What Solvent Will Clean Silicone?

Silicone Caulk Removal

• Silicone caulk lasts for many years, but it does wear out, and when it does, you need to remove it before you can apply fresh caulk. Anyone who has ever done this knows that some household solvents soften silicone caulk, but none dissolves it. A common removal strategy is to soften the caulk with a generous amount of a softening agent and then cut it off with a knife or pull it off with pliers. After the bulk is gone, you typically use the same solvent in combination with a scouring pad to clean up the residue.

Softening Solvents

• General Electric Co., which manufactures silicone caulk, recommends using mineral spirits to get it off hard surfaces like tile, marble or concrete. For removing it from plastic or painted surfaces, however, you should use rubbing alcohol, which won't harm the surface. Silicone caulk has an odor that resembles vinegar because, like vinegar, it contains acetic acid. Consequently, white vinegar is another solvent you can use to soften it. It may not work as well as mineral spirits or alcohol, but it poses little danger to the substrate to which the caulk adheres. Rubbing a tabletop exposed to silicone wax with vinegar may safely remove some of the silicone.

Cutting Out the Bulk

• Solvents such as vinegar or mineral spirits -- and even stronger ones like lacquer thinner -- swell cured silicone caulk. This loosens its adhesion to the substrate and makes the caulk easier to cut with a knife. To remove stubborn caulk, you can either apply the solvent repeatedly or soak a rag and place the rag on the caulk. Once it softens, cutting as closely to the substrate as possible with a sharp knife while you pull the bead is the most efficient way to remove the bulk. Once that's gone, a thin residue usually remains behind.

Removing Residue

• The residue that remains after you've cut out the bulk of a bead of caulk can still prevent new caulk from adhering and must be removed. Rubbing it with sandpaper or an abrasive pad isn't a good strategy because the caulk tends to form small balls that stick to each other and to the paper or pad. The best strategy is to soak the residue with more mineral spirits, alcohol or vinegar to further soften it and then scrape it with a pull scraper or sharp knife.