To apply caulk correctly, cut the tip of the nozzle at a 45-degree angle, put the cartridge in a caulking gun, test the bead size on a newspaper, pull the caulk tube nozzle along the joint, and apply the caulk, holding the gun at a 45-degree angle to the joint. Apply 3 feet caulk at a time with steady pressure. Tool immediately after caulk application.
Use a utility knife or caulk-removing tool to remove old caulk and dirt, and wipe the surface clean with a cloth. Apply painter's tape on the sides of the joint. Cut the nozzle at a 45-degree angle, and load the caulking gun. If needed, cut the nozzle to a size that matches the size of the joint you want to fill.
Before you begin caulking, test the caulk on a paper towel or newspaper to be sure that the cartridge releases the correct bead size. Hold the caulk gun at a 45-degree angle to the crack or joint. While pulling the caulk along the joint, apply consistent pressure to the trigger of the gun to squeeze out even-sized beads. After applying caulk, release the trigger, and pull back the rod behind the tube.
To tool caulk, first wet a latex glove-covered finger, caulk-smoothing tool, foam paint brush or spoon with water or alcohol. Slide the finger or tool over the entire bead of caulk until it is smooth. Remove painter's tape before the caulk begins to dry.