Tom Silva explains his tried and true method
The silicone caulking between the cultured-marble pan and the ceramic tile wall in my shower stall has to be replaced. Is there a special tool for this purpose?
–Gene Ackert, Ramona, CA
I’m sure there is, although I’ve never had to use one. I’ve had pretty good luck with a utility knife and a glass scraper with a razor blade. First, slice through each side of the bead with the knife, and pull out what you can by hand. Then, hold the scraper at a shallow angle to avoid scratching the surface, and remove any remaining caulk. Next, scrub the surface with an abrasive pad soaked in mineral spirits to get rid of any silicone residue, which will prevent the new sealant from sticking.
Buy new mildew-resistant caulk that’s formulated for use in bathrooms, and only apply it to surfaces that are bone-dry. If there’s any wetness, fresh silicone won’t adhere properly.
from March 2007