Plumber's Putty
Plumber's putty is a soft, oil-based sealing compound used to create watertight seals around non-pressurized plumbing fixtures — primarily sink drain baskets, faucet bases, and tub strainers. It stays pliable for years, allowing easy removal and re-sealing when fixtures need to be replaced.
How to use plumber's putty:
- Roll a rope of putty roughly ½ inch in diameter
- Press it around the underside of the drain flange or faucet base
- Press the fixture into position — putty squeezes out around the edges
- Wipe away excess with a damp cloth
- Tighten the mounting nut underneath — this draws the fixture tight against the putty seal
When NOT to use plumber's putty:
- On plastic or acrylic sinks — putty can stain or crack certain plastics
- On pressurized supply connections — use thread tape (PTFE) or pipe dope instead
- On porous stone countertops (marble, granite) — oil in putty can cause permanent staining
- In place of silicone caulk for shower fixtures — putty degrades when submerged
Plumber's putty vs. silicone caulk: putty is easier to remove and re-do; silicone forms a harder, more permanent bond. For kitchen sink strainers, either works. For shower drain covers or applications where water pools, silicone or waterproof caulk is preferred.
Shelf life: putty dries out over time in an opened container. Fresh putty is soft and pliable; putty that crumbles when rolled is too old and should be replaced. A good can of plumber's putty costs $4–$8 and lasts 2–5 years if the lid is kept tight.