Use latex bathtub caulk rather than silicone. Bathroom caulking will last longer if it’s good quality. Cut the tip of the tube small. Squeeze a small bead of caulk deep into the crack without getting too much caulk on the tile or the tub.
Watch this video of removing old silicone in the bathroom using De-Solv-It Contractors’ Solvent and learn a foolproof method for applying the new caulk. In this video, I re-caulk a counter top with DAP acrylic latex. Took about an hour to complete the whole job.
Use the methods in the video to replace caulking around a tub or shower. It’s easy with the proper preparation. In fact, many women caulk better than men do because they have more patience. With this in mind, take your time removing all the old caulk, completely. Use latex-tub caulk.
To clean, spray all the cracks and old caulking with a bathroom tile cleaner.
Give the product enough time to soak in and kill all the mold spores possible. While it is soaking in, scrape all the old caulk with any of these tools: a razor blade glass scraper, a utility knife, a grout scraper, or a large slotted screwdriver. One of my favorite tools is a sharp wood chisel. Be careful not to use one with any nicks in the blade as it could scratch the tub or the tiles.
Once all the old grout is removed, clean the area with ‘Soft Scrub’ or the like and rinse well.
Then, fill the tub with water, warm is nice because you will be kneeling in it while you are caulking. Usually when the caulk between the tub and the tile does not last it is because the tub is moving a tiny bit. Filling the tub with water can make it settle 1/16-inch. Now the caulking will not crack the next time someone takes a bath.
Do not get ahead of yourself. If you apply too much caulking around the tub, it could start to dry before you wipe it smooth. Use a sponge, some water and a towel to apply, clean and dry as you work your way around the tub.
Use your finger to first wipe off the surface caulk. Clean your finger on the sponge when you get too much caulk on it. After you finger the caulk out of the crack, clean the area with the sponge to remove any excess caulk. Work on small areas at a time, 30-inches or so. It is easier to do a professional job while the caulk is still soft.
If you clean too much caulk out of the joint, you can always add a second layer when the first hardens up. Whatever you do, do not leave a big cove of caulking on the tub and tile. It just gives dirt and mildew a place to hang out.