How to Fix Sticky Polyurethane? (4 Methods)

After you apply polyurethane, the last thing you want is for it to turn sticky. If that happens, how to fix sticky polyurethane?

To fix sticky polyurethane, expose the finish to heat using a hairdryer or heat lamp. The increased heat will speed up the evaporation rate of the solvent (oil), and make it dry faster. 

However, this is only a temporary fix. Even if it dries, the finish won’t be strong or durable. To get the best results possible, remove the finish and re-apply it. 

Why Does This Happen?

Polyurethane turns sticky if you don’t allow enough dry time between coats. If you apply a new coat before the old one is dry enough, the finish will turn sticky. 

The new coat won’t stick properly if the existing coating is still wet. Plus, the solvent that didn’t evaporate will be trapped between coats. After a while, the trapped solvent will bleed through and turn the finish wet and sticky.

You also must sand between coats; if you don’t, dirt and filth will be trapped between them. The dirt and filth will prevent good paint adhesion, and the finish will turn tacky. 

If you apply polyurethane when there’s high humidity in the atmosphere, its finish will turn sticky. That’s because the moisture in the atmosphere settles over the coating and gets the finish wet. This leads to poor paint adhesion.

Also, the finish turns tacky if you apply it over a stained material with high oily deposits. For example, mahogany, Bloodwood, and Rosewood have a high deposit of oils. As a result, the oils in the wood will bleed through the finish and turn it tacky.

If the finish is still sticky, it could be because you applied thick coats. The thicker the coating is, the longer it takes to dry.

Polyurethane Dry Time

Polyurethane Dry Time

It takes water-based polyurethane 3 hours to dry enough for a re-coat and 24 hours to cure. On the other hand, it oil-based polyurethane 12 hours to dry enough for a re-coat and 48-72 hours to cure.

The dry time and cure time are two different things. The dry time refers to the time it takes for the paint’s solvent to evaporate. Once the paint dries, it can be re-coated. The cure time refers to when the paint particles harden and the coating turns from liquid to solid. Once the paint cures, it can be used and cleaned.

Polyurethane takes longer to dry than regular paint because it is a sealant. As a sealant, it is formulated with several chemicals and resins to improve its durability, water resistance, and UV resistance. All these chemicals and resins need time to react and harden, making the cure time longer.

Also, polyurethane is plastic in liquid form, and it will take longer for the plastic to form and harden.

How To Fix Sticky Polyurethane?

How To Fix Sticky Polyurethane?

If polyurethane remains sticky after 24 hours, it’s best to remove it with a solvent such as turpentine or paint thinner and re-apply it. Once it is removed, clean the material, apply stain-blocking primer, and re-apply it. 

When polyurethane doesn’t dry or remains tacky, it’s because of poor preparation before applying it or not allowing enough dry time between coats. There’s nothing you can do in both scenarios, so removing it and starting from scratch is better.

However, if you don’t want to start from scratch, there are a few hacks that you can try out:

  1. Dry the coating using a hairdryer or heat lamp.
  2. Open all windows, vents, and doors for improved circulation. This will get the coating to dry more quicker.
  3. Use a dehumidifier to remove the excess moisture from the room.
  4. Apply Talcum powder to the polyurethane coating.

But, even if you get the coating dry using any of these hacks, the finish will not be as strong as it should be. It will get damaged by moisture. So it’s better to start from scratch.

How To Know When Polyurethane is Dry?

The following signs will indicate when the finish is dry:

  • The texture will be hard and silky-smooth.
  • The top layer will not be cool but warm when touched.
  • The top layer will be glossy.

You can also try to bend the polyurethane coating with your finger to know if it’s dry. Push your finger or thumb into the coating. If you notice an indent, then the coating isn’t dry yet.

To know if the finish has cured, sprinkle some water over it. If the coating absorbs the water, it hasn’t cured yet. If the water stays over the glossy finish, the coating has cured. Once polyurethane is cured, it becomes water-resistant. 

Polyurethane shouldn’t be sticky after it dries. At most, it should be sticky for 6 hours before it dries. After that, the coating should become hard, non-porous, and glossy.

If your polyurethane coating remains sticky or wet several hours after application, it’s usually due to one or more of the reasons below.

Related Read: How To Fix Yellow Polyurethane?

Final Words

Polyurethane shouldn’t be sticky after it dries, instead, its coating must be glossy and hard. So if the coating isn’t drying then it’s an indicator of poor preparation before painting. 

Tony Adams
Tony Adams

Tony is a professional painter and an author of DIY Geeks. Tony has completed over 1,000 painting projects for his clients. It's safe to say he knows what he Is talking about,

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