Can You Apply Polyurethane With A Rag?

Last Updated on May 5, 2023 by Ernest Godia

Cleaning up after a project can be such a hassle. After completing a project, your face lights up with a smile of satisfaction and contentment. That smile quickly disappears when you remember you have brushes to clean.

Manufacturers seem to understand woodworkers’ and DIYers’ pain by designing wipe-on stains and sealants. 

Can you apply polyurethane with a rag? Using a rag to apply polyurethane means you can dispose of the applicator after use instead of worrying about cleaning it.

Read along to learn whether you can apply polyurethane with a rag and how to go about it.

Can You Apply Polyurethane With A Rag?

Yes, applying polyurethane with a rag is quite simple. The trick is to use wipe-on poly or add mineral spirits to thin the brush-on polyurethane. Then, you must apply multiple coats because wipe-on polyurethane goes on thin, allowing each coat to dry thoroughly before recoating.

Use a clean, lint-free microfiber cloth, and do not saturate it with the sealant to avoid dripping. Three coats of your wipe-on poly should give the desired coverage and protection.

Can you apply polyurethane with a rag? Learn how.

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How To Apply Polyurethane With a Rag

You require no particular set of skills to apply polyurethane with a rag. Keenly follow the steps below for a successful project.

What you will need

  • Fine and coarse grit sandpaper
  • Wipe-on poly or oil-based polyurethane available in clear satin, semi-gloss, and gloss
  • A thinning agent like mineral spirits or turpentine and distilled water for water-based polyurethane
  • A lint-free rag or cloth
  • Rubber gloves
  • Foam brush
  • Drop cloth
  • Tack cloth
  • Clean container with seal

Applying Polyurethane With A Rag Step by Step 

Let’s dive into it:

STEP 1: Prepare your working space

Tape or spread a drop cloth to protect your work area from spillages and drips. The space also needs to be adequately ventilated, as polyurethane can have toxic fumes.

STEP 2: Sand the wood to smooth it

Sanding helps remove dents, cracks, and splinters on the wood surface. Start with a course-grade sanding piece like 100 or 120, and work toward 220 grit to smoothen the bare wood.

Also, consider the type of wood you are working on; for instance, fine sanding woods like maple or pine impairs its ability to take on the sealant.  

STEP3: Remove the sanding dust

Dust particles interfere with the adhesion of the sealant to the wood surface. Wipe off the dust with a tack cloth or vacuum it. Another alternative is to dampen a lint-free rag in mineral spirits and use it to dust off the surface.  

STEP 4: Stain the wood

If you desire to stain the wood, follow the manufacturer’s instructions.

STEP 5: Apply the first coat of polyurethane and let it dry

Mix the wipe-on polyurethane well using a wooden stirrer before using it. Next, pour out a portion of the sealant into the clean container, wear your pair of rubber gloves, and dip the lint-free rag inside it. 

Don’t let the cloth soak up too much of the poly; just a little will go a long way. You must apply thin coats.

In gentle circular-like motions, apply the wipe-on poly on the surface. Use even strokes, and don’t be afraid to overlap. However, wipe-on poly dries fast, so don’t go over the dry areas. You will fix any imperfections with a second coat.

If the wooden surface has corners go over those with a foam brush, as it can fit into the edges. That might also not be necessary as wipe-on polyurethane has a low viscosity and flows effortlessly right into the corners.  

STEP 6: Scuff sand the dry coat of poly with fine 320-grit sandpaper

Let the surface dry for at least two hours or so before attempting any sanding. For the finish not to fail, ensure the coat is dry. Expect weather conditions like temperature and humidity to affect the drying time.

Lightly sand the initial coat with 320 grit sandpaper.

STEP 7: Remove the sanding dust  

Clean the dust off with a tack cloth, vacuum, or lint-free rag damped in mineral spirits.

STEP 8: Apply the second coat of poly and let it dry 

Wipe on the second coat of polyurethane as you did the first and let it dry.

STEP 9: Scuff up the dry polyurethane surface and wipe the dust

Sand the second dry coat and wipe off the dust. Sanding between coats is essential as it affects the quality of your finish.

Here is what happens if you don’t sand between coats of polyurethane.

STEP 10: Wipe on the third/final coat of poly and let it dry

Apply the final coat of wipe-on polyurethane and let it dry. This time, do not sand the surface as you want it to retain its natural allure and plastic-like surface that protects the wood from moisture and other elements. 

Cover the container as you wait for the coats to dry to keep dust and other particles off the fresh poly.  

Can You Apply Brush-on Polyurethane With A Rag? 

Yes, it is possible. However, keep an open mind as there are numerous downsides you will encounter down this path. Some of them include the following:

  • Brush-on polyurethane has a high viscosity making it hard to apply thin and even coats with a rag
  • Rags create more streaks and bubbles compared to brushes, and stray specks are challenging to eliminate
  • It will take you twice as long when using a rag and considering you’ll need additional coats, which take even longer
  • Brush-on polyurethane is ideal for large wood surfaces, but using a rag is tedious. The rag will apply the product unevenly, creating undesirable patches over the surface
  • On vertical, edged, or contoured surfaces, rags will lose control over the sealant, and specific points will receive more product than others

While at it, remember not to shake the brush- on polyurethane, as that creates air bubbles within the container.

Tips for success when applying brush-on poly with a rag

If you have your mind set on applying the brush-on polyurethane with a rag, here are some tips for a successful finish:

  • Thin out the polyurethane by mixing it with mineral spirits or turpentine
  • Apply the first coat with a brush, then add the other two coats with a rag
  • Sand between coats for strong bonding
  • You can combine both wipe-on and brush-on coats and keep the finish smooth and clear or glossy

What Kind Of Cloth Do You Use To Apply Polyurethane?

The cloth or rag should be lint-free to avoid leaving fabric traces behind as you apply the polyurethane. Another option would be using a microfiber tack cloth as it absorbs polyurethane evenly. 

With the rag, apply thin coats of polyurethane and wipe on the poly in circular motions while overlapping to get an even coat. Amazon has some nice lint-free rags you may consider buying.

Remember to put on gloves, and polyurethane is sticky on bare hands.

Why Should You Apply Polyurethane With A Rag

Below are reasons as to why you should use a rag to apply polyurethane:

  • The polyurethane soaks up evenly on the rag, making it easier to apply thin coats
  • A rag is a great way to avoid brush marks
  • You won’t have to deal with drips and bubbles
  • You require no technical skills
  • It is easier to use a rag on vertical surfaces without making a mess

Pro Tips for Applying Polyurethane With A Rag

Here are some valuable tips on how to apply polyurethane with a rag:

  • If you are using water-based polyurethane thin with water and not mineral spirits
  • Temperature and humidity influence how long it will take the coats of polyurethane to dry
  • Don’t ignore the sanding step. Sanding improves the adhesion of the sealant to the wood
  • After sanding, remove the dust entirely as the particles interfere with the bonding, and any particles left can be permanently sealed in
  • Lay the coats thin and wipe in circular motions. Overlap and don’t wipe over dry areas
  • Wipe-on polyurethane dries quickly. Your hand should move fast for satisfactory results
  • It’s okay if the first coat isn’t pretty. Trust the process, as you’ll notice changes with subsequent coats
  • Pay attention to the amount of polyurethane the rag soaks up to avoid drips and applying thick coats

Applying Polyurethane With A Rag: Pros and Cons

Here are the several advantages and drawbacks of applying polyurethane with a rag:

Pros 

  • Wipe-on poly contains low levels of volatile organic compounds (VOCs), which makes it less toxic and pungent.
  • It is a better choice for users with sensitivities or allergies to chemicals.
  • Wipe-on poly protects the wood against moisture, heat, and outdoor elements. It is also durable.
  • You can custom-make your wipe-on polyurethane by mixing the brush-on poly with mineral spirits in a 50/50 ratio.
  • Wipe-on poly works wonders on vertical, highly detailed, and cylindrical surfaces.  

Cons

  • You’ll need more coats of wipe-on polyurethane on the wood than you would with brush-on poly
  • It is pricy
  • Its final finish is not similar to that of brush-on polyurethane

How Do I Get A Smooth Finish With Polyurethane?

To achieve a glassy smooth finish, apply thin coats of the polyurethane using a brush, foam pad, or lint-free rag. As you work your poly into the wood, move along the wood grain, and don’t move your rag or brush over the dry areas.

Another tip to achieve even better results is buffing the polyurethane finish. Buffing smoothens the nasty brush strokes and bubbles, giving your wood surface a glassy finish. If your polyurethane application isn’t as smooth, buffing will take the piece to another level.  

Should I Use A Brush Or Sponge To Apply Polyurethane?

The tool of choice depends on whether the poly is water or oil-based. Use a natural bristle, sponge, or foam brush for oil-based polyurethane. When working with oil or water-based wipe-on poly, use a lint-free cloth or a microfiber cloth. As for water-based polyurethane, use a sponge, foam brush, or a high-quality synthetic brush.

Can You Apply Polyurethane With A Rag: FAQs

Below are answers to some commonly asked questions:

Is wipe-on polyurethane oil or water-based?

Wipe-on polyurethane is available as either an oil-based or water-based sealant. The oil-based poly is more durable and protects the wood against the elements, heat, and mildew. It’s ideal for outdoor wood. On the other hand, some water-based polys are less durable and unideal for outdoor wood. 

However, water-based polyurethane is the best sealant when sealing over white-painted pieces and dries clear on dark wood.    

What is the best way to apply polyurethane?

There is no one particular way to apply polyurethane. The best way is to use the poly as the manufacturer intended. Spray the spray-on poly, brush the brush-on poly, and wipe the wipe-on poly. 

However, woodworkers and DIYers are allowed to get creative with their projects.

Here is a video on applying polyurethane like a pro:

Can you apply polyurethane with a towel?

Yes, you can grab some paper towels when you are out of options. A paper towel isn’t ideal, but it can work on a rainy day. Bath towels are mostly cotton and not a good fabric choice. The best option is a lint-free rag or a microfiber tack cloth.   

Can you apply water-based polyurethane with a rag?

Yes, you can. First, dampen the rag in water and squeeze out the excess. Then, apply the water-based polyurethane in thin coats. Sand and remove the sanding dust after the coats are dry. Finally, reapply the coats as needed and let the sealer dry.  

Are wet rags a fire hazard?

Yes, they are. Polyurethane contains a flammable compound to it. Dispose of the rags appropriately to prevent fire crises. To make matters worse wet rags can ignite on their own.

Can You Apply Polyurethane With A Rag: Conclusion 

This article has covered every aspect of what you’ll need to complete your project.

Ready-made wipe-on polyurethane is available on the market. However, if you have used the product before, you know it has a different appearance compared to the brush-on polyurethane. If you like how the finish dries out, knock yourself out.

For those who prefer the brush-on appearance, here is a tip. Thinning the brush-on poly with mineral spirits in a ratio of 50/50 creates a similar consistency as the wipe-on polyurethane.

Excellent results may take time and patience. The first coat may not appear desirable; trust the process. The finish improves with every coat of polyurethane and sanding between the coats. 

Don’t forget to buff your finish to achieve a glassy look, smooth enough to reflect light.

Happy woodworking!

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