There are few ways to better protect stained surfaces than with polyurethane. Polyurethane creates a protective coating that acts like a translucent shell, deflecting impacts while preventing damaging water from reaching the stain. But, to work its protective magic, polyurethane must have time to dry to create a hard coating.
It takes water-based polyurethanes between 2 and 4 hours and oil-based polyurethanes between 6 and 10 hours to dry enough to receive a second coat and at least a full day before it can receive light traffic.
While those numbers provide general guidelines for polyurethane drying times, drying time can depend on various factors, including the type of base, the humidity level, air temperature, and even the condition of the wood. This can leave one wondering, how long does polyurethane take to dry?
In this article, we’ll review the drying times of the 20 most popular polyurethane products and discuss the main factors that can impact those drying times. We’ll also go over a few methods for speeding up the drying time.
Contents (Jump to Topic)
- Polyurethane Cure Time
- Polyurethane Dry Time 20 Popular Products
- How Important Is Polyurethane Drying Time?
- Factors That Impact the Drying Time of Polyurethane
- How Long Does It Take for Polyurethane to Dry on Different Surfaces?
- How to Make Polyurethane Dry Faster?
- How Long to Wait Between Coats of Polyurethane?
- Conclusion
Oil Based Polyurethane Dry Time
While the drying time can vary depending on the manufacturer, most oil-based polyurethanes take between 6 and 10 hours to dry enough to receive a second coat.
While many manufacturers suggest waiting 24 hours before subjecting oil-based polyurethane to light foot traffic, it’s probably best to wait a full 48 hours.
This increased drying time is because oil-based paint has a greater amount of volatile organic compounds and is generally thicker than water-based paint.
Water-Based Polyurethane Drying Time
The drying for water-based polyurethane is significantly less. Most water-based polyurethane will dry to the touch and ready for light sanding and a second coat 2 hours after application. This difference is because it takes less time for the water base to evaporate into the air than the oil-based.
Despite this quick drying time, it’s a good idea to wait 24 hours before water-based polyurethane is hard enough to receive light traffic.
Polyurethane Cure Time
When working with polyurethane, it’s important to understand that drying times and cure times are not the same. During the dry time, polyurethane is changing from its liquid form to a solid. This happens for days or even weeks.
As we’ve discussed, drying time refers to when the polyurethane is dry to the touch or dry enough to receive a second coat.
Cure time is the amount of time it takes before the polyurethane has reached its maximum hardness. It takes 30 days for most polyurethanes to fully cure. Until that time, it’s best to treat the surface with care.
While it may be okay to put furniture on the surface, it’s best to leave items that can stick to it and leave material on the surface, such as a rug. It’s also a good idea not to introduce the polyurethane to water or cleaners until it has fully cured.
Polyurethane Dry Time 20 Popular Products
While all manufacturers will list a dry time on their polyurethane product, keep in mind that these dry times are based on optimal humidity of between 40 and 50 percent and a temperature range of between 65 to 75 degrees. You’ll also find that the water-based products below have a shorter dry time than the oil-based products.
Higher humidity or cooler temperatures will increase the dry time. Below is a list of the dry times for some of the most popular polyurethanes on the market. These dry times are for the amount of time the manufacturer recommends waiting before applying additional coats.
Most polyurethane manufacturers recommend waiting a full 24 hours after the last coat before subjecting the surface to light foot traffic or use with a few suggesting 48 hours.
Most manufacturers suggest waiting at least 3 days before moving furniture onto the surface and a full week before adding rugs.
| Brand | Type | Drying Time (to recoat, to use) |
|---|---|---|
| Minwax | Oil-based | 4-6 hours, 24 hours |
| Varathane | Water-based | 2-4 hours, 24 hours |
| ZAR | Water-based | 2 hours, 24 hours |
| Deft Defthane | Aerosol, oil-based | 6 hours, 24 hours |
| Deft Interior Exterior | Water-based | 2 hours, 24 hours |
| Old Masters | Oil-based | 6 hours, |
| Minwax One Coat | Water-based | 2 hours, 24 hours |
| Zar Ultra Max Oil | Water-based | 2 hours, 24 hours |
| Varathan Rustoleum | Water-based | 1 hour, 24 hours |
| Minwax Water Based Oil-Modified | Water-based | 2 hours, 24 hours |
| Minwax Water-Base Wipe-On | Water-based | 2-3 hours, 24 hours |
| Minwax Fast-Drying Aerosol | Water-based | 4-6 hours, 24 hours |
| Varathane Water-Based Ultimate | Water-based | 2 hours, 48 hours |
| TotalBoat Marine Spar Varnish | Water-based | 1 hour, 48 hours |
| Old Masters Oil-Based Finish | Oil-based | 6 hours, 48 hours |
| Rust-oleum Triple Thick | Water-based | 2 hours, 48 hours |
| Rust-Oleum Pro | Oil-based | 8-10 hours, 24 hours |
| Interlux Brightside | Oil-based | 12 hours, 24 hours |
| Minwax Polyshades | Oil-based | 6 hours, 24 hours |
| Vallejo Model Color | Water-based | 4 hours, 24 hours |
How Important Is Polyurethane Drying Time?
There are few important reasons why it’s crucial to understand the drying time for a polyurethane product before purchasing it and when using it.
If you’re applying polyurethane to an exterior surface, you’ll need to know how long it takes to dry to ensure that rain and wind don’t ruin the surface with water or airborne dirt and debris. Make sure to check the forecast to ensure the weather is suitable for applying the polyurethane based on its dry time.
Polyurethanes require at least three coats and sometimes as many as six to provide the smooth finish and protection they are known for. Most polyurethanes and especially oil-based products have a window of time when the polyurethane can receive a second coat.
Apply the second coat while the first coat is still wet and it will ruin the consistency of the first coat. Apply the second coat too late and it won’t adhere properly to the first coat.
Finally, dry time affects the length of the overall project. An oil-based polyurethane that requires 12 hours between coats may extend the length of the project to several days or more. This may not be practical for certain applications, such as the main hallway or living area in a home.
Factors That Impact the Drying Time of Polyurethane
Most manufacturers give dry times with ranges of several hours. This is because of all the environmental factors that can impact that dry time. In this section, we’ll review each of those factors and discuss how they impact drying time.
Temperature
Most polyurethane dry times are based on 70-degree temperatures. While that’s fine for polyurethanes applied in a climate-controlled building, it’s not always possible to achieve those temperatures when working in a garage, storage shed, or driveway.
Extreme high temperatures and low temperatures can impact drying time. Generally speaking, higher temperatures will shorten drying time as hotter air temperature will dry the chemicals or water vapor in the polyurethane more quickly.
Lower temperature, conversely, will lower the drying time as it takes longer for evaporation to occur. While temperatures below 65 degrees will begin to affect dry time, temperatures below 55 degrees are too cold and may cause the polyurethane to remain tacky indefinitely.
Humidity
Humidity works in conjunction with temperature to impact dry time. While high temperatures can increase dry time, high humidity can also increase dry time. This is because of the high percentage of moisture in the air. This high saturation level makes it difficult for the air to absorb more evaporated water, extending the dry time by as much as half a day.
In extreme humidity, the polyurethane may not be able to dry at all. Low humidity below 40 percent, in comparison, can cause the polyurethane to dry more quickly as the dry air sucks the moisture from it. In these conditions, it’s important to apply the polyurethane quickly while maintaining a wet edge to achieve a consistent coat.
Ventilation
Ventilation can also impact drying time. A well-ventilated room will allow the polyurethane to dry more quickly as the airflow will constantly supply fresh air that can collect more moisture from the drying polyurethane.
You need to be careful with ventilation though. Opening a window to add moist outside air to air-conditioned dry air could extend the dry time by increasing the humidity in the room. While fans are a good way to improve ventilation, keep in mind that they can also stir up dust and dirt to fall onto the wet polyurethane surface.
Polyurethane Base Type
The type of base the polyurethane uses has a huge impact on dry time. Whether it’s polyurethane, primer, stain, or paint, oil-based coatings take longer to dry than water-based coatings.
Whereas water-based polyurethane may be dry to the touch in minutes and dry enough for a second coat in an hour or two, oil-based polyurethane will remain tacky for up to 10 hours.
This difference can dramatically increase the time it takes to complete a polyurethane project from start to finish.
Absorbency of Wood and Wood Species
Wood is made up of a series of fibers with open cells. Stain works so well with wood because the wood can soak up the stain, creating a rich even color. However, like a sponge, those cells can only hold so much liquid before they are saturated.
With that in mind, polyurethane will dry more quickly depending on how saturated the wood is. Younger wood that has yet to fully dry will have a longer dry time as the polyurethane looks for vacant cells to inhabit.
Dry wood, in comparison, will suck up the polyurethane more easily, drying more quickly. This only applies for the first coat or two, as additional coats will adhere to and dry to the previous layer of polyurethane.
Most polyurethane manufacturers don’t take into account wood species when listing the drying times of their products. This is because most hardwoods and pine will respond to polyurethane similarly.
However, some woods have natural oils inside them that will inhibit the drying time of polyurethane, including cedar and rosewood. These woods can add several hours or more to the dry time.
Application Type
Polyurethane is applied with either a brush or a roller. While the application type will have a minimal impact on dry time, it is worth considering. Polyurethane tends to go on thicker when using a brush.
That thicker coat means it will take longer for the polyurethane to dry than if applied with a thinner coat with a roller.
Surface Type
Surface type is related to wood absorbency when it comes to dry time. Freshly sanded wood has open wood grains best suited for receiving moisture. Applying polyurethane to this raw surface will cause the wood to suck in the moisture from the polyurethane, greatly increasing the dry time.
This is important to pay attention to as most bare un-stained wood that is receiving polyurethane is freshly sanded. Once that first coat is on the unstained wood, the wood fibers become sealed and the subsequent coats will dry more in line with the manufacturer’s instructions.
How Long Does It Take for Polyurethane to Dry on Different Surfaces?
As if there wasn’t enough to think about already when applying polyurethane to a surface, polyurethane also has different drying qualities when it comes to the type of surface despite the fact that most manufacturers don’t indicate on their packaging that this impacts dry time.
Furniture
While the broad flat surfaces on wood furniture may adhere to the drying times on the package, most furniture has nooks and crannies where wood pieces are joined together to create a corner, in curved wooden legs that have been turned on a lathe, or in decorative carvings.
These spots present places where polyurethane can collect, creating a thicker coating than on the furniture’s flat surfaces. These areas also won’t see as much airflow as other parts of the piece. Both factors cause these areas to take longer to dry.
Hardwood Floors
Hardwood floors are broad and flat, making it easier to apply even coats of polyurethane over the surface. And, since most hardwood floors are in a climate-controlled space, they closely adhere to the manufacturer’s guidelines for drying time.
How to Make Polyurethane Dry Faster?
Several methods range from easy to a little more extreme to speed up the drying process with polyurethane.
Perhaps the easiest way to do it is by applying heat. This can be done by taking a simple hairdryer and blowing warm air over the surface. You can also employ space heaters or heat lamps to do the job.
Even simply choosing a warmer day to apply polyurethane will cause it to dry more quickly.
Just as bringing heat will lower the dry time, so will decreasing the humidity. This can be a little tougher, but it’s still possible. Use a room dehumidifier to remove moisture from the air, allowing the moisture in the polyurethane to evaporate more quickly.
If working outside, choose a dry day with low humidity to apply the polyurethane.
Improving ventilation by using a fan to blow air across the surface is also a good way to speed up drying time. Use this method with caution though as a fan can stir up dust and dirt, which can fall on top of the wet polyurethane and stick to it.
One more extreme option is to apply naphtha to polyurethane. Naphtha has a high evaporating rate, so adding it to the polyurethane increases its evaporating rate, allowing it to dry more quickly.
While all of these methods are effective ways of speeding up drying time, none of them will shorten the cure time. The polyurethane still needs a full 30 days to reach maximum hardness.
How Long to Wait Between Coats of Polyurethane?
Nearly all polyurethane manufacturers conveniently include the amount of time you should wait between applying coats of polyurethane. While this is helpful, there are a few important points to remember.
The first coat of polyurethane will typically dry more quickly than additional coats. This is because the first coat is applied to the bare wood, which will suck up the polyurethane quickly.
Additional coats will adhere to the previous coats rather than soak into the wood, so they may take longer to dry.
You should typically wait about 2 hours between coats of water-based polyurethanes and about 8 hours between coats of oil-based polyurethane before applying additional coats.
How Do You Know if Polyurethane Is Dry?
While tracking the amount of time that has passed after applying polyurethane is an effective way to determine the dry time, you can also employ the touch test as a backup. The polyurethane should feel smooth and no longer tacky once it is dry.
Polyurethane goes through a two-stage drying process. In the first stage, the solvent evaporates, leaving the resin in the polyurethane behind. When this stage is over, the polyurethane feels sticky.
During stage two, the molecules in the resin react to the oxygen in the air and begin to bond with one another. Once this bonding is complete, the polyurethane no longer feels sticky.
When Can You Walk on Polyurethane Wood Floors
While you can technically walk on polyurethane wood floors as soon as they are dry to the touch and are no longer tacky, most manufacturers recommend waiting 24 hours before subjecting the floor to light foot traffic and 72 hours before opening it up to normal duty.
This waiting period is to give the resin enough time to harden to the point that it can withstand the weight and friction of foot traffic.
Conclusion
It generally takes water-based polyurethane 2 hours and oil-based polyurethane about 8 hours to dry enough to receive a second coat of polyurethane and a full day before it can be handled or subjected to foot traffic.
Make sure to consider the numerous factors that can impact drying time, including temperature, humidity, wood species, surface condition, and even application types when applying polyurethane. Wood furniture will also take longer to dry than broad flat surfaces, such as flooring.
When applying any type of paint, stain, or sealer, always make sure to use the proper protective equipment to prevent the polyurethane from coming into contact with the eyes and mouth.
Some polyurethanes, especially oil-based, can also have high VOCs, so it’s important to remember to work in a well-ventilated space when working with polyurethane.