We have outlined all of these factors in detail below. Before looking into drying times, you will need to understand exactly which product you are working with. There are various different types of polyurethane coatings available, each one with a unique drying time. To better understand this, we have outlined some of the main considerations below for polyurethane coatings.
First, you will need to understand exactly what polyurethane is and how it is formulated. Polyurethane coatings, or varnish, is made up of polyurethane resins that are dissolved and carried by a liquid solvent. This basically forms a type of plastic in liquid form. When looking at the liquid base of polyurethane, there are two options: water or oil.
Both of these produce very different products with unique polyurethane dry times. Water-based polyurethane is a safer and less toxic option. These products contain far fewer amounts of VOCs — that is if they contain any at all. Water-based products do not produce strong odors, and they are safer and easier to work with. Because water evaporates quickly, this type of polyurethane is much faster drying.
The polyurethane cure time for water-based products is also lower because these finishes produce much thinner coatings. You will likely have to apply more coatings though — especially because water-based products are typically less durable.
Oil-based polyurethane is a different story. Unlike water-based products, these finishes are applied slightly thicker. This thickness, combined with the oil composition, makes the polyurethane dry time significantly longer.
However, you will achieve a stronger, more durable finish. Oil-based polyurethane can contain high levels of VOCs, and these products can be fairly harmful due to the many chemicals. Oil-based products also release a stronger odor. An important difference between these two types of polyurethane is their clarity. Both types of finish go on clear, but oil-based products will often yellow or darken over time.
Water-based polyurethane generally maintains a better level of clarity over the years. Another factor to consider on the drying time for polyurethane is the type of sheen that the product has.
Polyurethane varnishes come in three different types of sheen. These are the level of glossiness, or lack of gloss, that the finish offers after it has dried.
We have outlined the different sheen types below:. Now that we have covered the basic types and formulations of polyurethane, we can compare the different styles side by side. How long does polyurethane take to dry? Take a look at our polyurethane cure time table below to gain a better understanding of the drying times for each type.
This is just a general overview. It depends on the temperature and humidity, as well as the surface. Otherwise, you will have visible marks on the floor. When talking about polyurethane dry time, or polyurethane cure time, there is a distinct difference between the two. Dried polyurethane is not cured polyurethane.
When asking how long does polyurethane takes to dry, it is important to understand these two definitions. Drying is when the external finish of the polyurethane hardens. If you use quality products in the right way, oil-based polyurethane will perform well for a longer period. Oil-based polyurethane should be dried within 24 to 48 hours. To know whether or not your oil-based polyurethane is dried or not, check these things below:.
Oil-based polyurethane on any floor takes at least 30 days to cure. To safely speed up the process, you can use a blow dryer or room heater to increase the room temperature.
Water-based polyurethane takes about four to six hours to dry properly. To know whether or not your water-based polyurethane is dried or not, check these things below:. Water-based polyurethane takes 30 days to cure properly. After that period, you can bring back your furniture to your room. Follow the next segment to know them briefly:. In comparison, oil-based polyurethane takes 24 to 48 hour to dry and 30 days for curing. Tips: Always find yourself the Best Polyurethane for various purposes such as applying it on tabletops.
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 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.
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. The type of base the polyurethane uses has a huge impact on dry time. 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. 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. 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. 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 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. Both factors cause these areas to take longer to dry.
Hardwood floors are broad and flat, making it easier to apply even coats of polyurethane over the surface. 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.
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