Plumbing - Tips for Using Sealants and Plumber's Tape
Sealing pipes and hoses during plumbing projects is critical. That's obvious. But how to do that correctly can be a little trickier than it looks.
The first tip follows the old mechanic's rule: the right tool for the right job.
Select sealant according to its proper purpose. Use plumber's putty for securing sink flanges when installing a garbage disposal unit. Use special-made toilet bowl grease to seal the base of the bowl to the trap (the hole or pipe out which the water is flushed). Use silicon caulk for shower pipes and spouts. And so on.
Never be tempted to substitute, for example, PVC pipe glue to seal a flange or sink where plumber's putty is called for. Don't use it to secure hoses. You'll never get them loose again and, someday, they will have to be replaced.
Be sparing but not stingy.
The right amount of plumber's putty, say a 1/4 inch bead around the rim of a newly installed sink, makes for a good seal. Use too much and you have an unsightly mess. Too little and you can end up with small holes or cracks that lead to leaks.
Remove any excess before it can dry, but take care not to wipe so strongly that you take away what's supposed to be there. Also, excess sealant, whether plumber's putty or silicon caulk, can leave ridges that give you something to bump against with a pan or knife. That can lead to tearing. Simply wipe the excess with a finger or slightly damp sponge shortly after application. Then, carefully wipe up any smears before they dry.
Be generous with Teflon plumber's tape.
It is possible to use too much, leading to small channels through which water can escape. But it's rare. It's extremely flexible and compressible. That makes it hard to overdo the job. However, if you wind on too much it can make fitting on a new hose or threading a pipe difficult or impossible.
Wind it in the proper direction.
When fitting on a hose, it doesn't matter which way the tape is wound. But if the project calls for threading on a pipe, twisting can undo the Teflon tape. Wind the tape so that the tail points in the direction you will wind onto. That way, as you tighten the fitting, you're stretching the plumber's tape further. That leads to a good tight seal, rather than loosening the tape and making it useless.
Avoid torn ends.
Sometimes it will be a lot easier to simply stretch the tape until it breaks or tear it with your teeth. When you're under the sink on your back with only one hand, the temptation to do that is large. Resist it. Sometimes you'll get away with it. Many times, it will lead to re-doing the job after you've already tightened on the new fitting.
A clean end at the beginning allows the Teflon tape to seat into threads without leaving ragged high spots. Ditto on the tail. In either case, a ragged edge produces an uneven layer that will encourage small cracks. Water drips are not far behind.
Use sealants and tape according to their design and you'll have a well-sealed hose or pipe. That eliminates water damage and messes... and the need to re-do the job.
