Polyurethane is a special kind of varnish where the resin molecules in their minuscule chains bond tightly as they start to dry. Hence, it’s able to give superior protection and help to make your woodworks last for a very long time.
Polyurethane is preferred for ordinary varnishes because it protects the surface against abrasion, effects of impact and solvents, and keeps water away so that it doesn’t damage the wood grain in your prized family heirloom.
To get the most out of such a versatile varnish, you need the best brush for polyurethane. But how would you know which is the right one for you with so many brands flooding the market?
This is where this post comes into play. It has all the answers and relevant information regarding polyurethane brushes so that you are armed with the right knowledge before jumping into the purchase stage.
Without further ado, let’s find out what makes the perfect polyurethane brushes for your particular project.
Pro Grade 5 Ea - Paint Brush Set
5 out of 5
5 out of 5
Purdy 140853100 XL
4.5 out of 5
Presa Premium Paint Brushes Set
4 out of 5
Hiltex 00308 Paint Stain Varnish Brush Set
4.5 out of 5
Why Do You Need To Use Brushes For Polyurethane Application?
A brush is a means to transfer the polyurethane from the container to the desired surface. You need a brush basically for this purpose. Other than that, poly brushes provide some more benefits:
1. It enables you to reach properly into nooks, crannies, carvings, and detail work more effectively than a cloth or a spray.
2. A brush is a right tool for giving long and straight strokes to get a smooth finish. Plus, you won’t get bubbles on the surface either with a brush. Also, there’s no danger of leaving marks on the surface if you’re using the best polyurethane brush.
3. Polyurethane brushes also last longer than foam brushes if the bristles are of high quality. These won't dissolve in thinners or mineral spirits that oil-based polyurethane contains.
Therefore, you need to use brushes for polyurethane because they can give a smooth finish without bubbles, they are durable, and they are effective in painting hard to reach tight spaces.
Top 10 Best Brush for Polyurethane In 2020
1. Pro Grade 5 Ea - Paint Brush Set
For all small, medium, large, detailed, or flat swathes, this package contains 5 flat and angled brushes for polyurethane application.
These durable brushes are made from good quality materials to give you value for money and therefore you can repeat use these.
Besides using these brushes for polyurethane, you can use these to apply stains and paints, making these versatile and multipurpose. Protect your fences and decks with the help of these. Also suitable for crafts and arts projects, you can paint tricky nooks and corners easily with these.
To further seal the durability of these brushes, they are held together by a stainless steel ferrule. It not only keeps the bristles in place but also lasts longer as it’s resistant to rust and corrosion.
Don’t worry about bruised and callused hands as the handle is made from a smooth hardwood to provide you with both comfort and control. You would be left wondering where all the time went while you were engrossed in varnishing!
Save time by using these brushes with synthetic bristles. They are medium stiff and thick to allow you to hold more paint, hence saving time by completing projects faster. In addition, the special design of the bristles helps to achieve a satin-smooth finish.
As you might need to polish and protect wooden antiques with intricate carvings, the angled brushes with a thinner tip are perfect for trims and detail work. With the angled style, you get more precision and control. On top, you will not see any brush marks on the coats.
With only a few bristles coming off when cleaning, this kit is a steal. The brushes are easy to clean with water.
- A kit of 5 paintbrushes for all sizes of painting projects.
- Handle made from hardwood for comfort and control.
- Efficient and time-saving.
- Synthetic and thick bristles, medium-stiff for holding more polyurethane.
- Top grade stainless steel anti-rust ferrule.
- Paint Brush Set Includes 1 Ea of 1" Flat, 1-1/2" Angle, 2" Stubby Angle, 2" Flat & 2-1/2" Angle
- Paint Brushes For Interior Or Exterior Projects. Use Angle Sash Paint Brush For Cutting Crisp Lines.
- Professional Results On Walls, Trim, Cabinets, Doors, Fences, Decks, Touch Ups, Arts And Crafts.
- Premium Quality Paint Brushes At A Cheap Price! No Cardboard Covers Come With This Set.
2. Wooster Q3211-2 Shortcut Angle Sash Paintbrush
When challenged with painting detail work and trims with polyurethane, this brush can’t be beaten with its combination of style and design!
Its exclusive Shergrip handle is 2-1/4th inches long so that you have more control when coating tight spaces. The short handle is paired with a full-size brush head so that you get more coverage more smoothly without losing your grip or control.
Thanks to the soft, rubbery feel of the Shergrip handle made from an elastomeric material, the comfy grip enables you to apply polyurethane with ease. In hot and humid climates, this special handle provides a non-slip grip as well to prevent spills and spoils.
With its anti-wrap, anti-crack, and anti-peel property, the handle resists the harsh effects of solvents found in polyurethane, making it the best brush for polyurethane. Moreover, the brass-plated steel ferrule ensures further durability and reusability by holding together all the bristles in place.
Suitable for both water-based and oil-based polyurethane, the bristles have been made from a special blend of gold polyester and white nylon. Their softness and thickness enable the brush to hold more polyurethane and release it evenly on the surface. The result is a smoother and faster job, saving you time and stress.
The clever combination of a full-size brush head and the short handle provides fuller coverage and smoother application. To maintain this brush for repeated use, clean after each use with a solution of soapy water. Rinse with clean water and store after drying by hanging it upside down to retain its shape.
- 2-1/4th inches long handle on a full-size brush head for hard-to-reach areas.
- The exclusive flexible and short Shergrip handle for comfort.
- More control and accuracy level with a non-slip grip.
- Soft and thick bristles made from a blend of gold polyester and white nylon.
- Efficient, time-saving, smoother finish.
- Flexible purple Shergrip handle that measurers only 2 Inches long that adds maneuverability in tight...
- White nylon and gold polyester blend for all paints
- Brass-plated steel ferrule
- Package designed to peg hook brush by the handle and illustrate proper holding position
3. Purdy 140853100 XL- Best Brush for Water Based Polyurethane
A combination of Dupont solid, round, and tapered Tynex plus orel bristles make this brush suitable to apply both water-based and oil-based polyurethane.
The pack of three contains XL brushes of size 1-inch, 1.5-inch, and 2-inch length. Their unique bristle blend makes them capable of holding more polyurethane so you take fewer trips to the container and complete your project faster.
This versatile set enables you to do all kinds of paint and varnish jobs as the brushes are apt for that. With a copper ferrule, the bristles are held in place and won’t lose their shape when you apply the polyurethane.
The various bush sizes and styles allow for both painting and varnishing on the walls and ceilings, as well as on more intricate carvings, trim, and detail work. Primers and stains can also be applied with these brushes.
The natural Alderwood hardwood handle is comfortable giving you the ease of varnishing for a long time. Moreover, its lightweight adds to comfort. The durable handle absorbs moisture, thereby keeping sweat off your hands, giving them a dry feel even on humid days. The non-slip handle is durable to boot.
With the internal chisel placed strategically, the brush releases the polyurethane evenly, hence resulting in smooth strokes, free from brush marks, and a great bubble-free finish.
The bolstered epoxy creates a buffer for the bristles so that they are rendered more durable.
These brushes adhere to the top standards as they are carefully crafted with only the finest materials and are handmade.
- Pack of 3 XL brushes for painting walls, ceilings, detail, and trim.
- A natural Alderwood handle for lightweight and comfortable use.
- Suitable for use with both oil- and water-based polyurethane.
- Internal chisel for a smooth release of polyurethane.
- Non-slip, durable, and anti-sweat handle.
- -3 piece value pack, includes 1 inch XL Dale, 1-1/2 inch XL Glide & 2 inch XL Sprig
- -Purdy's XL is the most versatile brush series,
- -Designed for use with all paints and stains.
- -Ideal for interior and exterior projects with all types of paints
4. Presa Premium Paint Brushes Set
You may be a DIY-er or an amateur in using polyurethane, but these brushes will make you feel accomplished like an expert!
These are professional-grade and premium quality brushes for applying polyurethane. The specialty of these brushes is their 30% more holding capacity. Hence, these make you more productive and help you get on and finish your work faster.
The solid round tapered (SRT) style filaments are especially suitable for holding more polyurethane. With the narrower and smaller diameter bristle tips and a gradually wider diameter as they proceed toward the ferrule, these brushes are perfect for giving you painting and varnishing mastery.
A flawless and even finish is what you strive for and you won’t be disappointed as the SRT technology helps to achieve just that on any surface. With an even polyurethane distribution on the bristles, the release is smooth, making the whole process easy as you have more control and can achieve accuracy.
Don’t fret about maintaining these brushes as these SRT bristles are effortless to clean after using. Use can use them for repeated use and they will still be durable. The bristles won’t come off during painting or cleaning, which is another reason they are popular among serious users.
A rough surface that needs painting or varnishing is always daunting but these brushes are so well-equipped that they make polyurethane applications on such surfaces a breeze. You will be surprised to see the same smooth finish as on other easier projects.
No matter the size or depth of the project, you can depend on these brushes for a professional finish.
- Superior quality, professional-grade, synthetic brushes.
- Holding capacity of 30% more for a faster job.
- SRT bristles hold and release polyurethane evenly.
- Durable filaments that can be cleaned easily.
- Suitable for a uniform finish even on rough surfaces.
- PREMIUM: Increase your productivity with thoughtfully constructed premium paint brushes for pros
- MORE PAINT: Blending the finest SRT filaments gives brushes up to 30% more paint holding capacity
- SMOOTH: The premium filaments provide a smooth, even release: more finesse and precision
- HEAVY-DUTY: Can withstand even the most abrasive surfaces for versatility and heavy-duty jobs
5. Hiltex 00308 Paint Stain Varnish Brush Set
Just noticed your coffee table needs a quick touch-up before the guests come over? Reach out for this set of 5 brushes for polyurethane that have been designed for quick varnishing jobs.
The various sizes – 1, 1.5, 2, 2.5 and 3 inches – make for the most versatile pack. Besides touchups on furniture, you can also do a great job on trims, cabinets, corners, windows, doors, and decks.
The tapered and flagged ends of the bristles enable you to hold more polyurethane and apply it evenly. Besides, the thick polyester bristles allow you to save time by helping you to finish a job quicker.
Grab the smaller brushes for painting thin lines on edges and even under the edges. Their narrow tips allow you to do so without any hassle as these can reach small spaces. You are always assured of an even finish as these brushes don’t leave any brush marks behind.
The light handles are manufactured from natural wood that makes them durable. The brushes are ideal for working with water-based polyurethane. The comfortable handle makes it easy to work on any size of a project as you can grip the brush suitably without getting your hands tired.
Besides interior and exterior use, these brushes are also great for craft projects. To keep them well-maintained, clean these after each use with a soapy water solution.
The polyester bristles can be cleaned quickly and with ease. They retain their shape naturally and you will find them the same even after multiple uses. Moreover, unlike other brands, these brushes don’t lose many bristles while being cleaned.
- 5 paintbrushes of mixed sizes suitable for trims and detail work.
- Reusable, effortless cleaning and upkeep.
- Thick and tapered polyester bristles greater holding capacity.
- Natural wood handles for comfort and control.
- A great choice for water-based polyurethane.
- Great value in quality paint brushes for work, home, arts and craft projects
- Includes brushes in most-popular widths for versatility, one each 1-Inch, 1-1/2-Inch, 2-Inch, 2-1/2-Inch...
- Polyester bristles with feathered ends have extra paint-holding capacity
- Sturdy natural wood handles, perfect for paint, stain and varnish
6. Wooster Q3108-2 Softip Paint Brush
A sure way to finish your woodwork varnishing projects faster and smoother is by using this special brush!
The fine tips of the bristles lay the polyurethane evenly so that you don’t need to go over the coats again and again. Hence, you can complete your work faster and get more satisfaction from that smooth finish that glows with warmth.
The bristles are a blend of white nylon and gold polyester. The fine and feathery filaments make it the best paint brush for polyurethane as they are durable, won’t bend out of shape, will not shed during painting or cleaning. Moreover, they do not leave brush strokes and mar the even surface.
You can use either water-based or oil-based polyurethane with this brush as it is compatible for use with both. This saves you from the headache of planning which type of varnish to use and to buy a suitable brush.
The brass-plated ferrule is sturdy and keeps the bristles in place so that you can apply polyurethane without worrying about losing the bristles in the container or on the surface.
The 4-inch pearl-yellow plastic Kaiser handle is short and makes it comfortable for use for larger projects or long working hours. You will also get more control over the strokes with this lightweight handle. The beavertail design of the handle also contributes to comfort and a firm grip.
With the right width of this brush, you can do a great job on intricate edges, corners, and carvings. Plus, the bristles hold up the polyurethane without causing drips and wastage.
- Soft, feathery, and fine polyester filaments for a perfect finish.
- Pearl-yellow beavertail plastic handle for comfort and grip.
- Brass-plated ferrule to hold all in place together.
- The right width of the 4-inch brush for painting trims, edges, and corners.
- Compatible with both water- and oil-based polyurethane.
- Soft brush tips provide a smooth and even finish with all latex and oil-based paints
- White nylon and gold polyester with chisel trim
- Brass-plated steel ferrule
- Pearl-yellow solid plastic Kaiser handle
7. Pro Grade - Chip Paint Brushes
If you don’t want to invest too much in a project where novices are involved, then this set of chip paintbrushes will give you what you’re looking for.
With 36 of these all-natural white Chinese bristled brushes, you can take care of a large project like a mural without thinking too much about taking care of the brush. These are one-time use and disposable so there’s no hassle of cleaning and maintenance for repeated use.
This versatile and utility 2-inch brush is the best brush for polycrylic. It can be used to apply glue, gesso, stains, varnishes, paints. Use it for teaching art and craft projects to amateurs or kids as you don’t need a high-end brush for this purpose. It can also be used for minor touch-up jobs.
The handle is durable and is made from advanced solid wood so that you can get the comfort and precision even though you might be working on a short-term project or one that does not need to look very professional.
With the tin ferrule nailed properly, the bristles stay in place while you are applying polyurethane. Perfect for doing those projects that generate a lot of mess which you don’t want to clean up, this set of brushes gives you the results without the hassle.
To get more from these brushes, users suggest to wrap them up in aluminum foil between each coat of polyurethane application. There are mixed reviews about the bristles coming off on the surface while varnishing.
All in all, these brushes give you value for money.
- Set of 36 brushes with all-natural white Chinese bristles.
- Disposable and low-maintenance for less hassle.
- Perfect for murals and other projects with amateurs.
- Advanced solid wood handle for comfort.
- 2-inch brushes suitable for applying glue, paints, polyurethane, stains, etc.
- 36 pack of 2" wide chip brushes is ideal for painting, staining, cleaning arts, crafts & more.
- These disposable brushes have 1-1/2" long all-natural china bristles and an all-square trim shape.
- The solid wood handles make these painting brushes durable for all kinds of home improvement tasks.
- These versatile utility brushes for painting are great for home, business, and industrial projects.
8. Wooster 3103-2 Foam King Brush
This foam brush for polyurethane is from the Special Use series of Wooster as some people prefer using a foam brush to complete varnishing or painting projects.
A few properties make this brush a really special one. Firstly, it has an open-cell polyurethane foam technology that allows it to hold more paint or polyurethane. This translates to faster project completion and therefore, more time on your hands.
Secondly, you get better coverage with the foam and that too saves time and polyurethane as you need fewer coats. The thickness of the foam and the beveled end design work in tandem to create smooth, uniform finishes. Last but not least, there are no brush marks on the surface as there are no bristles!
The built-in stiffener blade in the white plastic handle results in consistent flexing so that you have more control over the application. Also, the finish is much neater and speaks of more accurate strokes. The foam material matches the composition of the varnish.
Besides, it can also be used to apply stains, oil- and latex-based paints, chalk style enamels, polyacrylic, glue, crème wax, liquid wax, paste wax, and a whole range of other types of compounds.
Users swear by the product as they always get the same consistent and smooth results. Thanks to the smaller and consistent size of the foam and the compact foam formation on the brush. Also, they are not stiff like bristles but are soft, making it easy to use.
- 2-inch width foam brush for a no-brush marks finish.
- Beveled end design for a smooth finish.
- Suitable for all clear coats, paints, varnishes, and stains.
- Smooth and accurate strokes with a built-in stiffener blade.
- White plastic handle for comfort and durability.
- High-quality made in USA brushes for all paints as well as varnishes and stains
- Thick polyurethane foam for the smoothest no-brush marks finish
- White plastic handle with built-in stiffener blade for consistent flex and neat results
9. Minwax 427350008 Polyurethane 2" Bristle Blend Brush
If you have a lot of oil-based polyurethane in your stock and many projects to complete, try this brush for quicker and smoother results.
Made from natural bristles, this 2-inch width brush can hold and distribute oil-based paints smoothly, resulting in smooth and glass-like reflective finishes. The bristles absorb more polyurethane and therefore, you need fewer trips to the container and you can focus more on your project at hand.
It’s not recommended for use with water-based polyurethane as the bristles will absorb the water, making the brush go limp, out of shape, and hence, difficult to give smooth and long strokes.
The stainless steel ferrule is anti-rust and anti-corrosion, making it durable so that you can use it repeatedly. Before using this brush, it’s advised to dip it in mineral spirits as you will be using oil-based polyurethane. Then get rid of the dust and the excess solvent by brushing it out on a drop cloth or board.
You also need to fan a new brush to get rid of the loose bristles so that you won’t have these spoil your work.
Being best brush for oil based polyurethane by far, you can use it to preserve and protect your valuable family heirlooms and antiques like chests, tables, and other delicate wood projects.
It also works great when you are varnishing your cabinet doors as the brush enables you to reach the corners and edges with the polyurethane. With a brush edge shape that’s flat, you can work with it comfortably on all sizes and types of projects.
After use, clean with mineral spirits so that they last longer and continue to satisfy you.
- Natural bristles, 2-inch width brush for use with oil-based polyurethane.
- Smooth and reflective finishes each time.
- Thicker bristles for holding more polyurethane.
- Anti-rust stainless steel ferrule for durability.
- Recommended dipping in mineral spirits before and after use for cleaning.
- Designed with natural bristle for a smooth, glass like finish
- Natural bristle for increased absorption and hold of clear coatings
- Use with Minwax Polyurethane
- Excellent for all sheens
10. Magimate Paint Brushes Set
For all types of painting and staining projects conceivable, this set of 10 brushes will serve your purpose every time with efficiency.
These brushes for polyurethane application come in a pack of ten with five different sizes – ½-inch, 1-inch, 1.5-inch, 2-inch, and 3-inch. Hence, you can use these for all types of projects ranging from those that require long and straight brushstrokes to ones that require working around and on trims and edges.
With the thick polyester bristles, you get more holding power and smoother release so that the finish is consistently flawless and uniform. Plus, these enable you to complete projects quicker so that you can move on to the next one sooner.
Besides furniture and floor staining, you can use these brushes for exterior and interior painting as well as painting or varnishing decks and fences. The users of these brushes have praised them for their quality and that they don’t shed many bristles while painting or getting cleaned.
Moreover, you can use them with a variety of paints and stains including anti-rust paint, mixed paint, latex paint, as well as both oil- and water-based paints.
The bright green plastic handles are comfortable and give you a solid grip for more control and precise strokes. No matter if the surface is rough, semi-rough, or smooth, you can get the desired finish if you work with these brushes.
You get more value for money as the brushes come in different sizes and you don’t need to buy a new brush with each new project or even minor touch-ups.
- Set of 10 brushes with 5 sizes to tackle all project types and sizes.
- Thick brush head for holding more polyurethane and smooth release.
- Suitable for use with all types of paints and stains.
- Plastic handles afford a comfortable grip.
- Uniform results on rough, semi-rough, and smooth surfaces.
- 10 Pack 5 different Sizes of Paint Brushes for Flexible Use:1/2 inch, 1 inch, 1.5 inch, 2 inch and 3...
- Suitable for All Paints, Quick Release and Uniform Dispersion.
- Works well for Furniture, Wall, Fence Painting, Deck Staining, Interior and Exterior Painting Projects.
- Economical and Practical. Plastic Grips Comfortable to Hold.
Comparison Chart of Top 10 Polyurethane Brush
Number of Brushes
Comfortable grip with hardwood handle.
Wooster Brush Q3211-2 Shortcut Angle Sash Paintbrush
An exclusive Shergrip handle to varnish details.
Purdy 140853100 XL Brush
Suitable for both water- and oil-based polyurethane.
Presa Premium Paint Brushes Set
30% more holding capacity.
Hiltex 00308 Brush Paint Stain Varnish Set
Tapered bristle style for holding more paint.
Wooster Q3108-2 Softip Paintbrush
Soft tips for an ultra-smooth finish.
Pro Grade - Chip Paint Brushes
Wooster 3103-2 Foam King Paintbrush
No brushmarks finish.
Minwax 427350008 Polyurethane 2" Bristle Blend Brush
Suitable for oil-based polyurethane.
Magimate Paint Brushes Set
All sizes and styles.
How To Choose The Right Brush for Polyurethane?
Choosing the right poly brushes depends on the type of polyurethane you are going to use and a few other factors. Below is a breakdown of the buying guide so that you can make the right choice.
There are two basic types of bristles in a polyurethane brush – natural and synthetic.
Since water is absorbed by natural bristles and changes the shape of the brush, it’s recommended to use a natural polyurethane brush when you are using oil-based polyurethane.
For water-based polyurethane, synthetic brushes are recommended as they don’t bend out of shape and make it a hassle for smooth application.
Therefore, to pick the best brush to apply polyurethane, you must know the type of polyurethane you are going to use.
Style and Width
The next important factor to look at when shopping for a brush for polyurethane is the width and style of the brush. This depends on the scale of your project.
For large projects that need applications on a large area, a flat brush with a 4-inch length is ideal. But for projects that require trim and detail work, an angled brush with a 2-inch length is the right deal.
Make sure the brush you are eyeing has bristles that end in splits or are flagged in other words. Not only do these flagged ends hold more polyurethane and thus save time from frequent dipping, but they also leave a smooth finish.
Check the handle of the polyurethane applying brush as that may or may not give you comfort and ease to carry on your project without tiring your hands.
While a short and thick handle is good for handling trim and detail work varnishing, for larger projects that need bigger swathes, a well-contoured and long handle will give you the ultimate comfort and a firm grip.
This is the part that holds all the bristles together. Before buying the brush, tug the bristles gently to see if they come loose. If they don’t, then the ferrule is securely holding the bristles in place. Look for a stainless steel ferrule as that is resistant to corrosion and rust, hence it’s durable.
Tips on Using Polyurethane Brush
There are a few stages of using a polyurethane brush. These include a prepping stage, an application stage, and a post-application stage. Let’s look at each of these in detail.
1. The Prepping Stage
In this stage, you need to prepare the wooden surface where you will apply polyurethane. This involves ensuring the wood is clean and smooth. With 220-grit sandpaper, sand the wood surface. The sanding dust should be thoroughly removed using a vacuum or cloth before you apply each coat.
Just remember that the cloth to remove the sanding dust should be a cheesecloth one doused in denatured alcohol if you’re using a water-based polyurethane. In case you’re using oil-based polyurethane, dip the rag in mineral spirits.
Putting a wood grain filler before you apply the polyurethane is a good idea for wood types like ash, oak, and walnut. As these are open-grain woods, a filler helps to achieve a smooth polish.
2. The Application Stage
Stirring The Polyurethane
Do not shake the polyurethane can as this will cause bubbles to form and you won’t get a smooth finish. Always stir it slowly before you apply each coat. Make sure that the stirring is not a vigorous one.
Always choose a well-ventilated, indoor area for putting on coats of polyurethane. As both water-based and oil-based polyurethane give off fumes, the place should have proper ventilation.
Secondly, the place should be clean also so that dust, insects, or other elements can’t settle on the surface while it’s getting dried. Drying takes a few hours and care should be taken that unwanted elements do not stick on the surface.
Dipping The Bristles
Before you start using the polyurethane brush, to keep it easy for cleaning afterward, it’s a good idea to dip the bristles in mineral spirits if you’re using oil-based polyurethane or in water, if you’re using the water-based type. Roll the handle of the brush quickly to let the excess off before you start using it.
It’s better to apply the polyurethane in horizontal or flat strokes as this prevents drips and helps self-leveling to a great degree. However, if you must work on a vertical surface, it’s better to apply thin coats using a spray or a wipe-on.
Between each coat, sand out the runs and drip that may result from vertical application. You can also use a sharp razor blade for removing these and follow it up with sanding.
Always tap the brush for polyurethane application gently against the inside of the container after you have dipped one-third of it in the polyurethane. This will ensure you have the right amount of it on the bristles to get the right coat thickness.
Checking Work In Progress
To check if each coat has the effect as it should have, use a side-light to bounce off the surface. Kneel down and have the surface at your eye level to spot any parts lit up by the side-light that needs more attention. Bubbles, brush marks, and a light finish are some of the problems that the light will show.
Water-Based Polyurethane Application
If the surface had an oil-based stain, then you need to remove this using synthetic steel wool. As water and oil do not mix, this step will prevent the water-based polyurethane from forming beads on the surface.
Using a foam pad, cloth, or fine brush, apply a thin coat of the water-based polyurethane. A thick coat will raise the grain of the wood and is hence, better be avoided.
After the first coat dries within two hours, apply the second coat. If you wait for each coat to dry properly, you don’t need to sand between each application.
For projects that are not used heavily, you should apply at least three coats. For floors or other high-traffic areas that need more protection, aim to apply four coats for maximum effectiveness.
Oil-Based Polyurethane Application
You may need to use Naphtha or mineral spirits to thin out the oil-based polyurethane. This helps the substance to reach the carvings, nooks, and crannies easily.
Use a foam or a fine-bristled brush, preferably a natural one, to apply the oil-based polyurethane. A good quality bristle brush will permit penetration into fine details and edges which won’t be the case if you’re using a foam brush. The foam brush is okay for flat surfaces.
Apply the brushstrokes in a parallel way to the wood grain. Avoid using a very thick coat. Using straight and long strokes, try to flatten out the polyurethane so that no bubbles or brush marks remain.
Wait till the first coat is completely dry before you sand the surface lightly, keeping the strokes parallel to the wood grain. You could use 320-grit sandpaper for this purpose. Practice caution while sanding so that it doesn’t penetrate the thin coat and damage the stain or wood grain.
Before getting on the second coat, use a vacuum cleaner or a cloth to remove the sanding dust. Two coats of oil-based polyurethane are enough for the protection of most projects.
However, for floors and other surfaces that may be subject to moisture and more wear and tear, three coats are necessary.
Remember to sand the surface each time you apply subsequent coats.
Application With Spray And Wipe-on Polyurethanes
The spray and wipe-on methods of application allow for very thin coats of polyurethane to be applied. This is useful when you don’t want a build-up when applying on trim, crannies, and detail work. A lint-free cloth is used for the wipe-on type of application.
Both types produce a smooth, bubble-free, brushmark-free coat. These are used when varnishing vertical surfaces as there is a lower chance of drips and build-ups.
The downside of wipe-on and spray polyurethane application is that you will need five to six coats to reach the optimum level of protection.
3. The Post-Application Stage
After your final coat is dry, use a ball of steel wool to bring a smooth sheen on the surface. For a final glow, apply paste wax.
Frequently Asked Questions (FAQ)
1. What’s the Difference Between Oil-Based and Water-Based Polyurethane?
Answer: Apart from the obvious difference in composition – oil versus water – there are other differences between an oil-based and water-based polyurethane.
The oil-based type is easier to apply and since it contains more solids, it’s thicker and needs two to three coats of application.
However, oil-based polyurethane takes a longer time to dry. Plus, it’s more likely that there will be brush marks left behind.
Water-based polyurethane is more difficult to control and needs three to four applications. It can leave watermarks and also raises the wood grain. However, it dries faster than the oil-based kind, is easier to level, and doesn’t give out any odor.
2. Is It Okay to Use a Foam Brush for Polyurethane?
Answer: A foam brush is not recommended for use with polyurethane because it has a blade instead of bristles and this leaves parallel marks caused by the blunt sides of the foam brush. Thus, you don’t get a smooth finish with a foam brush.
Plus, the heads of the foam contain air that will leave bubbles on the coating.
3. Why are Brushes with Natural Bristles Recommended for Oil-Based Polyurethane?
Answer: Oil-based polyurethane contains minerals that do not get absorbed by the natural bristles and therefore, the brush retains its shape and you can varnish comfortably. With water-based polyurethane, the natural bristles absorb water, the brush goes limp, making it difficult to give a smooth sweep.
4. For Wood Projects, Should I use an Oil-Based or a Water-Based Polyurethane?
Answer: It depends on whether you want a warm glow added to the wood or you just want to retain the original wood color.
If the former, then use an oil-based polyurethane as it would leave an amber glow, especially on woods of lighter tone like birch, oak, or maple.
Although a water-based polyurethane looks milky, it gets clear as it dries and leaves only a clear and protective film.
There’s nothing more satisfying than polishing your wood projects and watch them glow with a sheen that promises of long-time protection. Polyurethane is the ideal varnish to guarantee that your precious possessions continue to be protected and stay beautiful.
With the best brush for polyurethane, you can be sure of doing a great job for yourself or others. It’s important to have a good quality brush so that you can apply polyurethane smoothly for a flawless finish. Just remember to choose the brush as per the polyurethane type – oil- or water-based.
By following some simple but effective tips on getting the right brush and using it to varnish your projects properly with polyurethane, you will become a pro in no time! You can indulge in DIY projects or have this as a side business if you have the right polyurethane brush that gives you comfort and control.