How Long Between Polyurethane Coats?
Whenever using polyurethane, there’s a good chance you’ll end up applying multiple coats. Additional coats of polyurethane will add protection to your project and ensure it lasts for years to come.
But how long should you wait between coats?
In this post, I’ll explain exactly how long you should be between applying coats of polyurethane and much more. Let’s dig in!
The amount of time you should wait between coats of polyurethane will depend on the type of polyurethane you use and how quickly it dries. For water based polyurethane, you may only have to wait a couple of hours between coats. For oil based polyurethane, it can take up to 24 hours between coats for a smooth finish. Be sure that your poly isn’t tacky when applying additional coats.
How Long Between Oil Based Polyurethane Coats
For oil based polyurethane, it’s best to wait around 8 to 24 hours between coats.
This will depend on several factors including the temperature of the room, humidity levels, the thickness you’re applying polyurethane, the brand of polyurethane, and more.
To be safe, you should wait 24 hours, just in case. However, if you notice that the poly has dried in 12 hours, it should be fine to add your second coat.
Don’t forget! It’s important to sand in between coats of polyurethane to get the best finish possible. This will give you more protection and a better appearance.
How Long Between Water Based Polyurethane Coats
For water based polyurethane, it’s best to wait between 2 to 4 hours between coats.
Just like with oil based polyurethane, there are many factors that will affect how long you should wait in between coats such as the temperature, humidity, airflow, and thickness of the polyurethane you apply.
Wondering if you can stain over polyurethane? Check out this guide to using wood stain over polyurethane for more info!
How to Tell if the Surface is Ready for an Additional Coat
The main way to tell if your project is ready for another coat of polyurethane is by feeling the surface. If your polyurethane is sticky or tacky, you’ll want to keep letting it dry. Additionally, if marks are left when touching, you should keep waiting.
How Long Between Polyurethane Coats on Floors
Flooring is slightly different when it comes to applying polyurethane and the amount of time you should wait between coats.
Because floors must withstand a significant amount of wear and tear, it’s recommended to let it almost dry completely between coats for maximum strength. I recommend at least 12 hours of drying time for polyurethane between coats on wood floors.
What Happens if You Don’t Wait Long Enough to Apply Additional Coats?
You might be thinking, “okay, but what would happen if I just start applying polyurethane even if it’s not completely dry?”
The short answer, just don’t!
You will end up with some of the common polyurethane mistakes such as:
- A rougher surface
- A weaker finish
- A cloudy finish
Can You Wait Too Long Between Coats Of Polyurethane?
Depending on how many coats of polyurethane of end up applying, you might be wondering if it’s possible to wait too long.
The short answer is no, not really.
Even if you let the polyurethane completely dry between coats, that’s fine!
Benefits of Additional Coats of Polyurethane
While it’s not required to apply multiple coats of a polyurethane resin, there are a few benefits you’ll want to be aware of.
- Additional protection
- Smoother finish
- A different look or sheen
How to Apply Polyurethane
Sand Surface
Start by sanding the surface of your wood with a medium grit sandpaper. This will help the polyurethane adhere to the surface better.
Wipe Clean
Next, wipe away any dust with a dry cloth to leave a smooth surface. You want to be sure there is no dust when you apply your first coat of polyurethane.
Thin Polyurethane
If you’re using an oil based polyurethane, thinning it can yield a better finish. While it’s not required, I typically like to thin polyurethane a bit because it makes the application process easier. You’ll just need to add some mineral spirits to the polyurethane to thin it out.
Apply First Coat
Once the surface is clear, you can use a foam brush or sprayer to apply a thin coat of polyurethane on the bare wood. If you use a natural bristled brush, be on the lookout for brush marks that can affect the final result.
I always recommend applying thin coats to decrease the chances of making a mistake when applying it.
Let it Dry
Next, allow the first polyurethane coating to dry. This can take a few hours depending on the type of polyurethane and several other factors.
Sand Lightly and Wipe
Once it’s dried, lightly sand the previous coat of polyurethane with a fine grit sandpaper. The first coat will always require the most sanding. Some people will use steel wool for sanding, but I don’t recommend this. It doesn’t work as well and can ruin your project if you aren’t careful.
Apply Next Coat
Once the previous coat has been sanded and cleared, apply new coat to add more protection. Always aim to apply thin coats to avoid air bubbles and other issues that can arise when you applying polyurethane to thick.
Repeat Steps Until Final Coat
Continue to apply subsequent coats as desired until you reach the final coat. You’ll want to sand the surface lightly in between coats until you reach the last coat.
The number of coats you should apply will vary depending on your project, how much protection you want, and the color or sheen you desire.
Some people will claim you should use at least three coats, while others recommend four or five coats. It all depends!
Three coats should be fine on projects that don’t deal with tons of wear and tear. However, if you’re coating hardwood floors, I’d recommend going with up to five coats for greater protection and durability.
Need more help? Check out the video below!
FAQs
What happens if I apply a second coat of polyurethane too soon?
If you apply a second coats of polyurethane too soon, you’ll likely get a rough or cloudy surface that can ruin your project or floors.
How long should Minwax polyurethane dry between coats?
For Minwax oil based polyurethane, you should wait between 4 to 6 hours between recoats. For Minwax water based polyurethane, you should wait between 2 to 4 hours between coats.
Final Thoughts
Applying polyurethane is a great way to add protection to your project or hardwood floors, but applying it correctly is essential.
Depending on how many coats of polyurethane you’re applying, it’s critical to give it time to dry in between coats.
Depending on the type of polyurethane you use, you’ll need to wait between 4 and 24 hours before applying additional coats.