side of the bead with a utility knife and pull it away by hand. To remove any remaining sealant, scrape it with a paint scraper held at a shallow angle. If no sealant is in place, clean the surface of any dirt, dust, grime or oil that would prevent the sealant from adhering. Scrub the surface with mineral spirits and an abrasive pad to get rid of any residue prior to applying the caulk. Cut the Nozzle Correctly. Most pros bypass the nozzle cutter of a caulk gun in favor of using a utility knife to start a new cartridge. The razor blade slices smoothly through the plastic without clamping it. The clamping action of a caulk-gun cutter can distort he nozzle opening, which can then impede application of the product. Cut the cartridge nozzle at a 45-degree angle with an opening size of 3/8 inch. For the same reason, cut the nozzle of squeeze tubes with a utility knife while hold- ing the crimped end of the tube vertically. Lay the bead parallel to the 45-degree nozzle. Backer Rods for Big Joints. To seal a joint larger than 1/4- in. wide, use a foam backer rod as a filler before applying the caulk. Less expensive than caulk, the rods provide a cheaper way to fill the empty space than using caulk alone. Plus, when caulk is applied over a backer rod, it forms an “hourglass” shape with two
For bathroom applications or anywhere the caulk/sealant will be prone to moisture exposure, choose a product that is marketed as "mold and mildew resistant."