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Seeing that polyurethane paint is one of the unique types of paint, what is the possibility of combining polyurethane with acrylic. So, can you put polyurethane over acrylic paint? You can paint polyurethane over acrylic and even get good results.
Painting polyurethane over acrylic offers a great outlook for both water-based and oil-based varieties. Howbeit, you must first allow the acrylic paint undercoat to be completely cured and cleaned before applying polyurethane over it. Also, you need to be careful of discoloration, specifically while using oil-based polyurethane.
Now that we’ve established the possibility of painting polyurethane over acrylic paint let’s keep reading to learn more details.
- What Is Polyurethane?
- Can You Put Polyurethane Over Acrylic Paint?
- Can You Mix Polyurethane With Acrylic Paint?
- Why Should You Add Polyurethane To Acrylic Paints?
- Other Types of Coatings You Can Put Over Acrylic Paint
- Final Words
What Is Polyurethane?
Polyurethane is a unique petroleum-based liquidized plastic product ideal for adhesion and coating to reinforce the sturdiness of your furniture. The paint comes in two variations; oil-based and water-based. Remarkably, each of these variations comes with its specific usability and functionality. All the same, they both serve the same purpose—to give an additional protective coating to any surface.
The oil-based polyurethane creates an amber coloring when used above a paint undercoat. Since it is oil-based, it’s denser, takes a much longer time to dry and solidify, and gives off a slight odor when it dries up. On the other hand, water-based polyurethane dries swiftly, doesn’t leave any amber coloring, and isn’t as odorous as its oil-based counterpart.
Polyurethane layers provide extra durability against scratches and abrasion and are resistant to water. The outlook is clear and tough when it dries up, thus providing the surface more resistant to heat damage.
Moreover, it’s important to note that, although poly isn’t fragile, it is still prone to breaking and chipping in extreme weather conditions. Also, applying highly-concentrated chemicals to it affects it badly. You can apply polyurethane as a coat on a surface or object by spraying or using your paintbrush. In addition, you can as well use polyurethane to paint roadways and bridges.
Can You Put Polyurethane Over Acrylic Paint?
You can apply both forms of polyurethane paint to acrylic paint. Poly paint offers better protection to the undercoat paint, protecting it from corrosion and weather extremities. It also gives a better, smoother, and more professional outlook on the appearance of the furniture or surface you’re painting or coating.
So the answer to can you put polyurethane over acrylic paint is that it’s possible to paint polyurethane over acrylic. But you’d need to prepare the surface and ensure that it’s not dusty or dirty. That established, let’s consider the steps on how to paint polyurethane over acrylic paint.
How to Paint Polyurethane over Acrylic?
As we’ve acknowledged that we need to know how to paint polyurethane over acrylic, we also need to consider the tools you’ll need to make this happen.
Tools for Painting Polyurethane over Acrylic
- Clean water.
- Tack cloth
- Either oil-based or water-based.
- Lint-free material.
- Vacuum cleaner.
- 120-grit sandpaper.
- 220-grit sandpaper.
- Applicator—roller, paintbrush, spray, or pad.
- Rubber gloves.
Steps to Painting Polyurethane over Acrylic Paint
Step 1: Prepare the Surface
It’s important to note that polyurethane doesn’t stick properly to oil surfaces. Therefore, wash the surface in question carefully with water and detergent or TSP (trisodium phosphate). Although TSP is a renowned food additive, using it in concentrated quantities is effective as a cleaning agent.
TSP is ideal for old paint, while detergent is better if you work on a recent paint application. Also, ensure to put on goggles and your rubber gloves while applying TSP to avoid
Step 2: Sand the Surface using the Sandpaper
Then, use 120-grit sandpaper for sanding the surface and ensure to remove all deep scratches on the furniture’s surface. Sand consistently to thin out the paint’s sheen. Notably, if the 120-grit sandpaper doesn’t give you a flat smooth texture manually, get yourself a palm sander.
Step 3: Tack the Wood
Now, using a tack cloth and vacuum cleaner, clean the residue. Ensure that there’s no more residue of grimes or dust left, as this will ruin the applied polyurethane. Also, you can soak a lint-free cloth in water, then clean the surface properly using the cloth. Remarkably, this does a great job of removing dust from the surface. After that, allow the surface to dry out completely before heading over to the next step.
Step 4: Apply the First Layer of Polyurethane
It’s time to apply a single layer of any form of polyurethane (water-based or oil-based) you desire. In addition, you can apply the first layer using any tool—spray, roller, brush, or pad. When you’re done with that, allow the poly paint to dry completely.
Step 5: Sand the Surface
After the polyurethane varnish dies, smoothen the surface with 220-grit sandpaper. Ensure that you clean off all dust nibs, imperfections, blemishes, etc.
Step 6: Again, Clean the painted surface.
Then, do the same thing you did in step 3 to remove all sanding residues effectively, and tiny grimes or dust particles.
Step 7: Apply the Second Layer of Polyurethane
Usually, the first layer of polyurethane isn’t sufficient, so you’d need to apply one more coat. This time, apply another thin layer of poly paint, following the same procedure as you did earlier. Let it dry completely, then repeat the sanding to reapplying process (steps 5-7) again until you see the level of smoothness you desire.
We recommend that you apply at least two more coats, especially if you’re using water-based polyurethane.
See Also: Can You Use Acrylic Paint on Glass?
Can You Mix Polyurethane With Acrylic Paint?
It’s possible to mix acrylic paint with water-based polyurethane, especially if the acrylic is also water-based. Since water and oil are a terrible combination, then mixing oil-based polyurethane with acrylic will be a bad idea. The mixture will have bubbles within them, which is not a good idea for a painting.
If you’re using flat paint, combining the paint with polyurethane will not add sheen to that paint. Thus, if you’re looking for a shiny, glossy finish, go for a sheen product.
Why Should You Add Polyurethane To Acrylic Paints?
There are several reasons why you should consider applying polyurethane to acrylic paints. As poly paints provide certain benefits to acrylic underpaints, you might even consider using them on your furniture or any desired surface.
Now that we’ve stated that, let’s consider some reasons to add polyurethane to acrylic paint below.
Gives a Tougher Protection from High Temperatures
Polyurethane offers a great coating to surfaces. In fact, the poly material is more durable than foam, rubber, paint, or other applications. So, applying polyurethane to any substance will invariably prolong the lifespan of that substance. As opposed to most other types of paint (especially water-based paints), polyurethane isn’t very prone to rain, mud, dirt, mold, and fungus.
In addition, since the integrity and texture of the paint aren’t ruined, then it can last longer than without polyurethane paint.
Provides a Longer Lifespan
Polyurethane is a synthetic product that functions similarly to paint, metal, wood, rubber, and several other materials. Polyurethane gives the paint undercoat a longer lifespan. Protecting the color, texture, and integrity of the underlying paint coat, polyurethane will enable your paint last longer than just the acrylic paint itself.
This is very effective if the acrylic paint is water-based because, as water-based paints wash off easily and faster than other products, a protective coating will be helpful. The acrylic undercoat pant will no longer be exposed to the elements and extreme temperatures. The poly paint will be the one taking the blow, preserving the undercoat.
Gives a Better Finish
Another major advantage of polyurethane paint over acrylic paint is that it gives the acrylic paint job a better finish. Without the poly paint applied to the surface or furniture, your painting might look incomplete, even after painting it properly. However, poly paint fills up the loops and gives the paint job a final and amazing paint outlook.
Other Types of Coatings You Can Put Over Acrylic Paint
Polyurethane is one of the most renowned kinds of paint coatings. But, asides from polyurethane, some other kinds of paint are effective for overcoating paint on acrylic paints.
This coating comes in both liquid and solid forms, although the liquid form is the most preferred. The liquid form provides a longer and better shelf life than its solid counterpart. Notably, you can apply shellac on wood and non-wood objects and surfaces. You’d need to apply the shellac with a cotton rag or bristle brush to do this.
The varnish usually refers to a finish or topcoat of paint. More often, it comprises a higher number of solids, making it highly durable. One great example is the spar varnish.
Types of Varnish
While there is various varnish you can select from for your acrylic painting, there are two major types. These include the acrylic polymer varnish and the acrylic resin varnish. Interestingly, the acrylic resin variety is smoother, more robust, glossier, and more effective than the acrylic polymer version. If you need a high-gloss outlook, we recommend the acrylic resin varnish.
On the downside, acrylic resin varnishes contain high toxicity. So, if you’re using this varnish type, ensure to provide sufficient ventilation in the room you’re working. On the other hand, the acrylic polymer varnish is non-toxic, and you can dilute it using alcohol solvent or water before using it. If you hope to incorporate a satin outlook, apply a layer of isolation coat on the paint to prevent the frosty finish and destruction of paint.
An isolation paint is simply a transparent coat that differentiates the paint layer and the varnish to be used from each other. It protects the paint from being destroyed by the varnish when dissolved.
Lastly, another finish that gives a great and beautiful appearance is lacquer. The intriguing thing about lacquer is its amazing durability and high abrasion resistance. Moreover, one limitation of this topcoat is that, over time, the color slowly wears off.
All the same, lacquer is extremely smooth when used on wood. This happens thanks to its ultra-thin texture, which is much different from other finish coats discussed in this article. Also, you’d need a low-pressure, high-volume sprayer and a well-aerated space.
Can You Put Polyurethane Over Acrylic Paint? You can apply polyurethane over acrylic. However, ensure to cure the acrylic undercoat properly before applying the polyurethane. Also, be sure to prepare the surface where you’re applying the polyurethane.