Plumber’s putty is moldable and is used to seal the joints of pipes to prevent water leaks. Bathroom sink drains are commonly sealed with plumber’s putty. When used properly, plumber’s putty provides an airtight seal that will remain leak-free for many years. Plumber’s putty is either oil or water based. Water-based balms are designed for use in materials that are stained if oil-based putty is used. If you are not sure of the composition of your sink, it is best to use water-based putty to avoid unwanted stains.
- Clean the built-in area of the kitchen or bathroom sink with the mastic knife to remove large debris that may interfere with the application of the plumber’s putty.
- Spray an ammonia-based cleaner around the base of the sink, and leave the cleaner to soak for a minute.
- Clean the recessed area of the sink with a clean cloth. Use additional rags, if necessary, to ensure that the bottom of the drain is completely dry.
- Remove a piece of plumber’s putty the size of a coin from its container, and roll the plumber’s putty between your hands to form a rope that is 1/4 inch (0.65 cm) in diameter and about 5 inches (7.5 cm) in length.
- Place the plumber’s putty rope around the drain opening on the bottom of the sink. Once you have formed a circle of plumber putty, remove the excess rope that extends beyond the point where you started to put the rope of putty.
- Slide the sink drain into the opening at the bottom of the sink, surrounded by plumber’s putty, and install the sink drain as specified by the manufacturer. Squeeze the sink drain with a socket wrench to place it in the sink.
- Pass a 2 inch (5 cm) wide knife around the edge of the drain stack to cut out the putty that protrudes from below the sink drain.
- Replace excess plumber’s putty in the putty container for later use.
- Fill the sink with water after connecting the sink drain to the pipe to check for leaks. If a leak is observed, remove the drain from the sink, scrape the plumber’s putty from the drain, and re-apply putty as described in the previous steps.