Remove all of the damaged grout around the kitchen sink with a grout saw. Simply move the saw back and forth over the grout until none, or only very little, remains.
Wipe up the remaining grout debris that was left from sawing using a slightly damp sponge. This will allow the caulk to firmly cling to the surface when it is applied.
Run a bead of caulk across the joint where the grout was just removed. Ensure the caulk completely covers the joint, leaving no holes or gaps. Instead of using new grout, it's easier to replace the old grout with caulk, and it works well for use around the kitchen sink as it's water resistant, flexible, and prevents future cracking.
Allow the caulk to sit for at least one hour before using the kitchen sink. This will allow it to harden and set in the joint properly. Do not get water on the caulk before it has dried completely.
Check the caulk for any holes or damage once it has dried. If there are any, patch the area with a small bead of caulk and allow it to dry again before using.
Things You Will Need
- Grout saw
- A razor knife or a hammer and chisel can be used to remove old grout. Always use them with care, to avoid injury to self or the sink.