Polyurethane will give your wooden finish a luxurious touch with sleek and luxurious effects. Having wooden projects that have pleasing looks is what most people want to achieve.
If you have a plan to apply polyurethane after painting your wooden finish, you need to wait for some time until the paint is dry.
You might wonder how long you must wait before completely applying polyurethane is safe for the paint to dry.
How Long Should I Wait Before I Can Apply Polyurethane Safely?
Typically, the paint takes around 23 to 49 hours to dry fully. If you want to be extra safe so the paint doesn’t get ruined, add the waiting time of up to 72 hours. Then, after that, you can start applying polyurethane.
However, you need to understand that not every paint is created equal. There are many kinds of paints with various ingredients, and each type has a different dry time.
There are even some paints that don’t require you to apply polyurethane at all.
There are many things to consider before you start the painting process.
How Do You Know If the Paint Is Dry or Cured?
There is an easy way to tell if your paint is dry or has “cured.” Touch a spot with the tip of your finger to see if it’s dry.
It’s dry if it doesn’t feel sticky.
If you want to know if the paint is dry, you can touch it with your fingernail. If the paint leaves a mark, it hasn’t dried all the way.
You Need To Learn Many Types Of Wooden Surface Paints
When painting wooden surfaces, you must learn a few paint types.
As stated in the above paragraphs, not all paints are created equal, and different paint types have different dry times. Each type of paint has its characteristics and qualities.
Here are various types of paint you need to learn:
Latex Paint
This type of paint is good for wooden surfaces. You can acquire them by visiting your local hardware stores or improvement stores.
Many professionals with good experience in woodworking consider it easy to work with latex paint when working with wooden surfaces such as furniture.
You can skip using polyurethane if you paint your surface with gloss sheen or semigloss. It also depends on the surface size you want to paint with.
However, polyurethane is needed if you apply satin, flat, or eggshell types of latex paint on the surface because polyurethane will act as a final touch. The polyurethane topcoat will act as protection that protects the paint.
Furthermore, it is advised to use a high-quality paintbrush and combine it with Flotetrol to reduce brushstrokes.
Latex paint typically takes a relatively short time to dry. You can wait for an hour, and it will dry. You can recoat it after waiting 4 hours if you want to be extra safe.
The more time you give for it to dry, the better the paint will set on the surface.
Oil-Based Paint
This oil-based type of paint is known to be durable over time. The advantage of oil-based compared to latex paint is that the oil-based won’t chip as easily as some types of latex paint do.
The Oil-based paint works best when you use a brush to paint the surface instead of a roller. If the surface is too wide, you will need more time to finish painting it.
You can use paint thinner or mineral spirits to remove the oil-based paint from the brush or your body.
It typically takes around 6 to 8 hours of waiting time for this oil-based type of paint to be fully dry. Then, you can pour another layer of liquid on top of it.
Velvet Finishes Paint
This type of finish is mainly used for furniture painting.
You don’t need to primer or sand your surface beforehand unless the surface is glossy already.
Velvet Finishes requires 8 to 9 times to be fully cured on your wooden surface.
Chalk Paint
Chalk paint is another special paint that is made for furniture. It is a great option because you don’t need to prime or sand the surface before painting.
On the contrary, some chalk paints need topcoat sealers such as wax, polyacrylic, or polyurethane. Before you apply the sealer, wait for about 24 hours to allow the paint to be fully dry.
Milk Paint
Milk paint is a suitable choice if you wish to create a farmhouse-like effect on your furniture. Milk Paint does not offer a finished appearance after you are done painting.
The benefit of using milk paint is that the dry time it requires is almost instantly.
You put it on the surface, and it just dries. However, wait 24 hours for the paint to fully dry to be extra safe.
What Factors Can Impact The Paint’s Dry Time?
The factors mentioned below can accelerate or delay the time it needs for your paint to be fully dry.
Here are the contributing factors for your paint’s dry time that you need to consider:
Wood Types Play Important Role For The Paint To Dry
Some wood types don’t let the paint cure properly since they have chemicals that prevent the drying.
Some wood types, such as aromatic cedars and rosewoods, cause dry time problems. So, you need to avoid painting surfaces made using those woods.
Different Paints Have Different Dry Time
As mentioned above, Different paints have different dry times since they have different ingredients.
Temperature Affects The Paint’s Dry Time
Placing the surface in a room with a lower ambient temperature for some paint types can delay the drying process.
The longer it takes to dry, the more likely the surface will sag or run.
As a result, the sagging and running will make the paint ugly and have an uneven surface. If this happens, you must redo the painting process repeatedly.
Conversely, if the temperature is too cold, it will shorten the paint’s life span.
High Humidity Impacts Paint Result
Putting your wooden surface in place with high humidity might make the paint peel off or have a bubble due to the added moisture.
The reason is that wooden furniture has a porous surface and absorbs any moisture in the air that is in excess and will affect the paint badly.
What is the distinction between dry and cured paint?
To paint with polyurethane, you need to know these two terms.
So that the paint can dry, the solvents in the paint have to evaporate.
When you touch the paint, it should feel dry.
But it’s not scorched. For paint to be “cured,” it must be as hard as possible. It’s completely dry at this point.
For the best result, let the paint dry before applying it to the polyurethane. But many people don’t want to wait that long, so once the paint is dry, they put polyurethane on it immediately.
Polyurethane Application Over a Painted Surface
To begin, decide whether you want an oil-based or water-based polyurethane. To eliminate amber coloring, I recommend using water-based polyurethane.
If you wish to protect the paint while adding beauty to the painted surface, apply two or more coats over the surface. This increases the surface resistance and strength.
Remember that polyurethane can be used on any paint. Let the paint dry well; if it was just painted, clean the surface and prepare it for the next step.
First, let’s talk about how to put a polyurethane finish over paint.
Step 1: Wash the Surface
If the surface has been painted for a long time, you should start by giving it a good wash. Washing it will eliminate the grease, stains, dirt, and other kinds of grime, which is important for keeping it clean.
To clean the area, use a soft sponge and a strong soap. Another way to clean the surface is to mix a half cup of trisodium phosphate with a cup of warm water.
Trisodium phosphate is a good cleaner, and most painters use it to clean surfaces that have already been painted.
Step 2: Remove the Scuffs
After washing, give the painted surface enough time to dry. Most of the time, this takes 24 to 72 hours.
Use 120-grit sandpaper to rough up the surface after it has dried. By doing this, you’ll stop deep scratches from happening and make the surface flat.
If you don’t sand the surface first, you’ll see deep scratches and uneven spots after you put the polyurethane on.
You can use your hand or a palm sander to flatten the surface. Wipe away the dust with a damp cloth when you’re done.
Step 3: Choose Your Applicator
If you use a roller to put on the polyurethane, bubbles will be left behind. Use it with a brush or spray it on for the greatest results.
The best place to use a brush is on a flat surface where you need to build a strong or thick film. Spraying is best for surfaces that are hard to get to. But the film isn’t as thick or strong as the one that forms when you brush the surface.
Polyurethane can also be used by wiping it on. This method works best on surfaces with curves, such as crown molding.
The method makes the coat thinner. Make sure the surface you want to use this method on does not wear down easily.
Step 4: Choose the product
You can choose an oil- or water-based finish for a polyurethane product. Here, we’ll discuss these two types of finishes and when each works best.
Oil-based polyurethane
With fewer coats than water-based finishes, oil-based finishes give your surface a hard shell. When the coats are put on a flat surface, they will smooth out on their own.
But each coat takes a long time to dry. Oil-based polyurethane also has a strong smell that most people don’t like, but it goes away after it cures. Also, this kind of finish tends to turn yellow over time.
When Do I Use Oil-based Polyurethane?
Oil-based polyurethane coatings are great for countertops, cabinets, and wood floors because they are hard to scratch.
You can also use it if you care a lot about how hard the finish is. This oil-based finish dries more quickly than the water-based version.
Water-based polyurethane
Like oil-based polyurethane, water-based polyurethane can form a hard shell, but it will take more coats to do so.
The polyurethane made with water dries faster, so you can put on many more coats in less time. This finish looks milky white when still in the can, but it dries clear. This kind of polyurethane doesn’t smell much at all.
Mineral spirits are needed to clean oil-based polyurethane, but warm water and soap are all you need to clean water-based polyurethane.
When Do I Use Water-based Polyurethane?
Water-based polyurethane is a good choice if you want a product that dries faster.
It is also a good choice if you want the color of the paint to stay the same and show through the finish.
Oil-based polyurethane is more scratch-resistant than water-based polyurethane, but water-based polyurethane is better for surfaces that won’t get as much wear and tear.
Step 5: Apply the First Coat
After you put on the first coat, give it some time to dry.
Once the surface is completely dry, use sandpaper to scuff it up, remove any dust, and make it flat.
Step 6: Allow the polyurethane to dry
Within two to three hours, water-based polyurethane will have reached the dryness level required to be sanded.
Polyurethane made with oil will take 12 to 24 hours.
Step 7: Sanding the polyurethane
Once the polyurethane is dry, use 220-grit sandpaper for scratching the surface lightly and a vacuum and tack cloths to eliminate all the dust.
Step 8: Apply Second Coat
Once the surface is dry and scuffed, you can put on the second coat. Most of the time, you won’t need more than two layers. After you put on the second coat, give it at least 24 hours to dry.
Final thought
If you follow some fundamental techniques, applying polyurethane as a topcoat on paint is not a difficult task at all.
When a base coat has finished curing completely, you are free to apply any polyurethane you like on top of it.
If you are patient and follow the processes we have outlined, you will end up with a finish that is of good quality, will last for a long time, and will make you proud.
