with some mineral spirits. Lastly, wipe down the surface with a tack cloth.

Step #3 Secure the Surface

Dilute the oil-based polyurethane with a single part of mineral spirits and two parts of polyurethane. Run the mixture into a container and smoothly stir it with a stir stick. Apply the sealer using a natural-bristle brush following long and even strokes. Make sure you spot any runs.

Make sure to check the information from the can of the stain since some stains are characterized as self-sealing. Now, if you got a self-sealing stain, then you can simply skip step 3.

Step #4 Apply your First Coating for Polyurethane

Apply a finish directly from the can and it has to be done within 24 hours after the application of the seal coat. Smear the varnish throughout the whole surface while following long and even strokes. Lie over the strokes so you can achieve even coating. Lay hold of the drips, specifically those that are near the lower edges.

Step #5 Cut off the Bumps

Wait for at least 12 hours and touch the surface to feel if it has completely dried. Once the surface has dried, cut off any drips through a razor blade. However, you have to be careful when cutting off the drips as you do not want to cut the underneath surface.

Step #6 Do Wet-Sanding

After drying the first coating for 24 hours, get rid of the little blotches by doing wet-sanding while mounting 400-grit sandpaper to a sanding block. Drench the paper to water and perform strokes in a circular motion to get rid of the blotches as well as the dust bumps.

Once the surface is already smooth to touch, wipe it down with a moistened cloth and dry it with a dust-free cloth.

Step #7 Apply Second Coating

Apply second and final coating 24 to 48 hours after the application of your first coating. This should be easy for you as you will only have to perform the same steps as the first coating. After drying the second coating, cut off any bumps and do wet-sanding again on the surface.

Step #8 Polish the Object if you did Wet-Sanding during the Second Coating

After waiting for 48 hours and with an automotive rubbing compound, polish your finish. Moisten a cloth with some water and use the compound by rubbing it in a circular motion. Once done, wait for the surface to completely dry and smoothen the finish with a dry and clean cloth.


Learning how to apply polyurethane is a smart way of taking care of your furniture at home. You wouldn’t want to hire somebody to do this simple task. Regardless if it is going to be the first time to apply polyurethane, you can carry out this task well if you carefully follow the steps above.

You wouldn’t have a hard time grasping the instructions in this tutorial as they were very detailed and clear. Enjoy the experience of learning something new. Learning how to apply polyurethane is a skill you can use throughout.

To apply polyurethane without bubbles, avoid using a natural brush as you apply polyurethane. Use a synthetic brush for bubbles. Synthetic brushes have bristles made with synthetic material that gives better application.

They come in a wide range of sizes as they match various projects, from small to big projects.

Synthetic brushes do not absorb polyurethane during use. Use water on the polyurethane brush to dampen it for a smooth and flawless application. Do not shake up the can since that creates bubbles. Rather stir the polyurethane.

What causes bubbles

Shaking the gallon

When you want to take your juice, it is thicker at the bottom hence the need to shake first. The polyurethane mixture comes in that form before use since it has been in the shop for a while after production before use.

The first thing you might think of as a user is to shake the gallon for a well-mixed chemical. You are allowed to shake spray paint, not water-based polyurethane. Shaking is not allowed on woodworking or painting products.

Stirring prevents bubbles, and shaking forms bubbles on top of the polyurethane. The moment you dip in your brush, it takes up the bubbles and leaves them on the surface you are painting, and they dry just like that.

Leaving air on the brush

There are air pockets in your brush that cause bubbles when applying polyurethane. To avoid air on your polyurethane brush, dampens it with water under the sink. Soaking them will not affect your task. However, there is a need to remove dripping water using your hands before use.

All the bristles have to be wet, and as they stick together, they glide well on the surface. When your polyurethane is oil-based, dampen your brush using a solvent-based product, but when it is water-based, water does the trick.

If you choose to use solvent-based products on water polyurethane, you will deal with bubbles only, but more problems come with such a move. The finish will not be flawless. Please do not use a roller since it creates bubbles.

Contaminated surfaces

Contaminated surfaces make polyurethane act funny as you are applying it on the surface. Sand down your projects to the extent that they look like bare wood or strip them down. That is the initial stage of the project.

Deep cleaning gets rid of dust and dirt. Use mineral spirits when cleaning. Mineral spirits are also solvent-based products, and they clean the surface well. As soon as you finish using the spirits, they evaporate instantly. Before you start using the polyurethane, make sure the spirits dry.

Use Shellac

Using Shellac first prevents bubbles on your surfaces. Make sure there is no contamination before applying the polyurethane. Shellac seals anything underneath, and that does not allow bubbles to show. Apply Shellac and make sure it dries first before polyurethane. Shellac stops your product from bleeding as well.

How to apply polyurethane


  • Sanding block
  • Shop vacuum


  • Lint-free cloth
  • Mineral spirits
  • Oil-based polyurethane
  • Sandpaper
  • Tack cloth
  • Wet/dry sandpaper
  • Automotive rubbing and polishing compound


  • Sand the surface
  • Remove dust
  • Seal the surface
  • Apply first coat
  • Remove bumps
  • Wet sand the first coat
  • Apply the second coat
  • For more coats, repeat the process

Bubbles in Fresh finish

Wiping the brush along the side of the can creates bubbles. It brings bubbles inside the mixture in the gallon. Take your project brush to the surface to start the process as it transfers the bubbles to the surface.

You still have the chance to get rid of the bubbles whilst the polyurethane is still fresh. Dab the bubbles with the tip of the brush and run the project brush along the surface. By doing so, you are flattening the bubbles, and they disappear into the finish.

Bubbles in a hard finish

There are chances that you will not notice the bubbles when the finish is still wet. That means the bubbles are hardened together with the rest of the finish. The chances of failing to notice bubbles happen to users who use the finished applicator aggressively. They continue to complete the project without monitoring the outcome. Another coat covers up the bubbles, but if it fails, you try other methods.

How to get rid of dried polyurethane bubbles

Use steel wool

Start by using the 0000 as you try to rub the dry bubbles. Steel wool is graded in 0s and 0000 as the flexible and ultra-fine grade. It gives you a polish and cleans delicate surfaces (Source). Steel wool is so fine that it rubs bubbles with ease.

There will not be a trace of scratches, and the surfaces become glossy. There is a need to buff out the whole surface to match if you are not giving the wood surface an additional coat. If the 0000 does not give you satisfactory results, try going down to 000 or 00 steel wool. Work on a smaller patch before you try out the whole surface.

Use a sander

Sanding the surface can be the answer to rubbing off polyurethane bubbles. High grit sandpaper such as the 400 is the ideal tool for bubbles. It polishes off your work surface as it sand off the bubbles.

Choose to sand the bubbled area to match the surface or sand the whole surface since that almost removes the affected area. Use an electric sander, and there are multiple models, such as a random orbital sander.

Sanding is riskier than the mentioned methods. Be careful as you sand off the bubbles. You will lose the entire surface when you want to lose the bubbles only.

A high grit sanding sponge ensures safety in removing the bubbles. Washable sponges bring less damage to the surface. Do not wet them but look for high-quality sanding sponges. Softer sponges perform better than hard ones.

Starting all over

If the bubbles are bad, starting all over again might be the best way to get rid of the bubbles. You may have tried the above methods, and they did not work, and the option might be to remove the entire layer and re-start the process.

Starting all over again protects your surface more than sanding since the chances are high that you will damage your project surface. Poor quality sanders and hard ones damage the bubbled polyurethane surface.

As you start again, working on affected areas saves time and reduces the chances of bringing more damage to the surface. Staining or painting the affected area can be the best option if you cover the bubbles. Starting again can be draining, but it is worth it.

Thinning polyurethane

When polyurethane is still inside the gallon, it is thick and hard. That makes it hard to apply, and the chances of using the product without making bubbles are high. Although manufacturers advise users to run with the one coat idea, there is a need for lore coats for durability and effectiveness.

Thicker surfaces have multiple layers of protection, and they are a product of multiple, thinner coats. Just in case there are bubbles from the first coat, a second coat hides the bubbles. The question remains, how do you then the product?

Mix the polyurethane mixture with solvents on a 3:1 ratio. Three parts represent the polyurethane, and one part, solvent. The solvents are mineral spirits used on both oil and water-based polyurethane. Thinning is a process that reduces the thickness of polyurethane.

Oil-based polyurethane protects wood furniture as well as enhances the natural wood appearance. The finish is clear and shows off the grain of the wood. To apply oil-based polyurethane to your furniture, follow the directions in this step-by-step guide.

Step 1 – Sand the Wood Surface

Sand the surface of the furniture until it is smooth.

Step 2 – Clean and Vacuum the Dust

Use a cloth and shop vac to remove dust from the furniture.

Step 3 – Seal the Surface

Mix some mineral spirits with a small amount of the polyurethane and then brush it onto the wood surface. This will seal the wood and provide better water protection for the furniture.

Step 4 – Apply the First Coat

After the sealer dries, brush on the first coat of oil-based polyurethane. When applying the finish, use long and even brush strokes.

Step 5 – Sand Again

After the first coat dries, sand the entire surface of the wood again. Start with 100-grit sandpaper and work your way up to 220- (or higher) grit paper.

Step 5 – Apply More Coats

Apply two to three more coats of polyurethane. Sand in between coats with higher grits of sandpaper, and wet-sand with 400- (or higher) grit sandpaper before you apply the final coat. Use the razor blade to gently scrape away drops of polyurethane. Carefully apply the last coat of oil-based polyurethane. Lightly wet-sand again.

Step 6 – Clean Up and Polish

Use rubbing compound and polishing compound to polish and shine the furniture.

Also know, how do you apply water based polyurethane?

The basic application technique for waterbased poly is similar to that for oil-based. Apply a very thin coat of polyurethane with a fine brush, foam pad, or cloth. Work with the grain, and avoid applying too much polyurethane to avoid raising the grain.

Subsequently, question is, how long does it take for varathane polyurethane to dry? Dry and recoat times are based on 70°F and 50% relative humidity. Allow more time at cooler temperatures. Dries to the touch in 1-2 hours and can be recoated in 4 hours. It is fully cured in 72 hours.

Also know, can you apply water based polyurethane with a roller?

Yes, you can use a paint roller to apply polyurethane. Polyurethane is easily applied with a paint brush or roller and dries quickly. Applying the material with a roller eliminates brush strokes and lines and prevents over-applying the material.

How long does water based polyurethane last?

But, if you are using a mid grade water poly (or low grade), expect the durability to be significantly lower than oil based poly. When I say lower durability, I mean that it will scratch and peel more easily and it won’t last last as long (often 2 to 4 years less, but everyone’s wear and tear is different).

Posted on Last updated: April 19, 2022

Polyurethane is a very useful product with multiple uses. For those individuals who don’t know specifically what polyurethane is, it’s a synthetic product that works in the same way as paint, rubber, metal, wood, and other materials do. It’s durable, flexible, and resilient.

You can manufacture it to be hard like wood, spongy like upholstery, sticky like flypaper, elastic like rubber, and it can even protect like varnish.

In addition to this, polyurethane will not rust, it’s not affected by mold and mildew, it can withstand extremely hot and cold temperatures, and when it comes to wet surfaces, it’s is one of the best choices to use. The best part? Polyurethane has a longer life-span than rubber, paint, foam, or other applications.

As a result, you won’t have to replace it as often. This will save you both time and money. Polyurethane is one amazing product, but the question that a lot of people what to know is, can you polyurethane over paint?

Can you put polyurethane over paint?

Why do people use polyurethane over paint? Well first, polyurethane protects your paint and makes it last a whole lot longer. It does this by serving as a highly resistant barrier which protects your paint from rain, dirt, mud, fungus, and mold. Polyurethane can even help prevent the color of the paint from fading as a result of being exposed to the sun.

Although polyurethane is mainly used on stained wood due to the durable finish it provides, some homeowners use it over paint. However, there are some oil-based paints when coated with polyurethane have been known to turn a yellowish color overtime. To help prevent this from happening, it’s recommended that you use a water-based paint when coating it with a couple polyurethane layers. So, how do you polyurethane over paint?

The proper way to polyurethane over paint

Before you add a few polyurethane layers over dried paint, you’ll need make a few preparations before you can get started. It’s important to note that your paint should be fully cured before you apply a layer of polyurethane.

Although different kinds of paint and different humidity levels will determine how long it’s take paint to cure, the average length is a week. So, to properly apply polyurethane over paint:

Step 1: Wash the surface

Grease stains, dirt, dried mud, and any sort of other filth needs to be washed off before you can apply the first coat of polyurethane. Use a soft sponge or rag and a powerful detergent to clean up the painted surface. You can take a ½ cup of trisodium phosphate and mix it with warm water. This is a really effective cleaning solution. This process helps increase the polyurethane adhesion by deglossing the finish while also cleaning it too.

Step 2: Scuff away

Once your painted surface is dry, then you’ll want to equip yourself with a 120-grit sandpaper, so you can scratch the surface. Why? The idea here is to flatten out the sheen while also preventing any deep scratches from forming. Large and/or deep scratches can be visible under the polyurethane.

When etching the surface, you can do this by hand, or you can also use a palm sander. It really depends on your preference, but if you’re wanting to apply polyurethane to a floor, it’s advised that you use a floor buffer with a 120-grit sanding screen. After you are done sanding, wipe the dust away with a damp cloth.

Step 3: Decide on an application

Choose between oil-based and water-based polyurethane. The real difference between these two polyurethanes is that oil-based polyurethane has an amber tint to it whereas water-based polyurethane is clear. In addition to this, oil-based polyurethane has a stronger scent to it and tends to dry slower than water-based polyurethane.

When applying your polyurethane, make sure you don’t use a roller. Rollers tend to leave bubbles. It’s recommended that you use either a brush or spray it on. If you do decide to spray on your polyurethane, you don’t have to thin it out. Thinning your polyurethane out can cause it to run excessively.

Step 4: Apply your first coat and then etch the surface again

Apply your first coat and then let the polyurethane dry for the time listed on the container. After your polyurethane has fully dried, you’ll want to scuff scratch up the surface again with a piece of 120-grit sandpaper. By doing this, you’ll remove small dust particles in addition to squishing and flatting any bubbles that have became hard in the finish.

Step 5: Apply your second coat

Apply your second coat. Typically, you’ll never need more than two coats. Very rarely will you ever need a 3rd. Make sure you let whatever it is you coated 24 hours to fully dry. After that, you should be good.

Table of Contents


Polyurethane is one of the greatest wood finishes on the market today. This layer can protect the surfaces from scratches, moisture, and other defects. But Can You Apply Polyurethane With a Roller?

In this article, we will discuss some key points relating to this topic along with other tips to complete your work without a glitch. So let’s get started!

Can You Apply Polyurethane With A Roller?

Yes, of course, you can. A paint roller is a good choice for people who want to ease and speed up this work as they cover a larger area.

What Kind Of Roller Should You Use For Polyurethane?

So long as your target has a flat finish, you need to use short paint rollers made of lambswool or fiber. They avoid the mixing of lint and dust with the end exterior of polyurethane.

At first, many people may find it complicated to get rid of those problems.

Advantages Of Using The Roller

Polyurethane is a hard layer that you can apply to a surface with a roller.

The first and foremost benefit of adding the substance with a roller in comparison to other techniques is how fast it could be.

Besides saving a portion of time, using this method can allow you to work without the help of more than one person.

How to apply polyurethane

Another advantage is that the amount of applying substance is much easier to control. As you roll this over the floor, you can use less or more pressure.

Furthermore, a nap roller will also help prevent any surplus material. It might cause other application methods to be a usual problem and discoloration in some areas when they are broken.

Unlike brushes, nap rollers are made for the use of lots of modern materials, including liquid ornamental plaster.

Disadvantages Of Using The Roller

There are a few criteria you need to consider before you use a roller to add polyurethane.

A roller costs an arm and a leg compared to a common brush. Even so, get a renewal cover, and you can have the roller as a useful tool in the long term.

Another drawback is that a nap roller does not work in inaccessible places such as joints and corners. In these cases, a brush can help you effectively.

How to apply polyurethane

How Can You Apply Polyurethane With A Roller?

  • Prepare rubber gloves and masks to protect yourself from contacting toxic substances and inhaling fumes in polyurethane.

Fill a paint pot with some mineral spirits. Place another paint pot closer to the flat and beside the pot you just prepared. Fill it with a polyurethane formula.

  • Soak a clean rag in mineral spirits and wipe the flat down. By doing this, you can remove almost all dust from the flat. Then wait a few minutes for the substance to evaporate, and you can start the work.

How to apply polyurethane

  • Put the nap roller gradually into the pot that contains the mineral spirits and thoroughly humidify its surface.

Shake off excess mineral turpentines to ensure that they don’t fall in small drops. To properly stick polyurethane, we need a clean, humid paint roller.

  • Then, you put the same roller inside the polyurethane pot and let it soak.
  • Roll a sparse layer of the compound over the wooden floor surface that you want to cover. Roll quickly until the roller no longer has polyurethane.
  • Wait until the compound gets dry. The drying process differs according to ambient temperature, but generally, a new polyurethane coat can be added after three hours.
  • Prepare high sandpaper. After finishing the first layer, you need to sand the flat where you are working to enhance its stability before taking the second one.

How to apply polyurethane

Then soak a clean rag in mineral spirits, remove excess and wipe the flat to clear any dust before moving to the next layer of polyurethane.

  • Repeat the above process until you have added two or three polyurethane layers.

Related Articles:

Cleaning Up After Finishing

Remember to clean up after finishing your work.

  • Polyurethane can be poisonous to your skin, so before washing the used material, make sure you dispose of the excess.
  • Use hot water to wash the nap roller to remove all the substances off it.
  • To get off all remaining mineral spirits and polyurethane from the roller, use hot water to wash it.
  • Eliminate the dried material from the pot with a flat blade screwdriver. Then use hot water to wash the pot.
  • Unless you have used up the polyurethane, ensure to transfer it to a different can and close tightly to reduce the quality of the product.
  • Dry all the tools with a cotton cloth and put them away for future use.


Now that you have got the answer about “ Can you apply polyurethane with a roller? ” and some further details on this topic. Hopefully, with this article, you can paint the wooden floor by yourself.

by Kitchen Cabinet Depot • October 15, 2018

How to apply polyurethane

A polyurethane varnish finish can cut down on the wear and tear of kitchen cabinets, help keep them looking new and extend the life of the cabinets. Polyurethane works best on unfinished wood but can also be painted directly onto painted surfaces.

When you apply polyurethane varnish, you’re actually sealing it in plastic. It is a plastic so tough that hardly anything can penetrate it. In addition to this exceptional durability, polyurethane is easy to put on; fairly fast-drying; super-resistant to chemicals and water; and available in low-gloss, satin, and high-gloss finishes. It also comes in oil based and water based.

Preparation before applying polyurethane to kitchen cabinets

Before applying polyurethane, complete the preparation steps for either stripping paint or preparing for new paint. These steps may include using paint remover, sanding and filling and sealing. If you’ve applied a stain or wood filler to the surface, make sure it is absolutely dry before adding the polyurethane.

Apply either oil-based or water-based polyurethane with a brush, lambs-wool applicator, or lint-free cloth. Latex polyurethane is easy to use with a sprayer; oil-based poly tends to clog up the works, so you’re better off doing this by hand.

All types of wood require at least two coats of oil-based polyurethane. The first coat works as a primer and sealer; the second serves as a finish coat. With water-based polyurethane, a third coat is recommended, because the finish wears away fairly quickly. Sand between coats if dust or lint gets into the wet finish. Sanding also makes it easier to tell where you applied the subsequent coat.

Troubleshooting polyurethane finishes on kitchen cabinets

When you add the finish – both coats – keep the work surface between you and a light (if possible). In this way, you will see missed spots as the finish is applied. Missed spots are caused by poor penetration into the wood or inadequate application. They leave little dimples in the finish, and they’re almost impossible to touch up after the material has dried.

Not all polyurethanes are clear. Some are colored to resemble pigmented shellac. With these, you’ll usually need to apply several coats of the finish to reach the color tone that you want on your kitchen cabinets. Each coat will produce a deeper tone; so try a test run on a scrap of the same material to determine how many coats you will need.

If you reach the color tone before achieving the sheen you want, let the surface of the cabinets dry thoroughly, and then apply clear polyurethane finish to complete the project. However, the clear finish will slightly change the color tone underneath.

You can apply a clear polyurethane finish over paint. Don’t expect the polyurethane to hide any defects in the material. In addition, if you are painting your kitchen cabinets solid white, you must understand they will yellow somewhat over time.

Low-gloss polyurethanes are less durable than high-gloss products. Use low-gloss finishes as top coals to cut the shine off high-gloss coatings underneath. High gloss is recommended for applying to kitchen cabinets.

Important note

As with varnish and shellac finishes, dust and dirt control is critical with polyurethane. Cover all ducts carrying air currents blowing from heating and cooling. Avoid doing anything that would cause dust to become airborne, especially sweeping the floor just before the finish to the kitchen cabinets is applied. Use a tack cloth to remove dust from the work.

Introduction: Applying Wipe-On Polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

Wipe-On (also called oil-based) polyurethane blends the best of both worlds of finishing: the high durability and protection of polyurethane with the simple wipe on application of an oil finish. Unlike water-based polyurethanes, you don’t have to worry about drips or brush marks. This type of finish is ideal for a piece that may experience a lot of wear and tear inside your home. I like to use the Minwax brand. Here is how I apply wipe-on poly to my woodworking projects.

Step 1: Materials

Lint free rag or cloth

220 grit or higher sandpaper

Step 2: Prep the Work Piece

Begin by preparing the wood surface for the finish. This means sanding the finish as smooth as you want. For most indoor furniture, I will move my way up through the sanding grits on a hand-held random orbit sander, beginning at 120, then going to 150 or 180 and finally finishing at 220.

Before applying finish, it is important to remove as much of the dust as possible from the work piece. I staring by vacuuming the piece with shop-vac. Then, I dust the entire piece with a micro-fiber tack cloth to remove any remaining dust.

Step 3: Wipe on First Coat

Give the can a shake before getting started. Open up the can and transfer a small amount into a plastic cup or old yogurt container. Put a small amount of finish on the cloth and rub it over the wood. You should be trying to apply an even finish over the whole piece – this is very easy to achieve. Don’t flood the surface and don’t leave any excess on the surface. It will take 3-4 hours for this coat to dry.

Step 4: Sand and Reapply

After 3-4 hours check to see if the piece is dry. They dry time will vary depending on temperature and humidity. If the piece is dry give it a light sanding with a high grit sandpaper. I like to use 220 grit, but you could use a higher grit like 320 if you want. You could also use 0000 Steel Wool.

One you are done sanding, wipe off any dust with a lint-free cloth or a micro-fiber tack cloth. Repeat the steps to reapply as many coats as you want. For most of my projects I will apply 2-3 coats, but you could apply more.

Be the First to Share

Did you make this project? Share it with us!

How to apply polyurethane

Related Articles

  • How to Make the Dining Table Look Glossy
  • How to Finish a Bamboo Plywood Countertop
  • How to Restain a Table
  • How to Stain Pine Floor Boards
  • How to Cover a Cushion With Fabric

Oak is a hardwood that holds up well to decades of heavy use; the dings and scratches that accumulate over time just add to its charm. A polyurethane finish protects and enhances an oak tabletop’s surface while allowing its charm to shine through.

Types of Polyurethane

Oil-based polyurethane is easiest to apply and requires fewer coats, but it leaves a thick finish that takes a long time to cure. Water-based polyurethane is harder to apply without leaving brush marks. It also requires more coats and heavier sanding between coats because it raises the wood’s grain. Tung oil — oil-based polyurethane mixed with paint thinner — requires many coats but has a thin, more natural-looking finish.

Surface Preparation

Sand the tabletop. Start with 100-grit paper and work your way up to 220. Vacuum or brush the sawdust off the table, then wipe the surface with a cloth dampened with denatured alcohol. Wipe the wood with a tack cloth to remove any last bits of dust.

Applying Polyurethane

Brush thin coats of polyurethane with the grain, using a foam brush. Work side to side, then front to back in small sections. Keep wet edges. As you move from one section to the next, work the polyurethane into the previous section’s edges to avoid lines and brush marks. Cure the finish until it’s completely dry, then lightly sand the surface with 220-grit sandpaper. Remove the dust with a tack cloth before applying the next coat. Continue these steps until you achieve the desired finish.

  • The Berkeley Daily Planet: The Art of Applying Polyurethane
  • Popular Woodworking Magazine: Finishing for First-Timers

Daria Kelly Uhlig began writing professionally for websites in 2008. She is a licensed real-estate agent who specializes in resort real estate rentals in Ocean City, Md. Her real estate, business and finance articles have appeared on a number of sites, including Motley Fool, The Nest and more. Uhlig holds an associate degree in communications from Centenary College.

There are more than a few reasons behind why polyurethane is considered one widely revered and durable hardwood finish. It makes a protective layer that keeps your wooden floor in a better form as the days keep passing. There are two types of polyurethane finish that differs in application and performance.

Today I’ll be disclosing the right method of how to apply water based polyurethane to wood floors using formulas that work best.

Best Way to Apply Water Based Polyurethane to Wood Floors

Here’s a piece of quick information I want you to know about before we discuss what is the best way to apply polyurethane on wood floors. And that’s about the floor types you can consider for applying water based polyurethane floor finish.

Maple, white washed and gray stained floors are the ones that do not complement well with oil-based polyurethane. These are more appropriate to fit best with a water-based poly finish.

Now Let’s Proceed with The Guide!

Prep Up the Wooden Floor First

This step is basically the answer for those who wonder, how do I get a smooth finish with water based polyurethane that will not look any less professional. And it’s about preparing the wooden floor for application.

People feel discouraged to spend more time here and want to rush things over. And that’s probably why some end up getting a less attractive outlook by the end of application.

You need to make your wooden surface clean to let the finish better stick with it. And when the case is about a clear finish, this step becomes even more crucial.

Use 220-grit sandpaper here and nicely even out the surface. You can try using a filler for open grain woods such as oak, ash, and also walnut. So that an ultra-smooth finish can be achieved on that surface.

After sanding, don’t forget to clean those dust before going for a coat. You can simply use a vacuum here. Also, regular tack cloth can be used. In the case of a water-based poly, you should use denatured alcohol moistened cheesecloth.

An improper brush preparation can lead to creating bubbles. You should soak the bristles of brush in water before application to avoid that problem. However, water-based polyurethane is very less likely to create such a problem. But you still don’t want to take a risk.

Another important note is that if your floor previously had an oil-based stain then you must rough up it slightly. Because the water-based polyurethane will not go well with oil-based stains. So, get synthetic steel wool and give it some gentle roughing out. This will avoid any beading over the surface.

Application Phase

You can use a fine brush applicator for polyurethane to get an even coat. Foam pads and clothes also work for the purpose. Just focus on applying a very thin coat of water-based poly finish. Of course, you don’t want to take too much polyurethane in the applicators since that will not allow level application. Try to follow the grain and don’t raise it very frequently.

Give first coat the required amount of time to dry completely. After that, you can go for the second coat. Here you don’t need to sand between coats and that’s something different from the oil-based poly application.

However, some manufacturers may advise you to do that. So, make sure you check the instructions before and then skip sanding process. Floors are not lightly used and so you want to have the maximum protection here. That’s why it’s best to go for at least four coatings of water-based polyurethane for wooden floors.

Overall Drying & Curing Period to Follow

I already told you about applying four coats of water-based polyurethane applications. Just make sure you are applying each coat maintaining a gap of 4-6 hours. That way you will be able to end things within 24 hours or less. And then it’s okay to move furniture on that floor.

Make sure you avoid shoes and even bare feet until 24 hours have passed. Pets have nails and that can cause damage to the floor. So, avoid letting them into that area for at least a week.

The complete curing process will need at least 30 days. And so, you should avoid placing area rugs before completing that time period. At the very least, this period should not be any less than first two weeks.

Also, some manufacturers have a very specific recommendation in this matter. So, you must check the instructions to be completely sure.


And that’s basically how to apply water-based polyurethane to wood floors. The process needs your complete attention to end up into a satisfying result. So, make sure you don’t ignore any important factor and go by following the right rules.

I also have a guide on how to apply oil based polyurethane to wood floors if that’s something within your concern.

No matter what type of polyurethane you use, it’ll only be able to provide the best results when applied the right way. So, make sure you are not sidestepping proper application. And ultimately everything should fall into its best place.

How to apply polyurethane

Related Articles

  • How to Get a Wood Door Unstuck
  • How to Prepare a Luan Door for Paint
  • How to Paint Metal Doors With Oil-Based Paints
  • How to Varnish Large Knots in a Door
  • How to Fix Cracked Luan Doors

Polyurethane provides a glossy, clear finish to interior oak doors that protects against scratches and moisture. Its shiny finish is also easy to clean and enhances oak’s natural warmth and beauty. Applying polyurethane to an interior oak door requires attention to detail and the right tools, but you don’t have to pay a professional to get a perfect finish. With a little time and patience, most homeowners can apply polyurethane themselves with professional-looking results.

Clean the door of dust, dirt and grime with soapy water and rinse with clean water. Let the wood dry before sanding.

Remove the door from the doorway if it is already installed. Remove the bottom hinge first to avoid causing stress to the hinge, which may result in damage to the door.

Remove all hardware, such as knobs and hinges, and lay the door on a flat work surface. You can apply polyurethane to interior doors that are still installed, but make sure to cover floors, walls and furniture with plastic sheeting.

Open the windows in your work space, and utilize fans and exhaust vents where possible. Wear a painter’s mask and safety goggles to protect your eyes and lungs.

Sand both sides of the door with 100-grit sandpaper to remove deep gouges and scratches. Work in the direction of the grain

Wipe away sanding dust with a tack cloth. Sand a second time using 120- or 150-grit sandpaper to remove fine scratches that might remain.

Sand the door a final time with 220-grit sandpaper to smooth the wood grain and even out any rough spots that might remain.

Wipe the sanding dust with a tack cloth and clean the surface with a cloth soaked in denatured alcohol. If you plan to stain your oak door, this should be done after sanding. Wipe the stain onto the door using a soft cloth. Let it soak into the wood before wiping away the excess. Leave the stain to dry overnight before finishing with polyurethane.

Thin the first coat of polyurethane by mixing three parts polyurethane to two parts mineral spirits. This ensures that the polyurethane will better penetrate the wood and reduces brush marks.

Brush the thinned polyurethane onto one side of the door using a natural-bristled brush. Synthetic brushes are designed for water-based products and will leave brush marks in oil-based coatings.

Leave the first coat to dry overnight. When dry, sand it lightly with 220-grit sandpaper.

Wipe the sanding dust with a tack cloth and apply a second coat of polyurethane. Do not thin with mineral spirits this time.

Allow the second coat to dry and sand it again. Follow with a third coat. New wood may require up to five coats of polyurethane for ideal protection.

Repeat the process on the other side of the door once the first side has fully dried.

  • On the House: The Art of Applying Polyurethane
  • Cabot: Step-by-Step Guide to Interior Staining Projects
  • When painting with polyurethane, keep a wet edge and don’t let the previous stroke dry before blending with the next stroke. This causes brush marks and will make the polyurethane difficult to spread.
  • Do not shake a can of polyurethane. This may result in bubbles in the finish. Stirring too vigorously can also cause bubbles to form.
  • Do not apply polyurethane with a roller. This can lead to stippled or bubbled finishes that are difficult to fix.

Renee Miller began writing professionally in 2008, contributing to websites and the “Community Press” newspaper. She is co-founder of On Fiction Writing, a website for writers. Miller holds a diploma in social services from Clarke College in Belleville, Ontario.

How to apply polyurethane

Polyurethane is one of the most popular finishing products used in crafts making. However, it can be problematic as bubbles and brush strokes often ruin its appearance at the end. Some DIY enthusiasts use a rag to apply polyurethane to avoid these problems, but is this a good idea?

You can apply polyurethane with a rag if you use the wipe-on variants. These formulas are less viscous and deliver better results where brush-applied polyurethane is problematic. However, you need to apply multiple coats of this product, wait until each layer drains, and work with a lint-free cloth.

I’ll look at why polyurethane applied with rags works great and the application process below.

Table of Contents

Why Use Wipe-On Polyurethane?

The main advantage of using wipe-on polyurethane is the smooth finish it guarantees when used correctly. However, some people also love these products because of their thinness. Applying some thin coats with a rag ensures less buildup in the corners of the material you’re working on.

This is why wipe-on polyurethane formulas are most useful when you’re working tricky jobs like on vertical surfaces and fine details. With buildup and drips eliminated, there’s a higher chance of doing a perfect job the first time.

The main downside to choosing this type of polyurethane made for rag application is that you’ll need multiple coats to get the same results as standard polyurethane. Where you’ll need five coats to get the job done with conventional polyurethane, you’ll need ten with wipe-on polyurethane. This can increase your overall budget for the project.

Can You Apply Brush-On Polyurethane With a Rag?

You can apply brush-on polyurethane with a rag, but all the standard downsides apply here. When applying on wood, you have to work in line with the grain to avoid raising the grain. You also have to pay attention to the quantity applied to reduce buildups and streaks as much as possible.

However, more brands are working hard to produce polyurethane that’s less problematic to apply with rags. For example, Miniwax has multiple polyurethane products (available on Amazon), which they say are easy to apply using rags. Some of these products dry quickly and can be cleaned easily with soap and water. This makes the application process a lot less frustrating.

How To Apply Polyurethane With a Rag

Whether you choose to go with wipe-on polyurethane or more conventional variants for rag application, you still need to go about the application process correctly for the right results. I’ll look at what you should do below, assuming you’re working on a wooden piece.

  1. Move the piece to a properly ventilated area.
  2. Sand the wood properly, starting with coarse-grit sandpaper (like 120) and finishing with 220-grit papers.
  3. Use a vacuum or tack rag to remove dust from the sanding process.
  4. Dip a lint-free rag in some mineral spirits to wipe down the surface.
  5. Stain the surface in line with the stain manufacturer’s instructions. You can skip this part if it’s not necessary for the project.
  6. Pour out the polyurethane into a container and use a lint-free rag for the application process. Wipe the polyurethane onto the surface in smooth, even strokes. Pay attention to ensure adequate coverage by overlapping strokes. Focus on one section and move down progressively.
  7. Wait a couple of minutes for the polyurethane to dry. Some manufacturers may recommend different wait times, though. Applying the second coat before the first one has dried will ruin your finish.
  8. Once the first coat has dried, sand the surface lightly using 320-grit sandpaper. Clean the residue with a vacuum or tack rag as before and wipe again with dampened lint-free rag (mineral spirits, not water!).
  9. Apply the second coat of polyurethane. If you need to apply a third, fourth, or fifth coat, repeat the slight sanding and cleaning process I’ve discussed above until you’re done.

Avoid sanding wood such as maple or pine using very fine sandpaper (above 220-grit) if you intend to use a pigment stain on the surface. Fine sanding on such wood can make taking on color a lot harder.

Also, even though multiple layers of polyurethane delivers better protection for the surface overall, you need to consider the aesthetic result you’ll achieve in the end. Multiple layers of polyurethane can be distracting, making the wooden piece look less natural overall.

Final Words

You can apply polyurethane with a rag. The special wipe-on formulas are designed for this coating method, but you can also apply conventional brush-on polyurethane with a rag.

For the best results, use a lint-free cloth and apply the poly using smooth, even, and overlapping strokes.

Simply so, how do you seal an interior wood door?

How to Seal Wood Doors

  1. Set the door on a pair of padded sawhorses so you can easily access all areas.
  2. Sand the door.
  3. Coat the door with a wood treatment solution or sanding sealer.
  4. Apply stain to the door to create the desired finish.
  5. Seal the door with a polyurethane sealer.

Also Know, how do you varnish an interior door? How to stain and varnish a door

  1. Brush down the door and use a tack cloth to remove all traces of dust. Then apply the stain with a paintbrush, starting with the panels.
  2. Use a good quality clean brush to apply the varnish, making sure you’ve read the instructions on the tin.

Simply so, can you use a roller to apply polyurethane?

Yes, you can use a paint roller to apply polyurethane. Polyurethane is easily applied with a paint brush or roller and dries quickly. Applying the material with a roller eliminates brush strokes and lines and prevents over-applying the material.

How do you apply polyurethane without bubbles?

Then apply mineral spirits to a rag and wipe off your loose dust. At this point, you will have one coat of finish with some scratches in it. Next, apply your second coat, Minwax Fast-Drying Polyurethane, with a natural bristle brush, not a foam brush. A foam brush leaves air bubbles in the finish.

I am working on an acrylic-painted game board and am starting to put polyurethane on it to get a high gloss finish. But being that it is a game board, I think it needs to be put on one layer at a time so as to avoid any kind of marks from setting wet poly on a stand, which leads to my question: what is the proper method of putting polyurethane on the board one side at a time? Would I be better off completely finishing the top, and then start on the bottom? Or should I do the top, let it dry, then the bottom, for each coat?

How to apply polyurethane

3 Answers 3

Top, then bottom, then top, then bottom will greatly reduce the odds of the board warping due to differential moisture uptake/release when one surface is sealed and the other is open to the air. While the acrylic paint is sealing it somewhat, the conventional wisdom of long experience is to try and keep the number of coats per side the same to prevent (or at least reduce) warpage.

How to apply polyurethane

Doesn’t make any difference, really; the question is number of coats per surface, not order they’re applied in.

The thing to watch out for is that there will be a tendency for drips to run down the edges and onto the other face. You may want to use masking tape or other techniques to guard against that, though going with multiple thin coats rather than fewer thick coats will also help (and is the better practice in any case).

(This is one advantage of HVLP spray—the atomized finish dries almost on contact, so it doesn’t tend to run unless you seriously over-apply it.)

Always start with your bottom or “B” side. Most things have a side that is unseen or at least less visible. Often these B sides need to be sealed but not completely finished out, so you can apply your sealer coat to the bottom, let dry, flip it, and then finish out your top with out ever having to set your piece A side down with green finish on it. If you put a coat on your show side, then turn it over, if it hasn’t completely cured it could stick and ruin the finish. If you have a piece that has no B side, I still prefer finishing one side at a time (time permitting) but if you must flip use these

They’ll minimize sticking.

Not the answer you’re looking for? Browse other questions tagged wood woodworking polyurethane or ask your own question.


Hot Network Questions

To subscribe to this RSS feed, copy and paste this URL into your RSS reader.

  • Blog
  • Facebook
  • Twitter
  • LinkedIn
  • Instagram

Site design / logo © 2022 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2022.5.17.42149

By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy.

In order to apply the sprayed polyurethane foam correctly, we should take a series of factors into account, ranging from atmospheric conditions to different types of of substrate and their temperature and water content.

Surfaces must be clean, dry and free of dust and grease to ensure the good adhesion of polyurethane foam to the substrate; if the substrate is metallic, the surfaces must also be free of rust. To ensure good adhesion on metallic substrates, it is recommended to use a suitable primer. The recommended minimum temperature of the substrate during spraying is 5ºC.

The coating thickness is perfectly controllable and can be modified by altering the application speed and/or mixing chamber of the gun. It should be noted that the lower the number of layers applied to achieve a certain thickness, will achieve a higher density foam, achieving better thermal properties. When applying a very large thickness, the applicator must apply in thinner layers rather than one thick layer, and must allow time for the spray foam applied to cool between adding each layer to prevent high exothermic reactions, which would influence the quality of the foam. The information on maximum thickness per layer is in the TDS (Technical Data Sheet) for that product.

How to apply polyurethane

UV protection

Sprayed polyurethane foam applied in situ has an excellent behaviour against atmospheric agents (water, extreme temperatures, wind, . ). It is only attacked by long-term exposure to ultraviolet radiation, contained, for example, in direct sunlight.

This attack causes the destruction of the polyurethane surface, resulting in a dusty appearance on the surface of the foam. This attack produces a decrease in thickness at a rate of 1 or 2 millimeters per year, depending on the combined effect of rain and wind, being lower during the first year thanks to the presence of the external skin of the foam, a layer of high density polyurethane.

To avoid this action, exterior applications must be coated with specific materials such as polyurethane elastomers, polyurethanes, paints or any other specific coating for exterior use. These protections, like any other material, must be monitored for their conservation and maintenance. In the case of partially degraded foams, sanitizing must be carried out by means of a barbed brush or water under pressure and the subsequent application of a new layer of polyurethane foam and the suitable surface protection.

How to apply polyurethane

Prevention of cracking by expansion joints

In the polyurethane foam that is directly applied on expansion joints, cracks may occur due to the movement of the substrate by expansion or contraction. This effect is especially important in decks or terraces where cracking can break the waterproofing. It is easily avoidable if, at the time of the application, the proper precautions are taken by treating the joint properly.

Although polyurethane foam does admit some permanent deformation, the stresses generated by the effects of expansion-contraction on very wide joints, from 2 to 4 cm, cannot be absorbed by the foam. The way in which these stresses can be absorbed is to distribute them, minimizing their effects, by installing an elastic separating membrane, for example, made of synthetic rubber with a width of 30 cm, and applying polyurethane on top of it.

Its time to finally finish up this dresser that we began painting weeks ago! In all actuality I painted it in 3 days but you are going to see the final results today! And I really cannot wait to share them with you! The final step to painting this dresser is adding the durable polyurethane top coat to finish it off. If you missed it this is part of my introduction to furniture painting series! You can start Here and link to each of the posts detailing the steps to get to this one!

Having worked with other polyurethane top coats in the past I admit that this step can be a little bit daunting! Without the right product and tools the last piece I painted which was a bedframe, ended up yellow and with lots of imperfections to the topcoat application. Streaky, brush steaks and drips that dried in place. The exact things I would have wanted to avoid to begin with. That being said I get it. Its not easy and it can be a pain in the butt to execute well!

That was about 5 years ago and there are some great products out there now that I think will give you a huge headstart from what I worked with then.

Disclaimer this post contains affiliate links.

Step One to Applying a Polyurethane Top Coat

Using a paint brush was my biggest mistake with my first polyurethane top coat application. DO NOT USE A BRUSH! You can solve the majority of polyurethane top coat applications by simply using a foam paint roller! I like to also follow up with a small foam paint brush so that I can easily get into the cracks and crevices and all the little details.

Having the right tools and products are going to be a game changer!

Also its important to note that polyurethane doesn’t come out of what ever you use to apply it with. That’s another reason I like foam rollers and foam paint brushes. They are inexpensive and I don’t have to feel bad about tossing them after I finish the polyurethane top coat.

Picking the Right Polyurethane Top Coat For Your Project

I can’t lie before I started painting furniture I didn’t even realize there was more than one option for polyurethane top coats. I just assumed it was a single product and that was it! Wrong! Then and even more now, there are quite a few different options for polyurethane top coats. I’ve been testing out new ones to see if they are better than ones I’ve used in the past and YES! they really are!

I decided that for this project I needed something very durable that could hold up to my 7 year old twin boys. This dresser is going to live in their room and they are rambunctious boys after all so It needed to be able to hold up to hot wheels, dinosaur travels and so much more! As I was in the hardware store looking for a polyurethane top coat I found this one on the shelf. It is a triple thick ultra durable Varathane poly top coat. It sounded like just the product for the job! I decided that it would be worth the gamble if it did what it said it would!

Review of the Triple Polyurethane Top Coat Used For This Dresser

It boasts that it applies 3 coats in one! and that it can withstand the heaviest traffic. The dresser is finished and has been in my boys room for about 4 weeks. I can attest that this is true! The first week one of my boys scribbled on the top with a pen #seriously. I was really surprised that even though the pen indention still remained the pen marks washed off, and the top coat stayed in tact! They have played on it as usual with their toys and it still looks as it did on day one! I am truly impressed!

It also applied in one coat very well I only added a second coat to just the top. I was worried that because it was “triple thick” it would be goopy and tough to work with and apply. Not the case at all It applied beautifully and evenly. Before the first coat dried down I could still see the roller strokes. Once it dried completely those pretty much disappeared as well.

The only thing I didn’t love about this product was even though I purchased the “matte” one it wasn’t truly matte. I would say its more of an eggshell/satin finish. That didn’t bother me for the dresser I used it on. However, if you’re looking for a product that is truly matte. THIS ONE is your guy!product that is truly matte. THIS ONE is your guy! I’ll talk more about it when I share the next project for this series!

Step Two

Now that you have your polyurethane top coat?your polyurethane top coat and tools your ready to begin! make sure you piece is nice and clean and dust free. If you don’t anything that’s on it will get trapped in this clear layer of polyurethane and will be frozen in time forever!

I like to start at the top and work my way down. That way if anything drips or spills I can see it and fix it as I work my way from one portion to the next.

I just dip my foam roller right into the can and start applying smooth even strokes. I also make sure to work quick so that the polyurethane top coat doesn’t begin to dry as I apply it. Top coats have a tendency to dry quick! So quick but smooth strokes are key.

I like to work on one area finish it and move on to the next. If I have a surface like the sides that have more details its time to pull out the foam paint brush. I apply the polyurethane top coat using the foam paint brush where the roller wont reach. Then I go back and roll it out with the roller so the consistency is the same.

Step three

Let it dry! This product dried down very quickly and like I said really had great coverage. For added protection I added a second coat just to the top.

Step Four

That’s it!! Once the polyurethane top coats dried its done!

Here is also a quick picture of the contrast between the areas that have the polyurethane top coat vs. those that don’t. It really enhances the paint.

I add my hardware back on and moved it inside and let me tell you I love it! If you missed the before head over to THIS post!?

Thank you for joining me as I painted this dresser from start to finish! If you are looking for more furniture painting tutorials don’t worry! I’ll be back next week to start on a second piece using milk paint! One of my all time favorite products! I can’t wait to show you! Thanks again for stopping by!

Wondering what kind of polyurethane sealant is right for your project? We’ll explain the difference between sealant and adhesive, how to apply it and direct you to the best polyurethane caulk for heavy-duty structural jobs.

  • What is polyurethane sealant?
  • Are polyurethane sealants the same as PL adhesives?
  • How to apply polyurethane sealant.
  • The best polyurethane caulk for structural applications.

What is polyurethane sealant?

Polyurethane sealers are flexible and versatile construction sealants appropriate for a number of surfaces like wood, metal, plastic, masonry, aluminum, stucco and much more. They’re water tight and flexible under any weather condition, making them perfect for sealing gaps and joints on the exterior of structures.

Are polyurethane sealants the same as PL adhesives?

While polyurethane sealants have some of the same properties as their adhesive counterpart, they are not the same and shouldn’t be used for the same applications. Polyurethane adhesives are specifically designed to provide load bearing strength to structures. Whereas polyurethane sealants are very flexible and intended to provide air and water-tight seals.

How to apply polyurethane sealant.

Applying polyurethane sealant is simple with the right tools. Here’s what you’ll need, and how to do it.

  • A caulk gun
  • Utility knife
  • Polyurethane sealant cartridge
  • A compatible smoothing agent
  1. Cut the application tip to the desired bead size.
  2. Puncture the cartridge and insert it into the caulk gun.
  3. Prime the cartridge and do a test stream on a disposable surface to make sure the bead size is correct.
  4. Apply sealant according to the manufacturer’s instructions.
  5. Apply smoothing agent according to the manufacturer’s instructions.

Prepare your surfaces: For achieving the strongest seal, surfaces will need to be free from dust, grime, grease, rust and brittle paint. Concrete should be scrubbed with a wire brush, and rust should be removed from metals. Joints deeper than 0.5 inches might need a backer rod. Different surfaces will require different preparation such as using a primer, so check individual product instructions for details.

The best polyurethane caulk for structural applications.

Loctite has designed a number of polyurethane sealants that are suited for any outdoor structural application.

If you’re sealing gaps around windows, doors, siding, garage framing, fascia and sill plates, pick up Loctite PL S40 Polyurethane Window, Door & Siding Sealant. This permanent and flexible polyurethane caulk sealant is tear-resistant and will not lose its function when exposed to UV rays. It’s water proof, paintable and compatible with all common construction materials.

If you’re working on a roof, reach for Loctite PL S30 Roof & Flashing Polyurethane Sealant. This professional grade sealant complies with Federal & State Regulatory Requirements, and provides extra protection against corrosion. Its non-sag formula makes it perfect for sealing flashing around roof edging and chimneys, and is perfect for shingle tabbing.

We don’t stop there:

Check out Loctite’s full range of polyurethane sealants and construction adhesives.

I have built a set of free standing pantries. Each is about 3′ wide, 2 feet deep and 6′ tall made out of a combination of 3/4″ maple plywood and maple hardwood. I have them all stained and they look good, but I am concerned about applying the polyurethane on the interior and exterior vertical surfaces. Applying it on flat surfaces is enough of a hassle and wee bit of a chore to do it without creating bubbles. Looking for suggestions as to specifics for applying poly on a vertical surface. I’d rather not lay the things down and run the risk of scratches.

How to apply polyurethane

2 Answers 2

Preventing runs is as easy as following one simple approach: Start heavy, finish light.

What that means is that you immerse your brush to maybe inch of depth, scrape off one side on the can, and apply the remaining product load to the project in a new area adjacent to the previous work. The idea of “starting heavy” is that you apply enough product to thoroughly coat and fill the texture of the surface.

You then brush to distribute that load, working it outward until you achieve a uniform film that’s blended with the previous area. This will not run. Finish with long strokes parallel to the grain. Do not work the finish so long that it begins to dry and get tacky.

With a bit of practice you’ll be able to apply a uniform, drip-free coat to surfaces at any angle.

I’m finishing a very rough piece of scrap wood for use as a tabletop and to practice applying polyurethane. I’ve since found that the holes and gaps aren’t really “filled” by the material and that I should have used wood putty first.

I’ve already applied multiple coats of polyurethane. How can I address the surface to smooth out the gaps, gouges, deep scratches, and holes, before applying another coat?

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

2 Answers 2

Apply several coats of polyurethane in the recessed areas, using a small brush.

It will take you an obscene amount of time because you will have to wait for it to cure between coats. You will need to sand it back some between coats. Then when you are done, you will have to sand some of it to match the surface transition over the gaps. The final result should look good, though: it will have a transparent, epoxy-like finish.

This is a good example of why the unevenness should be addressed before applying the finish, much like how you want to put body filler on panels and sand them smooth before applying the paint, because paint does not fill holes very well (too thin).

Keep in mind that around the longer gaps, the height of the surface on either side of the gap might not be the same. Use a straightedge to quickly check for flatness across the gap.

Alternately, you can sand off some of the finish in the gaps and fill with colored epoxy or plain wood filler. You will not have to put as many coats to achieve desired flatness.

You should look up two-part Polly And if I had the peace do you have I would seal up the bottom side of the larger holes and divots ( if they go all the way through) with tape then fill to desired height with a clear epoxy something that cures rather quickly . then drop some small bits of turquoise in or some other rare Stone ( to take up space and accent that spot)and then two-part poly over the entire deal. Then sand smooth _ I don’t recommend that you completely frame in your work piece but it would help to make a perfectly level end piece. If that’s what your after . After sanding flat no more dimples holes or blemishes. You will have to put a very light last coat to bring it back to glass smooth. I would not waste my time trying to make it glass Moon from sanding paper. It takes forever I’ve used quite a bit of polishing agents polishing compounds buffing compounds sandpaper down to 5000 wet . Still never brought it all the way back to perfect.

Two-part poly tips Make sure you put something under the piece to collect the drip. it will drip . When mixing two-part polyurethane mix it slow to avoid creating bubbles After pouring use a torch to pop any bubbles that you did , Make sure you do not overheat or cook the poly. it will happen shortly after it starts to smoke if you keep the flame on it Don’t mix up more than you’ll use ,, do not try to save it Use xylene to thin out Use acetone to clean

PS This is the first, I’ve ever commented to anything on the internet ever. So if I’m doing this wrong🤔 please disregard🤓👍 and have a good rest of your evening😁

Introduction: DIY Wipe on Polyurethane

How to apply polyurethane

How to apply polyurethane

How to apply polyurethane

In this Instructable I’ll teach you how to easily mix your own wipe on polyurethane. It will not only save you some money, but you’ll also be able to get the exact mixture you’re looking for in order to achieve a perfect finish

1. Oil based polyurethane (in the gloss of your choice)
2. Mineral spirits
3. Glass mason jar for storage
4. Something to measure with (I used a solo cup)

Step 1: Identifying the Proper Polyurethane

In order for this finish to work properly you need to use the proper polyurethane. You’ll want to use OIL based polyurethane, not WATER based polyurethane. Water based polyurethane will not thin with mineral spirits.

There are a couple ways to identify whether or not you’ve got water based or oil based polyurethane.
1. read the back label and it should tell you
2. the look of the polyurethane itself

If your label doesn’t indicate the type of polyurethane it’s easily identifiable just by the way it looks. Oil based polyurethane will be semi transparent and have an amber color to it. Water based polyurethane is white and milky.

Step 2: Mix Up the Wipe on Polyurethane

Start by mixing up your polyurethane with a stir stick, making sure everything is combined and mixed evenly.

After mixing up the polyurethane measure out the amount you need. Since this process is so fast I like to mix mine as needed. I used a solo cup to measure mine because it has a lot of lines that make it easier for measuring. After filling it to a specific line remembering it pour it in to your glass jar.

The best mixture to start off with is 50/50 see how it goes, and adjust as needed. More mineral spirits for a thinner mix, less mineral spirits for a thicker mix.

After dumping your polyurethane in to the glass jar, measure out your mineral spirits by filling it up to the same line in your solo cup. Pour the mineral spirits in to the jar with the polyurethane, put the lid on, give it a good shake, and it’ ready to use.

Step 3: Label Your Mixture

If I end up with leftovers after the job I like to label the mixture. Sometimes I’ll have multiple jars of different finishes so it’s important to keep track of what is what.

I like to put a piece of painters tape on top of the jar and write on that so I don’t write on the actual top of the jar.

I’ll label it with the type of gloss I used and the mixture of polyurethane to mineral spirits.

Thanks for checking out my Instructable! If you’d like more info on this check out the video I did on it and please consider subscribing to my youtube channel. Thanks!

Be the First to Share

Did you make this project? Share it with us!

Repainting the furniture in your house can be such a hassle, especially when it keeps fading, peeling, and chipping away. Not only that it will tire you out eventually, but you’ll also spend a large number of unnecessary expenses just to fix the paint.

Hence, having a nice, long-lasting paint coating is essential to ensure the quality of your furniture. Polyurethane is a great example if you want to protect your paint from dirt and peel. One or two layers of polyurethane will last a long way, and you’ll definitely be grateful for how much money and time you can save.

The question is, can you put polyurethane over paint? What kind of paint is suitable for polyurethane, and what is the best method to apply it?

Worry no more! To help you, here’s a foolproof introduction to polyurethane and the best practices to use it. How to apply

What is polyurethane?

Known for its reputation as being durable, resilient, and flexible, polyurethane is a polymer that can be used on many different surfaces as well as to create many different things. While the term might be unfamiliar for most people, we actually often come across polyurethane in the forms of sponges, spandex, and skateboard wheels, to name a few.

Polyurethane also acts as an excellent coating for furniture to ensure its quality through the years. The reason is that polyurethane doesn’t rust and mold. It is also able to handle extreme temperatures and has a longer lifespan in comparison to foam, paint, or rubber.

Consequently, once you apply polyurethane to your furniture, it’ll protect your paint from chipping and fading away due to rain, dirt, mold, or sun exposure.

Can you put polyurethane over the paint?

While polyurethane is undoubtedly beneficial for your furniture, many people still ask “can you put polyurethane over paint?”

Fortunately, the answer is yes. You can put polyurethane finish to coat any surfaces as long as it has been dried and prepared. Moreover, polyurethane also needs to be applied correctly for the best result. Different surfaces might require different types of polyurethane, so make sure to note what material and paint you want to coat before applying the polyurethane.

Different types of polyurethane

Generally, there are two types of polyurethane coating: oil-based polyurethane and water-based polyurethane.

Water-based polyurethane is most often used by homeowners as it doesn’t yellow much as the oil-based polyurethane one. Water-based polyurethane also dries quicker, produces less odor, and once it dries, the color clears up and won’t affect the original paint color.

On the other hand, while oil-based polyurethane is less quick to dry, it provides a stronger finish and has higher durability to UV and heat exposure. The downside of oil-based polyurethane is that it leaves a yellow undertone which might affect the overall color of the original paint.

What kind of paint you can put over the polyurethane-coated surfaces?

To put it simply, you can use polyurethane to any surface as long as it’s been prepped and treated accordingly. However, there are several types of paint that are best fit for polyurethane, some of which are:

1. Acrylic Latex Paint

Regarded as the best-quality latex paint, acrylic latex paint is water-based paint consisting of synthetic polymer or plastic as its base. Acrylic latex paint is also superior to basic oil-based paint as it lasts longer, has higher breathability, flexibility, and opacity. Not to mention that acrylic latex paint is also easier to wash and clean from surfaces.

2. Oil-based Enamel Paint

Oil-based enamel paint can be your best pick if you’re looking for a surface that will endure a lot of duress. The paint is less long to dry, but it has excellent resistance to outer forces including abrasion and tear. Moreover, oil-based enamel paint is also superior if you’re looking for a gloss or smooth finish.

How to apply polyurethane over paint

While the answer to “can you put polyurethane over paint?” is a big yes, there are some steps that you need to undergo before applying polyurethane over any surface. These steps are required to ensure the result of the coating and the paint underneath it.

1. Wash the surface

Polyurethane won’t stick to a dirty surface. Hence, make sure to wash away stains, mud, dirt, and any other filth before applying your first layer of polyurethane.

For a maximum result, wash the surface using detergent, warm water, and a sponge. A clean surface will increase polyurethane adhesion as well as glossing the result.

2. Sand away the surface

Once the surface is clean, let’s start the second step by picking 120-grit sandpaper and scuffing the surface. The scuffing step is important as it prevents deep scratches from forming on the surface.

After you’re done scuffing, don’t forget to clean the dust before moving on to the next step.

3. Choose the applicator

Whether it’s oil-based or water-based, each polyurethane paint has a different method to apply it. The best way to apply polyurethane is by using a brush or sprayer. Never use a roller as it leaves a bubble on the surface, making it look messy.

If you’re using a sprayer, leave out the thinner since an overly thin polyurethane will end up running away from the paint.

4. Apply the first coat

Apply the first coat and let the polyurethane dry according to the time listed on the container. Once the paint has dried, scuff it again with 120-grit sandpaper to remove bubbles and dust particles that may get caught during the process.

5. Apply the second coat

Once the surface is ready, apply the second coat and wait for it to dry completely. Usually, it’ll only need two coats, but it may vary depending on the paint and furniture.

Your paint is now perfectly secured with polyurethane and you’re ready to go!


The next time you ask “can you put polyurethane over paint?”, the answer is a big yes. Polyurethane is a great way to protect and ensure the quality of your furniture. It is durable, flexible, and resilient to abrasion, heat, and wear. Additionally, it’s easy to clean and you won’t need to make unnecessary expenses just to fix the dirt, chip, or fade on your household items.

Many outdoor projects require the use of an adhesive or glue. Outdoor weather conditions in North America are extremely varied from north to south and east to west. Your outdoor project can be exposed to torrential rains, high humidity levels, excessive temperatures, very low temperatures, dramatic temperature swings and very dry periods.

Figure 1 – Polyurethane glue

Polyurethane glue, as shown in Figure 1, is one of the few adhesives that can withstand the extreme North American weather conditions. Its application is somewhat different to most adhesives.

Most home handymen are familiar with the common use of polyurethane, that being as a finish that is applied to wood both outdoors and indoors. Polyurethane glue has no relationship to the polyurethane finishes. Unlike many of the outdoor adhesives which are two parts and require that they be mixed together; polyurethane glue is a homogeneous product that is not mixed with other products.

Using polyurethane glue

If you have not worked with polyurethane glue you may be somewhat surprised to learn that its method of curing is quite different from its outdoor adhesive competitors. Most adhesives cure by evaporation or chemical reaction. Polyurethane glue, on the other hand, reacts with the moisture that is in the wood.

Polyurethane glues will bond wood, glass, ceramics, metal, stone and most rigid plastics.

Because the polyurethane glue reacts with the moisture in the wood, it is important to ensure that the wood has enough moisture within it to actually allow the polyurethane glue to cure.

How to make good polyurethane glue joints:

  1. Use a misting spray of water on one of the pieces of wood that is being joined. This will ensure that there is enough moisture to allow the polyurethane glue to cure properly.
  2. Apply the polyurethane glue to the other piece of wood, the one that wasn’t missed. Use a scrapper or spreader to coat the polyurethane glue over the entire surface of the wood. Unlike other adhesives where you want to make sure that you have a lot of glue on the surfaces, you only need a very thin coating of the polyurethane glue to obtain a very strong joint. Similar to applying contact cement, although you only apply the glue to one side, not both.
  3. Mate the two surfaces to be joined together, square the joined wood and apply clamps. One of the advantages to polyurethane glue is the working time. Polyurethane glue is a relatively slow curing adhesive; you have at least 15 minutes to properly align the pieces of wood being glued together before the adhesive begins to cure.
  4. Leave the pieces of wood clamped together for at least 5 hours.
  5. When you clamp the pieces of wood together a foam like substance will ooze from the joints. This is common with polyurethane glue and should not be wiped off until the clamps are removed. The glue that comes out of the joint is easier to remove once it has cured. Use sandpaper or a cabinet scraper. You will find that the excess glue does not become rock hard like other glues making it difficult to remove.

Shelf life of polyurethane glue

If there is one disadvantage to using polyurethane glue it is its shelf life. Depending on the environment that the glue is stored in the maximum shelf life of a container of polyurethane glue that has been opened is a maximum of six months and under certain conditions it may not be usable after as little as a month.

From an economic standpoint, as polyurethane glue is more expensive than other adhesives, it is best to purchase just enough glue for the project that you are working on.

Safety issues of polyurethane glue

Polyurethane glue contains isocyanates so it is important to work in a very well ventilated area or use a resperator when working with this adhesive.

As the polyurethane glue reacts when it is in contact with moisture it will react to the moisture on your skin. When working with polyurethane glues, safety glasses and plastic gloves are highly recommended.

Selection of polyurethane glues

The website is 100% free. If you click on an ad or link we may receive a fee or a commission if you purchase an item.

How to apply polyurethane

Stickers are designed to be long lasting, but sometimes you want to give them that extra bit of protection. You can put polyurethane over your stickers, but be careful how you do it. Some surfaces react to polyurethane differently to others and you may end up damaging your sticker.

Why Would You Polyurethane Over Stickers?

Given the life span of most adhesive vinyls, many people don’t see the need to add a coat of polyurethane to seal them. Others like to coat their sticker to make them more permanent. Whether you add it to your sticker is entirely your own opinion, but before you do, there are a few things you should consider.

  • Adding a coating of polyurethane makes your sticker more permanent. If you are making a bench or box for a special occasion, you may want to protect your sticker so it doesn’t wear off. If you’re making something like a house sign or wall decal, you may at some point want to change it and adding polyurethane makes it a whole lot harder to remove the old sticker.
  • If you want to waterproof your item, polyurethane won’t do this. Stickers designed to go outside are already waterproof and will last several years. If your sticker starts to show signs of wear and tear, you can easily print another to replace it.
  • Don’t use an oil based polyurethane. This can damage the surface of your sticker. A water based one is preferable.
  • Don’t be tempted to use an adhesive designed for inside the home as an outdoor sticker if you intend to add polyurethane. The vinyl still needs the additional adhesive which outdoors stickers have.
  • Polyurethane will work better on some surfaces than it will on others so always test it on the material you will be working on first. Ideally, print off a smaller vinyl and apply this to your surface and add the polyurethane. Before working on your actual project leave your test piece to dry completely and then check that your vinyl is still intact and that it is not peeling off the surface.
  • If you are applying your vinyl to wood, you may wish to stain the wood first. If you do, add a coat of polyurethane on top of the stain before you apply the sticker, as the wood stain can affect how well the sticker adheres to the wood.
  • Adding polyurethane to wood may seal the sticker, but over time you may still find that it starts to come unstuck. Water will soak through the polyurethane in to the wood and if it runs along a seam, it could get underneath your sticker and loosen it.
  • If you are applying a wall decal, only use a light coating of polyurethane. Wall surfaces can absorb some of the polyurethane and this can actually cause the sticker to start to peel off.

How to apply polyurethane

Applying Polyurethane To Stickers

To get the best result, use the right vinyl for your job and print it in the same way. When working with polyurethane, always make sure the room is well ventilated as it can give off harmful fumes.

    Before you do anything, make sure the surface you are working on is clean and dry. Use a dry or damp cloth to wipe it down and wait until it has dried out. If you’re working with wood, sand it down before you apply your sticker. The smooth surface means your sticker will be easier to apply and the adhesive has a better surface to stick to. Wipe down your sticker to remove any dust or dirt and then apply it to your surface. Prepare your polyurethane. Refer carefully to the instructions given. Before you apply it, wipe your vinyl again to make sure it is dust free. Carefully brush the polyurethane over the vinyl. Use smooth brush strokes and then leave it to dry. This can take up to an hour. When it has dried, feel around the edges of the vinyl. If you can still feel the edges, apply another coat of polyurethane.

If you use the right vinyl for each project and follow the instructions, you should never need to cover your stickers with anything.

While vinyls are always sold with a projected lifespan, many vinyls last a lot longer than this and if they are uncoated you can always replace them with a different design if you want one.

Thread Tools
  • Show Printable Version
  • Email this Page…
  • Rate This Thread
    • Linear Mode
    • Switch to Hybrid Mode
    • Switch to Threaded Mode
  • Using Polyurethane 1 hour after staining.

    I am staining some spruce with Minwax Oilbased Dark Walnut Stain. I initially use wood conditioner, then I apply the stain. After 10 minutes I wipe of the excess stain. I was just wondering, if I don’t want to apply a second coat of stain, do I really need to wait 8 hours to apply polyurethene over top of the stain? Can I put oil based polyurethane right after I wipe of the excess stain?

    No. it will likely cause drying problems.

    IIRC Minwax stains also have some type of sealants in them, so they need to dry fully first. Otherwise when you start brushing poly you might brush the stain around as well.

    Although I’ve gone right from stain to applying poly finish – with no drying time in between, and, never had a problem – – both with oil based poly and water based poly (yes – WB poly over wet oil stain).

    Listen to the other two posters above.

    I only did it – well – -because I was rushed & willing to risk disaster. I was also ready to take all the blame for it had something bad happened.

    I never had a problem doing it – but – – that means exactly nothing.
    Guys also stop and bend their elbow a bit too much on their way home on Friday night, then get behind the wheel and weave their way home – – and nothing bad ever happens to them either.

    Doesn’t make either right .

    If your stain is not fully dry, you run the risk of your first coat of finish not drying for days. Wait at least the amount of time recommended or more if the temp is low or the humidity is high.

    The first coat of finish does not bond to stained wood well if it’s applied to soon after the wood is stained. If the finish does not bond well in the beginning, it will never bond well. I see this happen too often on floors. I put rosin paper down to protect floors (done more than couple weeks, months or even years ago) where I work and secure it with blue painter’s tape. Pull the tape up at end of day (just one day) and I peel off the finish floor the stained floor. Sure, everything looks great until. the damn tape.

    I did do a test quite a whiles ago on a sample. Applying finish too soon after staining and the tape test tells the tales.

    Last edited by Bill Orbine; 11-08-2015 at 8:35 PM .

    On an “open grain” wood like oaks, walnut, etc., the poly will want to “pull” the stain out of any reservoirs of stain (the open pores). You will see it bleed out and float in the poly or lacquer. You may be able to seal with light dust coats, or with shellac. But otherwise I can almost guarantee the effect will not be that you desire.

    Sometimes on the web a whole chorus of people keep repeating the same information and it turns out to be false. This isn’t one of those times. Don’t rush the dry times on the stain, it will not benefit you in any way. Exercise patience and follow the schedule. And the “suggestion” on the can is under ideal conditions of temperature, humidity and air movement. The real test. if you can smell solvent it ain’t ready. With minwax that might be 8 hours, it might be 2 days. Minimax stains are formulated to work well under certain conditions, large scale flooring projects, slow moving DIY’rs. Its got a lot of binder in it so it doesn’t blotch as easily or dry out too fast and leave streaks, witness lines etc, the color is more even, but also more muddy IMO than some others. You can flood the surface, take your time, wipe it off, repeat as desired. Down side is it dries real slow.

    If you cover uncured stain with a top coat, and that top coat skins over and flashes off to form a coating, it will trap the stains unflashed slow drying solvents beneath its skin. These will keep trying to get out, possibly breaking the bond between wood and finish. Minwax has enough binder in it to nearly be called a sealer, you need to let that dry. There are stains that dry much faster, NGR’s both alcohol and lacquer based, water based stains and dyes, metal acid dyes in a solved formula, but you will find these much more difficult to apply if you are accustomed to minwax products. The finisher where I work detests minwax, he’s got far too much time pressure to wait for that, and not enough space to to let things cure for days with stain, so we don’t use it much. But I’ve used it plenty in the past. The other problem is the solved in the poly can interact with and lift the color from the stain, reactivate the uncured stain. You stand less chance of this if the top coat has a different solved than the stain, but in many cases you still need to respect the dry times required. Water based coatings don’t adhere well to uncured oil based stain.

    I’d encourage to to structure your production to work within the finishing schedules requirements, its no place cut corners.