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Most wood projects are not finished until they have received a coat of polyurethane. However, before you begin to apply it, you will need to understand the drying time for polyurethane. There are several different types of polyurethane, each with its own curing times and unique properties. We have put this guide together to equip you with the knowledge of how long it takes polyurethane to dry.
Table of Contents
- 1 Types of Polyurethane
- 2 Polyurethane Curing Time Table
- 3 Drying and Curing Polyurethane
- 4 Frequently Asked Questions
- 4.1 How Long Does It Take for Minwax Polyurethane to Dry?
- 4.2 How Long Does Polyurethane Take to Dry?
- 4.3 How Can I Shorten the Drying Time for Polyurethane?
- 4.4 How Long Does It Take for Water-Based Polyurethane to Dry on Hardwood Floors?
- 4.5 What Is the Usual Water-Based Polyurethane Cure Time?
- 4.6 How Long Is an Oil-Based Polyurethane’s Cure Time?
Types of Polyurethane
Before you can address the drying time for polyurethane, you need to have a better understanding of the product you are working with. There are a few different polyurethane coatings available, each of which has its own unique drying time.
Water-Based or Oil-Based Polyurethane
Before you begin, you will need to understand how polyurethane is formulated and what it is. This type of coating (or varnish) is a polyurethane resin that has been dissolved and carried by a liquid solvent, which creates a kind of liquified plastic. There are two options when looking at liquid polyurethane, where it can have either an oil or a water base. Each of these creates different products, all with their own unique polyurethane curing times.
The safer, less toxic option is water-based polyurethane, which produces much lower volumes of volatile organic compounds (VOCs), and in some cases, no VOCs at all. There are no strong odors given off by water-based products and they are much easier to work with and clean up. As water evaporates quickly, this form of polyurethane will dry very quickly. The consistency of the coatings is also a lot thinner, which further speeds up the drying time. However, this does mean that water-based polyurethane offers less protection than those with an oil base, and you will likely need to apply several coats of polyurethane in order to increase its durability.
Oil-based polyurethanes, on the other hand, are much thicker as a result of their oil base. This increases the polyurethane’s dry time significantly, although you will in turn achieve a stronger, more durable finish. Oil-based polyurethane contains many more chemicals than its water-based counterpart, which means that it emits higher levels of VOCs and has more of an odor. Thus, you must always take care when working with this type of polyurethane and ensure that you wear a respiratory mask and work in a well-ventilated area.
The overall clarity of the polyurethane also offers a significant difference between the two options. While both finishes dry clear, oil-based polyurethane has a tendency to darken or yellow over time, whereas water-based polyurethane will maintain its transparency.
Polyurethane is available in a variety of sheens that will become apparent once the varnish has dried. Typically, polyurethane sheens include a range of those with more of a matte finish to those with a high level of gloss. We have outlined the three main sheen types below:
- Satin: While not as shiny as the other finishes, this form of polyurethane is almost matte with a subtle, minimal shine. If polyurethane has a satin finish when dried, you will know that it dries quickly, as this sheen dries the fastest.
- Semi-Gloss: This finish has more of a shine, but the high-gloss option is shinier. This is the middle-ground between flat and glossy, and is a popular choice thanks to its durability and versatile nature. This polyurethane dries faster than that with a high-gloss, but a little bit slower than those with a satin finish.
- High-Gloss: This polyurethane provides a slick and shiny finish with amazing flexibility and durability. It can be used on items both outside and inside on an assortment of wooden surfaces. The drying time for polyurethane with a high gloss is the longest of the three options.
Polyurethane Curing Time Table
Now that we have provided you with details about the formulation and basic types of polyurethane, we can compare them side by side. To determine how long polyurethane takes to dry, have a look at our polyurethane curing table below, which classifies the drying time for each type of polyurethane as an overview. Keep in mind that the temperature and overall humidity will impact the drying time as well.
Although a surface may be dry to the touch, this does not mean that the polyurethane has cured. It is imperative that you wait for the polyurethane to cure completely before using it, as it is only once cured that it will reach its maximum strength and durability. The curing time depends on which type of polyurethane you have used, how many layers have been applied, and the surrounding temperature and humidity.
|Ready to Apply Another Layer||8 hours||1 day|
|Dry to the Touch||1 day||2 days|
|Able to Place Things on the Surface*||Longer than 2 days||Longer than 4 days|
|Cured Completely||20 days||A month|
* Allow at least a month before you place any plasticized materials (such as rubber mats) onto the surface, as otherwise a visible mark will be left.
Drying and Curing Polyurethane
When dealing with the drying and curing times of polyurethane, there is a significant difference between the two. While polyurethane may be dry, it does not necessarily mean that it has cured, and it is extremely important that you comprehend the difference between the two.
When the external finish of the polyurethane has hardened, it is thought to be dry (or touch-dry). The polyurethane is no longer in a liquid form. However, because the polyurethane has not yet cured, you will still be able to damage or wrinkle the dried polyurethane surface with too much pressure.
The polyurethane has cured once it has hardened throughout. This is when the polyurethane has undergone the complete chemical reaction that occurs once it has been exposed to oxygen. Polyurethane is in its final and hardest form when it has cured, and you can apply pressure to the surface without any fear of damaging the surface. However, it takes a long time for the polyurethane to cure – anywhere from a day to a month.
Factors That Influence Curing Time
External factors can also impact the drying time of polyurethane. If you were to use the same product under two different conditions, you will notice the polyurethane dry times differ considerably. What follows are some of the most important factors that will impact your polyurethane dry time.
An imperative factor to consider when applying a polyurethane finish is the external temperature. The ideal temperature is roughly 70 degrees Fahrenheit (21 degrees Celsius). If the temperature is colder than this, the drying time will take significantly longer. If the polyurethane dries in cold conditions, an odd white film can develop. On the other hand, if the temperature is too warm, the resulting finish of the polyurethane will also be significantly impacted.
When applying polyurethane to wood, the ideal conditions you are looking for are 50 to 70% humidity. If the humidity is too high, the polyurethane will struggle to dry correctly and the finish will be impacted negatively. If you are concerned about humidity, we recommend that you use an oil-based polyurethane, as water-based polyurethane has a greater sensitivity to humidity.
Your polyurethane cure time will also be affected by how thickly you have applied the layers. The thicker the application, the longer it will take to dry. The thickness is impacted by two factors, being the product you are using and the method you have chosen to apply it.
If you use a brush to apply the polyurethane, you will end up with fairly thick layers, which will take much longer to dry. If you spray on the polyurethane or use a roller, the layers will be thinner and the drying time shorter. If you are looking for an extremely fast drying time and even thinner layers, you can also get special wipe-on polyurethane products.
The type of polyurethane you choose to use will also influence the thickness of your coatings. Oil-based products are a lot thicker than those with a water base, which means that they take much longer to dry. Water-based polyurethane, on the other hand, is much thinner, resulting in a quicker drying time.
Tips and Tricks for Altering Your Polyurethane Dry Time
Now that we have an understanding of what assists and hinders your polyurethane cure time, we can attempt to make the product dry faster by adding our own external influences. If you cannot make your polyurethane dry quickly, then consult our tips and tricks below to assist you.
- If the external conditions are cold, just apply some heat. Adding a heat source when the weather is too cold will speed up the drying process of your polyurethane. You can use a hairdryer or a wall heater – just ensure that you are only using gentle heating, as too much will impact the overall finish.
- If you apply your polyurethane too thickly, you can speed up the drying time by smoothing it out with a paint roller. Use a roller over the freshly applied finish to create layers that are thinner and more even by smoothing out the coating.
- Always check the weather before beginning with the application of your polyurethane. If it says it will be raining or there is high humidity, rather wait for another day to tackle your DIY project.
- If you are working in a particularly humid environment, we recommend that you use an oil-based polyurethane as water-based polyurethane is more sensitive to humidity.
- Always prepare your surface properly before you begin applying the polyurethane. You will always require a smooth, clean, and sanded surface to ensure that the polyurethane adheres to the surface properly and dries quicker.
What Is the Drying Time for Polyurethane Coats?
When you are painting polyurethane in layers, how long does will each coat take to dry? This is important to understand as you will more often than not need to apply multiple layers of polyurethane, whether oil- or water-based. Thus, you need to know when the underlying coat has dried sufficiently so that you can apply the next layer.
You should always wait for a coat of polyurethane to dry to the touch before applying the next, and this can take anywhere from one to eight hours, depending on the product you have used. You will know when the polyurethane is dry when it is not at all wet or tacky upon touching the surface. Once you have applied the final coat, you will need to allow the polyurethane to cure completely before use.
Thinner layers dry more quickly, and to achieve extra-thin coatings of polyurethane, we recommend that you use a cordless paint sprayer or airbrush. This will allow the finish to be applied more quickly and in much thinner layers. Always ensure that the sprayer you are using is able to handle polyurethane, as otherwise, you will need to apply it with a brush or roller.
Before you begin to finish off your new woodworking project, you will need to know the polyurethane dry time. This great finish comes in an assortment of options, each of which has its own drying time. We hope that our guide has given you a greater understanding of polyurethane and its various drying times, as well as how to work with the product to ensure that the finish dries correctly.
Frequently Asked Questions
How Long Does It Take for Minwax Polyurethane to Dry?
As one of the most popular brands of polyurethane, people often ask how long it takes for Minwax polyurethane to dry. The answer is linked to the external conditions and the product specifications. This product, which is advertised as fast-drying, can dry to the touch in roughly four to six hours, after which time it is ready for recoating It should then take about a day to cure completely.
How Long Does Polyurethane Take to Dry?
Water-based polyurethane takes about six hours to dry to the touch, while oil-based polyurethane takes roughly 24 hours to dry. For the correct specifications, we recommend that you consult the manufacturer’s guidelines.
How Can I Shorten the Drying Time for Polyurethane?
By altering the thickness of the layers and the temperature, you can increase the speed of the polyurethane’s drying time. Your ideal temperature should be 70 degrees Fahrenheit (21 degrees Celsius) with minimal humidity. Also keep in mind that the thinner the layers, the quicker they will dry.
How Long Does It Take for Water-Based Polyurethane to Dry on Hardwood Floors?
Polyurethane is often used to coat wooden flooring, so the question is, how long will it take to dry? As noted previously, the environmental conditions and the product used both play a significant role. On average, water-based polyurethane dries in about six hours and will be cured in roughly two days. We suggest that you wait about a day before you attempt to walk on the floors.
What Is the Usual Water-Based Polyurethane Cure Time?
It will take between one and three days for a water-based polyurethane to cure completely. The drying time is about six hours, but as previously mentioned, this can all be greatly impacted by the environmental conditions and which product you have used.
How Long Is an Oil-Based Polyurethane’s Cure Time?
On average, an oil-based polyurethane will take about 24 hours to cure, although certain products can take as long as two days. As always, take the conditions you are applying the product in and which product you are using into consideration.