Can You Apply Polyurethane With A Rag? (How-To)

Yes, you can apply polyurethane with a rag. Applying polyurethane with a rag is a good way to avoid paint bubbles and brush marks. Plus, it helps you paint hard-to-reach surfaces.

There are many ways to apply polyurethane, but the most common methods include spraying it or wiping it on with a rag.

Earlier, most professionals preferred to apply polyurethane with a brush. But with the development of new formulations, polyurethane can now be used with a rag, or you can even spray it on the surface. Therefore, you only have to decide which way is more convenient for you.

Why Should You Use A Rag To Apply Polyurethane?

The main advantage of using a rag to apply polyurethane is that you get thin coats of polyurethane. This means the polyurethane will dry faster, and you won’t deal with polyurethane drip. Also, you will avoid brush marks if you apply polyurethane with a rag. 

Applying polyurethane with a brush has some disadvantages. For example, the brush can cause dripping and building up of bubbles, bumps, and brush marks. And, some parts of the surface are left uncovered sometimes.

On the other hand, applying polyurethane using a rag prevents drips or bubbles and provides a consistent coat with a beautiful finish. Plus, if you are dealing with hard-to-reach areas, such as vertical surfaces, it’s better to use a rag than a roller. A rag applies polyurethane very neatly without any buildup or drips.

However, there are also a few disadvantages of using a rag to apply polyurethane over a surface. You will need more coats of polyurethane when using a rag than when using a brush. You need 8 coats of wipe-on polyurethane to get the same finish you would with 3 coats of applying polyurethane with a brush. 

So, if you want to apply polyurethane without brush marks use a rag. 

Types of Rags To Use For Polyurethane

Types of Rags To Use For Polyurethane

A lint-free or microfiber tack cloth is the best type of rag to apply polyurethane. Choosing the right type of rag is important if you want a smooth finish without drippings.

If you select a bad-quality rag, or the wrong type of rag, such as a tint rag, you will get a bad and uneven finish. So, never use a tint rag to apply polyurethane.

If you don’t want to use a lint-free cloth, you can use a microfiber tack rag. Microfiber tack rags are specially made to remove dust from different surfaces, but these rags are also good with polyurethane. 

Microfiber tack rags won’t give you problems related to grain. Plus, they absorb polyurethane in a limited amount, giving you a much smoother finish.

However, you should never use an old cloth twice to apply a top coat. After the first time, the rag absorption power will be reduced, and that can cause an uneven finish for the next time. But, you can use an old rag that hasn’t been used to apply top coats before. Just make sure to remove the dirt before you use it.

How To Apply Polyurethane With A Rag?

Polyurethane is a top coat that can be challenging to apply. However, you can avoid common brush strokes and bubbles complaints by applying it using a rag.

Suppose you are working on a wooden piece and applying polyurethane over it. Then you will need to follow these steps.

1. Prepare The Surface

You should work in a ventilated area. You can choose outdoors too but only if there is no wind or moving dust.

Before applying polyurethane, you should sand the wood. Start with 120-grit coarse-grit sandpaper, and finish with 220-grit sandpaper. After sanding, there will be a lot of dust on the surface. Remove dust using a vacuum cleaner or with a microfiber tack rag.

Next, clean the surface by using mineral spirits. Leave the mineral spirits on the surface for a few minutes before removing it. 

2. Dip The Rag Into The Polyurethane Paint

Pour the polyurethane into a container. Avoid shaking the can before opening as it can cause air bubbles in the polyurethane.

Take a lint-free rag or microfibre tack rag, dip it into the polyurethane in an even amount, and wipe it on the surface in fine strokes. Apply thin layers of polyurethane and move the rag in a lined motion. Overlap the strokes to ensure good coverage.

3. Sand The Surface

After you cover the whole surface, leave the polyurethane to dry. It takes oil-based polyurethane 6 hours to dry for a re-coat, while water-based polyurethane takes 4 hours to dry. But, since you applied a thin coat, the polyurethane will dry faster.

When the first coat dries, sand the polyurethane coat with 320-grit sandpaper. This will help the next coat stick better. 

After sanding, clean the surface using a lint-free rag to remove dust.

4. Apply The Second Coat Using a Rag

Once the first coat of polyurethane is dry, sanded, and clean, you can apply the second coat. Use the same technique to apply the second coat. 

After you apply the second coat, wait for it to dry. Once the second coat of polyurethane dries, sand and clean it, and apply the next one. The number of polyurethane coats depends on your needs. But, 5 coats is the maximum. 

You should always wait for the previous coat of polyurethane to dry before applying the next one. 

Do You Wipe Off Excess Polyurethane?

You should always wipe off the excess polyurethane to prevent paint drips. This is so important that many polyurethane manufacturing companies print this instruction on the can so that users get a smooth finish.

If you don’t wipe off the excess polyurethane, the polyurethane will turn sticky, and it can cause polyurethane to drip. If the polyurethane dries in that condition, the only way to make it correct is to sand it again. But sanding the drips can cause the removal of the whole layer if you accidentally apply pressure while sanding.

So, to avoid it, leave the polyurethane to dry for 30 minutes, then wipe the excess paint off the surface. You can use a lint-free rag to remove excess paint. If the polyurethane dries faster, you can dip the rag into mineral spirits and then wipe the polyurethane. 

However, don’t leave the mineral spirits over polyurethane for too long as it can remove the whole layer. 

Can You Apply Brush-on Polyurethane With a Rag?

You can apply brush-on polyurethane with a rag. But, applying brush-on polyurethane with a rag is harder than applying wipe-on polyurethane. 

Wipe-on polyurethane is thinned with mineral spirit. Due to its thin nature, a lint-free rag doesn’t absorb too much wipe-on polyurethane. But, if the polyurethane is too thick, the rag will absorb more than the needed amount. That can lead to polyurethane dripping and turning sticky after it has been applied. Plus, it takes longer to dry.

So, you need to pay attention to the quantity of the polyurethane the rag absorbs. However, the best way to apply brush-on polyurethane is to thin it and then use a rag to apply it. 

Conclusion

If you want a thin and clear topcoat, consider using polyurethane with a rag. A clean and lint-free rag is the best way to apply it as an alternative to spraying or brushing it. That’s because a rag gives you more control over how much goes onto your surface. You can also use multiple layers of polyurethane if desired for thicker protection against wear and tear.

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