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 polyurethane dry faster. 

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

Why is Polyurethane Sticky?

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

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

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

If you apply polyurethane when there’s high humidity in the atmosphere, the polyurethane turns sticky. After applying polyurethane, the moisture in the atmosphere settles over the coating and gets the finish wet. This leads to poor paint adhesion and sticky polyurethane. 

Also, polyurethane 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 polyurethane and turn it sticky.

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

Polyurethane Dry Time

Polyurethane Dry Time

Polyurethane takes 12-48 hours to dry. Water-based polyurethane takes 8 hours to dry enough for use. On the other hand, oil-based polyurethane takes 24 hours to dry enough for light use.

It takes water-based polyurethane 3 hours to dry enough for a re-coat, while oil-based polyurethane takes 12 hours to dry enough for a re-coat. 

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 paint turns from liquid to solid. Once the paint cures, it can be used.

Water-based polyurethane takes 24 hours to cure, while oil-based polyurethane takes 48-72 hours to cure. 

Polyurethane takes longer to dry than regular paint because polyurethane is a sealant. As a sealant, polyurethane 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 the polyurethane is removed, clean the material, apply stain-blocking primer, and re-apply polyurethane. 

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 polyurethane using a hairdryer or heat lamp.
  2. Open all windows, vents, and doors for improved circulation. This will get the polyurethane coating to dry 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 polyurethane 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.

If polyurethane is still sticky after 24-48 hours, remove it with a chemical-based paint remover and re-apply it. 

How To Know When Polyurethane is Dry?

The following signs will indicate when the polyurethane 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.
  • Polyurethane will no longer produce a strong smell.

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

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

Polyurethane Shouldn’t Be Sticky After It Dries

Polyurethane shouldn’t be sticky after it dries. At most, polyurethane should be sticky for 6 hours before it dries. After polyurethane dries, 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. Polyurethane not drying is an indicator of poor preparation before painting. 

You must remove dust and water over the surface before applying polyurethane. You also must sand between coats of polyurethane for better adhesion. 

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