Old cracked caulk is a common bathroom eyesore and easy to fix. A fresh bead takes about an hour, and prevents serious water damage.
STEP 1: Remove All Old Caulk Completely
Use a caulk removal tool or utility knife to cut along both edges of the old caulk and peel it away. Take your time leaving even small bits of old caulk will cause the new bead to fail and peel. Use a plastic scraper to remove the last residue without scratching the sink, tub or shower surface.
STEP 2: Clean and Dry the Surface Thoroughly
Spray the joint with rubbing alcohol or a mold-killing cleaner and wipe completely dry. New caulk will not bond properly to a damp, dirty, or greasy surface. Let the area dry for at least one hour — overnight if you spot any lingering moisture.
STEP 3: Apply Painter’s Tape on Both Sides
Run painter’s tape along each side of the joint about an eighth of an inch back from the edge. This gives you a clean, straight caulk line and makes cleanup much easier when you pull the tape off.
STEP 4: Apply the Caulk in One Smooth Pass
Cut the caulk tube tip at a 45-degree angle, making the opening about an eighth of an inch wide. Hold the gun at a consistent angle and apply a smooth, continuous bead along the entire joint in one uninterrupted pass.
STEP 5: Smooth the Bead and Remove Tape Immediately
Wet your fingertip with water and run it firmly along the bead in one smooth stroke to press caulk into the joint and create a concave surface. Pull the painter’s tape away immediately while the caulk is still wet, pulling at a 45-degree angle for a clean edge.
STEP 6: Allow Full Cure Before Getting Wet
Most bath caulks need 24 hours to cure before any water exposure. Some products specify 48 hours for full waterproofing. Do not rush this step or the seal will fail sooner than it should.
PRO TIP
Fill the tub with water before caulking — the weight slightly expands the joint so the caulk will not crack when the tub is loaded in normal use. A caulk finishing tool gives a more consistent smooth line than your fingertip on long runs.
SUPPLIES NEEDED
Silicone or siliconized latex bath caulk — mold-resistant
Caulk gun
Caulk removal tool or utility knife
Painter’s tape
Rubbing alcohol or mold-killing spray
Damp cloth and paper towels