How to Spray Polyurethane

In this post today, I will tell you the complete process to spray polyurethane paint without making any mistakes on your desired surface.

Follow this guide in order to achieve the best results and satisfactory finish which you wanted out of your work.

Newbies should follow each step explained in this guide without hesitation and confusion.

Polyurethane spray is a type of synthetic resin. It is different from other coatings that are used to give any surface a protective covering.

It also gives a smooth, hard finish to every surface it is applied. It is widely used as a coating material that covers various surfaces.

How to Spray Polyurethane?

Tools we need to do the job

These tools are required to spray polyurethane paint on your desired surface with the best finish and results which you want. Here is the list of those tools:

• Spray gun or paint sprayer
• Face mask
• Glasses
• Gloves
• Polyurethane paint
• Paint thinner
• 220-grit Sandpaper/low grit
• Drop cloth or rags
• Vacuum cleaner for cleaning purposes
• Mesh filter for filtering paint
• Painters tape or newspaper

Wear protective gear

When spraying polyurethane, UV-resistant rubber gloves should be worn at all times, as should eye goggles and a respirator.

Long-sleeved shirts and long pants are recommended, particularly of a material that is woven or knitted to increase durability.

Prolonged exposure to spray fumes can cause asthma or respiratory problems.

So if you have any doubt about your own health when working with this problematic substance, please visit your doctor first before deciding whether it is suitable for you!

Stir the polyurethane paint

Stir the polyurethane. However, this is not a problem for spray painting; stirring instead adds bubbles to it.

We mix any solids and flattening agents (determine sheen) which have sunk to the bottom by stirring to create a nice coating of non-streaking finish.

That gives off an even coat without streaks in your final paint job.

To stir polyurethane paint properly, there are three main things to keep in mind. First and foremost, you need to be thorough with stirring or the paint won’t have a uniform mixture.

Secondly, you have to use the best technique possible while stirring the paint. There are actually two recommended ways to stir paint.

In the first method, you can use a paint stick, or any other object that would produce stirring action in the bucket.

This is known as the “cut and dip” method. In this method, you simply stir the paint with a paint stick by cutting the surface of the paint with the stick and then dipping the stick back into the paint.

This way, the paint and the air in the mixture are stirred together, creating a more even texture. This is the best way to stir paint.

Process of thinning polyurethane paint

When adding the polyurethane to your paint sprayer you can choose to either thin it down or skip that step.

Adding thinner will make it easier to spray, but it is not necessary. If you choose to thin the finish with water or mineral spirits, follow the instructions on the can when you add your thinner.

Thin polyurethane paint by adding 25% of mineral spirits or another solvent-based thinner to it. You can use lacquer thinner, but mineral spirits and water-based thinners are safer to use.

Select polyurethane paint

When picking spray polyurethane for your project, there are several factors to consider. The kind of spray you choose will affect the drying time and the final result.

Both types of polyurethane can give different results, but they have similar benefits too.

Decide if you want an oil-based or water-based spray so that you can start your project on the right foot with a product that will achieve what it should for less frustration.

Prepare the workplace for spraying polyurethane paint

Spraying polyurethane is tricky, so the finish will probably get onto other wooden surfaces. Use an old sheet to protect other items in your workshop you don’t want to be sprayed.

Also, crack open the windows to ensure proper ventilation. If there is a fan blowing in your direction turn it away or switch it off.

Prepare the surface for painting polyurethane

It’s important to get rid of any excess particles when prepping your wood surface prior to painting.

Dust left over can destroy paint, so we recommend using a tack cloth or vacuum cleaner to remove it.

No matter what type of paint you choose (spray, brush-on, roller), there will still probably be some form of dust on your project.

So, make sure to keep that in mind when you’re working and if anything is blowing outside that may blow some dust onto your surface or floor coverings.

Test the sprayer

When it comes down to spray paint, even motorized sprayers can be a little bit unpredictable.

Just like other motorized tools and machines, you might have to learn how to use the motorized sprayer properly before getting any useful results by doing a first test run on random surfaces.

Once you get a smooth flow with no spluttering, and a relatively even coating over the surface you’re planning on application.

It would be advisable that you test out your own particular item or art piece on one small area of the wooded surface first in order for you to see if there are any modifications.

Or adjustments that need to be made during your second and subsequent sprays so as not to leave unwanted marks on your wooden project’s finish.

Start spraying polyurethane paint

Start spraying the first coat of polyurethane from a distance of about 10-12 inches, so nothing gets left behind on one side of the canister and onto your wood.

This does not need to be explained in great detail. The idea is to explain how it works without being too technical for your target audience.

Don’t use jargon that could turn off potential customers or keep them from buying the product.

Applying polyurethane takes anywhere from two to four hours to dry completely and be ready for a new coat.

Once it’s dry, use 220-grit sandpaper to eliminate dust nibs, uneven spots or runs. Sand gently, following the grain of the wood.

Don’t go too deep, just enough to make the surface even, and give it a bit of roughness for the next coat to cling to!

Smooth the surface

After sanding, use cloth again to clean the remaining. Be patient while you do this because there will surely be dust particles that haven’t blown back yet – they’re just waiting to be cleaned up.

Apply another coat of polyurethane paint

Apply the second coat in the same manner that you did with your first coat, and make sure to try out the substance first on unfinished wood, thus making sure it is still functioning correctly.

Repeat this process until you have reached the sufficient layer for a satisfying finish.

What most people will usually do is add about 3 or 4 layers onto their surfaces because smoothness generally takes time.

However, if you are watching your budget, feel free to improvise as long as the quality doesn’t suffer too much.

Allow the polyurethane to cure fully before placing heavy items atop its surface because this could cause warping of your work and at times ruin it completely.

This process should take between 3 weeks to 4 weeks depending on whether it is water-based or oil-based polyurethane;

However, keep in mind that drying time does not equate to curing time when working with water-based substances.

So make sure it has dried enough (2 hours) to begin applying another coat if needed.

Tips for spraying polyurethane paint

To ensure a great finish on large pieces of furniture, you’re going to want to apply polyurethane using spray equipment.

Never apply more than one thin coat too quickly, allowing the previous layer to dry first before adding another.

In the case of drips and runs, always cut small sections at a time when applying polyurethane.

Never use this type of product in direct sunlight or with the sun high in the sky; spray instead in full shade on a warm but not hot day.

When fabricating polyurethane, one must keep in mind that applying it is not a get-rich-quick situation.

It can be quite tricky, as this particular substance is not very forgiving – it doesn’t wait for you to make mistakes while you’re putting it on.

Instead, it will hold onto those imperfections and let others know just how badly you messed up the moment you decide to showcase what should have been a beautiful work of art.

Therefore, please do us both a favor and DO NOT spray runny wet coats of poly on surfaces.

Spray Polyurethane Vs. Brush On

Almost any homemade paint job is going to have brush strokes.

That’s why it takes a lot of good scrubbing, feather-light taping, and a second coat to achieve the look you want. But with a little helpful advice from a mentor.

You can use this paint project as the perfect opportunity to practice just the right motions for making your own crafty decor items.

Like picture frames and plates that look good enough for framing!

Here are some helpful hints so you can make smooth surfaces without destroying your home.

Does polyurethane need to be thinned to spray?

Polyurethane is a thick, viscous material that needs to be thinned in order to be sprayed through a paint sprayer.

The amount of thinning required will depend on the specific type of polyurethane and the type of sprayer being used.

When thinning polyurethane for spraying, it is important to use the appropriate thinner or reducer.

The type of thinner or reducer used will depend on the type of polyurethane and the desired final consistency.

For example, some polyurethane products require the use of a specific type of reducer or thinner, while others may be thinned with mineral spirits or lacquer thinner.

It’s always best to check the manufacturer’s instructions for the specific polyurethane product you are using.

As well as the sprayer you will be using, as they will provide the recommended thinning ratios.

In general, a good starting point is to mix the polyurethane with a thinner or reducer at a ratio of about 20-25% thinner to 75-80% polyurethane.

This will give you a consistency that will flow through the sprayer easily.

It’s worth noting that thinning polyurethane will affect its final properties, such as its curing time.

Gloss, and durability, so it’s important to use the recommended thinner or reducer and thinning ratio.

Can polyurethane be applied with a sprayer?

Yes, polyurethane can be applied with a sprayer. It is important to use the correct type of sprayer and to properly prepare the surface to be coated.

Additionally, the polyurethane should be thinned to the appropriate consistency for the sprayer being used.

It is also highly recommended to use a respirator or mask and protective clothing as the fumes of polyurethane can be harmful to inhale.

Is it better to spray or brush polyurethane?

Both spraying and brushing polyurethane can result in a good finish, but they have different advantages and disadvantages.

Spraying polyurethane can result in a smoother and more even finish than brushing, as it eliminates brush marks.

However, it can be more difficult to achieve a consistent finish with spraying, and it requires specialized equipment and more experience to use properly.

Additionally, it can be messy and requires more prep work for the surrounding area.

Brushing polyurethane can be more forgiving, as it is easier to control the amount of finish being applied and to work it into tight spaces.

However, it can be more time consuming and result in brush marks.

So, whether to spray or brush polyurethane depends on your specific situation, including the type of surface you’re finishing.

The size of the area you’re working on, and your own skills and experience.

What type of spray gun is best for polyurethane?

The type of spray gun that is best for polyurethane depends on the specific application and the viscosity of the polyurethane.

For thicker viscosity polyurethane, an airless spray gun is a good option. These types of spray guns use high pressure to atomize the finish, which allows for a smooth and even application.

For thinner viscosity polyurethane, a HVLP (high volume, low pressure) spray gun would be a better option.

HVLP spray guns use a lower pressure than airless spray guns, which results in less overspray and more control over the application of the finish.

It’s important to match the spray gun tip size to the viscosity of the polyurethane, and the tip size needed can vary depending on the manufacturer of the polyurethane.

Also it’s recommended to use a respirator or mask and protective clothing as the fumes of polyurethane can be harmful to inhale.

FAQ’s of How to Spray Polyurethane

Conclusion of How to Spray Polyurethane

I hope you enjoyed reading our blog post on How to spray polyurethane. If you are looking for more tips, we highly recommend reading our other blog posts daily.

I hope I have been able to clear up any questions you may have had on how to spray polyurethane.

And now, you are able to use polyurethane with ease! If you have any other questions, please feel free to contact us in the comments section.