You can use plumber’s putty around the rim of the sink to create a watertight barrier, but you should not use it if your countertop is granite or another kind of stone. It is compatible with Formica countertops.
If you form the seal correctly, no water will be able to seep into the area under the sink and create mold or water damage. In order to install the sink correctly, apply the soft plumber’s putty to the bottom of the sink and place, with pressure to the countertop. Some sinks come with clips meant for the bottom of the sink (under the countertop). The clips ensure that the proper amount of pressure is placed on the plumber’s putty for it to be effective.
You may use plumber’s putty to seal drains in the sink or the bathtub. Place the putty underneath the drain before you place the drain. Then you should apply pressure in order to create a watertight bond.
You may use the putty to seal a toilet to the floor. Be careful; if you seal the toilet all the way around and it develops a leak somewhere, the water will be trapped in. The water will then rot the floor without any signs. In order to avoid this scenario, don’t seal the toilet all the way around. Then any seeping water will alert you of a leak.
Pipes and Plumbing
Plumber’s putty in pipes and plumbing does not hold up to water pressure. Use it only on pipes that will not experience a great deal of pressure. To seal pipes together, place the putty on the inside of the pipe, where the threads will twist together. Twist the other end of the pipe into the threads and the putty. Wipe away excess putty and allow time for it to set.
Exercise caution whenever you use plumber’s putty, as it contains oils that can discolor some surfaces. You generally should not use it on granite, plastics, marble or any other porous surfaces. (You can find certain brands, though, manufactured for use on surfaces such as these.) Be sure to read the warning labels on the putty you buy in order to avoid these problems.