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Dive in: How to caulk a bathtub

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Caulking bathtubs requires a good deal of attention to ensure water will not seep into the wall cavity. With some patience and time, you can easily improve your existing seal or complete a new installation. Premium bathroom caulk goes on cleanly and precisely, making this an easy do-it-yourself project.


Knowing how to caulk a bathtub is one of the most critical steps in the installation process. Get it right, and it will last. Applying new caulk is easy with the right tools and products. If you are replacing a current seal, you absolutely must remove all existing product to ensure proper application. This how-to guide explains everything you need to know about caulking bathtubs.

A hand cuts off the tip of a tube with sealant.
First, you cut off the tip of the silicone tube and insert it into the caulking gun


You will need a few tools to do this job right:

  1. Plastic razor scraper – For removing the existing seal
  2. Tweezers – For removing hard-to-reach or stubborn caulk
  3. Vacuum – For cleaning up old product
  4. Denatured alcohol and a cloth – For cleaning the tub’s surface
  5. Bleach solution – For removing any mold or mildew
  6. Painter’s tape – For guaranteeing a clean line in your new application
  7. Caulking gun – For applying caulk, available at most hardware stores
  8. Bath caulk – For creating your new seal
  9. Applicator tool – For smoothing out the caulk


Picking the right sealant is critical to ensure your work will last for years and prevent water damage. Loctite Polyseamseal Tub & Tile Adhesive Caulk has been specifically formulated to create a long-lasting, flexible seal that is resistant to mold and mildew. It works on both fiberglass and ceramic surfaces as a two-in-one product, making it highly versatile. It dries in an almond, white, or clear finish, and you can paint it to match your decor. It also resists color change and damage from harsh chemical cleaners, which means the finish will last longer and stay fresh for years.

Recommended applications for Loctite Polyseamseal Tub & Tile Adhesive Caulk include sealing around bathtubs, sinks, shower stalls, tiles, and backsplashes. It has excellent adhesion to ceramic, porcelain, glass, fiberglass composites, enamel, aluminum, stainless steel, wood, many plastics, and wallboard.

A man with a caulking gun applies some product to seal a bathtub. The edges are taped.
To obtain a seal with clean edges, it’s best to apply tape to the areas above and below the seal

How to caulk a bathtub

How to remove caulk from tubs

If the caulk around your bathtub is lifting, broken or moldy, it’s important to re-caulk it. A compromised caulk line can mean trouble, so avoid structural damage by removing the old sealant and reapplying new. Here’s how to remove old caulk from a tub.

  1. Use the plastic razor blade scraper to remove any existing caulk. With quick strokes, push the razor flush against the old caulk. This causes the sealant to come off in longer strips that can be easily cleaned up. Use the tweezers to remove any remaining caulk.
  2. Vacuum up the old caulk. Suck up any remaining pieces so you have a perfectly clean workspace.
  3. Wipe down the tub with denatured alcohol. Using a cloth, wipe down where the old caulk was to ensure you get the best seal possible when you apply the new product.
  4. Clean with bleach. Cleaning with a 1:4 solution of bleach and water removes any mold or mildew that has grown. Make sure your workspace is well ventilated, and wear protective gloves. Use an old rag and allow the bleach to dry completely before applying the new caulk.

How to recaulk a bathtub

Now that you know how to remove bathtub caulk, let’s learn about resealing. Here’s how to recaulk a bathtub.

Prepare your work area before applying the caulk. Ensure that your workspace is free of debris and oils and that it is perfectly dry. Apply two strips of painter’s tape parallel to the seam that requires caulking. This will ensure you get a clean, straight line.

Load Loctite Polyseamseal Tub & Tile Adhesive Caulk into the caulking gun. After loading the sealant into the gun, cut the tip to the desired bead size at a 45-degree angle. The tube should be firmly in place with the tip secured in the front of the caulking gun.

Apply the caulk at a 45-degree angle. The tip of the caulking tube should be close to the surface when you want to apply caulk to the seam. Slowly apply a smooth bead of sealant as required.

Smooth the caulk. Using the applicator tool, press the caulk into the seam, smoothing it out. Try to create a straight finish with a gradient of approximately 45 degrees. This will help the joint sealant dry more quickly after being exposed to water – and make it last longer. Do not use your finger to smooth the caulk. This would create a concave shape that will stay wet longer or allow water to accumulate.

Remove the tape promptly. After you have smoothed all required areas, peel the tape off before the caulk dries.

Clean off any excess caulk before it dries. Using a wet rag, wipe down the areas that require cleaning.

Painting and bathtub use. You can paint it with a latex- or oil-based paint two hours after application. Let it sit for at least 48 hours before use.

After at least two days, your seal will be fully set and can now protect the seam from water. If you notice unwanted dried sealant on a surface, you can use a rag soaked with denatured alcohol and a plastic razor to scrape it off. To remove any tacky residue, simply use a damp rag to wipe the surface.

Products used

  • loctite polyseamseal tub tile white 10oz cartridge
    Loctite Polyseamseal Tub & Tile

    Provides a durable bond and seal for kitchen & bath projects.

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