How to Spray Polyurethane

by

In this post today, I will tell you the complete process to spray polyurethane paint without making any mistake 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.

spray paint polyurethane

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

Tools we need to do the job

These tools are required to spray polyurethane paint on your desired surface with 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 purpose
  • 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 other solvent-based thinner to it. You can use lacquer thinner, but mineral spirits and water-based thinner 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 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 painting, 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 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.

spraying polyurethane paint

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 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 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’s 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 pictures frames and plates that look good enough for framing! Here are some helpful hints so you can make smooth surfaces without destroying your home.

FAQ’s

Yes. We need to thin polyurethane to spray it across the surface. This is because the original product is in a thick liquid form. Hence it must be mixed with other solvents like thinner, thinner oil, thinner paint etc. This is required to make the solution thin enough to spray on large surfaces. Things to consider when mixing thinner for polyurethane. The amount of thinner used determines how easily the sprayer is moved. If the correct amount is not mixed in, the sprayer will spray wildly and create a mess. If too much thinner is mixed in, the paint will be thin and will not cover properly.

General polyurethane spraying for furniture (chair, table, etc.) would use about 25 psi, but the best sprayer can spray polyurethane with just 15psi. Large production polyurethane spraying would use 60psi. And finally, one of the fastest polyurethane spraying would use 80psi. (This is to avoid air in the polyurethane.) In conclusion, the pressure of polyurethane spraying is relative to the size of the project. The best way to spray polyurethane faster is to have a fast sprayer. I hope you enjoy your new furniture and have a nice day.

There are two different ways of spray polyurethane. One is to spray on a vertical surface. The other way is to spray on a horizontal surface. The tip size we should use is different in both cases. 1. For a vertical surface, we should use a tip size between .012 and .016 inches. This is the size we use when we paint the ceiling. 2. For a horizontal surface, the tip size we should use is between .021 and .029 inches. This is the size we use when we paint the wall. We are supposed to consider the thickness of the material we are spraying. We should use a tip size that is appropriate for the thickness or material. The .012 and .016 tips are used for thickness up to 1/16. The .021 and .029 tips are used for thickness up to 1/8. If we want to use a tip size that is between these numbers, we can use the rule of 3 to get the exact size. For example, we want to use the tip size to spray the material that is 1/16 thick. We can use the 1/8 +1/16 rule to find the exact tip size. The size we are looking for is .049 inches.

There are some factors which effect the thickness of the paint: -How much is the temperature of the room? -The temperature of the paint -The air pressure of the spray gun -The distance between the gun and the surface -The type of surface being painted I have tested these factors and prepared a chart below to help you prepare the right ratio of thinning the paint. Temperature of the room: 70F Age of the paint: 7 days The distance between the gun and the surface 3 inches The pressure of the spray gun 25 psi Type of surface being painted: Oak The ratio painted on the surface is: 1 part thinning solution: 1.5 parts paint Just remember, thinning of paint will affect the drying time and durability of the paint. It’s always best to thin paint thinner than required rather than add more than required.

The method of spraying water based polyurethane paint is quite the same as spraying any other type of polyurethane paint. It does not differ in any manner. There are a few things you need to keep in mind.  For starters, you need to take a clear understanding of how much amount of paint you are going to require to cover your surface. Once you have done that, you can begin to measure the amount of paint. You can do so by pouring the paint into an empty paint can. Once the paint is ready, you can proceed to the spray gun. It is recommended that you use a high-quality spray gun, since this will ensure high efficiency in your work. Spray the paint from a distance of around 3-10 feet away from your surface.

There are tons of questions on the internet with same title but they are not exactly the same. The reason is that there are different ways to spray oil based polyurethane with HVLP. The first method is by using oil based primer. The idea behind this method is to protect the wood. In this method, you have to apply primer first, it will protect the wood and later you can apply the top coat. This method is the most used method because it makes the wood last longer. You can also use the oil based primer, but if you want to use the water based top coat, then you should go for this method. The second method is by using a pre-sanding primer. Pre-sanding primer is good for the projects which are not so good looking, or you are working with a large surface. In this method, you have to sand the wood first and then apply the primer, and finally apply the oil based top coat. This method will save your time and money because it doesn’t need so much preparation. The last method is by using a water based primer. This method is good if you want the wood to look very nice and you don’t want to use oil based primer. This method is also good for the people who have problems with the oil-based primer.

One of the best ways to thin water-based polyurethane for spraying is to use a spray bottle. It is extremely simple and effective. The steps are as follows: add water to the spray bottle and then add polyurethane to the water. It is very important to stir the polyurethane and water before adding them to the spray bottle, otherwise you will end up with clumps in the spray. Squeeze the trigger of the spray bottle lightly to get the polyurethane flowing and then spray the polyurethane. I hope that answers your question. Please feel free to ask if you are having any issues or you would like to know anything else.

Conclusion

We 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 post daily. We hope we 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 comments section.

Related Posts:

Leave a Comment