Thompson’s Water Seal Dry Time? (& Speed Up Tips)

Thompson’s water seal is a waterproof sealer that protects against water damage. But before the seal becomes waterproof, it needs to dry first. So, how long does it take for Thompson’s water seal to dry?

It takes 4 hours for each coat of Thompson’s water seal to dry but the entire sealer finish takes 24-48 hours to dry. If you want to apply a top coat or paint on the Thompson’s water seal, you should let it dry for at least 30 days.

According to the manufacturer, the level of humidity, room temperature, and substrate all determine how long it takes for Thompson’s water seal to dry. If you want the water seal to dry faster, you should apply thin coats in the right drying conditions.

This post reveals more about the dry time of Thompson’s water seal including expert tips to make the sealer dry faster. Let’s dive in.

How Long Should Thompson’s Water Seal Dry Between Coats?

How Long Should Thompson’s Water Seal Dry Between Coats?

You should let Thompson’s water seal dry for at most 90 minutes between coats. Thompson’s seal manufacturer states to apply the next coat within 2 hours after applying the existing coat. This is to prevent the existing coat from drying up and repelling the new coat.

Unlike other paints that have to completely dry and cure before another coat can be applied, Thompson’s water seal needs to be recoated before it completely dries. With other paints, you need the first coat to dry before applying the next coat to prevent bleed-through and a tacky finish.

Thompson’s water seal on the other hand is not a paint, the product is a sealer and if you allow each coat to dry before applying the next coat, the next coat will not stick. This is because the existing coat when dry will become moisture resistant and will repel the next coat.

So, the best way to recoat Thompson’s water seal is to do so while the first coat is drying and this happens within 2 hours after applying the first coat. After 2 hours, the first coat will begin to solidify and it will be very difficult to recoat.

How Long Does It Take Thompson’s Water Seal To Cure?

It takes Thompson’s water seal between 2 weeks and 30 days to cure. On average, a coat of Thompson’s water seal takes 21 days to cure while 2 coats take 30 days to cure. Only when the water seal has cured are you allowed to apply paint over it. You should know that the cure time of the Thompson’s water seal depends on the air current and not heat.

The cure time of Thompson’s water seal is very different from the dry time. When the water seal is dry, it means that the solvent (or moisture) in the seal has been completely evaporated. So, when the seal is said to have cured, it means that the particles have become hard and waterproof.

For the sealer to cure, the particles need to be oxidized and this happens when the water seal is exposed to air current (or oxygen). The oxidization process takes several days and is completed in about 30 days. So, you should leave the water seal to cure for at least 30 days.

Only when the Thompson’s water seal has cured can it be top coated, painted, or exposed to moisture. If you expose the sealer to high moisture content or paint before it has cured, then the finish will be ruined. That said, you should only use oil-based paint on a cured Thompson’s water seal.

How To Speed Up Drying Time of Thompson’s Water Seal?

As good as Thompson’s water seal is, DIYers often cringe at the thought of waiting over 4 hours before the sealer dries. Here are 3 effective methods to speed up the dry time of Thompson’s water seal:

  1. Use a hairdryer
  2. Use a fan to speed up the dry time of the water seal
  3. Apply thin coats of the water seal
  4. Apply the water seal in the right drying conditions

This guide will show you how to use each of these methods and the tools and supplies needed for each method.

1. Use A Hairdryer

Use A Hairdryer

The first method to make Thompson’s water seal dry faster is to use a hairdryer. Hairdryers can generate heat over 100 degrees Fahrenheit and at this temperature, the Thompson’s water seal will dry faster.

The idea here is to expose the Thompson’s water seal coat to increased heat. When the Thompson’s water seal is exposed to increased heat, the evaporation of the solvent in the sealer will occur faster causing the sealer to dry quickly.

For this method, you’ll need these tools and supplies:

  • A hairdryer
  • A pair of gloves
  • A face mask

Here is a guide for this method:

  1. Power or plug-in the hairdryer.
  2. Set the temperature to medium or about 90 degrees Fahrenheit.
  3. Put on a pair of gloves and a face mask for protection.
  4. Move the hairdryer around the Thompson’s water seal coating for 5 minutes.
  5. Repeat step 4 every 15 minutes for an hour.
  6. Leave the Thompson’s water seal to dry completely.

Tip: You should only use this method immediately after applying the Thompson’s water seal. Also, don’t dry the sealer completely with a hairdryer as doing this will cause the finish to dry too quickly and will offer little to no moisture protection this way.

2. Use Fans To Speed Up The Dry Time

Use Fans To Speed Up The Dry Time

Another way to speed up the dry time of Thompson’s water seal is to expose the sealer to dry air. The idea here is to increase the air current around the Thompson’s water seal so it dries faster.

The increased air circulation will speed up the evaporation and solidification of the sealer particles so it dries and cures faster.

Here is a guide for this method:

  1. Open all doors and windows for ventilation.
  2. Turn on the fans in the room.
  3. Open the air vents.
  4. Leave the fans on for hours till the sealer begins to dry.

Tip: Direct the air current from the fans directly at the Thompson’s water seal coating.

3. Apply Thin Coats

Apply Thin Coats

The third method to dry Thompson’s water seal faster is to apply thin coats. When you apply thin coats of the water seal, the sealer will dry faster than when you apply thick coats.

You can use a paint sprayer or bristled paintbrush to apply thin coats of the sealer. You shouldn’t thin or dilute the sealer for any reason. Diluting the sealer will ruin it.

4. Apply The Thompson’s Water Seal In The Right Drying Conditions

Apply The Thompson’s Water Seal In The Right Drying Conditions

Another method to make Thompson’s water seal dry faster is to apply the sealer in the right conditions. According to the Thompson’s water seal manufacturer, you are to apply the water seal when the room temperature is above 50 degrees Fahrenheit and when the substrate layer or undercoat is dry.

If you apply the water seal when the room temperature drops below 50 degrees Fahrenheit, it will take longer to dry because the temperature is not right.

A common problem encountered by DIYers while applying Thompson’s water seal is that the water seal isn’t drying. So why does this happen? Let’s find out.

Common Causes for Thompson’s Water Seal Not Drying?

The most popular reason for Thompson’s water seal not drying is excess water seal. This happens when you apply too many coats of the Thompson’s water sealant.

When this happens, the extra coats that you add will not stick or dry. Instead, the extra coats will gunk up the surface and remain sticky and wet. After a while and due to the exposure to dirt and debris, the water seal will turn dark and begin to smell.

Here are other reasons for Thompson’s water seal not drying:

1. The Drying Condition Is Not Optimal

Thompson’s water seal has to be applied in temperatures above 50 degrees Fahrenheit and in a dry environment.

If the water seal is applied when the drying conditions and environment aren’t favorable, the water seal will take longer to dry.

For instance, if you apply the sealer when the room temperature is below 50 degrees F, it will take longer to dry and might not even dry eventually.

2. You Exposed The Water Seal To Water Too Soon

A common mistake among DIYers is exposing the water seal to moisture before the finish becomes waterproof. Thompson’s water sealer is waterproof but the finish only attains this waterproofing when it has dried completely.

If you wipe, clean, or pour water on the sealer before it has dried, it will absorb the water and this will cause it to stay wet for several hours without drying.

3. You Applied The Thompson’s Water Seal On An Existing Sealant

Thompson’s water sealer needs to bite into the surface to stick and dry properly. If there is an existing sealant like polyurethane or lacquer on the surface, the Thompson’s water sealer wouldn’t bite into, stick, or dry on the surface.

So, you need to remove the existing sealant with a chemical-based paint stripper before applying the water seal.

If you already applied the water seal on an existing sealant, it will not dry and the only way to fix this fault is to strip the water seal, remove the existing sealant and reapply the water seal.

4. You Waited Too Long For Recoat

Thompson’s water seal is a sealant and if you wait more than 2 hours before applying another coat, the first coat would have dried and sealed the surface making it impossible for the next coat to stick. Since the next coat doesn’t stick well, it won’t dry.

5. The Thompson’s Water Seal Has Gone Bad

If the water seal has expired or has been contaminated, then it will not dry when you apply it. To know if the water seal has gone bad, smell the water seal and if it smells foul or rotten, it has gone bad and shouldn’t be used.

Final Words

In summary, Thompson’s water seal takes between 24 and 48 hours to dry. Under optimal drying conditions, the sealer will dry in 24 hours.

But, when the drying condition is cool or not favorable, the sealer can take up to 48 hours to dry. If the sealer isn’t drying after 48 hours, it’s a sign of a problem usually caused by excess water sealer or improper prep work.

Finally, to make the Thompson’s water seal dry faster, you can use a hairdryer or heater. You can also apply thin coats using a paint sprayer or paintbrush but don’t dilute the water seal.

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