Old cracked caulk leads to water damage and mold. Learn how to remove old caulk and apply a fresh waterproof bead that lasts for years.
Use a caulk remover tool or utility knife to score and peel away all existing caulk. Take your time — any old caulk left behind will prevent the new caulk from bonding properly. Use a plastic scraper to avoid scratching the tub.
Spray the joint with rubbing alcohol or a mold-killing bathroom cleaner and wipe clean. This step is critical — any moisture, soap scum, or mold will cause the new caulk to fail early. Let dry for at least 2 hours before caulking.
This is the pro tip most people miss. Fill the tub with water before caulking. When someone gets in the tub it flexes and expands slightly. If you caulk an empty tub the caulk will crack when the tub flexes under weight.
Cut the caulk tube tip at a 45 degree angle to create a small opening. Apply in one continuous smooth bead along the joint holding the gun at a consistent angle. Work in one direction without stopping. Less is more — a thin bead is easier to smooth than a thick one.
Wet your finger with water and run it along the bead in one smooth motion to press it into the joint and create a concave surface. Remove tape if used. Let cure for 24 hours before getting the tub wet — 48 hours for full waterproof cure.
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