Will Flex Seal Fix a Cracked Bathtub?

Flex seal is the adhesive glue used to fix cracks in wood, ceramic, concrete, and fiberglass material. You can use these to seal the bathtub cracks and holes and prevent moisture entry.

Will Flex Seal Fix a Cracked Bathtub? You can use the flex seals to fix cracked bathtubs, but it is not a permanent solution. Moreover, these are not suitable for ceramic and porcelain bathtubs. Wash the surface with bathroom cleaner for their application. Buff the cracked area with sandpaper and adhere to the flex tape. Coat the tape with flex seal liquid spray and then wait for drying.

It is necessary to fix the cracks in the bathtubs to protect the water from seeping into the subfloors. The water entry through these cracks can completely ruin the lower floorings.

Can you use a flex seal to fix a cracked bathtub?

Flex seal is the adhesive liquid spray used to fill the cracks in the bathtubs. The cracks in these items come when heavy things fall on them or the use of abrasive cleaners.

It is beneficial because it cannot fade or lose its strength for long after its application.

Because of their waterproofing properties, people use them to fill the creaks and holes. These are the only temporary solutions to fix water leaks.

It forms the protective layer on the affected surface and the watertight bond to prevent leakage into the subflooring.

You have to adopt other methods to resolve this issue permanently. This is because the protective loses its strength and adhesive properties after some time.

You can use the epoxy resin, bathtub repair kit, or hire a professional for permanent solutions. Furthermore, welding the creaked area is the best solution for iron or steel material.

How do you fix a crack in the bathtub with a flex seal?

You can use them as temporary solutions to fix the holes in bathtubs because these can lose their structural value after some years. These are available in different colors, and you can select the required one from the market to give perfect finishing.

Wipe off the cracked area

It is necessary to make the affected area clean to apply flex seals. You can remove the dust and dirt from their surface using a soft cloth.

Avoid using abrasive cloths because it produces more scratches and worsens the situation. You can also use the old towels for their cleanliness because of their soft and delicate fabric.

Use a cleaning agent to remove the stains from their surroundings and make the area neat and clean.

Use a dry cloth or towel to remove excess moisture from them. The cleanliness and removal of dust increase the adhesive properties.


Use high grit sandpaper to fix the sharp edges of the cracked area. Moreover, sanding makes the surface smooth, perfect for applying flex seal tape.

It is difficult for liquid sprays to adhere to these rough and rigid surfaces. Use sandpaper to level the surface instead of an electric sander because it can cause more damage.

Sanding causes the dust and grout to come into the bathtubs, and you have to remove it. Use a vacuum cleaner or hair dryer to get rid of these tiny particles.

You can also wipe off the dust with a dry cloth or towel and then coat it with alcohol.

Application of seal

Make the smaller strips according to the extent of the damage. Then, cut the strips according to the size and dimension of the cracked surface.

Apply these tape strips on the affected area, making the adhesion process easier. In addition, the liquid flex provides more adhesion to these tape patches.

Spray the liquid material on all the sides of the tape and add multiple coats to make a thick layer that lasts for a longer time.

Leave it for 2 to 3 days, and do not use water on it to make them completely dry. Do the water leakage test after 2 to 3 days and mark the water level with a marker.

Check the water level on these marked lines after 1 or 2 hours to check leakage.

How long will a flex seal last on a bathtub when you apply it?

The flex seal will last for months to years when you apply them on the cracked bathtubs. However, these start to lose their gluey texture and structural integrity after time passes.

It is necessary to coat the creaked area again when the protective coating starts to peel off after the year and becomes faded.

The reapplication time depends on the cleaning practices and types of cleaning detergents. However, you can increase their longevity by keeping them clean and using mild abrasive detergents.

It depends on drying time after applying the adhesive spray. This is because the coat starts to scrap off when you start using it immediately.

The proper sanding of the affected area for the application of adhesive glue is also necessary to keep them in their place for longer.

Things to consider when using flex seal for bathtubs

It is necessary to consider these things when you are using to resolve the creaking issues in bathtubs. It only forms a thick layer on the affected area to prevent further damage.

Material of bathtubs

The adhesion of this adhesive spray depends on the material of the bathtubs. Therefore, you must check their material before using it.

It sticks to the fiberglass material more perfectly and also stays there for a longer time. The adhesion with ceramic and porcelain material is less as compared to fiberglass.

The stay time with ceramic and porcelain material is also less because of their different texture. Hire a professional, or use a repair kit to fix these materials.

Moreover, these can stick to these hard materials but cannot stay there longer. This is because the bond between the protective layer and ceramic is weak and loses its strength after some time.

Temperature of water

It is not sensitive to temperature and works best with optimal range. However, extreme freezing or warmer temperature can affect their adhesive properties.

People often want to take a warm bath in winter to relax their bodies. In addition, sitting in warm water for longer is a cozy feeling in winter.

Regular exposure to warm water damage this protective layer. In addition, it starts to come off from the cracked area because of high water temperature.

Check the water temperature after their application so these can last for a longer time.

Number of coats

The number of coatings is the primary factor that affects the adhesion of the flex seals on the different materials.

You have to apply several coats on your bathtub for better strength and increasing longevity. Many people coat them 3 to 4 times, making them lose their strength due to regular exposure to warm water.

The thick protective layer is beneficial and provides more durability against different materials. However, applying multiple coats on the cracked area is better to fill them perfectly.

The thick coating can increase their longevity, and you do not have to move toward the permanent solution quickly.

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