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Caulking a bathtub: How to re-caulk your bathtub

Live in any house long enough, and you will need to recaulk your bathtub. Learning how to recaulk a bathtub is not that hard! However, it will require time and patience, as caulking can be a tricky business. The key to caulking your bathtub is preparation. Make sure you have all the tools needed handy before you begin caulking your tub.


Can I caulk over old caulk?

If you are new to caulking, you might be wondering if you can caulk over caulking. Caulking over caulking is not recommended. It is tricky and not recommended by most experts. If you want to know more, you can read “Can you caulk over old caulk” for details on how to do it, but for the best results, you should avoid caulking over caulking.


How to recaulk a bathtub

Hopefully, you are sold on the idea of removing the old caulk and re-caulking your bathtub. Here are the steps you need to follow to re-caulk your bathtub (this can also work on a bathroom sink as well).

What you will need:

  • Caulk gun
  • Caulk tube
  • Masking tape
  • Sponge brush
  • Caulking rasp, caulking knife, or razor scraper


Remove old caulking

Removing Old Caulk

There are many ways to remove existing caulk. For example, you can use a caulk remover but be careful not to scratch the surface of the bathtub with the sharp tip of the tool.

Remove the old caulk with a sharp tool or razor blade (utility knife or putty knife), being careful not to scratch the surface of the bathtub. It’s best to use a silicone peeler, the kind used to peel off paint. You can also use caulk removers or a razor scraper, but you need to be sure that you do not damage the area as any scratch could create mildew issues.

If the old silicone caulk is hard to remove, turn on a steam cleaner to loosen it up for easier scraping.

Remove any dirt, grime, or loose material from the surface of the bathtub.

This step can take some time, but it is worth it.


Clean and prepare the surface.

Before you can apply any new caulk, clean off the walls with a wet rag and let them dry before moving forward–this will prevent getting fresh sealant on surfaces that haven’t yet dried after cleaning.

Clean the area with soap and water or solvent and a lint-free rag (check with the label for best practice). You want to remove any oil, grease, or dirt that might be present. Ensure there is no mold or mildew present. As soapy residue can prevent the silicone from sticking, make sure to clean the entire edge of the surface with the proper cleaner.


Dry the area

If you are re-caulking your bathtub right away, allow time for the surface to dry. Otherwise, the moisture will act as a barrier and prevent the caulk from sticking properly.

Press a piece of paper towel into the crack where there was old caulk. This will help prevent water from getting under the new caulking and causing it to peel off prematurely.

Make sure the surface is completely dry before applying the new caulking. 

If you want to dry the area faster, you can use a hairdryer. But time is the best way to let it dry. Leave it overnight and tackle the bathroom the next day.

If you use a blow-dryer, be careful not to heat it too much.

Tape off the area you don’t want caulk.

recaulking a bathtub

Next, you will want to apply two long strips of masking tape to your fiberglass bathtub and tile to ensure you apply the caulk in the right area.

The purpose of the masking tape is to prevent the caulk from oozing out the side, closing off any gaps you can’t fill with caulk. It also allows for the best caulks and ensures you have a straight line. You can use the blue painter’s tape that peels right off if you don’t like it and won’t leave any residue or mark on your tub.

If you are refinishing the tub surface or applying a new coating to it, you will want to tape off the area where you do not want sealant. Use painter’s tape to cover up areas that shouldn’t be treated with caulk.


Apply the new caulk

caulking a bathtub

There are many ways to get caulk. You can use a squeeze tube, application gun (I get the best caulk results with this method). Or you can mix it in a tub and apply it. We will use the tube and gun method (though squeeze tubes are pretty similar).

  1. Next, trim the tip of the caulking tube in the caulk gun at a 45-degree angle (be sure not to make it too large) and apply a thin bead to the joint.
  2. Gently apply steady pressure to the caulking gun and run the gun at a 45-degree angle and let the sealant set for 24 hours before you remove the tape and clean up any mess that may have occurred.
  3. Apply in one direction, from top to bottom and then across. If you get caulk on your fingers or if it is getting messy, don’t wipe off the excess until after application, as doing so will just move the caulk around. Try to only use the amount you need to fill in any gaps. 
  4. Be sure to smooth it out as you go, pulling down gently with your finger or a razor blade to make it even and flush with the surrounding surface.
  5. Once the bead has been applied, run your tool (or finger) smoothly across the surface of the tub to remove any extra caulk.
  6. With your finger, run along both long sides of the bead, removing the excess caulk. It is not necessary to wipe a lot off since it will level out after it has cured. You might have trouble with little blobs of caulk that stick out from between the tiles. Just go over them again before they set with your finger.
  7. Release the pressure from the application gun and all the bathroom caulking to dry.

Note: When applying the caulk to ensure that the caulk gun smoothly pushes out in a steady manner, there is a lock. When you are done, release the lock so that the caulk doesn’t keep coming out and making a mess on your even bead or ruin your seal.

applying caulk in bathtub

Remove the tape

Remove the tape in a crisscrossing motion, ensuring it does not leave any residue on the tub surface. Next, remove tape and clean up and remove excess caulk.


Clean up

Once you have finished recaulking your bathtub, you will need to clean up any excess caulk. This is as simple as using a wet paper towel or sponge and wiping the caulk away from the surface of your tub.

Before the caulk has cured, it is possible to peel off any mistakes or excess caulk. So don’t despair if you get too much at first! Just go over the area again before it sets up and clean up any overflow with your finger. 

There you have recaulked your bathtub!


Caulking Bathtub FAQ

Caulk is a simple material to use but can sometimes be hard to fix. In order to help you troubleshoot any problems in your bathroom using caulk, I have provided a list of the most common problems and how to solve them.

How Do I Know When To Change My Caulk?

The best way to know when you have old caulk is by doing a visual inspection of the joints themselves for cracks and other signs of wear that would indicate replacement. If water gets through long enough to get into the wood or drywall, you can experience mold growth and even structural damage.


What is the Best Way to Remove Old Caulk?

The best way to remove old caulk would be using a caulk remover tool like a heat gun or chemical stripper.  The tool will allow you to remove caulking painlessly and keep it from damaging the rest of your caulking.


Should you caulk your bathtub?

Yes, caulking your bathtub can help prevent water damage to the walls of your home. A small amount of caulking can go a long way in helping you save money and time from fixing problems later.

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