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Will Flex Seal Fix a Cracked Bathtub? (Read This First!)

Flex seal is generally a thick liquid coating. When you spray a flex seal into cracks and holes, it seals the cracks and holes.

Flex seal is so convenient that you can use it on almost all surfaces. For example, glass, metal, ceramics, wood, etc., materials can be fixed with a flex seal.

So, you might be confused about whether a flex seal will fix a cracked bathtub or not. Well, when the flex seal dries, it becomes watertight. But you have to the detailed properties of flex seal to know its ability to fix a cracked bathtub.

Will flex seal fix a cracked bathtub?

You can use flex seal into a cracked bathtub. But a flex seal will not permanently fix a cracked bathtub. Generally, a flex seal can be used on any surface. So, this can also be used on the bathtub and the crack will be watertight. But gradually the seal will start to open and lose the coating.

You might know that flex seal is a liquid spray coating. This coating fix cracks and holes in almost any surface. But you have to know how strong the bonding between the flex seal and the surface will be.

For example, you might use a flex seal for a DIY project. This will work instantly and temporarily. But if you want to fix a permanent problem like the cracked bathtub fixing, you should not use a flex seal.

Flex seal doesn’t have the structural properties to fix a cracked bathtub. For fixing a cracked bathtub, you will need something that has a strong chemical bond with the ceramic or porcelain bathtub.

So, since flex seal doesn’t create a permanent strong bond with porcelain or ceramic, it will not fix the cracked bathtub. Though it will stop the leakage of water, the crack will open gradually after some days. So, the crack will return and leak water from the bathtub again.

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Does flex seal work on bathtubs?

Flex seal works on bathtubs temporarily. Generally, a flex seal can be used on so many surfaces that you might think it can fix any crack or hole. But flex seal will not be a permanent solution on bathtubs.

Most bathtubs are made of ceramic or porcelain. So, when you apply flex seal on bathtubs, it will temporarily solve your problem. For example, if the bathtub is cracked, a flex seal will stop the leakage of water.

But the seal will not create a strong structural bond with bathtub material. So, it will not seal the bathtub permanently. So, flex seal works on bathtub but not for a long time.

Can You Use Flex Seal on fiberglass tub?

Yes, you can use a flex seal on a fiberglass tub. Generally, you can use a flex seal on glass and fiberglass surfaces. The liquid spray of flex seal will seal the cracked bathtub after it dries.

So, when you apply the flex seal on the bathtub and it will dry after some time. Then you will see it removes the leakage. So, the flex seal is convenient for instant use.

But flex seals don’t have the structural value to permanently fix fiberglass material. So, the fiberglass bathtub will return to its leakage problems gradually.

Flex Seal Spray Rubber Sealant Coating, 14-oz, Clear (2 Pack)

How to fix a cracked bathtub using a flex seal?

A flex seal can be an instant solution for your cracked bathtub. It will repair the bathtub temporarily so well that the leakage of water will be stopped. But you have to dry the bathtub surface first.

After draining all the water from the bathtub and drying it, you have to use flex seal on the cracked surface. Put the cracked pieces of the bathtub together and spray flex seal on the crack.

After sealing the crack, remove excess material from the surface using your fingers. After 20 to 30 minutes, the flex seal will dry. But you should wait for 2 days to dry the bathtub completely. Otherwise, the leakage might not be fixed fully.

How long does the flex seal last once applied?

The flex seal will last for years once applied. Generally, how long the seal will last depend on the surface of the application and its use. Moreover, if you coat the flex seal on a surface multiple times, it will last long.

Generally, flex seals will last at least 1 year on any surface. If you keep the surface clean, it will last even a long time. Moreover, a flex seal can last for a couple of years too.

Many people start to use the surface after drying the flex seal immediately. But if you wait for 2 to 3 days to dry the flex seal surface completely, the seal will work better on it.

Moreover, the flex seal will be long-lasting. So, once you apply the flex seal on cracks and holes, it will work for years.

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How do you fix a crack in a bathtub permanently?

Fiberglass and porcelain bathtubs are likely to get cracked. You might have used sealing or filler material to fix the cracks in your bathtub. But those might have worked temporarily. So, you have to find a permanent solution. However, let’s see how you can fix a crack in a bathtub permanently.

  • Get ready with all the fiberglass repairing tools and kit.
  • Dry the cracked bathtub well and rub the cracked area with sandpaper to remove excess putty and rough inclusions.
  • Wipe off the sanding dust and dry the cracked area well.
  • Mix the epoxy gel coat with the tools of the fiberglass kit.
  • Apply the gel with a painting brush on the cracked line and additional 2 inches area.
  • Place the fiberglass cloth on the gel and press it with your hand so that the air bubbles are removed.
  • Then paint the second coat of gel over the fiberglass cloth and press it again well.
  • Apply the sealer to finish the repairing process.
  • Keep the coating dry and don’t use water in the bathtub until it is completely dry.

Flex Seal Spray Rubber Sealant Coating, 14-oz, Black (2 Pack)

Is flex seal safe or good for bathtubs?

Yes, a flex seal is safe or good for bathtubs. Generally, flex seals are liquid sprays that don’t harm the bathtub materials. It can be used on almost all surfaces. So, the flex seal is safe for bathtubs. Whatever material is the bathtub made of, you can use a flex seal on it.  

Moreover, the flex seal doesn’t look bad when you apply it to bathtubs. It will dry soon and make the bathtubs look good. It will prevent water leakage from the bathtubs and won’t make the bathtub unsafe.

Besides, if you use a flex seal on the bathtubs, it will not react with water after it dries. Once the flex seal is dried, it will last for years and will not cause a problem in contact with water. So, the flex seal is completely safe for bathtubs.

How to prevent bathtub cracks?

Bathtub cracks can be pretty irritating. Generally, ceramic, porcelain, fiberglass, etc., bathtubs are likely to get cracking. So, you have to prevent the bathtubs from getting cracks.

For preventing cracks, you need to install the bathtub with proper support. If the bathtub is not installed properly, it will not support more weight. So, you have to install the bathtub in such a way that it can withstand enough weight.

Moreover, you need to avoid cleaning the bathtub with abrasive material. For example, you should not use bleach in the bathtub. It will abrade the bathtub surface and create cracks gradually. Moreover, avoid dropping heavy materials on the bathtub.

What will flex seal not stick to?

Flex seal is so convenient that it will stick to almost all surfaces. But flex seal will not stick to some plastics, vinyl, and rubbers.

Generally, flex seal will stick to rubbers and many other rubbery materials. But some plastics and rubbers will not be stuck to the flex seal. The reason might be the structural properties of the flex seal.

The structural properties of flex seals are not strong enough for some plastics, vinyl, and rubbers. Moreover, flex seal will also not stick to silicone.

So, if you want to repair anything containing silicon parts, you need to remove the silicon parts first. Otherwise, the flex seal will not adhere to it.

Final Thoughts:

If you want an instant and temporary solution for a cracked bathtub, a flex seal will work on it. But might not create a strong bond with the bathtub material. So, the seal might be loose and reopen the crack gradually. So, flex seal is good for stopping leakage, but for temporary usage.