Spray paints are super easy to apply. But before you can re-coat it, its coating has to dry. So how long does spray paint take to dry?
It takes spray paint 10-30 minutes to dry to touch, 1-4 hours to dry enough for a re-coat, and 24 hours before you can use its coating. It’s best to allow it 3 days to cure before cleaning and regularly using it.
However, its dry time depends on the type you use, room temperature, humidity levels, and the number of coats.
Dry Time Between Coats
It takes spray paint 1-4 hours to dry between coats. Water-based spray paint takes less time to dry because it uses water as its solvent, and water evaporates fast.
On the other hand, oil-based spray paint takes longer to dry because it uses oil as its solvent, and oil takes longer to evaporate from the coating.
However, room temperature and humidity levels determine their dry time. For instance, during cold or moist conditions, the coating takes longer to dry because the evaporation rate of the solvent is halved.
If you re-coat too soon, the finish will turn sticky. That’s because the solvent of the existing coat will be trapped between the coatings. This prevents the new coating from sticking (since the existing coating is wet), but also prevents the existing coating from drying because the solvent can’t evaporate. This is why you should always await until one coating fully dries before re-coating it.
Spray Paint Cure Time
It takes spray paints between 12-72 hours to cure. Spray sealants especially oil-based variations take longer to cure due to the presence of gloss in the finish. These sealants like oil-based Polyurethane can take well over 3 days to cure.
The cure time of the paint refers to how long to wait before the finish can be subjected to regular use. For the finish to handle weight, foot traffic, spills, stains, and cleaning, it has to cure. This means the coating has to be hard, rigid, and strong.
For paint to cure, the solvent has to be completely evaporated and the particles must become rigid and compact enough. Spray paint cures through oxidization, which takes longer.
3 Methods To Speed Up Spray Paint Dry Time
There are a few methods to make spray paint dry faster. These methods will have varying effects on its dry time based on the type you used and environmental conditions.
The first method on the list is:
1. Using A Hairdryer
Since spray paint coating dries through evaporation, you can increase the evaporation rate to make it dry faster. To increase the evaporation rate, increase the heat around the coating using a hairdryer.
To use this method, you’ll need:
- A hairdryer
Here’s how to do it:
- Set The Heat To Medium – Set the heat of the hairdryer to low or medium.
- Hover The Hairdryer Around The Coating – Move the hairdryer over the coating. Ensure to cover all the areas of the paint and do not spend too much time on one part as the paint will dry unevenly. Do this for about 10 minutes.
- Turn Off The Hairdryer – Turn off the hairdryer and let the paint dry fully. Hairdryers are known to speed-up paint drying by over 50%.
Note: You shouldn’t fully dry a coating using a hairdryer. That’s because the particles will harden too fast and won’t have enough time to bond, so the finish will crack and might peel off.
2. Ensuring Proper Ventilation
Spray paints dry when the solvent evaporates from their coating. Evaporation occurs through heat and air circulation. So, you can also increase the air circulation around the coating to make the solvent evaporate faster.
To ensure proper ventilation, you should:
- Open all doors in the room
- Open all vents and windows
- Turn on the fans
- Set the air conditioner on blow or fan.
3. Reduce The Humidity
If there’s a high level of humidity on the atmosphere, the paint will dry slower because the evaporation rate is slower. Also, during humid conditions, the water in the atmosphere will settle on the coating, increasing the level of solvent and causing the paint to take longer to dry.
To reduce the humidity, you can use a dehumidifier. All you need to do is plug in and turn on the dehumidifier. The device will suck in and trap moisture in the air while releasing cool dry air. The good thing about this method is you can use it with any other method.
Here are some other tips you can use:
- Spray light coats: with paint, heavy coats mean a longer drying time.
- Paint when the temperature is above 60 degrees F and humidity is less than 50%.
- Spray the paint outdoors for better ventilation.
The dry time of the coating also depends on the surface type it is applied. Here are some different types of surfaces and their drying time:
Spray paints dry quickly on plastic because they can’t penetrate it. As such, they stay over the top layer of plastic and start to dry immediately. On average, a coating dries within 1 hour over a plastic.
Spray paint dries slower on wood because wood is a porous surface that absorbs the paint deeply. This makes it difficult for the solvent to evaporate since most of it is soaked into the wood grain where there’s no air circulation. On average, a coating dries within 2 hours over a wooden surface.
Spray paints dry super-quick on cardboard. That’s because cardboards are light and porous, meaning they allow air to penetrate from both sides; this increases the evaporation rate. On average, a coating will dry within 30 minutes over cardboard.
Spray paints dry fast on metal because of the high thermal conductivity of the metal. When the weather gets hot, the metal will get hotter too making the solvent evaporate faster. However, the paint will dry slower if the weather is cold as the metal will turn cool and sometimes moist.
On average, a coating dries within 30-60 minutes over a metal.
Spray paints dry fast on glass because their surface is non-porous, so the coating doesn’t soak into the glass. Since most of the coating is exposed to air, the solvent evaporates faster. On average, a coating dries within 30 minutes over a glass surface.
Related Read: Can You Spray Paint Glass?
Spray paints don’t dry quickly on plaster as it is porous — so the coating soaks into the plaster. On average, a coating dries within 60-90 minutes over a plaster.
Dry Time Before Sanding
The spray paint coating must fully dry before you can sand it. This takes 1-4 hours. The coating must be fully dry and rigid enough to handle rough sandpaper. If you sand too soon, you will remove the entire coating.
What Happens if Spray Paint Dries Too Fast?
If the spray paint dries too fast, it will start to crack after a while. The particles have to bond naturally for the coating to be durable. So, if you use a hairdryer to speed up the drying time, the particles won’t have enough time to harden and compact, so the coating won’t be durable.
Why Isn’t Spray Paint Drying?
If the spray paint isn’t drying that means that you re-coated too soon or you applied more coats than required. To fix this spray paint problem, you have to make the coating dry by using a hairdryer.