Plumbers Putty: 5 Practical Uses
It’s easy to take plumbers putty for granted. Soft, malleable, adhesive and waterproof, it forms watertight seals in various plumbing applications.
Composed of clay, talc, limestone and natural oils, the compound we know today was developed during World War II for the US government. When the war was over, the manufacturer, Industrial Paint and Varnish Co. (now Black Swan), sought commercial applications and plumbers putty was born. It doesn’t shrink like many other sealants, so it can be used to:
- Set drains. This is one of the most common uses. Applied to the underside of the drain flange, the putty holds the drain in position until the putty sets or the drain is tightened into place.
- Set toilets. The putty forms a seal between the toilet base and floor, and holds the base in place while the toilet is assembled and connections are made. Until the 1940s, plumbers used a mix of linseed oil combined with powdered clay, talc or glazing compounds. Hand mixed on site, the effectiveness of these blends varied greatly and tended to stain everything they contacted including toilet bases, tile, grout and flooring.
- Seal toilet tank bolts. Some plumbers use putty to seal the bolts that hold the toilet tank to the bowl. It reduces the chances the bolts will loosen and create a leak, but it’s easy to remove if the bowl or tank needs to be replaced.
- Install drop-in sinks. The putty forms a watertight seal between the sink and countertop and holds the sink in place while the installation clips are tightened. For the best seal, apply a generous rope of putty to the underside of the sink rim, position the sink in the opening and press firmly around the rim. Avoid scratching the sink or counter by using a soft putty knife to remove any excess.
- Seal pipes. Putty can be used to seal threaded pipes that aren’t subjected to water pressure. Apply the putty to the threads, twist the pipes together and wipe away any excess. Just remember putty can’t resist water pressure, so it shouldn’t be used to seal pipes or threaded attachments (showerheads, aerators) subjected to water under pressure.
Always allow the putty to dry thoroughly before you use the fixture in question, or you risk damaging the seal and causing leaks now or down the road. Follow the manufacturer’s recommendations or test the putty with your finger: It should be dry enough to resist an imprint.
Avoid using standard putty on materials such as granite, marble, soapstone and plastic, because it contains oils that can stain these materials. Opt for non-staining formulations instead, and if you’re working with stainless steel sinks or components, use putty approved for stainless steel.