How to Caulk

Old caulk can sometimes harden and be difficult to remove, so the first step in removing it is to soften it.

• Water-Based Caulk (Also Known As Latex Caulk): Soak a towel in hot water then place the towel on the caulk.
• Silicone-Based Caulk: Soak a towel in one of the following substances: white vinegar, isopropyl alcohol, acetone, mineral spirits or a commercial caulk remover. Because silicone-based caulk is difficult to remove, allow the substance to stay on the caulk for several hours or longer to soften. Once the silicone is softened, use a utility knife or a caulk remover tool to carefully remove it.
  

A clean surface is key to ensuring a sealant will bond. Make sure that the surface is clear of old caulk, peeling paint, dirt, rust, mold or moisture. Use a wire brush to clean the surface. For indoor projects, wipe the area down with rubbing alcohol or surface disinfectant.

Add touch-up paint to any weathered areas or spots that were damaged when the caulk was removed.

If your project is indoors, apply painters tape around the area you’re caulking. This will result in cleaner caulk lines.

If you’re applying caulk to the bathtub, put a strip of painters tape along the top of the tub, about 1/8 to 1/4 of an inch away from the wall, and another strip along the top. Don’t skip or rush this step. This extra effort in the beginning creates a gap that makes it easy to apply a straight bead of caulk.

Put the tube into the gun with the nozzle in the front. Push the plunger tightly into the back of the tube and remove your thumb. The gun is now loaded.

When applying the caulk, it’s better to pull the caulk gun toward you, along the joint you’re sealing, with the caulk coming out behind the gun. Pushing it can result in an uneven bead. Hold the tube at a 45-degree angle to the joint. Place one hand close to the tip of the gun for better control. Using steady pressure on the trigger of the caulk gun, apply a thin bead of caulk to the area. To stop the flow of caulk, release the trigger and pull back the rod behind the cartridge.

When caulking a bathtub, be sure to use a caulk that’s specifically designed for plumbing use. Recaulking the bathtub with a watertight seal is important because the tub can develop water damage when leaks and cracks have formed.

Tool the newly applied caulk (pass over the entire applied bead of caulk to smooth it and push caulk into the gap between your substrates). Use a caulk finishing tool to pass over the entire bead. If you don't have a finishing tool, you can use a paint stirrer, a spoon, a foam paint brush or a glove-covered finger dipped in rubbing alcohol or water.

Tooling and painters tape removal should be done before the caulk begins to cure and skin over. For best results, remove tape by carefully pulling it away from you at a 45-degree angle.