You can use a utility knife or putty knife, slicing through the caulk and peeling it away. For multiple layers of caulk, needle-nosed pliers might work best. There are also specialized caulk removal tools designed to tear away caulk cleanly.
Apply A Softening Agent
There are several substances you can use to soften the silicone caulking. Among the easiest and most affordable are vinegar, alcohol, and WD-40. If you need something stronger, you can use industrial-grade isopropyl alcohol, and we recommend contacting a professional.
WD-40 is very good at removing silicone sealant but just make sure to completely remove it from the surface before applying any new silicone sealant as they can react.
CHELA Digesil is a catalytic solvent that, as mentioned before, digests that Silicone Oxygen bond, breaking down the silicone polymers into smaller molecules that can be more easily rinsed away with water, removing it from the surface they are bonded to.
You can use either a small cup of vinegar or a paste of 1-part water to 1-part baking soda. Applied either of these to the caulking with an old toothbrush and scrub vigorously. Do not mix the vinegar and the baking soda. Some people advise mixing the two because the chemical reaction is dramatic.
Once you have removed most of the silicone, wipe the remnants off using a cloth. You can make the job a bit eaiser by soaking the cloth in methylated spirits. The methylated spirits act as a solvent, breaking down the last of the silicone, making it less sticky and easier to wipe up.
As it contains acetic acid, silicone can be softened with white vinegar.
Replacing Your Silicone Sealant
Remove tape as soon as possible to before product has a chance to skin. Clean up any residual excess silicone with turps.
If the caulk has lost some of its adhesion, it may have allowed moisture to seep in under it, possibly creating decay. The old caulk must be removed to properly treat and seal the area, so it does not happen again. The old caulk may have deteriorated due to age, decomposition, or the wrong type of caulk being used.
Hold a glass scraper at a very shallow angle to one of the surfaces. Scrape the caulk residue off the surface the way you would with a razor blade. Repeat this with the other surface. Pull out the slivers of caulk with the pliers.
The good news is, in this age of COVID, an abundant use of hand sanitizers and soaps of various ingredients will not damage your silicone ring. Hand sanitizers are comprised mainly of isopropyl alcohol, which will not degrade or “melt” your silicone ring in any way.
Most aromatic (ring structure) solvents are effective at dissolving silicone oil. These include toluene, xylene and naphtha. Additionally, silicone oils are reported to be soluble in chlorinated solvents such as trichloroethylene, perchloroethylene and methylene chloride.
Baking Soda
Baking soda is another effective method for cleaning silicone. Simply put half a cup of baking soda into a bowl of hot water and let it sit for 10 minutes before rinsing the item with cold water. This process will help remove any residue left by oils, grease, and grime.
If you find there are still bits of old bathroom sealant that won't come away, you can use white spirit to help you remove the old bathroom sealant easily. dab a little bit onto a cloth and rub it over the leftover sealant until they dissolve.
The main difference between white spirit and methylated spirit is their respective chemical basis or source. The former is a solvent derived from petroleum, while the latter is a solvent derived from alcohol.
Combine 1/3 cup (80 ml) bleach with 1 gallon (4 L) of water until well mixed. Apply this solution to the gap from which the caulk was removed. Use paintbrush or foam brush too apply the bleach solution. Let the solution sit on the caulk for about five minutes before disturbing it.
Yes, silicone is not adversely affected by prolonged submersion in either fresh or salt water.
EDIT: BTW, you can also use acetone (i.e. nail polish remover) to remove silicone caulking.
Removing the old caulk and replacing it with a new bead of caulk instead usually creates a better seal. However, you can effectively caulk over caulk as long as the bottom layer of caulk isn't damaged or moldy. The old caulk should also be clean, dry, and free of oil for the best adhesion.
Take a grouting sponge with rounded corners, get it wet, squeeze out all excess water and rub the sponge across the caulk several times to really smooth the joint, Use the sponge to remove excess caulk from the smooth parts of the backsplash and countertop.