Can You Use Flex Seal on Bathroom Sink?

Flex seal is a thick rubber liquid material that creates a watertight and strong seal around the seams and cracks to prevent leaks and wobbling.

Can You Use Flex Seal on Bathroom Sink? You can use flex seal on the bathroom sink by checking for leaks and cracks on its surface, cleaning the fixture, and removing the old caulk. Apply the flex liquid sealant or flex shot around the sink leaks and gaps and let it dry before turning the water on. It can last 20-25 years, providing the appropriate conditions and more coating layers.

It has become famous in recent years because traditional caulk and adhesives can deteriorate over time under high moisture levels and cause leaks. 

How can you use flex seal on the bathroom sink?

Applying flex seal around the sink is easy. Many people use it around the sink to cover the small seams from the wall and under the base to avoid the water seeping through the cracks.

Check for cracks or leaks

If you drop something heavy on its surface or notice seams between the wall and the plumbing fixture, the sink can get cracks on the base and underside.

Turn on the water and check for the place where the water is leaking, and you can apply it on the cracked surfaces and small holes after spotting the leakage point.

Measure the gap between the sink and wall, and flex sealing paste can work well if the gap is larger.

Clean the surface and remove the old caulk

It is better to clean the surface and remove the water splashes and moisture before applying the sealant on the sink surface.

Remove the old caulk around the seams or the cracked surface using a razor scraper to apply the sealant accurately on the sink.

The dust and debris particles on it can cause an unappealing finish, and the liquid cannot stick well with the cracked surface and grime seams.

However, you can use vinegar or warm water to remove the grime and mold from the surface and clean it with a soft dry cloth.

Apply the flex sealant

Select a flex seal in liquid or spray form, depending on the area you want to cover or the nature of the cracks.

For example, you can use a spray with a nozzle that fills the seams in corners and around the edges, while for liquid sealant, you can use a paintbrush or roller.

Apply it on the sink surface using a brush and make sure to cover the full area to prevent any leakage spots. Press the nozzle from the end if you are using a flex shot around the gaps.

Smoothen it with your fingers if you apply it around the gaps between the wall and the fixture to give it a uniform and finished appearance.

Let it cure, and do a leak test

Let the sealant coating dry for 22-24 hours, depending on the number of coating layers you have applied on the sink surface or the thickness of the flex shot around the seams and cracks.

It can take more than 24 hours if you apply 3-4 coatings therefore, allow proper time for the sealant to dry because a wet seal can peel off if you turn on the water immediately and use the plumbing fixture before it dries.

You can do a leak test after the sealing is dried by turning the water on in the sink and noticing if there is any leakage around the edges and the base.

Why would you use flex seal on the bathroom sink?

Many people apply flex seal on the bathroom plumbing fixtures, such as the sink.


It uses a 100 percent water-proof formulation, which includes silicone, aliphatic petroleum solvent, Toluene, and other water-resistant chemicals in its formation.

The flex seal liquid does not dissolve or peel off underwater and creates a watertight and waterproof sealing around the sink and other plumbing fixtures.

It can withstand high moisture-level and the specific formulation can cure or dry underwater, which makes it one of the finest and most amazing fully water-proof sealants in various adhesive classes.

Mold and corrosion resistant

This seal can prevent mold and mildew growth around the wet places and creates a rubber sealing when dry.

As a result, moisture cannot enter the cracks and seams, which minimizes the chances of mold growth inside the gaps and cracks.

The sink edges and the drain can get rusty because of the water’s leakage and the high iron level, which interacts with oxygen and causes corrosion. 

The sealing liquid can prevent these problems and keeps the plumbing fixture in good condition by covering the surface and its water-proof nature. 

Fill the cracks and holes

The flex paste is a thick rubber liquid material that can fill the cracks, gaps, and holes in the bathroom sink, and you do not have to replace the plumbing fixture with a new one.

You can apply it as a thick layer, as you want to cover the larger gaps and cracks, but make sure to cure the surface properly because it can take 2-3 days depending on the thickness of the coats.

Some people use it around the base of the pedestal sink where the pedestal meets the floor to cover the space between the floor and the plumbing fixture using a nozzle flex shot. 

Available in a variety of options and colors

It is available in various colors and options, such as spray sealant, liquid cans, flex shot, and flex tape or glue. In addition, you can select different options depending on the location to want it to apply.

It provides different color options in Flex Seal products, such as red, white, black, almond, grey, brown, and many others options.

You can choose the sealant color that matches the plumbing fixture and offers the same appearance as the sink color.

They are available in different ranges, such as the flex shot ranges from $12 to $30 depending on the bottle size and the type of sealant. You can also apply paints on the sealing material to match the sink color.

How long does a flex seal last on the bathroom sink?

This seal can last for 20-25 years, and its life duration depends on different factors, such as the surface on which you are going to apply the sealant, the type of flex sealant, and temperature.

The expertise and the skills to accurately and smoothly apply the sealant and the number of coatings also affect the lifespan of the sealing material.

It will not deteriorate or turn yellow over time as other sealants, and you can use it in high moisture areas without worrying about damage to the sealing.

However, the excessive hot water use in the sink can cause it to deteriorate soon. It can affect the product’s lifetime because the seal cannot withstand extreme temperatures.

You can enhance the durability of the sealant by providing appropriate conditions and calling a professional plumber to fix the leaks and apply them accurately if you do not know how to use them on bathroom sink leaks and cracks.

Things to consider while using flex seal on the bathroom sink

This sealing product is a flexible material that can be used on various surfaces, such as wood, porcelain, glass, plastic, drywall, rubber, cement, aluminum, and vinyl.

However, the type of flex sealant used on the specific area and material depends on the nature of the gap and the place where you notice the leak.

For example, you cannot use sealing liquid around the sink gap with the wall, as the flex shot can do this job well to fill the seams between the wall and the plumbing fixture.

Using harsh chemical cleaners will cause the sealant to peel off over time if you often use those cleaners to clean the stains on its sink surface.

It is better to turn on the bathroom fans and open the windows for adequate ventilation in this place, as it will reduce the drying time for the sealant.

You can use the sink to wash your hands and face soon after applying the sealant because low moisture levels in the bathroom can cause a surface cure soon.

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